Temperature compensation circuit of phase-locked loop, phase-locked loop circuit and electronic equipment

Abstract

The invention provides a temperature compensation circuit of a phase-locked loop, a phase-locked loop circuit and electronic equipment, and belongs to the technical field of electronic information. In the temperature compensation circuit, the voltage generation circuit can output the temperature compensation voltage to the frequency regulation and control circuit based on the temperature compensation control word generated by the temperature control coding circuit, so that the frequency regulation and control circuit adjusts and controls the oscillation frequency of the voltage-controlled oscillator under the control of the temperature compensation voltage; therefore, the influence of temperature change on the oscillation frequency of the voltage-controlled oscillator can be avoided, and the phase-locked loop is ensured to be in a locked state and generate a stable and clean clock signal.

Description

Technical Field

[0001] This application relates to the field of electronic information technology, and in particular to a phase-locked loop (PLL) temperature compensation circuit, a PLL circuit, and an electronic device. Background Technology

[0002] A phase-locked loop (PLL) is a circuit that can generate a stable and clean clock signal.

[0003] Typically, a PLL includes a phase frequency detector (PFD), a charge pump (CP), a loop filter (LPF), a voltage-controlled oscillator (VCO), and a feedback divider (FBDIV) connected in sequence to form a loop. These components work together to generate the required clock signal. Summary of the Invention

[0004] A temperature compensation circuit, a phase-locked loop circuit, and an electronic device are provided to compensate for the frequency drift of the voltage-controlled oscillator (VCO) in the phase-locked loop due to temperature. The technical solution is as follows: On one hand, a temperature compensation circuit for a phase-locked loop is provided, the phase-locked loop including a voltage-controlled oscillator; the temperature compensation circuit includes: a temperature control encoding circuit, a voltage generation circuit and a frequency control circuit connected in sequence, and the frequency control circuit is also connected to the voltage-controlled oscillator; The temperature control encoding circuit is used to: generate a temperature compensation control word and transmit the temperature compensation control word to the voltage generation circuit; The voltage generation circuit is used to: generate a temperature compensation voltage based on the temperature compensation control word, and transmit the temperature compensation voltage to the frequency control circuit; The frequency control circuit is used to: output a frequency control signal in response to the temperature compensation voltage, the frequency control signal being used to adjust the oscillation frequency of the voltage-controlled oscillator.

[0005] Optionally, the phase-locked loop further includes: a loop filter connected to the voltage-controlled oscillator; the temperature control encoding circuit is also connected to the loop filter; The temperature control encoding circuit is used to: receive the control voltage transmitted from the loop filter to the voltage-controlled oscillator, and generate the temperature compensation control word based on the control voltage.

[0006] Optionally, the temperature control encoding circuit includes: a voltage detector and a digital state machine connected sequentially between the loop filter and the voltage generation circuit; The voltage detector is used to: receive a reference voltage range and the control voltage, detect whether the control voltage is within the reference voltage range, and transmit the voltage detection result to the digital state machine; The digital state machine is used to generate the temperature compensation control word based on the voltage detection result.

[0007] Optionally, the digital state machine is configured to: generate a first temperature compensation control word if the voltage detection result indicates that the control voltage is within the reference voltage range; decrease the first temperature compensation control word to generate a second temperature compensation control word if the voltage detection result indicates that the control voltage is not within the reference voltage range and is greater than the upper limit of the reference voltage range; increase the first temperature compensation control word to generate a third temperature compensation control word if the voltage detection result indicates that the control voltage is equal to the upper limit or the lower limit of the reference voltage range; and maintain the first temperature compensation control word if the voltage detection result indicates that the control voltage is equal to the upper limit or the lower limit of the reference voltage range.

[0008] Optionally, the voltage detector includes: a first comparator, a second comparator, and a reference voltage generator; the first input terminal of the first comparator and the second input terminal of the second comparator are both connected to the loop filter, the second input terminal of the first comparator and the first input terminal of the second comparator are both connected to the reference voltage generator, and the output terminal of the first comparator and the output terminal of the second comparator are both connected to the digital state machine. The reference voltage generator is configured to: generate the reference voltage range, and transmit the upper limit of the reference voltage range to the first comparator, and transmit the lower limit of the reference voltage range to the second comparator; The first comparator is configured to: receive the control voltage, compare the control voltage with the upper limit of the reference voltage range to obtain a first voltage detection result indicating the relationship between the two, and transmit the first voltage detection result to the digital state machine; The second comparator is configured to: receive the control voltage, compare the control voltage with the lower limit of the reference voltage range to obtain a second voltage detection result indicating the relationship between the two, and transmit the second voltage detection result to the digital state machine.

[0009] Optionally, the temperature control encoding circuit is used to: detect the temperature of the phase-locked loop and generate the temperature compensation control word based on the temperature of the phase-locked loop.

[0010] Optionally, the temperature control encoding circuit includes: a temperature detector, an analog-to-digital converter, and a control word generator connected in sequence to the voltage generation circuit; The temperature detector is used to: detect the temperature of the phase-locked loop, generate a sensing voltage that varies with temperature based on the temperature of the phase-locked loop, and transmit the sensing voltage to the analog-to-digital converter; The analog-to-digital converter is used to: convert the sensing voltage transmitted by the temperature detector from analog voltage to digital voltage and then transmit it to the control word generator; The control word generator is used to generate the temperature compensation control word based on the sensed voltage transmitted by the analog-to-digital converter.

[0011] Optionally, the temperature detector is a temperature sensor.

[0012] Optionally, the control word generator includes a lookup table, and the lookup table stores a one-to-one correspondence between multiple sensing voltages and multiple temperature compensation control words; The control word generator is used to: look up the corresponding temperature compensation control word from the lookup table based on the received sensed voltage.

[0013] Optionally, when the temperature control encoding circuit is used to generate the temperature compensation control word based on the control voltage transmitted from the loop filter in the phase-locked loop to the voltage-controlled oscillator, and to generate the temperature compensation control word based on the temperature of the phase-locked loop, the temperature control encoding circuit includes: a first temperature control encoding circuit and a second temperature control encoding circuit, and the temperature compensation circuit further includes: a selector; and the first temperature control encoding circuit is connected to the loop filter and the selector respectively, the second temperature control encoding circuit is connected to the selector, and the selector is also connected to the voltage generation circuit; The first temperature control encoding circuit is used to: generate a temperature compensation control word based on the control voltage and transmit it to the selector; The second temperature control encoding circuit is used to: generate a temperature compensation control word based on the temperature of the phase-locked loop and transmit it to the selector; The selector is configured to: receive a control command, and in response to the control command select one of the temperature compensation control words generated by the first temperature control encoding circuit and the second temperature control encoding circuit, and transmit the selected temperature compensation control word to the voltage generating circuit.

[0014] Optionally, the voltage generating circuit includes: a switch control unit and a voltage generating capacitor; the switch control unit is connected to the temperature control encoding circuit, the bias power supply terminal, the pull-up power supply terminal, the pull-down power supply terminal and the output node respectively; the voltage generating capacitor is connected between the output node and the pull-down power supply terminal; and the output node is connected to the frequency control circuit. The switch control unit is used to: receive the temperature compensation control word, and in response to the temperature compensation control word and the bias power signal provided by the bias power supply terminal, control the connection and disconnection of the pull-up power supply terminal or the pull-down power supply terminal with the output node to charge and discharge the voltage generating capacitor to generate a continuously and slowly varying temperature compensation voltage, and transmit the temperature compensation voltage to the frequency control circuit through the output node.

[0015] Optionally, the switch control unit includes: a first switch group and a second switch group; the bias power supply terminal includes: a first bias power supply terminal and a second bias power supply terminal; the first switch group is respectively connected to the temperature control encoding circuit, the pull-up power supply terminal, the first bias power supply terminal and the output node; the second switch group is respectively connected to the temperature control encoding circuit, the pull-down power supply terminal, the second bias power supply terminal and the output node; The first switch group is used to: receive the temperature compensation control word, and in response to the temperature compensation control word and the first bias power signal provided by the first bias power supply terminal, control the connection and disconnection between the pull-up power supply terminal and the output node; The second switch group is used to: receive the temperature compensation control word, and in response to the temperature compensation control word and the second bias power signal provided by the second bias power supply terminal, control the connection and disconnection between the pull-down power supply terminal and the output node.

[0016] Optionally, the first switch group includes two first switching transistors; the second switch group includes two second switching transistors; and the first switching transistors and the second switching transistors are of different types. The two first switching transistors are connected in series between the pull-up power supply terminal and the output node, and are respectively connected to the temperature control encoding circuit and the first bias power supply terminal. The two second switching transistors are connected in series between the pull-down power supply terminal and the output node, and are respectively connected to the temperature control encoding circuit and the second bias power supply terminal.

[0017] Optionally, the temperature compensation control word includes two temperature compensation control words that are inverse signals; the voltage generation circuit includes two switch control units and two voltage generation capacitors that are connected in a one-to-one correspondence. The two switch control units are configured to: receive the two temperature compensation control words respectively, and in response to the two temperature compensation control words, charge and discharge the two voltage generating capacitors to generate two temperature compensation voltages that are opposite signals to each other.

[0018] Optionally, the temperature compensation circuit further includes: at least one inverter; the at least one inverter is connected between the temperature control encoding circuit and the voltage generation circuit; The at least one inverter is used to: invert the temperature compensation control word generated by the temperature control encoding circuit and then transmit it to the voltage generation circuit.

[0019] Optionally, the frequency control circuit includes: a multi-channel capacitor switch array connected in parallel between the differential output terminals of the voltage-controlled oscillator; the temperature compensation circuit includes: a plurality of voltage generating circuits corresponding one-to-one with the multi-channel capacitor switch array; and each of the capacitor switch arrays includes: a switch section connected in sequence between the differential output terminals of the voltage-controlled oscillator and at least one temperature compensation capacitor, wherein the switch section is also connected to the corresponding voltage generating circuit; The switching unit is used to: control the on / off state of at least one temperature compensation capacitor connected to the differential output terminal of the voltage-controlled oscillator in response to the temperature compensation voltage transmitted by the connected voltage generation circuit, so as to output the frequency control signal to adjust the oscillation frequency of the voltage-controlled oscillator.

[0020] Optionally, the switching section includes a switching unit and a biasing unit connected in sequence, and both the switching unit and the biasing unit are connected to the corresponding voltage generating circuit; and the voltage generating circuit is used to generate two temperature compensation voltages that are opposite signals to each other. The switching unit is used to: control the on / off state of at least one connected temperature compensation capacitor and the differential output terminal of the voltage-controlled oscillator in response to one of the two temperature compensation voltages; The bias unit is used to provide a bias voltage to the switching unit in response to the other of the two temperature compensation voltages.

[0021] Optionally, the switching unit includes a third switching transistor; the biasing unit includes a first resistor and a second resistor; and each of the capacitor switch arrays includes two temperature-compensating capacitors. The third switch is connected between the two temperature compensation capacitors and is also used to receive one of the two temperature compensation voltages. The first resistor and the second resistor are connected in series between the two temperature compensation capacitors and in parallel with the third switch, and are also used to receive the other of the two temperature compensation voltages.

[0022] On the other hand, a phase-locked loop circuit is provided, the phase-locked loop circuit comprising: a phase-locked loop, and a temperature compensation circuit as described in the above aspect; the temperature compensation circuit is connected to a voltage-controlled oscillator in the phase-locked loop; The temperature compensation circuit is used to compensate for the drift in the oscillation frequency of the voltage-controlled oscillator caused by temperature changes.

[0023] In another aspect, an electronic device is provided, comprising: a load, and a phase-locked loop circuit as described in the other aspect above; the phase-locked loop circuit is connected to the load; The phase-locked loop circuit is used to generate a clock signal and transmit it to the load to drive the load to work.

[0024] In summary, the beneficial effects of the technical solution provided in this application can include at least the following: A phase-locked loop (PLL) temperature compensation circuit, a PLL circuit, and an electronic device are provided. In this temperature compensation circuit, the voltage generation circuit outputs a temperature compensation voltage to the frequency control circuit based on the temperature compensation control word generated by the temperature control encoding circuit. This allows the frequency control circuit to adjust the oscillation frequency of the voltage-controlled oscillator (VCO) under the control of this temperature compensation voltage. Therefore, it avoids the influence of temperature changes on the VCO's oscillation frequency, ensuring that the PLL remains locked and generates a stable and clean clock signal. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a phase-locked loop provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a phase-locked loop and its temperature compensation circuit provided in an embodiment of this application; Figure 3 This is a schematic diagram of another phase-locked loop and its temperature compensation circuit provided in an embodiment of this application; Figure 4 This is a schematic diagram of another temperature compensation circuit provided in the embodiments of this application; Figure 5 This is a schematic diagram of another phase-locked loop and its temperature compensation circuit provided in the embodiments of this application; Figure 6This is a schematic diagram of another phase-locked loop and its temperature compensation circuit provided in the embodiments of this application; Figure 7 This is a schematic diagram of another phase-locked loop and its temperature compensation circuit provided in the embodiments of this application; Figure 8 This is a schematic diagram of the voltage generation circuit in a temperature compensation circuit provided in an embodiment of this application; Figure 9 This is a schematic diagram of the voltage generation circuit in another temperature compensation circuit provided in this application embodiment; Figure 10 This is a schematic diagram of the voltage generation circuit in another temperature compensation circuit provided in the embodiments of this application; Figure 11 This is a schematic diagram of the voltage generation circuit in another temperature compensation circuit provided in the embodiments of this application; Figure 12 This is a schematic diagram of the circuit structure of a voltage-controlled oscillator provided in an embodiment of this application; Figure 13 This is a schematic diagram of the frequency control circuit in a temperature compensation circuit provided in an embodiment of this application; Figure 14 This is a schematic diagram of the voltage generation circuit in another temperature compensation circuit provided in the embodiments of this application; Figure 15 This is a schematic diagram of the frequency control circuit in another temperature compensation circuit provided in this application embodiment; Figure 16 This is a schematic diagram of the frequency control circuit in another temperature compensation circuit provided in the embodiments of this application; Figure 17 This is a schematic diagram of the frequency control circuit in another temperature compensation circuit provided in the embodiments of this application; Figure 18 This is a schematic diagram of another phase-locked loop and its temperature compensation circuit provided in the embodiments of this application; Figure 19 This is a schematic diagram of a phase-locked loop circuit provided in an embodiment of this application; Figure 20 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0028] Figure 1 A schematic diagram of a phase-locked loop (PLL) is shown. (Reference) Figure 1As can be seen, a phase-locked loop (PLL) can include a phase-frequency discriminator (PFD), a charge pump (CP), a loop filter (LPF), a voltage-controlled oscillator (VCO), and a feedback divider (FBDIV). The PFD is connected to the charge pump (CP), which in turn is connected to the loop filter (LPF), which is then connected to the VCO. The VCO is further connected to the feedback divider (FBDIV), which in turn is connected to the PFD, thus forming a loop. Furthermore, the PFD can also be connected to the reference clock terminal (REF_CLK), and the VCO can be connected to an electronic module or system requiring a clock signal (not shown in the figure) via the PLL output terminal (PLL OUTPUT).

[0029] The phase-frequency discriminator (PFD) receives the reference signal (also known as the input signal) provided by the reference clock terminal REF_CLK, as well as the oscillation signal output by the voltage-controlled oscillator (VCO). This oscillation signal can be the direct output of the VCO, in which case no feedback divider (FBDIV) is needed; or it can be the feedback oscillation signal obtained after the VCO output oscillation signal has been divided by the feedback divider (FBDIV). Frequency division refers to reducing the frequency of the received signal by a fixed ratio. Generally, the frequency of the divided signal is 1 / N of the original frequency, where N is a positive integer greater than 1. The PFD detects and compares the phase difference between the received input signal and the oscillation signal, and based on the detection result, outputs phase difference signals UP and DN to the charge pump (CP) indicating this phase difference.

[0030] The charge pump CP charges and discharges the loop filter LPF based on the phase difference signals UP and DN output by the phase detector PFD, ultimately outputting a correction voltage to specifically reduce the phase difference detected by the phase detector PFD, thus providing a basis for the filtering and smoothing processing of the loop filter LPF. Optionally, refer to... Figure 1It can also be seen that the charge pump CP shown is a current source type charge pump architecture, including a current source CS1, a switch k1, a switch k2, and a current source CS2 connected in series between the power supply terminal and the ground terminal. The connection node of switches k1 and k2 is connected to the loop filter LPF. When the level of UP in the phase difference signal is an effective level, switch k1 can be turned on, thereby connecting the power supply terminal to the loop filter LPF via current source CS1 and switch k1, charging the loop filter LPF and increasing its voltage. When the level of DN in the phase difference signal is an effective level, switch k2 can be turned on, thereby connecting the ground terminal to the loop filter LPF via current source CS2 and switch k2, discharging the loop filter LPF and decreasing its voltage. Thus, it can also be seen that the effective level described in the embodiments of this application can refer to the level at which the control switch is turned on or off; conversely, the ineffective level can refer to the level at which the control switch is turned off.

[0031] The loop filter (LPF) outputs a control voltage (Vctrl) to the voltage-controlled oscillator (VCO) based on the correction voltage output by the charge pump (CP). The change in Vctrl is synchronized with the correction voltage. For example, if the correction voltage indicates an increase in the oscillation frequency of the oscillation signal, the LPF can control Vctrl to rise; conversely, if the correction voltage indicates a decrease in the oscillation frequency, the LPF can control Vctrl to fall. This achieves the goal of adjusting the oscillation frequency based on the phase difference signal, ultimately canceling the phase difference and achieving frequency locking, also known as phase-locked loop (PLL). Optionally, refer to... Figure 1 It can also be seen that the loop filter LPF shown is a second-order RC loop filter, including two resistors r1 and r2, and three capacitors c1, c2 and c3. The connection method of each component is as follows. Figure 1 As shown, it will not be elaborated further here.

[0032] The voltage-controlled oscillator (VCO) responds to the control voltage Vctrl output by the loop filter (LPF). It outputs an oscillation signal at the frequency corresponding to Vctrl (also known as the VCO output frequency) through the phase-locked loop (PLL) output terminal (PLL OUTPUT). As mentioned earlier, this oscillation signal is also fed back to the phase-frequency detector (PFD), which compares the phase difference between the oscillation signal and the input signal. This ensures that the oscillation frequency of the PLL output signal is locked to the frequency of the input signal, achieving input-output synchronization. Furthermore, the relationship between the control voltage Vctrl and the oscillation frequency can be set according to the frequency-voltage (FV) characteristic control signal. This allows the VCO to strictly adhere to the preset FV rule, outputting an oscillation signal at the corresponding frequency based on the control voltage Vctrl, thus achieving precise control of the oscillation frequency.

[0033] It is understandable that when the oscillation frequency of the voltage-controlled oscillator (VCO) output signal reaches the required frequency, and the phase difference between the VCO output signal and the reference signal provided by the reference clock terminal REF_CLK remains constant, the phase-locked loop (PLL) can be considered to be in a locked state; conversely, it can be considered to be in an unlocked state. This demonstrates that the VCO is the core component for frequency synthesis. However, the VCO's oscillation frequency is susceptible to drift due to temperature changes. If the control voltage Vctrl transmitted from the loop filter LPF to the VCO is not adjusted in time to correct the VCO's oscillation frequency, the accuracy and stability of the VCO output signal will decrease, ultimately causing the PLL to lose lock.

[0034] Based on this, in some embodiments, analog circuits are considered for temperature compensation to ensure that the oscillation signal output by the voltage-controlled oscillator (VCO) is unaffected by temperature. However, on the one hand, the parameters of analog circuits are difficult to precisely match the relationship between temperature and frequency changes, making it impossible to correct frequency drift to the ideal range; on the other hand, the compensation of analog circuits varies significantly across different temperature ranges (also known as temperature domains). In other words, the design of analog circuits still suffers from low compensation accuracy and poor temperature domain adaptability. Therefore, in other embodiments, the temperature characteristics of transistors are also considered to generate a corresponding compensation voltage, which is then used to control the capacitance value of varactor diodes, thereby offsetting the effect of temperature on frequency. However, on the one hand, transistors and subsequent control links can easily introduce additional noise, affecting the output quality of the VCO; on the other hand, the parameters of components such as transistors and varactor diodes may differ in actual production, leading to inconsistent compensation effects. In other words, the design of transistors still suffers from drawbacks such as poor noise and large process deviations.

[0035] Therefore, in response to the above technical problems, the embodiments of this application provide a novel temperature compensation circuit. This temperature compensation circuit not only has high compensation accuracy and good temperature range adaptability, but also does not have the disadvantages of poor noise and large process deviation.

[0036] Figure 2 This is a schematic diagram of the structure of a temperature compensation circuit 00 for a phase-locked loop (PLL) provided in an embodiment of this application. Combined with... Figure 1 It can be seen that a phase-locked loop (PLL) includes a voltage-controlled oscillator (VCO). Combined with... Figure 2 It can be seen that the temperature compensation circuit 00 includes: a temperature control encoding circuit 01, a voltage generation circuit 02 and a frequency control circuit 03 connected in sequence, and the frequency control circuit 03 is also connected to a voltage-controlled oscillator (VCO).

[0037] The temperature control encoding circuit 01 is used to generate the temperature compensation control word Tc_code and transmit the temperature compensation control word Tc_code to the voltage generation circuit 02.

[0038] In this embodiment, the temperature control encoding circuit 01 can generate a temperature compensation control word Tc_code based on the control voltage Vctrl received by the voltage-controlled oscillator VCO or the detected phase-locked loop (PLL) temperature, and transmit it to the voltage generation circuit 02 to reflect the temperature change.

[0039] As mentioned earlier, the control voltage Vctrl received by the voltage-controlled oscillator (VCO) is the voltage transmitted by the loop filter LPF to the VCO to control the oscillation frequency of the oscillation signal output by the VCO. When the temperature changes, the oscillation frequency of the VCO will drift. To compensate for this drift, the loop filter LPF will adjust the control voltage Vctrl transmitted to the VCO to prevent the phase-locked loop (PLL) from losing lock. Therefore, the temperature control encoding circuit 01 can generate a temperature compensation control word Tc_code based on the magnitude of this control voltage Vctrl, reflecting the PLL lock-in state under the influence of temperature changes. Of course, in this embodiment, the temperature control encoding circuit 01 also needs to be connected to the loop filter LPF to receive the control voltage Vctrl output by the loop filter LPF.

[0040] The voltage generation circuit 02 is used to generate a temperature compensation voltage Vtc based on the temperature compensation control word Tc_code, and transmit the temperature compensation voltage Vtc to the frequency control circuit 03.

[0041] In this embodiment, after receiving the temperature compensation control word Tc_code reflecting the temperature change, the voltage generation circuit 02 can generate a temperature compensation voltage Vtc related to the temperature change based on the temperature compensation control word Tc_code and transmit it to the frequency control circuit 03 for temperature compensation.

[0042] The frequency control circuit 03 is used to output a frequency control signal in response to the temperature compensation voltage Vtc, which is used to adjust the oscillation frequency of the voltage-controlled oscillator VCO.

[0043] In this embodiment, after receiving the temperature compensation voltage Vtc, the frequency control circuit 03 can generate and output a frequency control signal under the control of the temperature compensation voltage Vtc to flexibly adjust the oscillation frequency of the voltage-controlled oscillator (VCO), thereby compensating for the drift caused by temperature changes in the oscillation frequency. That is, it avoids abnormally adjusting the control voltage Vctrl transmitted from the loop filter LPF to the VCO to counteract the effect of temperature changes on the oscillation frequency, thus preventing the control voltage Vctrl from deviating from the normal range. Ultimately, it ensures that the VCO can reliably and stably output an oscillation signal even when the temperature changes, preventing the phase-locked loop (PLL) from losing lock.

[0044] For example, when the temperature is abnormally high and the control voltage Vctrl is abnormally high, the frequency control circuit 03 can output a frequency control signal in response to the received temperature compensation voltage Vtc to increase the oscillation frequency of the voltage-controlled oscillator (VCO), thereby reducing the control voltage Vctrl. Conversely, when the temperature is abnormally low and the control voltage Vctrl is abnormally low, the frequency control circuit 03 can output a frequency control signal in response to the received temperature compensation voltage Vtc to reduce the oscillation frequency of the VCO, thereby increasing the control voltage Vctrl. This ensures that the control voltage Vctrl remains within the normal range, and that the VCO consistently outputs a reliable and stable oscillation signal.

[0045] Based on the above description, the temperature compensation circuit 00 provided in this application is a digital circuit combining numerical control algorithms, rather than an analog circuit. This temperature compensation circuit 00 can flexibly and dynamically adjust the oscillation frequency of the voltage-controlled oscillator (VCO) based on the real-time detected temperature, or it can flexibly and dynamically adjust the oscillation frequency of the VCO based on the control voltage Vctrl reflecting the lock-up state of the phase-locked loop (PLL), performing adaptive temperature compensation calibration. Therefore, it not only has high compensation accuracy but also good temperature range adaptability, achieving frequency stability across the entire temperature range (i.e., any temperature range) and full-temperature-range locking stability. Furthermore, it does not suffer from drawbacks such as poor noise or large process deviations.

[0046] In summary, this application provides a temperature compensation circuit for a phase-locked loop (PLL). Because the voltage generation circuit in this circuit can output a temperature compensation voltage to the frequency control circuit based on the temperature compensation control word generated by the temperature control encoding circuit, and the frequency control circuit adjusts the oscillation frequency of the voltage-controlled oscillator (VCO) under the control of this temperature compensation voltage, it can avoid the influence of temperature changes on the oscillation frequency of the VCO, ensuring that the PLL is in a locked state and generates a stable and clean clock signal.

[0047] Optionally, as described above, in combination with Figure 1 The phase-locked loop (PLL) also includes a loop filter (LPF) connected to the voltage-controlled oscillator (VCO). Based on this, in one embodiment: combined with... Figure 2 It can be seen that the temperature control encoder circuit 01 can also be connected to the loop filter LPF.

[0048] The temperature control encoding circuit 01 can be used to: receive the control voltage Vctrl transmitted from the loop filter LPF to the voltage-controlled oscillator VCO, and generate the temperature compensation control word Tc_code based on the control voltage Vctrl.

[0049] That is, in this embodiment, the temperature control encoding circuit 01 can automatically detect the locking state of the phase-locked loop (PLL) based on the control voltage Vctrl output by the loop filter LPF, and perform adaptive temperature compensation calibration based on the locking state of the PLL to achieve full-temperature-range locking stability.

[0050] Alternatively, in this one embodiment, in Figure 2 On this basis, continue to combine Figure 3 As can be seen, the temperature control encoding circuit 01 may include a voltage detector 011 and a digital state machine 012 connected sequentially between the loop filter LPF and the voltage generation circuit 02. That is, the voltage detector 011 can be connected to the loop filter LPF and the digital state machine 012 respectively, and the digital state machine 012 can also be connected to the voltage generation circuit 02.

[0051] Voltage detector 011 can be used to: receive a reference voltage range and a control voltage Vctrl, detect whether the control voltage Vctrl is within the reference voltage range, and transmit the voltage detection result to digital state machine 012.

[0052] Optionally, the reference voltage range can be the ideal voltage range for the phase-locked loop (PLL) to be in a locked state, generally within the linear operating voltage range of the charge pump CP in the PLL. That is, if the control voltage Vctrl is within this reference voltage range, the PLL can be in a locked state; conversely, if the control voltage Vctrl is not within this reference voltage range, the PLL may lose lock.

[0053] Furthermore, it is understood that the reference voltage range may include an upper limit (i.e., the maximum voltage value Vref_high) and a lower limit (i.e., the minimum voltage value Vref_low). For example, in one instance, the reference voltage range could be from 0.3 volts (V) to 0.9V. That is, Vref_low = 0.3V; Vref_high = 0.9V.

[0054] In this embodiment, the voltage detector 011, while the phase-locked loop (PLL) is in a locked state, detects whether the control voltage Vctrl transmitted from the loop filter LPF to the voltage-controlled oscillator (VCO) is within the ideal reference voltage range. That is, it determines whether the control voltage Vctrl output by the loop filter LPF, or the control voltage Vctrl received by the VCO, is within the ideal reference voltage range, and obtains a voltage detection result indicating whether the control voltage Vctrl is within the reference voltage range. This voltage detection result can be transmitted to the digital state machine 012. The detection result can also reflect whether the control voltage Vctrl is within the linear operating voltage range of the charge pump CP, reliably indicating the locked state of the PLL.

[0055] Digital state machine 012 can be used to generate temperature compensation control word Tc_code based on voltage detection results.

[0056] That is, in the embodiments of this application, the digital state machine 012 can refer to the voltage detection result of whether the control voltage Vctrl is within the reference voltage range to determine whether the oscillation frequency of the voltage-controlled oscillator VCO needs to be adjusted, and the degree of adjustment, thereby generating the corresponding temperature compensation control word Tc_code.

[0057] Optionally, the digital state machine 012 can be used to: generate a first temperature compensation control word Tc_code if the voltage detection result indicates that the control voltage Vctrl is within the reference voltage range; decrease the first temperature compensation control word Tc_code to generate a second temperature compensation control word Tc_code if the voltage detection result indicates that the control voltage Vctrl is not within the reference voltage range and is greater than the upper limit of the reference voltage range; increase the first temperature compensation control word Tc_code to generate a third temperature compensation control word Tc_code if the voltage detection result indicates that the control voltage is equal to the upper limit or the lower limit of the reference voltage range; that is, the first temperature compensation control word can be kept unchanged without adjustment.

[0058] That is, when the control voltage Vctrl is within the ideal reference voltage range, i.e., Vref_low ≤ Vctrl ≤ Vref_high, it can be considered that the phase-locked loop PLL can be normally locked, and the oscillation frequency of the voltage-controlled oscillator VCO is not affected by temperature changes or is less affected by temperature. At this time, the digital state machine 012 can generate the initial first temperature compensation control word Tc_code. At any subsequent moment, if it is detected again that the control voltage Vctrl is within this ideal reference voltage range, the current first temperature compensation control word Tc_code will remain unchanged. When the control voltage Vctrl is affected by temperature changes and deviates from this ideal reference voltage range and is greater than the upper limit of the reference voltage range, i.e., Vctrl > Vref_high, the digital state machine 012 can choose to decrease the most recently generated first temperature compensation control word Tc_code to generate a new second temperature compensation control word Tc_code. This second temperature compensation control word Tc_code can be used to increase the oscillation frequency of the voltage-controlled oscillator VCO, thereby decreasing the control voltage Vctrl so that the control voltage Vctrl drops to less than the upper limit of the reference voltage range and is within the reference voltage range. On the contrary, when the control voltage Vctrl is affected by temperature changes and deviates from this ideal reference voltage range and is less than the lower limit of the reference voltage range, i.e., Vctrl < Vref_low, the digital state machine 012 can choose to increase the most recently generated first temperature compensation control word Tc_code to generate a new third temperature compensation control word Tc_code. This third temperature compensation control word Tc_code can be used to decrease the oscillation frequency of the voltage-controlled oscillator VCO, thereby increasing the control voltage Vctrl so that the control voltage Vctrl increases to greater than the lower limit of the reference voltage range and is within the reference voltage range.

[0059] Optionally, in the embodiment of the present application, the digital state machine 012 can also be used to: adjust the temperature compensation control word Tc_code in the form of a temperature code.

[0060] The temperature code is the digital representation of the temperature parameter, typically converted into a binary code, with one code value corresponding to 1 degree Celsius (°C). Adjusting the temperature compensation control word Tc_code using the temperature code allows the adjustment to be quantized into small steps, adjusting Tc_code sequentially. For example, for every 0.1°C increase in temperature, the temperature code increases by one bit. Based on this sequential adjustment of the temperature compensation control word Tc_code, the voltage generation circuit 02 can gradually change the temperature compensation voltage Vtc based on it, such as adjusting Vtc by only a millivolt unit each time. Furthermore, the frequency control circuit 03 can respond to the temperature compensation voltage Vtc by slightly adjusting the oscillation frequency of the voltage-controlled oscillator (VCO). This avoids excessively large single frequency adjustments that could cause the phase-locked loop (PLL) to lose lock, resulting in high adjustment reliability.

[0061] Optionally, in Figure 3 Based on this, further reference Figure 4 As can be seen, the voltage detector 011 may include: a first comparator (CMP) CMP1, a second comparator CMP2, and a reference voltage generator VrefGen (ReferenceVoltage Generator, Vref Gen).

[0062] The first input terminal of the first comparator CMP1 and the second input terminal of the second comparator CMP2 can both be connected to the loop filter LPF ( Figure 4 (The loop filter LPF is not shown; instead, it is represented by the control voltage Vctrl.) The second input terminal of the first comparator CMP1 and the first input terminal of the second comparator CMP2 can both be connected to the reference voltage generator VrefGen. The output terminals of the first comparator CMP1 and the second comparator CMP2 can both be connected to the digital state machine 012.

[0063] Optionally, for either the first comparator CMP1 or the second comparator CMP2, the first input terminal can refer to its positive input terminal (+), and the second input terminal can refer to its negative input terminal (-). Of course, the first and second input terminals can also be interchanged.

[0064] The reference voltage generator Vref Gen can be used to: generate a reference voltage range and transmit the upper limit of the reference voltage range Vref_high to the first comparator CMP1, and the lower limit of the reference voltage range Vref_low to the second comparator CMP2.

[0065] That is, in the embodiments of the present application, two voltages, namely Vref_low and Vref_high, can be generated by a dedicated reference voltage generator Vref Gen, so as to obtain a reference voltage range between Vref_low and Vref_high. Moreover, the reference voltage generator Vref Gen can transmit the two generated voltages Vref_low and Vref_high to the first comparator CMP1 and the second comparator CMP2 respectively.

[0066] The first comparator CMP1 can be used to: receive the control voltage Vctrl, compare the control voltage Vctrl with the upper limit Vref_high of the reference voltage range to obtain a first voltage detection result indicating the magnitude relationship between the two, and transmit the first voltage detection result to the digital state machine 012.

[0067] That is, in the embodiments of the present application, taking the first comparator CMP1 receiving the upper limit Vref_high of the reference voltage range as an example, the first comparator CMP1 can compare the magnitudes of the control voltage Vctrl and Vref_high and obtain a first voltage detection result indicating the magnitude relationship between Vctrl and Vref_high. In other words, the first voltage detection result can include three cases: Vctrl > Vref_high, Vctrl < Vref_high, and Vctrl = Vref_high. Then, the first comparator CMP1 can transmit the first voltage detection result to the digital state machine 012.

[0068] The second comparator CMP2 can be used to: receive the control voltage Vctrl, compare the control voltage Vctrl with the lower limit Vref_low of the reference voltage range to obtain a second voltage detection result indicating the magnitude relationship between the two, and transmit the second voltage detection result to the digital state machine 012.

[0069] Similarly, in the embodiments of the present application, taking the second comparator CMP2 receiving the lower limit Vref_low of the reference voltage range as an example, the second comparator CMP2 can compare the magnitudes of the control voltage Vctrl and Vref_low and obtain a second voltage detection result indicating the magnitude relationship between Vctrl and Vref_low. In other words, the second voltage detection result can include three cases: Vctrl > Vref_low, Vctrl < Vref_low, and Vctrl = Vref_low. Then, the second comparator CMP2 can transmit the second voltage detection result to the digital state machine 012.

[0070] It can be understood that when the first voltage detection result is Vctrl > Vref_high, it can indicate that the control voltage Vctrl is not within the reference voltage range and is greater than the upper limit Vref_high of the reference voltage range; when the second voltage detection result is Vctrl < Vref_low, it can indicate that the control voltage Vctrl is not within the reference voltage range and is less than the lower limit Vref_low of the reference voltage range; when the first voltage detection result is Vctrl ≤ Vref_high and the second voltage detection result is Vctrl ≥ Vref_low, it can indicate that the control voltage Vctrl is within the reference voltage range between Vref_low and Vref_high.

[0071] Optionally, in the embodiments of the present application, the reference voltage generator Vref Gen may further have a hysteresis characteristic. That is, the reference voltage generator Vref Gen may also be used to: when the control voltage Vctrl is greater than the upper limit Vref_high of the reference voltage range, reduce the upper limit Vref_high of the reference voltage range; when the control voltage Vctrl is less than the lower limit Vref_low of the reference voltage range, increase the lower limit Vref_low of the reference voltage range.

[0072] For example, assume that initially, the upper limit Vref_high of the reference voltage range is 0.9V and the lower limit Vref_low of the reference voltage range is 0.3V. Then when the control voltage Vctrl is first greater than 0.9V or less than 0.3V, the reference voltage generator Vref Gen can reduce the upper limit Vref_high of the reference voltage range to, for example, 0.7V, and can increase the lower limit Vref_low of the reference voltage range to, for example, 0.5V, that is, adjust the reference voltage range from 0.3V to 0.9V to the range of 0.5V to 0.7V. Thus, by dynamically adjusting the reference voltage range, the small fluctuations of the control voltage Vctrl during the temperature change process can be effectively filtered out, avoiding unnecessary temperature compensation actions triggered by the frequent drift of the control voltage Vctrl within a wide reference voltage range due to temperature changes, and reducing the number of temperature compensations. That is, it is possible to avoid frequent temperature compensation for different control voltages Vctrl with temperature changes and reduce the number of temperature compensations. Furthermore, not only can the operating power consumption of the circuit be reduced, but also the abnormal jitter of the control voltage Vctrl caused by frequent temperature compensation can be avoided, and thus the output stability of the voltage-controlled oscillator VCO can be ensured, and finally the working reliability and stability of the phase-locked loop PLL can be ensured to be better.

[0073] Optionally, as described above, in another embodiment, the temperature control encoding circuit 01 can be used to: detect the temperature of the phase-locked loop (PLL) and generate a temperature compensation control word Tc_code based on the temperature of the PLL.

[0074] That is, in this other embodiment, the temperature control encoding circuit 01 can detect the temperature of the phase-locked loop (PLL) in real time or periodically. Generally, the PLL can be integrated into a chip; therefore, the detected PLL temperature can also be referred to as the chip temperature. Furthermore, the temperature control encoding circuit 01 can dynamically adjust the temperature compensation control word Tc_code based on the detected chip temperature to achieve frequency stability across the entire temperature range. Correspondingly, combined with… Figure 5 As can be seen, in this embodiment, the temperature control encoder circuit 01 does not need to be connected to the loop filter LPF, and does not need to receive the control voltage Vctrl.

[0075] Alternatively, in this other embodiment, in Figure 5 Continue to combine on the basis Figure 6 As can be seen, the temperature control encoding circuit 01 may include: a temperature detector 013, an analog-to-digital converter (ADC), and a control word generator 014, which are connected in sequence to the voltage generation circuit 02.

[0076] Temperature detector 013 can be used to: detect the temperature of phase-locked loop (PLL), generate a sensing voltage that changes with temperature based on the temperature of PLL, and transmit the sensing voltage to analog-to-digital converter (ADC).

[0077] That is, in this embodiment of the application, a temperature detector 013 can be built into the phase-locked loop (PLL) to detect the temperature of the PLL in real time or periodically. The temperature detector 013 can also convert the detected temperature into a corresponding sensing voltage, that is, it can generate a sensing voltage that changes with temperature, and can transmit the generated sensing voltage to the analog-to-digital converter (ADC). For example, generally, as the temperature increases, the generated sensing voltage also increases; conversely, as the temperature decreases, the generated sensing voltage also decreases.

[0078] Optionally, combined Figure 6 It can also be seen that the temperature detector 013 can be, for example, a temperature sensor (Temp sensor).

[0079] The analog-to-digital converter (ADC) can be used to convert the sensed voltage transmitted by the temperature detector 013 from an analog voltage to a digital voltage and then transmit it to the control word generator 014.

[0080] It is understandable that the sensing voltage generated by the temperature detector 013 is generally an analog voltage. The control word generator 014 can generally process digital voltages. Therefore, an analog-to-digital converter (ADC) is also provided to convert the sensing voltage generated by the temperature detector 013 from analog to digital before transmitting it to the control word generator 014, ensuring that the control word generator 014 can reliably identify and process the voltage. Of course, if the control word generator 014 can directly process analog voltages, then the ADC is not necessary.

[0081] Control word generator 014 can be used to generate a temperature-compensated control word Tc_code based on the sensed voltage transmitted by the analog-to-digital converter (ADC).

[0082] That is, in this embodiment of the application, after receiving the sensing voltage transmitted by the analog-to-digital converter (ADC), the control word generator 014 can generate a corresponding temperature compensation control word Tc_code by referring to the temperature change reflected by the sensing voltage, so as to dynamically adjust the oscillation frequency of the voltage-controlled oscillator (VCO) and realize temperature compensation.

[0083] Optionally, combined Figure 6 It can also be seen that the control word generator 014 may include a lookup table (LUT), which can store a one-to-one correspondence between multiple sensing voltages and multiple temperature compensation control words Tc_code. That is, different sensing voltages and temperature compensation control words Tc_code can be pre-stored in the lookup table LUT in a corresponding relationship. For example, during the pre-shipment testing phase, multiple tests can be performed to obtain the correspondence between different sensing voltages and temperature compensation control words Tc_code. Furthermore, it can be understood that the temperature compensation control words Tc_code stored in the lookup table LUT are the temperature compensation control words Tc_code capable of reliably compensating for sensing voltages at different temperatures.

[0084] Therefore, the control word generator 014 can be used to: look up the corresponding temperature compensation control word Tc_code from the lookup table LUT based on the received sensed voltage.

[0085] In other words, after receiving the sensed voltage transmitted by the analog-to-digital converter (ADC), the control word generator 014 can quickly and accurately find the corresponding temperature compensation control word Tc_code from the pre-stored correspondence in the lookup table (LUT). Therefore, in this method, the control word generator 014 generates the temperature compensation control word Tc_code with high efficiency and accuracy.

[0086] Of course, in some embodiments, the control word generator 014 may also have a built-in algorithm for calculating the temperature compensation control word Tc_code based on the sensed voltage. Accordingly, the control word generator 014 can substitute the received sensed voltage into the algorithm to calculate the corresponding temperature compensation control word Tc_code. In this way, the control word generator 014 has greater flexibility in generating the temperature compensation control word Tc_code.

[0087] Optionally, in another embodiment, the temperature control encoding circuit 01 can be used both to generate a temperature compensation control word Tc_code based on the control voltage Vctrl transmitted from the loop filter LPF in the phase-locked loop (PLL) to the voltage-controlled oscillator (VCO), and to generate a temperature compensation control word Tc_code based on the temperature of the PLL. In this case, combined with Figure 7 As can be seen, the temperature control encoding circuit 01 may include: a first temperature control encoding circuit 01A and a second temperature control encoding circuit 01B, and the frequency control circuit 03 may also include: a multiplexer (MUX). Furthermore, the first temperature control encoding circuit 01A may be connected to the loop filter LPF and the multiplexer MUX respectively, the second temperature control encoding circuit 01B may be connected to the multiplexer MUX, and the multiplexer MUX may also be connected to the voltage generation circuit 02.

[0088] The first temperature control encoding circuit 01A can be used to: generate a temperature compensation control word Tc_code based on the control voltage Vctrl and transmit it to the selector MUX.

[0089] That is, the temperature compensation control word Tc_code can be generated by the first temperature control encoding circuit 01A based on the control voltage Vctrl transmitted from the loop filter LPF to the voltage-controlled oscillator VCO. Correspondingly, it can be seen that this first temperature control encoding circuit 01A is the one described in the preceding embodiment. Figures 2 to 4 The working principle of any of the temperature control encoder circuits shown is not described again here.

[0090] The second temperature control encoding circuit 01B can be used to generate a temperature compensation control word Tc_code based on the phase-locked loop (PLL) and transmit it to the selector MUX.

[0091] That is, the second temperature control encoding circuit 01B can generate a temperature compensation control word Tc_code based on the temperature of the phase-locked loop (PLL). Correspondingly, it can be seen that this second temperature control encoding circuit 01B is the same as described in the other embodiment above. Figure 5 or Figure 6 The working principle of the temperature control encoder circuit 01 shown will not be repeated here.

[0092] The selector MUX can be used to: receive a control command, and in response to the control command, select one of the temperature compensation control words Tc_code generated by the first temperature control encoding circuit 01A and the second temperature compensation control word Tc_code generated by the second temperature control encoding circuit 01B, and transmit the selected temperature compensation control word Tc_code to the voltage generation circuit 02.

[0093] That is, in this embodiment of the application, after receiving the temperature compensation control word Tc_code generated by the first temperature control encoding circuit 01A based on the control voltage Vctrl and the temperature compensation control word Tc_code generated by the second temperature control encoding circuit 01B based on the temperature of the phase-locked loop PLL, the selector MUX can select one of them as the final temperature compensation control word Tc_code and transmit it to the voltage generation circuit 02 under the control of the control command.

[0094] Optionally, the control command can originate from a processor-like device and can instruct the selection object so that the selector MUX can reliably select. For example, the control command can be transmitted in the form of a level signal. When the control command level is low, it can instruct the selection of the temperature compensation control word Tc_code generated by the second temperature control encoding circuit 01B based on the temperature of the phase-locked loop (PLL); when the control command level is high, it can instruct the selection of the temperature compensation control word Tc_code generated by the first temperature control encoding circuit 01A based on the control voltage Vctrl. Furthermore, in some embodiments, the control command can first instruct the selector MUX to select the temperature compensation control word Tc_code generated by the second temperature control encoding circuit 01B based on the temperature of the PLL to coarsely adjust the oscillation frequency of the voltage-controlled oscillator (VCO), and then instruct the selector MUX to select the temperature compensation control word Tc_code generated by the first temperature control encoding circuit 01A based on the control voltage Vctrl to finely adjust the oscillation frequency of the VCO, achieving a better temperature compensation effect. Of course, the control method described here is only illustrative.

[0095] Optionally, Figure 8 This is a schematic diagram of a voltage generation circuit 02 provided in an embodiment of this application. (Reference) Figure 8 It can be seen that the voltage generating circuit 02 may include: a switch control unit 021 and a voltage generating capacitor C1. The switch control unit 021 can be connected to the temperature control encoder circuit 01 ( Figure 8 (Not shown, represented by the temperature compensation control word Tc_code output by temperature control encoding circuit 01), bias power supply Vb, pull-up power supply VH, pull-down power supply VL and output node NO are connected, voltage generation capacitor C1 can be connected between output node NO and pull-down power supply VL, and output node NO can be connected to frequency control circuit 03 ( Figure 8(Not shown, represented by the temperature compensation voltage Vtc output to the frequency control circuit 03).

[0096] The switch control unit 021 can be used to: receive the temperature compensation control word Tc_code, and in response to the temperature compensation control word Tc_code and the bias power supply signal provided by the bias power supply terminal Vb, control the on / off state of the pull-up power supply terminal VH or the pull-down power supply terminal VL and the output node NO, so as to charge and discharge the voltage generation capacitor C1 to generate a continuously and slowly varying temperature compensation voltage Vtc, and transmit the temperature compensation voltage Vtc to the frequency control circuit 03 through the output node NO.

[0097] For example, when both the temperature compensation control word Tc_code and the bias power signal provided by the bias power supply terminal Vb are at a first level, the switch control unit 021 can control the pull-up power supply terminal VH to be turned on and the pull-down power supply terminal VL to be disconnected from the output node NO, so that the voltage generating capacitor C1 is connected between the pull-up power supply terminal VH and the pull-down power supply terminal VL to charge the voltage generating capacitor C1. Alternatively, when both the temperature compensation control word Tc_code and the bias power signal provided by the bias power supply terminal Vb are at a second level, the switch control unit 021 can control the pull-down power supply terminal VL to be turned on and the pull-up power supply terminal VH to be disconnected from the output node NO, so that the charge on the voltage generating capacitor C1 is transferred to the pull-down power supply terminal VL to discharge the voltage generating capacitor C1. Based on the charging and discharging of the voltage generating capacitor C1, a temperature compensation voltage Vtc can be generated at the output node NO. Furthermore, the rate of change of the generated temperature compensation voltage Vtc can be altered by controlling the bias power supply signal and the size of the voltage generation capacitor C1. Ultimately, the generated voltage Vtc can transition from a low level to a high level continuously and slowly, or from a high level to a low level continuously and slowly, a temperature compensation voltage also known as a ramp voltage Vramp. Accordingly, the voltage generation circuit 02 described in this application embodiment can also be called a ramp voltage generation circuit 02.

[0098] It is understood that the level of the temperature compensation control word Tc_code can be composed of multiple binary high and low levels (e.g., low level corresponds to logic 0, high level corresponds to logic 1). The first level described in the embodiments of this application is used to represent low level 0, and the second level is used to represent high level 1. Of course, it is not limited to this.

[0099] Optionally, the pull-up power supply terminal VH can be the power supply terminal VDD, which can provide a high-level pull-up power supply signal; the pull-down power supply terminal VL can be the ground terminal GND, which can provide a low-level pull-down power supply signal.

[0100] Optionally, in Figure 8Based on this, further reference Figure 9 It can be seen that in the voltage generation circuit 02, the switch control unit 021 may include: a first switch group 0211 and a second switch group 0212. The first switch group 0211 can be connected to the temperature control encoding circuit 01 ( Figure 9 (Not shown, represented by the temperature compensation control word Tc_code output by the temperature control encoding circuit 01), connected to the pull-up power supply VH, the first bias power supply Vbp, and the output node NO. The second switch group 0212 can be connected to the temperature control encoding circuit 01, the pull-down power supply VL, the second bias power supply Vbn, and the output node NO, respectively.

[0101] The first switch group 0211 can be used to: receive the temperature compensation control word Tc_code, and in response to the temperature compensation control word Tc_code and the first bias power signal provided by the first bias power supply terminal Vbp, control the connection and disconnection of the pull-up power supply terminal VH and the output node NO.

[0102] For example, the first switch group 0211 can control the pull-up power supply terminal VH to be turned on with the output node NO when both the level of the temperature compensation control word Tc_code and the level of the first bias power supply signal provided by the first bias power supply terminal Vbp are at the first level; the first switch group 0211 can control the pull-up power supply terminal VH to be disconnected from the output node NO when both the level of the temperature compensation control word Tc_code and the level of the first bias power supply signal provided by the first bias power supply terminal Vbp are at the second level.

[0103] The second switch group 0212 can be used to: receive the temperature compensation control word Tc_code, and in response to the temperature compensation control word Tc_code and the second bias power signal provided by the second bias power supply terminal Vbn, control the on / off state of the pull-down power supply terminal VL and the output node NO.

[0104] For example, the second switch group 0212 can control the pull-down power supply terminal VL to be turned on with the output node NO when both the level of the temperature compensation control word Tc_code and the level of the second bias power supply signal provided by the second bias power supply terminal Vbn are at the second level; the second switch group 0212 can also control the pull-down power supply terminal VL to be disconnected from the output node NO when both the level of the temperature compensation control word Tc_code and the level of the second bias power supply signal provided by the second bias power supply terminal Vbn are at the first level.

[0105] That is, in some embodiments, two switch groups can be configured to respond to different bias power supply signals, respectively controlling the switching of the pull-up power supply terminal VH and the output node NO, and the switching of the pull-down power supply terminal VL and the output node NO. Thus, the rate of change of the temperature compensation voltage Vtc can be controlled by the magnitudes of the different first and second bias power supply signals, as well as the capacitance value of the voltage generation capacitor C1.

[0106] Optionally, in some embodiments, when the temperature compensation voltage Vtc rises to the pull-up power supply signal or falls to the pull-down power supply signal, the level of the first bias power supply signal can be controlled to be a first level, and the level of the second bias power supply signal can be controlled to be a second level. That is, the level of the first bias power supply signal is pulled low, and the level of the second bias power supply signal is pulled high, so that the pull-up power supply terminal VH and the pull-down power supply terminal VL are connected, thereby reducing the impedance of the temperature compensation voltage Vtc to the pull-up power supply terminal VH or to the pull-down power supply terminal VL, and thus reducing the adverse effect on the phase noise of the voltage-controlled oscillator VCO.

[0107] Optionally, in Figure 9 Based on this, further reference Figure 10 It can be seen that the first switch group 0211 may include two first switch transistors T1a and T1b. The second switch group 0212 may include two second switch transistors T2a and T2b. Furthermore, the first and second switch transistors can be of different types. Here, "type" refers to either N-type or P-type.

[0108] The two first switching transistors T1a and T1b can be connected in series between the pull-up power supply terminal VH and the output node NO, and can also be connected to the temperature control encoder circuit 01 respectively. Figure 10 (Not shown) and connected to the first bias power supply terminal Vbp.

[0109] The two second switching transistors T2a and T2b can be connected in series between the pull-down power supply terminal VL and the output node NO, and can be connected to the temperature control encoder circuit 01 and the second bias power supply terminal Vbn, respectively.

[0110] Understandably, in combination Figure 10This could mean that the gates of the two first switching transistors T1a and T1b are respectively connected to the temperature control encoding circuit 01 (represented by Tc_code) and the first bias power supply terminal Vbp. For example, the gate of the first switching transistor T1a is connected to the temperature control encoding circuit 01, and the gate of the first switching transistor T1b is connected to the first bias power supply terminal Vbp. Alternatively, the source of the first switching transistor T1a can be connected to the pull-up power supply terminal VH, the drain of the first switching transistor T1a can be connected to the source of the first switching transistor T1b, and the drain of the first switching transistor T1b can be connected to the output node NO. Similarly, it could mean that the gates of the two second switching transistors T2a and T2b are respectively connected to the temperature control encoding circuit 01 (represented by Tc_code) and the second bias power supply terminal Vbn. For example, the gate of the second switching transistor T2a is connected to the temperature control encoding circuit 01, and the gate of the second switching transistor T2b is connected to the second bias power supply terminal Vbn. Alternatively, the source of the second switching transistor T2a can be connected to the pull-down source terminal, the drain of the second switching transistor T2a can be connected to the source of the second switching transistor T2b, and the drain of the second switching transistor T2b can be connected to the output node NO.

[0111] Optionally, refer to Figure 10 It can also be seen that the two first switching transistors T1a and T1b can both be P-type transistors; and the two second switching transistors T2a and T2b can both be N-type transistors. Of course, this is not the only possibility. Furthermore, for P-type transistors, a low level can be the effective level for controlling their conduction; a high level can be the ineffective level for controlling their turn-off. For N-type transistors, a high level can be the effective level for controlling their conduction; and a low level can be the ineffective level for controlling their turn-off.

[0112] Optionally, refer to Figure 10 The equivalent circuit diagram also shows that the first switch T1b connected to the first bias power supply terminal Vbp can be equivalent to a current source IA1; similarly, the second switch T2b connected to the second bias power supply terminal Vbn can be equivalent to a current source IA2. Thus, the voltage generation circuit O2 can also be considered as the voltage generation capacitor C1 being charged and discharged by the current source in conjunction with the switch to generate the required continuously and slowly varying temperature compensation voltage Vtc (Vramp).

[0113] Optionally, in some embodiments, the temperature compensation control word Tc_code may include two temperature compensation control words, Tc_code and Tc_code', which are inverted signals. The two signals are inverted signals, meaning they are at different levels at the same time. Correspondingly, in Figure 10 Based on this, further reference Figure 11 It can be seen that the voltage generating circuit 02 may include two switch control units 021 and two voltage generating capacitors C1 connected in a one-to-one correspondence.

[0114] The two switch control units 021 can be used to: receive two temperature compensation control words Tc_code and Tc_code' respectively, and charge and discharge two voltage generating capacitors C1 in response to the two temperature compensation control words Tc_code and Tc_code' to generate two temperature compensation voltages Vtcp and Vtcn that are opposite signals to each other.

[0115] That is, of the two switch control units 021, one switch control unit 021 can receive one of the two temperature compensation control words Tc_code, and in response to the temperature compensation control word Tc_code, charge and discharge the connected voltage generating capacitor C1 to generate a temperature compensation voltage Vtcp; the other switch control unit 021 can receive the other temperature compensation control word Tc_code', and in response to the other temperature compensation control word Tc_code', charge and discharge the connected voltage generating capacitor C1 to generate another temperature compensation voltage Vtcn. Since the two temperature compensation control words Tc_code and Tc_code' are inverted signals, the two temperature compensation voltages Vtcp and Vtcn generated by the two switch control units 021 can also be inverted signals.

[0116] Optionally, based on this, the temperature compensation circuit 00 provided in the embodiments of this application may further include at least one inverter F1. The at least one inverter F1 may be connected between the temperature control encoding circuit 01 and the voltage generation circuit 02.

[0117] At least one inverter F1 can be used to: invert the temperature compensation control word Tc_code generated by the temperature control encoding circuit 01 and then transmit it to the voltage generation circuit 02.

[0118] For example, continue to refer to Figure 11As can be seen, the temperature compensation circuit 00 shown includes two inverters F1. Of the two switch control units 021, one switch control unit 021 can be connected to the temperature control encoding circuit 01 via the two inverters F1 to receive the temperature compensation control word Tc_code obtained after the temperature compensation control word Tc_code generated by the temperature control encoding circuit 01 has been inverted twice via the two inverters F1; the other switch control unit 021 can be connected to the temperature control encoding circuit 01 via one of the inverters F1 to receive the temperature compensation control word Tc_code obtained after the temperature compensation control word Tc_code generated by the temperature control encoding circuit 01 has been inverted once via that inverter F1. It is understood that the temperature compensation control word Tc_code obtained after an even number of inversions is equal to the temperature compensation control word Tc_code before inversion, while the temperature compensation control word Tc_code obtained after an odd number of inversions is an inverted signal of the temperature compensation control word Tc_code before inversion. Therefore, this allows one switch control unit 021 to receive the temperature compensation control word Tc_code before inversion processing; and the other switch control unit 021 to receive the temperature compensation control word Tc_code after inversion processing. Of course, the number of inverters F1 here is only for illustrative purposes.

[0119] Optionally, Figure 12 This schematic diagram illustrates the circuit structure of a voltage-controlled oscillator (VCO) and a frequency control circuit 03; Figure 12 On this basis, Figure 13 The schematic diagram shows a circuit structure of a frequency control circuit 03.

[0120] refer to Figure 12 As can be seen, the voltage-controlled oscillator (VCO) includes core components: inductors L1 & L2, and capacitors C01 & C02. The control voltage Vctrl output from the loop filter LPF can be transmitted to one end of capacitors C01 & C02. Thus, the VCO can utilize the resonance phenomenon of the inductors and capacitors to output an oscillation signal with an oscillation frequency corresponding to the control voltage Vctrl. Furthermore, in some embodiments, a tuning frequency calibration capacitor FT CAP is connected between the differential output terminals of the VCO, so that the FT CAP responds to the frequency control word Ft_code. <n:0>The oscillation frequency is quickly pulled up to near the locking frequency of the phase-locked loop (PLL) when it is locked, and then the oscillation frequency is adjusted to the target frequency via the control voltage Vctrl. When the temperature changes, the oscillation frequency will increase or decrease. In this case, the PLL will maintain phase tracking after locking, and the control voltage Vctrl output by the loop filter LPF will adjust synchronously to prevent the PLL from losing lock. However, as mentioned earlier, when the temperature change is too large, the oscillation frequency will also drift significantly, causing the control voltage Vctrl to exceed the linear operating voltage range of the charge pump CP, which in turn leads to phase noise deterioration and eventually causes the PLL to lose lock. In addition, refer to Figure 12 It can also be seen that the voltage-controlled oscillator (VCO) may include components such as resistor R0, switching transistors M1 and M2, etc. The connection methods between these components are described in reference [reference needed]. Figure 12 This will not be elaborated upon here.

[0121] Based on this, the embodiments of this application further add a frequency adjustment circuit 03 between the differential output terminals of the voltage-controlled oscillator (VCO) to compensate for the drift of the oscillation frequency caused by temperature changes, and to avoid excessive adjustment of the control voltage Vctrl. Furthermore, combined with... Figure 12 and Figure 13 As can be seen, the frequency control circuit 03 described in this application embodiment may include a multi-channel capacitor switch array 031 connected in parallel between the differential output terminals of the voltage-controlled oscillator (VCO). Correspondingly, the temperature compensation circuit 00 may include multiple voltage generation circuits 02 corresponding one-to-one with the multi-channel capacitor switch array 031.

[0122] For example, Figure 13 This schematically illustrates a 6-channel capacitor switch array 031, correspondingly combined with... Figure 13 and Figure 14 As can be seen, it schematically illustrates five voltage generation circuits 02. Each of the five voltage generation circuits 02 outputs a temperature compensation voltage Vtcp, which is an inverse signal, to a corresponding six-channel capacitor switch array 031. <0> &Vtcn <0> Vtcp <1> &Vtcn <1> …Vtcp <4> &Vtcn <4> Vtcp <5> &Vtcn <5> It can be seen that... Figure 14 The voltage generation circuit 02 shown is based on Figure 11 The structure shown is an example, and for distinction, the temperature compensation control words Tc_code received by the five voltage generation circuits 02 are also identified as Tc_code. <0> Tc_code <1> …Tc_code <5> .

[0123] exist Figure 13 Based on this, further reference Figure 15 It can be seen that each capacitor switch array 031 may include: a switch section 031K and at least one temperature compensation capacitor C2 connected in sequence between the differential output terminals of the voltage-controlled oscillator VCO. The switch section 031K may also be connected to the corresponding voltage generation circuit 02 (not shown in the figure, but represented by the temperature compensation voltage output by the voltage generation circuit 02).

[0124] The switching unit 031K can be used to: control the on / off state of at least one temperature compensation capacitor C2 and the differential output terminal of the voltage-controlled oscillator VCO in response to the temperature compensation voltage Vtc transmitted by the connected voltage generation circuit 02, so as to adjust the oscillation frequency of the voltage-controlled oscillator VCO by outputting a frequency control signal.

[0125] For example, when the temperature compensation voltage Vtc is at a first level, the switch unit 031K can control at least one connected temperature compensation capacitor C2 to be connected to the differential output terminal of the voltage-controlled oscillator (VCO), so that at least one connected temperature compensation capacitor C2 is connected to the VCO. When the temperature compensation voltage Vtc is at a second level, the switch unit 031K can control at least one connected temperature compensation capacitor C2 to be disconnected from the differential output terminal of the VCO, so that at least one connected temperature compensation capacitor C2 is not connected to the VCO. In this way, the number of temperature compensation capacitors C2 connected to the VCO can be controlled by the multi-channel capacitor switch array 031 to output different frequency control signals to adjust the oscillation frequency of the VCO.

[0126] It is understandable that, since the multi-channel capacitor switch array 031 is connected in parallel between the differential output terminals of the voltage-controlled oscillator (VCO), the more capacitors connected, the larger the capacitance value; conversely, the fewer the capacitors connected, the smaller the capacitance value. Furthermore, according to the oscillation frequency calculation formula, the larger the capacitance value, the lower the oscillation frequency; conversely, the smaller the capacitance value, the higher the oscillation frequency. This achieves flexible control of the oscillation frequency. Therefore, combined with... Figure 13 It can also be seen that the frequency control circuit 03 described in the embodiments of this application can also be called a temperature-compensated capacitor (TC CAP) circuit. The TC CAP circuit can receive temperature compensation voltages Vtcp<5:0> & Vtcn<5:0>, and adjust the capacitance value of the capacitor connected to the voltage-controlled oscillator (VCO) under the control of the temperature compensation voltages Vtcp<5:0> & Vtcn<5:0>, thereby adjusting the oscillation frequency of the VCO.

[0127] Optionally, in Figure 15 Based on this, continue to refer to Figure 16 It can be seen that the switching unit 031K may include: a switching unit 031K1 and a biasing unit 031K2 connected in sequence, and the switching unit 031K1 and the biasing unit 031K2 may both be connected to the corresponding voltage generating circuit 02. Figure 16 (Not shown, but connected as follows: voltage generation circuit 02 outputs temperature compensation voltage Vtcp to switching unit 031K1, and temperature compensation voltage Vtcn to bias unit 031K2.) Furthermore, as described above, voltage generation circuit 02 can be used to generate two temperature compensation voltages, Vtcp and Vtcn, which are inverse signals.

[0128] The switching unit 031K1 can be used to control the switching on and off of at least one temperature compensation capacitor C2 connected to the differential output terminal of the voltage-controlled oscillator VCO in response to one of the two temperature compensation voltages Vtc (e.g., Vtcp).

[0129] The bias unit 031K2 can be used to provide a bias voltage for the switching unit 031K1 in response to another temperature compensation voltage Vtc (e.g., Vtcn) of the two temperature compensation voltages Vtc.

[0130] Optionally, in Figure 16 Based on this, continue to refer to Figure 17 It can be seen that the switching unit 031K1 may include: a third switching transistor T3. The biasing unit 031K2 may include: a first resistor R1 and a second resistor R2. And, each capacitor switch array 031 may include: two temperature compensation capacitors C2.

[0131] The third switch T3 can be connected between the two temperature compensation capacitors C2, and can also be used to receive one of the two temperature compensation voltages Vtc (e.g., Vtcp).

[0132] The first resistor R1 and the second resistor R2 can be connected in series between the two temperature compensation capacitors C2, and can be connected in parallel with the third switch T3. They can also be used to receive the other temperature compensation voltage Vtc (e.g., Vtcn) of the two temperature compensation voltages Vtc.

[0133] Understandably, in combination Figure 17 Alternatively, the gate of the third switch T3 can receive a temperature compensation voltage Vtcp. The source of the third switch T3 is connected to one end of one of the two temperature compensation capacitors C2, and the drain of the third switch T3 is connected to one end of the other temperature compensation capacitor C2. The other ends of the two temperature compensation capacitors C2 are respectively connected to the differential output terminal of the voltage-controlled oscillator (VCO). Alternatively, one end of the first resistor R1 can be connected to the source of the third switch T3, one end of the second resistor R2 can be connected to the drain of the third switch T3, and the other ends of the first resistor R1 and the other ends of the second resistor R2 are connected to receive another temperature compensation voltage Vtcn.

[0134] For example, combined Figure 17 For each capacitor switch array 031, when the received temperature compensation voltage Vtcp is high and the temperature compensation voltage Vtcn is low, the capacitor switch array 031 can be turned on, meaning that each temperature compensation capacitor C2 in the capacitor switch array 031 can be connected to the voltage-controlled oscillator (VCO). Conversely, when the received temperature compensation voltage Vtcp is low and the temperature compensation voltage Vtcn is high, the capacitor switch array 031 can be turned off, meaning that each temperature compensation capacitor C2 in the capacitor switch array 031 can be left unconnected to the VCO. Thus, by using multiple capacitor switch arrays 031, the capacitance values ​​connected to the VCO can be adjusted, thereby adjusting the oscillation frequency of the VCO.

[0135] Furthermore, in this embodiment, the voltage generation circuit 02 can also reduce the rate of change of the temperature compensation voltages Vtcp and Vtcn, transforming the discretely switched digitally controlled capacitor into a capacitor whose capacitance can be linearly adjusted with the continuously changing temperature compensation voltage. This reduces the rate of adjustment of the oscillation frequency of the voltage-controlled oscillator (VCO) during temperature compensation, i.e., reduces the rate of change of the oscillation frequency, making the frequency change smoother and preventing abrupt changes that exceed the linear operating voltage range of the charge pump CP, thereby preventing the phase-locked loop (PLL) from losing lock.

[0136] Optionally, in this embodiment, the capacitance value of the minimum capacitor unit can be flexibly set according to the rate of change of the temperature compensation voltage Vtc, such as a minimum capacitance value of 2 finfarums. Furthermore, the array size and bit depth of the capacitor switch array 031 can be set according to the temperature drift of the voltage-controlled oscillator (VCO) (i.e., the degree of drift of the oscillation frequency with temperature change). The array size refers to the maximum capacitance value that the multi-channel capacitor switch array 031 can provide; the bit depth refers to the number of capacitors in the multi-channel capacitor switch array 031 that can be independently controlled by the temperature compensation voltage Vtc. Generally, the more bits, the finer the control. For example, a 6-channel capacitor switch array 031, under binary signal control, can achieve, for example, 2 finfarums... 6 =64 levels of capacitance adjustment.

[0137] Optionally, combined Figure 4 , Figure 6 as well as Figures 7 to 17 Records Figure 18 A schematic diagram of the overall circuit structure of a temperature compensation circuit 00, including a first temperature control encoding circuit 01A and a second temperature control encoding circuit 01B, is also shown. (Refer to...) Figure 18 As described above, the first temperature control encoding circuit 01A may include: a voltage detector 011 and a digital state machine 012. Figure 18 The voltage detector 011 (identified as State Machine) includes a reference voltage generator Vref Gen, a first comparator CMP1, and a second comparator CMP2. The second temperature control encoding circuit 01B may include a temperature sensor (as temperature detector 013), an analog-to-digital converter (ADC), and a lookup table (LUT) (as control word generator 014). The temperature compensation circuit 00 may further include a selector MUX, a ramp voltage generation module (as voltage generation circuit 02), and a TC CAP (as frequency control circuit 03), which is connected to a voltage-controlled oscillator (VCO). Based on this, the following embodiments illustrate its operating principle: Combination Figure 18 , in the upper path, the control voltage Vctrl output from the loop filter LPF to the voltage-controlled oscillator VCO will first be sent to two comparators CMP1 and CMP2 included in the first temperature control encoding circuit 01A, and the reference voltage generator Vref Gen included in the first temperature control encoding circuit 01A will generate two voltages Vref_high and Vref_low and send them to the two comparators CMP1 and CMP2. On this basis, the two comparators CMP1 and CMP2 can compare and detect the control voltage Vctrl and Vref_high and Vref_low, and send the detection results to the digital state machine State Machine. And, as recorded above, when Vref_low ≤ Vctrl ≤ Vref_high, the digital state machine State Machine can keep the currently output temperature compensation control word Tc_code unchanged. When Vctrl > Vref_high, the digital state machine State Machine can reduce the temperature compensation control word Tc_code, so as to cooperate with the Ramp voltage generation module to reduce the capacitance value of the TC CAP connected to the voltage-controlled oscillator VCO, thereby increasing the oscillation frequency of the voltage-controlled oscillator VCO, and thus reducing the control voltage Vctrl, so that the control voltage Vctrl satisfies Vref_low ≤ Vctrl ≤ Vref_high. On the contrary, when Vctrl < Vref_low, the digital state machine StateMachine can increase the temperature compensation control word Tc_code, so as to cooperate with the Ramp voltage generation module to increase the capacitance value of the TC CAP connected to the voltage-controlled oscillator VCO, thereby reducing the oscillation frequency of the voltage-controlled oscillator VCO, and thus increasing the control voltage Vctrl, so that the control voltage Vctrl satisfies Vref_low ≤ Vctrl ≤ Vref_high. In addition, hysteresis can be added to the reference voltage generator VrefGen to avoid frequent temperature compensation for different control voltages Vctrl with temperature changes, which can reduce the number of temperature compensations. This can be referred to the description in the foregoing embodiments and will not be repeated here.

[0138] Combined with Figure 18 , in the lower path, the temperature sensor Temp Sensor can detect the chip temperature and generate a sensed voltage that changes with temperature. After this sensed voltage passes through the analog-to-digital converter ADC and is decoded by the look-up table LUT, a temperature compensation control word Tc_code reflecting the temperature change can be generated. Then, the Ramp voltage generation module can flexibly adjust the capacitance value of the TC CAP connected to the voltage-controlled oscillator VCO based on this temperature compensation control word Tc_code, and then flexibly adjust the oscillation frequency of the voltage-controlled oscillator VCO, so as to reliably control the control voltage Vctrl.

[0139] Furthermore, in application, coarse adjustments can be made via the lower channel while real-time monitoring and adjustment are performed via the upper channel, thereby achieving a better temperature compensation effect. As can be seen from the above embodiments, the temperature compensation circuit provided in this application is a VCO temperature compensation circuit based on numerical control technology. It can monitor the junction temperature in real time through a temperature sensor and dynamically adjust the compensation parameters using a numerical control algorithm to achieve frequency stability across the entire temperature range. It can also automatically detect the lock-up status of the phase-locked loop (PLL) and perform adaptive temperature compensation calibration using a numerical control algorithm to achieve full-temperature-range locking stability. Moreover, it can solve problems such as poor noise and large process deviations existing in traditional analog circuits.

[0140] In summary, this application provides a temperature compensation circuit for a phase-locked loop (PLL). Because the voltage generation circuit in this circuit can output a temperature compensation voltage to the frequency control circuit based on the temperature compensation control word generated by the temperature control encoding circuit, and the frequency control circuit adjusts the oscillation frequency of the voltage-controlled oscillator (VCO) under the control of this temperature compensation voltage, it can avoid the influence of temperature changes on the oscillation frequency of the VCO, ensuring that the PLL is in a locked state and generates a stable and clean clock signal.

[0141] This application provides a phase-locked loop circuit. For example... Figure 19 As shown, the phase-locked loop circuit 000 includes: a phase-locked loop PLL, and a temperature compensation circuit 00 as described above.

[0142] Based on the previous description, the temperature compensation circuit 00 and the voltage-controlled oscillator (VCO) in the phase-locked loop (PLL) Figure 19 (Not shown) Connection. Temperature compensation circuit 00 is used to compensate for the drift in oscillation frequency of the voltage-controlled oscillator (VCO) caused by temperature changes.

[0143] It is understandable that, since the phase-locked loop circuit and the aforementioned temperature compensation circuit have essentially the same technical effect, the technical effect of the phase-locked loop circuit will not be repeated here for the sake of brevity.

[0144] This application provides an electronic device, such as... Figure 20 As shown, the electronic device includes a load 100 and a phase-locked loop (PLL) circuit 000 as described above. The PLL circuit 000 is connected to the load 100. For example, refer to... Figure 20 As can be seen, the phase-locked loop circuit 000 can be connected to the load 100 through the phase-locked loop output terminal PLL OUTPUT.

[0145] The phase-locked loop circuit 000 is used to generate a clock signal and transmit it to the load 100 to drive the load 100 to work.

[0146] Optionally, the load 100 may include a display driver, also known as a display driver integrated circuit (DDIC). That is, the electronic device protected in this application embodiment may be a display device, such as a mobile phone or computer. Of course, in some other embodiments, the electronic device may be other non-display devices. This application embodiment does not limit this.

[0147] It is understandable that, since the electronic device and the aforementioned temperature compensation circuit have essentially the same technical effect, for the sake of brevity, the technical effect of the electronic device will not be described again here.

[0148] It is understood that the terminology used in the embodiments of this application is for explaining the embodiments of this application and is not intended to limit this application. Unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains.

[0149] For example, the use of words like "first," "second," "third," and similar terms does not indicate any order, quantity, or importance, but is merely used to distinguish different components. Similarly, words like "one" or "a" do not indicate a quantity limitation, but rather the existence of at least one. Words like "include" or "contain" mean that the element or object preceding "includes" covers the element or object listed after "includes" or "contains," and does not exclude other elements or objects. Words like "connect" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Above," "below," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly. "Or" indicates that three relationships can exist; for example, A or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following objects have an "or" relationship.

[0150] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A temperature compensation circuit for a phase-locked loop, wherein the phase-locked loop includes a voltage-controlled oscillator; characterized in that, The temperature compensation circuit includes: a temperature control encoding circuit, a voltage generation circuit, and a frequency control circuit connected in sequence, and the frequency control circuit is also connected to the voltage-controlled oscillator. The temperature control encoding circuit is used to: generate a temperature compensation control word and transmit the temperature compensation control word to the voltage generation circuit; The voltage generation circuit is used to: generate a temperature compensation voltage based on the temperature compensation control word, and transmit the temperature compensation voltage to the frequency control circuit; The frequency control circuit is used to: output a frequency control signal in response to the temperature compensation voltage, the frequency control signal being used to adjust the oscillation frequency of the voltage-controlled oscillator.

2. The temperature compensation circuit according to claim 1, characterized in that, The phase-locked loop further includes: a loop filter connected to the voltage-controlled oscillator; the temperature control encoding circuit is also connected to the loop filter; The temperature control encoding circuit is used to: receive the control voltage transmitted from the loop filter to the voltage-controlled oscillator, and generate the temperature compensation control word based on the control voltage.

3. The temperature compensation circuit according to claim 2, characterized in that, The temperature control encoding circuit includes: a voltage detector and a digital state machine connected sequentially between the loop filter and the voltage generation circuit; The voltage detector is used to: receive a reference voltage range and the control voltage, detect whether the control voltage is within the reference voltage range, and transmit the voltage detection result to the digital state machine; The digital state machine is used to generate the temperature compensation control word based on the voltage detection result.

4. The temperature compensation circuit according to claim 3, characterized in that, The digital state machine is used to: generate a first temperature compensation control word if the voltage detection result indicates that the control voltage is within the reference voltage range; and reduce the first temperature compensation control word to generate a second temperature compensation control word if the voltage detection result indicates that the control voltage is not within the reference voltage range and is greater than the upper limit of the reference voltage range. If the voltage detection result indicates that the control voltage is not within the reference voltage range and is less than the lower limit of the reference voltage range, then the first temperature compensation control word is increased to generate a third temperature compensation control word. If the voltage detection result indicates that the control voltage is equal to the upper limit of the reference voltage range or the lower limit of the reference voltage range, then the first temperature compensation control word is maintained.

5. The temperature compensation circuit according to claim 3, characterized in that, The voltage detector includes: a first comparator, a second comparator, and a reference voltage generator; the first input terminal of the first comparator and the second input terminal of the second comparator are both connected to the loop filter, the second input terminal of the first comparator and the first input terminal of the second comparator are both connected to the reference voltage generator, and the output terminal of the first comparator and the output terminal of the second comparator are both connected to the digital state machine. The reference voltage generator is configured to: generate the reference voltage range, and transmit the upper limit of the reference voltage range to the first comparator, and transmit the lower limit of the reference voltage range to the second comparator; The first comparator is configured to: receive the control voltage, compare the control voltage with the upper limit of the reference voltage range to obtain a first voltage detection result indicating the relationship between the two, and transmit the first voltage detection result to the digital state machine; The second comparator is configured to: receive the control voltage, compare the control voltage with the lower limit of the reference voltage range to obtain a second voltage detection result indicating the relationship between the two, and transmit the second voltage detection result to the digital state machine.

6. The temperature compensation circuit according to claim 1, characterized in that, The temperature control encoding circuit is used to: detect the temperature of the phase-locked loop and generate the temperature compensation control word based on the temperature of the phase-locked loop.

7. The temperature compensation circuit according to claim 6, characterized in that, The temperature control encoding circuit includes: a temperature detector, an analog-to-digital converter, and a control word generator connected in sequence to the voltage generation circuit; The temperature detector is used to: detect the temperature of the phase-locked loop, generate a sensing voltage that varies with temperature based on the temperature of the phase-locked loop, and transmit the sensing voltage to the analog-to-digital converter; The analog-to-digital converter is used to: convert the sensing voltage transmitted by the temperature detector from analog voltage to digital voltage and then transmit it to the control word generator; The control word generator is used to generate the temperature compensation control word based on the sensed voltage transmitted by the analog-to-digital converter.

8. The temperature compensation circuit according to claim 7, characterized in that, The temperature detector is a temperature sensor.

9. The temperature compensation circuit according to claim 7, characterized in that, The control word generator includes a lookup table, and the lookup table stores a one-to-one correspondence between multiple sensing voltages and multiple temperature compensation control words; The control word generator is used to: look up the corresponding temperature compensation control word from the lookup table based on the received sensed voltage.

10. The temperature compensation circuit according to any one of claims 1 to 9, characterized in that, In the case where the temperature control encoding circuit is used to generate the temperature compensation control word based on the control voltage transmitted from the loop filter in the phase-locked loop to the voltage-controlled oscillator, and is also used to generate the temperature compensation control word based on the temperature of the phase-locked loop, the temperature control encoding circuit includes: a first temperature control encoding circuit and a second temperature control encoding circuit, and the temperature compensation circuit further includes: a selector; and the first temperature control encoding circuit is connected to the loop filter and the selector respectively, the second temperature control encoding circuit is connected to the selector, and the selector is also connected to the voltage generation circuit; The first temperature control encoding circuit is used to: generate a temperature compensation control word based on the control voltage and transmit it to the selector; The second temperature control encoding circuit is used to: generate a temperature compensation control word based on the temperature of the phase-locked loop and transmit it to the selector; The selector is configured to: receive a control command, and in response to the control command select one of the temperature compensation control words generated by the first temperature control encoding circuit and the second temperature control encoding circuit, and transmit the selected temperature compensation control word to the voltage generating circuit.

11. The temperature compensation circuit according to any one of claims 1 to 9, characterized in that, The voltage generating circuit includes a switch control unit and a voltage generating capacitor. The switch control unit is connected to the temperature control encoding circuit, the bias power supply terminal, the pull-up power supply terminal, the pull-down power supply terminal, and the output node. The voltage generating capacitor is connected between the output node and the pull-down power supply terminal, and the output node is connected to the frequency control circuit. The switch control unit is used to: receive the temperature compensation control word, and in response to the temperature compensation control word and the bias power signal provided by the bias power supply terminal, control the connection and disconnection of the pull-up power supply terminal or the pull-down power supply terminal with the output node to charge and discharge the voltage generating capacitor to generate a continuously and slowly varying temperature compensation voltage, and transmit the temperature compensation voltage to the frequency control circuit through the output node.

12. The temperature compensation circuit according to claim 11, characterized in that, The switch control unit includes a first switch group and a second switch group; the bias power supply includes a first bias power supply and a second bias power supply; the first switch group is connected to the temperature control encoding circuit, the pull-up power supply, the first bias power supply and the output node respectively; the second switch group is connected to the temperature control encoding circuit, the pull-down power supply, the second bias power supply and the output node respectively. The first switch group is used to: receive the temperature compensation control word, and in response to the temperature compensation control word and the first bias power signal provided by the first bias power supply terminal, control the connection and disconnection between the pull-up power supply terminal and the output node; The second switch group is used to: receive the temperature compensation control word, and in response to the temperature compensation control word and the second bias power signal provided by the second bias power supply terminal, control the connection and disconnection between the pull-down power supply terminal and the output node.

13. The temperature compensation circuit according to claim 12, characterized in that, The first switch group includes two first switching transistors; the second switch group includes two second switching transistors; and the first switching transistors and the second switching transistors are of different types. The two first switching transistors are connected in series between the pull-up power supply terminal and the output node, and are respectively connected to the temperature control encoding circuit and the first bias power supply terminal. The two second switching transistors are connected in series between the pull-down power supply terminal and the output node, and are respectively connected to the temperature control encoding circuit and the second bias power supply terminal.

14. The temperature compensation circuit according to claim 11, characterized in that, The temperature compensation control word includes two temperature compensation control words that are inverse signals; the voltage generation circuit includes two switch control units and two voltage generation capacitors that are connected in a one-to-one correspondence. The two switch control units are configured to: receive the two temperature compensation control words respectively, and in response to the two temperature compensation control words, charge and discharge the two voltage generating capacitors to generate two temperature compensation voltages that are opposite signals to each other.

15. The temperature compensation circuit according to claim 14, characterized in that, The temperature compensation circuit further includes: at least one inverter; the at least one inverter is connected between the temperature control encoding circuit and the voltage generation circuit; The at least one inverter is used to: invert the temperature compensation control word generated by the temperature control encoding circuit and then transmit it to the voltage generation circuit.

16. The temperature compensation circuit according to any one of claims 1 to 9, characterized in that, The frequency control circuit includes a multi-channel capacitor switch array connected in parallel between the differential output terminals of the voltage-controlled oscillator; the temperature compensation circuit includes a plurality of voltage generating circuits corresponding one-to-one with the multi-channel capacitor switch array; and each of the capacitor switch arrays includes a switch section connected in sequence between the differential output terminals of the voltage-controlled oscillator and at least one temperature compensation capacitor, wherein the switch section is also connected to the corresponding voltage generating circuit. The switching unit is used to: control the on / off state of at least one temperature compensation capacitor connected to the differential output terminal of the voltage-controlled oscillator in response to the temperature compensation voltage transmitted by the connected voltage generation circuit, so as to output the frequency control signal to adjust the oscillation frequency of the voltage-controlled oscillator.

17. The temperature compensation circuit according to claim 16, characterized in that, The switching section includes a switching unit and a biasing unit connected in sequence, and both the switching unit and the biasing unit are connected to the corresponding voltage generating circuit; and the voltage generating circuit is used to generate two temperature compensation voltages that are opposite signals to each other. The switching unit is used to: control the on / off state of at least one connected temperature compensation capacitor and the differential output terminal of the voltage-controlled oscillator in response to one of the two temperature compensation voltages; The bias unit is used to provide a bias voltage to the switching unit in response to the other of the two temperature compensation voltages.

18. The temperature compensation circuit according to claim 17, characterized in that, The switching unit includes a third switching transistor; the biasing unit includes a first resistor and a second resistor; and each of the capacitor switch arrays includes two temperature compensation capacitors. The third switch is connected between the two temperature compensation capacitors and is also used to receive one of the two temperature compensation voltages. The first resistor and the second resistor are connected in series between the two temperature compensation capacitors and in parallel with the third switch, and are also used to receive the other of the two temperature compensation voltages.

19. A phase-locked loop circuit, characterized in that, The phase-locked loop circuit includes: a phase-locked loop, and a temperature compensation circuit as described in any one of claims 1 to 18; the temperature compensation circuit is connected to the voltage-controlled oscillator in the phase-locked loop; The temperature compensation circuit is used to compensate for the drift in the oscillation frequency of the voltage-controlled oscillator caused by temperature changes.

20. An electronic device, characterized in that, The electronic device includes: a load, and a phase-locked loop circuit as described in claim 19; the phase-locked loop circuit is connected to the load; The phase-locked loop circuit is used to generate a clock signal and transmit it to the load to drive the load to work.

Images