Frequency control device and ring oscillator system
By using a frequency control device to control the current with a MOSFET and a constant current source, a stable voltage signal is output, which solves the problem of frequency instability in the ring oscillator circuit and achieves higher precision and lower power consumption frequency control.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING ESWIN COMPUTING TECH CO LTD
- Filing Date
- 2026-02-26
- Publication Date
- 2026-06-05
AI Technical Summary
In the prior art, the oscillation frequency of a ring oscillator circuit is affected by the operating voltage, making it difficult to achieve stable and precise frequency control.
A frequency control device is adopted, which uses an operational amplifier, a first conduction module and a second conduction module, and a MOSFET as the conduction module. Combined with a constant current source to control the current, a stable second voltage signal is output to control the frequency of the ring oscillator circuit.
It achieves higher accuracy of output voltage signal under the influence of environmental factors such as temperature changes, more stable oscillation frequency of ring oscillator circuit, lower power consumption, and smaller area.
Smart Images
Figure CN122159867A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electronic technology, and in particular to a frequency control device and a ring oscillation system. Background Technology
[0002] In the field of electronics, a ring oscillator circuit achieves oscillation through loop self-excitation using multiple stages of inverters, generating an oscillation signal. The frequency of this oscillation signal is related to the operating voltage connected to the ring oscillator circuit. For example, the operating voltage determines the high-level amplitude of the oscillation signal; a larger high-level amplitude results in a longer transition time from high to low, a longer oscillation period, and a lower oscillation frequency. Therefore, a frequency control device is urgently needed to control the oscillation frequency of the ring oscillator circuit by providing an operating voltage to it. Summary of the Invention
[0003] This application provides a frequency control device and a ring oscillation system, which can be used to provide operating voltage to a ring oscillation circuit. The technical solution is as follows: In a first aspect, embodiments of this application provide a frequency control device, which includes an operational amplifier, a first conduction module, a second conduction module, a first resistor, and a second resistor. The stability of the first conduction module is higher than that of the first resistor, and the stability of the second conduction module is higher than that of the second resistor. The first conduction module is used to transmit a first current to the first resistor based on the first voltage signal output from the output terminal of the operational amplifier, so as to generate a voltage drop in the first resistor and obtain a first sampling signal; The second conduction module is used to transmit a first current to the second resistor based on the first voltage signal output from the output terminal of the operational amplifier, so as to generate a voltage drop in the second resistor and obtain a first sampling signal; The operational amplifier is used to adjust the first voltage signal output from the output terminal to the second voltage signal based on the reference voltage signal and the first sampling signal fed back by the first resistor and the second resistor; The second voltage signal is determined based on the reference voltage signal, the on-state voltage drop of the first conducting module, and the on-state voltage drop of the second conducting module.
[0004] In one possible implementation, the first conducting module is further configured to transmit a second current to the first resistor based on the second voltage signal output from the operational amplifier output terminal, so as to generate a voltage drop in the first resistor and obtain a second sampling signal; The second conduction module is also used to transmit a second current to the second resistor based on the second voltage signal output from the output terminal of the operational amplifier, so as to generate a voltage drop in the second resistor and obtain a second sampling signal; The second sampling signal is the same as the reference voltage signal.
[0005] In one possible implementation, one end of the first conduction module is connected to the output of the operational amplifier; The other end of the first conducting module is connected to one end of the first resistor and the negative terminal of the power supply; One end of the second conduction module is connected to the output terminal of the operational amplifier; The other end of the second conducting module is connected to one end of the second resistor and the negative terminal of the power supply; The other end of the first resistor is connected to the other end of the second resistor and the input terminal of the operational amplifier.
[0006] In one possible implementation, the first conducting module is connected to the negative terminal of the power supply via a first constant current source, which is used to control the magnitude of the current transmitted by the first conducting module to the first resistor. The second conduction module is connected to the negative terminal of the power supply through a second constant current source, which is used to control the magnitude of the current transmitted from the second conduction module to the second resistor.
[0007] In one possible implementation, the first conduction module is a first MOSFET, and the second conduction module is a second MOSFET.
[0008] In one possible implementation, the voltage drop generated by the first resistor is the same as the voltage drop generated by the second resistor.
[0009] In a second aspect, a ring oscillation system is provided, the ring oscillation system including a frequency control device and a ring oscillation circuit as described in the first aspect or any possible implementation of the first aspect, the frequency control device being used to provide a second voltage signal to the ring oscillation circuit, the ring oscillation circuit outputting an oscillation signal based on the second voltage signal, the second voltage signal being used to control the frequency of the oscillation signal.
[0010] In one possible implementation, the ring oscillator circuit includes a plurality of first inverters, wherein each of the plurality of first inverters is cascaded to form a closed loop; The frequency control device includes an operational amplifier whose output terminal is connected to each of the first inverters in the ring oscillator circuit to provide a second voltage signal to each of the first inverters.
[0011] In one possible implementation, the ring oscillator circuit includes a pull-up constant current source and a pull-down constant current source corresponding to each first inverter. The first inverter is connected to a frequency control device through the pull-up constant current source corresponding to the first inverter, and the first inverter is connected to the negative terminal of the power supply through the pull-down constant current source corresponding to the first inverter.
[0012] In one possible implementation, the second voltage signal is used to control the high-level amplitude of the first inverter in the ring oscillator circuit, and the high-level amplitude is used to control the oscillation frequency of the oscillation signal.
[0013] Thirdly, a clock system is provided, which includes the ring oscillation system and processing module in the second aspect or any possible implementation of the second aspect; The ring oscillation system is used to output an oscillation signal; The processing module is used to process the oscillation signal to obtain a clock signal.
[0014] Fourthly, a chip is provided, the chip including the clock system and operating module shown in the third aspect; The clock system is used to output clock signals; The operation module is used to perform at least one operation among calculation, reading / writing, or information interaction based on the clock signal.
[0015] The technical solution provided in this application brings at least the following beneficial effects: Because the stability of the first conducting module is higher than that of the first resistor, and the stability of the second conducting module is higher than that of the second resistor, the on-state voltage drop of the first and second conducting modules is less affected by the environment compared to the voltage drop of the first and second resistors. For example, when the temperature changes, the change in the on-state voltage drop of the first and second conducting modules is less than the change in the voltage drop of the first and second resistors. The magnitude of the second voltage signal is independent of the first and second resistors, and is determined only by the externally provided reference voltage signal and the on-state voltage drop of the first and second conducting modules. It is less affected by the environment, and the accuracy of the output second voltage signal is higher. The oscillation frequency of the ring oscillator circuit controlled by the higher accuracy second voltage signal is more stable. Attached Figure Description
[0016] 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.
[0017] Figure 1This is a schematic diagram of a ring oscillator circuit provided in an embodiment of this application; Figure 2 This is a schematic diagram of another ring oscillator circuit provided in an embodiment of this application; Figure 3 This is a waveform diagram of an oscillation signal provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a frequency control device provided by related technologies; Figure 5 This is a schematic diagram of the structure of a frequency control device provided in an embodiment of this application; Figure 6 This is a schematic diagram of another frequency control device provided in the embodiments of this application; Figure 7 This is a schematic diagram of the structure of another frequency control device provided in the embodiments of this application; Figure 8 This is a schematic diagram of the structure of a ring oscillation system provided in an embodiment of this application; Figure 9 This is a schematic diagram of another ring oscillation system provided in the embodiments of this application. Detailed Implementation
[0018] 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.
[0019] In the field of electronics, ring oscillator circuits are an indispensable module in clock systems. The oscillation signal provided by the ring oscillator circuit serves as the reference for the clock signal. In some cases, the oscillation frequency of the ring oscillator circuit's oscillation signal is determined based on voltage. Figure 1 This application provides a ring oscillation circuit based on voltage-controlled vibration frequency.
[0020] See Figure 1 A ring oscillator circuit includes multiple inverters cascaded to form a closed loop. These inverters are, for example,... Figure 1 The five inverters shown could also be any number of inverters. If the ring oscillator circuit is... Figure 1 The single-ended structure shown has an odd number of inverters in the ring oscillator circuit, while the double-ended structure has an even number of inverters.
[0021] In some cases, the ring oscillator circuit also includes other modules, such as Figure 2As shown, the ring oscillator circuit also includes inverters 6 and 7 as buffer modules. Inverters 6 and 7 are used to buffer the voltage signal output by inverter 5 to obtain FSW (Frequency Switching Signal).
[0022] The embodiments of this application do not limit the inverters included in the ring oscillation circuit; they can be any element that supports signal switching, such as inverters including PMOS (P-channel Metal-Oxide-Semiconductor Field-Effect Transistor) and NMOS (N-channel Metal-Oxide-Semiconductor Field-Effect Transistor). Furthermore, the inverters cascaded to form a closed loop will be referred to as the first inverter below to distinguish them from the inverters included in the ring oscillation circuit as other modules.
[0023] Regardless of the structure of the ring oscillator circuit, each of the first inverters constituting the ring oscillator circuit to achieve self-excited oscillation is connected to the positive terminal of the power supply through a pull-up constant current source and to the negative terminal of the power supply through a pull-down constant current source. Figure 2 In this circuit, VDD (Voltage Drain) corresponds to the positive terminal of the power supply, and GND (ground) corresponds to the negative terminal. Optionally, the voltage at the positive terminal of the power supply affects the oscillation frequency of the ring oscillator circuit, which can be understood as... Figure 2 The frequency of the FSW signal output by inverter 7 shown is... Figure 3 It shows Figure 2 The ring oscillator circuit shown outputs an oscillation signal.
[0024] Next, we will explain the principle that the voltage at the positive terminal of the power supply affects the oscillation frequency. Figure 2 The first inverter is connected to the positive and negative terminals of the power supply via constant current sources. The constant current source connected to the positive terminal is called a pull-up constant current source, and the constant current source connected to the negative terminal is called a pull-down constant current source. The constant current sources are used to output a current of constant magnitude. Therefore, through the pull-up constant current source, the positive terminal of the power supply provides a constant charging current to the parasitic capacitance of the first inverter, and through the pull-down constant current source, the parasitic capacitance of the first inverter outputs a constant discharging current to the negative terminal of the power supply. For example, the capacitor used for charging and discharging can also be a load capacitor.
[0025] Since parasitic capacitor charging is how the first inverter transitions its output voltage signal from low to high, the pull-up constant current source controls the rise time of this transition by controlling the charging current. Conversely, parasitic capacitor discharging is used to transition the output voltage from high to low; therefore, the pull-down constant current source controls the fall time of this transition by controlling the discharge current. By precisely controlling the charging and discharging process of the first inverter using both pull-up and pull-down constant current sources, the oscillation frequency can be stabilized and adjusted.
[0026] In some cases, the inverter includes a MOSFET, which generates parasitic capacitance. The first inverter achieves a high or low output level by charging or discharging the parasitic capacitance generated by the MOSFET. For any first inverter, the propagation time (TR, time rise) of the voltage signal from low to high level is given by Equation 1, and the propagation time (TF, time fall) of the output voltage from high to low level is given by Equation 2.
[0027] (Formula 1) (Formula 2) In formula 1, It refers to the propagation time of a voltage signal from a low level to a high level. This refers to the value of the parasitic capacitance of the MOSFET. This is the switching voltage of the first inverter, and Ip refers to the current value provided by the pull-up constant current source, indicating the charging current value of the parasitic capacitance. In Formula 2, VDD refers to the propagation time of a voltage signal from a high level to a low level. VDD refers to the voltage value at the positive terminal of the power supply. This refers to the current value provided by the pull-down constant current source, which is the discharge current value of the parasitic capacitance. Based on formulas 1 and 2, it can be seen that... and Each is determined by the charging current I P and discharge current I N Decide.
[0028] In some cases, and This will affect the oscillation frequency; for example, the average delay time of the first inverter is... If the size ratio of the current mirror is controlled so that I P =I N ,but The current mirror size refers to the ratio of the MOSFET's width (W) to its length (L). The average delay time is based on the first inverter. The oscillation period is determined to be The oscillation frequency is the reciprocal of the oscillation period, and the oscillation frequency is expressed as... .
[0029] As can be seen from the above embodiments, the oscillation frequency is determined by the charging and discharging current. Parasitic capacitance of MOSFET The charging and discharging current is determined by the voltage VDD at the positive terminal of the power supply. The charging and discharging current can be determined based on the size ratio of the current mirror. For example, the pull-up constant current source is a PMOS cascode (common gate) structure, the pull-down constant current source is an NMOS cascode structure, and the MOSFET in the first inverter is also a cascode structure. Furthermore, the pull-up constant current source, the pull-down constant current source, and the MOSFET corresponding to the first inverter are all designed with the same W / L ratio, belonging to a proportionally sized cascode current mirror. In this case, the charging and discharging current value can be set by adjusting the W / L ratio. Alternatively, the charging and discharging current value can be set by controlling the number of MOSFETs.
[0030] For example, since the parasitic capacitance of a MOSFET is determined by the size of the MOSFET, and the parasitic capacitance remains constant when the MOSFET remains unchanged, if the voltage VDD at the positive terminal of the power supply is guaranteed to be a stable and high-precision voltage, the required oscillation frequency can be obtained based on the ring oscillator circuit.
[0031] Figure 4 A frequency control device is provided for supplying voltage to the positive terminal of a ring oscillator circuit. The frequency control device includes an operational amplifier, resistor 1, and resistor 2. The output of the operational amplifier is connected to the ring oscillator circuit, for example, connected to... Figure 1 or Figure 2 The inverter in the ring oscillator circuit shown. Figure 2 For example, the output of the operational amplifier is used as VDD, which is connected to each of the first inverters in the ring oscillator circuit.
[0032] Figure 4 In this configuration, the output of the operational amplifier is connected to one end of resistor 1, the other end of resistor 1 is connected to one end of resistor 2, the other end of resistor 2 is grounded, and the other end of resistor 1 is also connected to the negative input of the operational amplifier to provide a sampling voltage signal. This sampling voltage signal is obtained by dividing the output voltage signal through resistors 1 and 2. The positive input of the operational amplifier is used to receive the reference voltage signal VREF. The operational amplifier continuously adjusts the output voltage signal based on the feedback sampling voltage signal and the reference voltage signal to ensure that the sampling voltage signal obtained by dividing the output voltage signal is the same as the reference voltage signal.
[0033] Figure 4The frequency control device shown in this application outputs a voltage signal whose ratio is determined by the reference voltage signal VREF and the resistance ratio, where the resistance ratio refers to the ratio of the resistance values of resistor 1 and resistor 2. If the total resistance of resistor 1 and resistor 2 is small, the Io flowing to resistor 1 and resistor 2 based on Vout is large, resulting in high power consumption. If the total resistance of resistor 1 and resistor 2 is large, although Io is small and power consumption is reduced, the area increases. Simultaneously, the manufacturing process error and temperature variation of the actual resistors affect the accuracy of the voltage division, thereby affecting the operational amplifier performance, and the output voltage signal may fluctuate due to temperature changes. Based on this, this application provides another frequency control device for outputting a second voltage signal to a ring oscillator circuit to control the oscillation frequency of the ring oscillator circuit based on the second voltage signal.
[0034] See Figure 5 The ring oscillator circuit includes an operational amplifier 01, a first conducting module 02, a second conducting module 03, a first resistor 04, and a second resistor 05. One end of the first conducting module 02 is connected to the output of the operational amplifier 01; the other end of the first conducting module 02 is connected to one end of the first resistor 04 and the negative terminal of the power supply. One end of the second conducting module 03 is connected to the output of the operational amplifier 01; the other end of the second conducting module 03 is connected to one end of the second resistor 05 and the negative terminal of the power supply; the other end of the first resistor 04 is connected to the other end of the second resistor 05 and the input of the operational amplifier 01.
[0035] Figure 5 In the diagram, a black circle represents the other end of the first resistor 04. This black circle is the feedback sampling point of the operational amplifier, used to feed back a sampling signal to the input of the operational amplifier based on the voltage signal output from the output terminal. The other input terminal of the operational amplifier 01 is used to receive the reference voltage signal Vref.
[0036] For example, the first conduction module 02 is used to transmit a first current to the first resistor 04 based on the first voltage signal output from the output terminal of the operational amplifier 01, so as to generate a voltage drop in the first resistor 04 and obtain a first sampling signal; the second conduction module 03 is used to transmit a first current to the second resistor 05 based on the first voltage signal output from the output terminal of the operational amplifier 01, so as to generate a voltage drop in the second resistor 05 and obtain a first sampling signal; the operational amplifier 01 is used to adjust the first voltage signal output from the output terminal to the second voltage signal based on the first sampling signal fed back from the first resistor and the second resistor and the reference voltage signal.
[0037] The first voltage signal refers to the voltage signal when operational amplifier 01 is unstable and still needs adjustment, while the second voltage signal refers to the voltage signal when operational amplifier 01 is stable and will not be adjusted further. The reason the second voltage signal will not be adjusted further is that when the voltage signal output by operational amplifier 01 is the second voltage signal, the first conduction module 02 transmits a second current to the first resistor based on the second voltage signal output by operational amplifier 01, causing a voltage drop in the first resistor and obtaining the second sampling signal; similarly, the second conduction module 03 transmits a second current to the second resistor based on the second voltage signal output by operational amplifier 01, causing a voltage drop in the second resistor and obtaining the second sampling signal. Since the second sampling signal is the same as the reference voltage signal, operational amplifier 01 will not adjust the voltage signal output by its output terminal.
[0038] For example, operational amplifier 01 can adjust the first voltage signal once to obtain the second voltage signal, or it can perform multiple adjustments on the first voltage signal. That is, the voltage signal obtained after adjustment is used as the new first voltage signal, and a new first sampling signal is fed back to the input terminal until the second voltage signal is obtained. The process of adjusting the first voltage signal will be illustrated below.
[0039] Before feedback is established, the operational amplifier 01 is in an open-loop state. The first voltage signal output by the output terminal of the operational amplifier 01 is close to saturation and close to the operating voltage of the operational amplifier 01. In this case, since the first conducting module 02 and the second conducting module 03 are not conducting, the voltage at the other end is 0V. Therefore, the voltage difference between the two ends is greater than the conducting voltage, and both the first conducting module 02 and the second conducting module 03 are conducting.
[0040] After conduction, the voltage at the other end of the first conducting module 02 is the first voltage signal - conduction voltage drop 1. Based on its connection to the negative terminal of the power supply, the first conducting module 02 forms a current path. Therefore, the first conducting module 02 transmits a first current to the first resistor 04. The voltage drop 1 generated by the first resistor 04 is the first current multiplied by the resistance of the first resistor. The first sampling signal is the first voltage signal - conduction voltage drop 1 - voltage drop 1. The operation of the second conducting module 03 is similar to that of the first conducting module 02. The first sampling signal is the first voltage signal - conduction voltage drop 2 - voltage drop 2. Furthermore, since the first sampling signals obtained based on the first resistor 04 and the second resistor 05 are the same, that is, the sum of the voltage drops between conduction voltage drop 1 and voltage drop 1 is the same as the sum of the voltage drops between conduction voltage drop 2 and voltage drop 2.
[0041] Operational amplifier 01, based on the difference between the received first sampled signal and the reference voltage signal, outputs a new first voltage signal based on the input differential voltage and open-loop gain of the first sampled signal and the reference voltage signal. Then, operational amplifier 01 transmits the output change through the feedback loop formed by the first conduction module 02, the second conduction module 03, the first resistor 04 and the second resistor 05, and continues to adjust until operational amplifier 01 achieves virtual short-circuit stability, that is, the second sampled signal obtained from the feedback of the output voltage signal is the same as the reference voltage signal. The voltage output of operational amplifier 01 no longer changes drastically, but enters a closed-loop stable working state. At this time, the voltage signal output by the output terminal of operational amplifier 01 is the second voltage signal in the stable state.
[0042] In some cases, the voltage drop 1 formed by the first resistor 04 and the voltage drop 2 formed by the second resistor 05 are the same. In this case, the final stable second voltage signal is not related to the resistance values of the first resistor 04 and the second resistor 05, but is determined based on the reference voltage signal, the conduction voltage drop of the first conduction module 02 and the conduction voltage drop of the second conduction module 03.
[0043] For example, the second sampling signal obtained based on the sampling of the first resistor 04 is equal to the second voltage signal minus the on-state voltage drop 3 minus the voltage drop 3. The second sampling signal obtained based on the sampling of the second resistor 05 is equal to the second voltage signal minus the on-state voltage drop 4 minus the voltage drop 4. Here, the on-state voltage drop 3 is the voltage drop generated by the first conducting module 02 under the second voltage signal, the voltage drop 3 is the voltage drop generated by the first resistor 04 under the second voltage signal, the on-state voltage drop 4 is the voltage drop generated by the second conducting module 03 under the second voltage signal, and the voltage drop 4 is the voltage drop generated by the second resistor 05 under the second voltage signal.
[0044] Adding the second sampled signals obtained based on the first resistor 04 and the second resistor 05, we get: 2 × second sampled signal = 2 × second voltage signal - on-state voltage drop 3 - voltage drop 3 - on-state voltage drop 4 + voltage drop 4. Since voltage drop 3 and voltage drop 4 are the same, and the second sampled signal and the reference voltage signal are the same, based on the above formula, we derive that the second voltage signal = reference voltage signal + 1 / 2 (on-state voltage drop 3 + on-state voltage drop 4).
[0045] For example, the voltage drop 3 of the first resistor 04 and the voltage drop 4 of the second resistor 05 can be controlled to be the same by controlling the magnitude of the current transmitted to the first resistor 04 and the second resistor 05. See also Figure 6 The first conducting module 02 is connected to the negative terminal of the power supply through a first constant current source. The first constant current source is used to control the magnitude of the current transmitted by the first conducting module 02 to the first resistor 04. The second conducting module 03 is connected to the negative terminal of the power supply through a second constant current source. The second constant current source is used to control the magnitude of the current transmitted by the second conducting module 03 to the second resistor 05.
[0046] If the resistance values of the first resistor 04 and the second resistor 05 are the same, the current value provided by the first conducting module 02 to the first resistor 04 is the same as the current value provided by the second conducting module 03 to the second resistor 05; for example, both are the second current. If the resistance values of the first resistor 04 and the second resistor 05 are different, then the current value provided by the first conducting module 02 to the first resistor 04 is different from the current value provided by the second conducting module 03 to the second resistor 05, and the ratio between the current value provided by the first conducting module 02 to the first resistor 04 and the current value provided by the second conducting module 03 to the second resistor 05 is the reciprocal of the ratio of the resistance values of the first resistor 04 and the second resistor 05.
[0047] For example, the first conducting module 02 has a higher stability than the first resistor 04, and the second conducting module 03 has a higher stability than the second resistor 05. Stability can be understood as the degree of voltage drop change when the temperature changes. Optionally, the first conducting module 02 and the second conducting module 03 are MOSFETs, that is, the first conducting module 02 is a first MOSFET, and the second conducting module 03 is a second MOSFET. Alternatively, the first conducting module 02 and the second conducting module 03 are diodes, and the conduction direction is from the output terminal of the operational amplifier to the negative terminal of the power supply.
[0048] See Figure 7 The first MOSFET is an NMOS transistor, and the second MOSFET is a PMOS transistor. The drain of the second MOSFET is connected to the output terminal of operational amplifier 01. The gate and source of the second MOSFET are shorted and connected to one end of the second resistor 05 and the negative power supply. The gate and source of the first MOSFET are shorted and connected to the output terminal of operational amplifier 01. The drain of the first MOSFET is connected to one end of the first resistor 04 and the negative power supply.
[0049] In this context, the MOSFETs, including the first and second MOSFETs, function as active diodes after a gate-source short circuit. For example, when the gate (G) and source (S) of a MOSFET are shorted, the gate potential is forcibly pulled to the same level as the source. At this time, the MOSFET channel is closed, and the conduction between the source and drain cannot be controlled by controlling the gate voltage. Furthermore, since the source and substrate of a MOSFET are usually internally connected, for an NMOS transistor, a PN junction is formed between the drain and the substrate. This PN junction is a parasitic diode, pointing from the source to the drain, allowing current to flow only from the source to the drain. For a PMOS transistor, the parasitic diode flows from the drain to the source, allowing current to flow only from the drain to the source.
[0050] Next, combine Figure 7 Explain the output process of operational amplifier 01, and Figure 4The circuit principle shown is similar. Before feedback is established, operational amplifier 01 is in an open-loop state. The first voltage signal output by operational amplifier 01 is close to saturation, for example, close to the operating voltage of operational amplifier 01. In this case, the first MOSFET, which is an NMOS transistor, will send current from its source to its drain. Since the source of the first MOSFET is connected to the output of the operational amplifier, the source will transfer current to the drain based on the first voltage signal output by the operational amplifier. The drain sends current to the negative terminal of the power supply on one hand, and transfers current I1 to the first resistor on the other hand, forming a voltage drop I1×R1. The voltage drop across the other end of the first resistor 04 is V. FB satisfy ,in, This is the forward voltage of the first MOSFET, and it belongs to the forward diode voltage drop of the first MOSFET. This is the voltage signal output by operational amplifier 01. The current value flowing through the first resistor 04 is... When it is the first voltage signal, For the first current, in When it is the second voltage signal, For the second current, This is the resistance value of the first resistor, 04.
[0051] When the gate and source of the second MOSFET (a PMOS transistor) are shorted, current flows from the drain to the source. Since the drain of the second MOSFET is connected to the output of the operational amplifier, the drain will transfer current to the source based on the first voltage signal output by the operational amplifier. The source then sends current to the negative terminal of the power supply and simultaneously transfers current I1 to the second resistor, forming a voltage drop I1 × R1. The resistance of the second resistor is also R1. The voltage across the other end of the second resistor is V. FB satisfy The relationship, among which, This is the forward-biased diode voltage of the second MOSFET, i.e., the forward voltage drop of the second MOSFET. Based on Figure 7 The obtained second voltage signal .
[0052] As can be seen from the above formula, the second voltage signal output by the frequency control device provided in this application when it is stable depends on the reference voltage signal VREF and the forward conduction diode voltage of the MOSFET, and is independent of the resistance values of the first resistor O4 and the second resistor O5. Meanwhile, the MOSFET is less affected by the manufacturing process, resulting in a relatively stable forward conduction diode voltage V. DSP and V DSN It is more precise than a resistor, and the current can be achieved at the nA level. Figure 4The device shown in this application provides a frequency control device with lower power consumption, smaller area, and more accurate output voltage. Furthermore, the MOSFET has lower on-resistance than a diode, resulting in higher efficiency, less heat generation, and reduced layout area for the frequency control device.
[0053] In one possible implementation, the output of operational amplifier 01 is connected to each of the first inverters included in the ring oscillator circuit. The first inverters are cascaded to form a closed loop, providing a second voltage signal to each of the first inverters. For example, the first inverter is... Figure 2 The five inverters shown are connected to VDD, which is the second voltage signal output by operational amplifier 01.
[0054] In summary, the frequency control device provided in this application has advantages over the first conducting module 02, which has higher stability than the first resistor 04, and the second conducting module 03, which has higher stability than the second resistor 05. This indicates that the on-state voltage drop of the first conducting module 02 and the second conducting module 03 is less affected by the environment than the voltage drop of the first resistor 04 and the second resistor 05. For example, when the temperature changes, the change in the on-state voltage drop of the first conducting module 02 and the second conducting module 03 is less than the change in the voltage drop of the first resistor 04 and the second resistor 05. The magnitude of the second voltage signal is independent of the first resistor 04 and the second resistor 05, and is determined only by the externally provided reference voltage signal and the on-state voltage drop of the first conducting module 02 and the second conducting module 03. It is less affected by the environment, and the output second voltage signal has higher accuracy. The oscillation frequency of the ring oscillation circuit controlled by the higher accuracy second voltage signal is more stable.
[0055] This application also provides a ring oscillation system, see [link to relevant documentation]. Figure 8 Ring oscillation systems include, for example, Figures 5-7 The frequency control device 71 and the ring oscillation circuit 72 shown are configured to provide a second voltage signal to the ring oscillation circuit 72, and the ring oscillation circuit 72 outputs an oscillation signal based on the second voltage signal, wherein the second voltage signal is used to control the frequency of the oscillation signal.
[0056] In one possible implementation, the ring oscillator circuit 72 includes a plurality of first inverters, wherein each of the plurality of first inverters is cascaded to form a closed loop, see [reference]. Figure 9 , Figure 9 The multiple first inverters in the circuit are inverter 1 to inverter 5. The output of the previous inverter is connected to the input of the next inverter, and the output of inverter 5 is connected to the input of inverter 1, forming a closed loop.
[0057] For example, the ring oscillator circuit 72 also includes pull-up constant current sources and pull-down constant current sources corresponding to each of the first inverters. In some cases, the ring oscillator circuit 72 includes the same number of pull-up constant current sources as the number of first inverters, and the ring oscillator circuit 72 includes the same number of pull-down constant current sources as the number of first inverters. See also... Figure 9 , Figure 9 I in P Corresponding to the pull-up constant current source, I N Corresponding to the pull-down constant current source, Figure 9 There are 5 first inverters, and 5 pull-up constant current sources and 5 pull-down constant current sources. Therefore, there is a one-to-one correspondence between the pull-up constant current sources and the first inverters, and also a one-to-one correspondence between the pull-down constant current sources and the first inverters. Each first inverter is connected to the frequency control device 71 through its corresponding pull-up constant current source, and connected to the negative terminal of the power supply through its corresponding pull-down constant current source.
[0058] Optionally, the output terminals of the operational amplifier included in the frequency control device 71 are respectively connected to each of the first inverters included in the ring oscillator circuit 72 to provide a second voltage signal to each of the first inverters. By providing the second voltage signal, it serves as the positive terminal of the power supply connected to the first inverter, i.e. Figure 9 VDD in the circuit controls the high-level amplitude of the first inverter, thereby controlling the oscillation frequency of the oscillation signal. For the operating principle of the ring oscillator circuit 72, please refer to [link to relevant documentation]. Figure 2 The relevant descriptions shown will not be repeated here.
[0059] The ring oscillator circuit 72 has the advantages of low power consumption, small area and high integration, which meets the frequency requirements of mobile devices, wearable electronics and other products. The frequency control device 71 ensures the frequency output accuracy and reduces the interference of process error.
[0060] This application also provides a clock system, the clock system including... Figure 8 or Figure 9 The ring oscillation system and processing module shown are configured to output an oscillation signal and process the oscillation signal to obtain a clock signal, wherein the processing is, for example, at least one of signal shaping or frequency division.
[0061] This application also provides a chip, which includes a clock system and an operation module. The clock system outputs a clock signal, and the operation module performs at least one operation based on the clock signal, such as calculation, reading / writing, or information interaction. The module performing the calculation is, for example, a processor; the module performing the reading / writing operation is, for example, a memory; and the module performing the information interaction operation is, for example, an input / output interface.
[0062] This application also provides an electronic device configured with the chip described in the above embodiments.
[0063] For example, the electronic device can be any terminal. Optionally, the terminal can be any electronic product that can interact with the user through one or more methods such as a keyboard, touchpad, touchscreen, remote control, voice interaction, or handwriting device, such as a PC (Personal Computer), mobile phone, smartphone, PDA (Personal Digital Assistant), wearable device, PPC (Pocket PC), tablet computer, smart car system, smart TV, etc. The electronic device can also be a server, such as a single server, a server cluster composed of multiple servers, or a cloud computing service center. The electronic device can also be any device that relies on a clock signal to operate, such as a switch, router, etc.
[0064] It should be noted that all information (including but not limited to user equipment information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.), and signals involved in this application are authorized by the user or fully authorized by all parties, and the collection, use, and processing of related data must comply with the relevant laws, regulations, and standards of the relevant countries and regions. For example, the reference voltage signals involved in this application were all obtained under fully authorized conditions.
[0065] It should be understood that "multiple" as used in this article refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.
[0066] The above description is merely an exemplary embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.
Claims
1. A frequency control device, characterized in that, The frequency control device includes an operational amplifier, a first conduction module, a second conduction module, a first resistor, and a second resistor. The stability of the first conduction module is higher than that of the first resistor, and the stability of the second conduction module is higher than that of the second resistor. The first conduction module is used to transmit a first current to the first resistor based on the first voltage signal output from the output terminal of the operational amplifier, so as to generate a voltage drop in the first resistor and obtain a first sampling signal; The second conduction module is used to transmit a first current to the second resistor based on the first voltage signal output from the output terminal of the operational amplifier, so as to generate a voltage drop in the second resistor and obtain a first sampling signal; The operational amplifier is used to adjust the first voltage signal output from the output terminal to the second voltage signal based on the reference voltage signal and the first sampling signal fed back by the first resistor and the second resistor; The second voltage signal is determined based on the reference voltage signal, the on-state voltage drop of the first conducting module, and the on-state voltage drop of the second conducting module.
2. The apparatus according to claim 1, characterized in that, The first conduction module is also used to transmit a second current to the first resistor based on the second voltage signal output from the output terminal of the operational amplifier, so as to generate a voltage drop in the first resistor and obtain a second sampling signal; The second conduction module is also used to transmit a second current to the second resistor based on the second voltage signal output from the output terminal of the operational amplifier, so as to generate a voltage drop in the second resistor and obtain a second sampling signal; The second sampling signal is the same as the reference voltage signal.
3. The apparatus according to claim 1, characterized in that, One end of the first conduction module is connected to the output terminal of the operational amplifier; The other end of the first conducting module is connected to one end of the first resistor and the negative terminal of the power supply; One end of the second conduction module is connected to the output terminal of the operational amplifier; The other end of the second conducting module is connected to one end of the second resistor and the negative terminal of the power supply; The other end of the first resistor is connected to the other end of the second resistor and the input terminal of the operational amplifier.
4. The apparatus according to claim 3, characterized in that, The first conducting module is connected to the negative terminal of the power supply through a first constant current source, and the first constant current source is used to control the magnitude of the current transmitted by the first conducting module to the first resistor. The second conduction module is connected to the negative terminal of the power supply through a second constant current source, which is used to control the magnitude of the current transmitted from the second conduction module to the second resistor.
5. The apparatus according to any one of claims 1-4, characterized in that, The first conduction module is a first MOSFET, and the second conduction module is a second MOSFET.
6. The apparatus according to any one of claims 1-4, characterized in that, The voltage drop generated by the first resistor is the same as the voltage drop generated by the second resistor.
7. A ring oscillation system, characterized in that, The ring oscillation system includes a frequency control device and a ring oscillation circuit as described in any one of claims 1-6. The frequency control device is used to provide a second voltage signal to the ring oscillation circuit, and the ring oscillation circuit outputs an oscillation signal based on the second voltage signal. The second voltage signal is used to control the frequency of the oscillation signal.
8. The system according to claim 7, characterized in that, The ring oscillator circuit includes a plurality of first inverters, and each of the plurality of first inverters is cascaded to form a closed loop. The frequency control device includes an operational amplifier whose output terminal is connected to each of the first inverters in the ring oscillator circuit to provide a second voltage signal to each of the first inverters.
9. The system according to claim 7 or 8, characterized in that, The ring oscillation circuit includes pull-up constant current sources and pull-down constant current sources corresponding to each first inverter. The first inverter is connected to the frequency control device through the pull-up constant current source corresponding to the first inverter, and the first inverter is connected to the negative terminal of the power supply through the pull-down constant current source corresponding to the first inverter.
10. The system according to claim 7 or 8, characterized in that, The second voltage signal is used to control the high-level amplitude of the first inverter in the ring oscillator circuit, and the high-level amplitude is used to control the oscillation frequency of the oscillation signal.
11. A clock system, characterized in that, The clock system includes a ring oscillation system and a processing module as described in any one of claims 7-10; The ring oscillation system is used to output an oscillation signal; The processing module is used to process the oscillation signal to obtain a clock signal.
12. A chip, characterized in that, The chip includes the clock system and operating module as described in claim 11; The clock system is used to output clock signals; The operation module is used to perform at least one operation among calculation, reading / writing, or information interaction based on the clock signal.