Circuit arrangement and oscillator

Abstract

A circuit device and an oscillator capable of making temperature compensation follow temperature variations due to various factors and timing. The circuit device includes an oscillation circuit that generates an oscillation signal using a vibrator, a temperature detection circuit that outputs temperature detection data, a temperature compensation circuit, and a temperature detection rate control circuit. The temperature compensation circuit temperature-compensates an oscillation frequency of the oscillation signal based on the temperature detection data. The temperature detection rate control circuit controls a temperature detection rate at which the temperature detection circuit performs temperature detection. At this time, the temperature detection rate control circuit controls the temperature detection rate based on a variation in the temperature detection data.

Description

Technical Field

[0001] This invention relates to circuit devices and oscillators, etc. Background Technology

[0002] Patent Document 1 discloses a quartz oscillator comprising: an inverter that causes a quartz oscillator to oscillate; a variable capacitor diode that adjusts the oscillation frequency; a temperature sensor; and a control unit that controls the capacitance value of the variable capacitor diode based on the output of the temperature sensor, thereby performing temperature correction control on the oscillation frequency. The control unit initiates the initial temperature correction control of the quartz oscillator or the surrounding power supply at a higher frequency than the normal temperature correction control frequency. Therefore, the quartz oscillator of Patent Document 1 achieves temperature correction that maintains stability in response to rapid changes in ambient temperature, or stabilizes in a shorter time.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2010-056986

[0004] In the aforementioned Patent Document 1, the frequency of temperature correction control is increased at a specific time, such as when the quartz oscillator or the power supply around it is initially turned on. However, when the temperature changes at a time other than the previously intended specific time, the frequency of temperature correction control remains at its normal level. Therefore, there is a problem that the temperature correction cannot keep up with the temperature change and cannot maintain a high-precision oscillation frequency. Summary of the Invention

[0005] One aspect of this disclosure relates to a circuit apparatus comprising: an oscillation circuit that generates an oscillation signal using an oscillator; a temperature detection circuit that outputs temperature detection data; a temperature compensation circuit that performs temperature compensation on the oscillation frequency of the oscillation signal based on the temperature detection data; and a temperature detection ratio control circuit that controls the temperature detection ratio of the temperature detection circuit, the temperature detection ratio control circuit controlling the temperature detection ratio based on changes in the temperature detection data.

[0006] Another aspect of this disclosure relates to an oscillator comprising: an oscillator; and a circuit arrangement including: an oscillation circuit that generates an oscillation signal using the oscillator; a temperature detection circuit that outputs temperature detection data; a temperature compensation circuit that performs temperature compensation on the oscillation frequency of the oscillation signal based on the temperature detection data; and a temperature detection ratio control circuit that controls the temperature detection ratio of the temperature detection circuit, the temperature detection ratio control circuit controlling the temperature detection ratio based on changes in the temperature detection data. Attached Figure Description

[0007] Figure 1These are structural examples of oscillators and circuit devices.

[0008] Figure 2 This is a detailed structural example of a temperature detection ratio control circuit.

[0009] Figure 3 This is a timing diagram representing the operation of the temperature detection ratio control circuit.

[0010] Figure 4 This is a flowchart of the processing performed by the temperature detection ratio control circuit.

[0011] Figure 5 This is a waveform example showing the change in the temperature detection ratio when the ambient temperature of the circuit device changes.

[0012] Figure 6 This is a detailed structural example of a temperature detection circuit.

[0013] Figure 7 It is a timing diagram showing the operation of the temperature detection circuit and the temperature compensation circuit.

[0014] Figure 8 This is an example of a conversion performed by an operational circuit.

[0015] Figure 9 This is an example of frequency sensitivity.

[0016] Figure 10 This is a detailed structural example of an operational circuit.

[0017] Figure 11 This is a detailed structural example of the start point setting circuit and the multiplication circuit.

[0018] Figure 12 It provides detailed structural examples of temperature compensation circuits and adjustment circuits, as well as examples of the connection structure of the oscillator, oscillation circuit, and adjustment circuit.

[0019] Label Explanation

[0020] 10: Oscillator; 100: Circuit device; 105: Temperature detection circuit; 110: Temperature sensor circuit; 112: Ring oscillator; 113: Counter; 120: Arithmetic circuit; 126: Adder circuit; 130: Storage circuit; 131: Lookup table; 135: Temperature compensation circuit; 152: Interpolation circuit; 154: Adjustment circuit; 160: Oscillation circuit; 170: Register; 190: Temperature detection ratio control circuit; 191: Temperature adjustment ratio generation counter; 192: Selector; 193: Ratio control circuit; 194: Ratio setting circuit; 195: Temperature variation calculation circuit; 196: Ratio control counter; 200: Oscillator; CLK: Clock signal; ENR: Enable signal; ETD: Temperature detection data; QCL: Adjustment data; RT: Temperature detection ratio. Detailed Implementation

[0021] The preferred embodiments of this disclosure are described in detail below. Furthermore, the embodiments described below do not unduly limit the scope of the claims, and the structures described in these embodiments are not necessarily all essential components.

[0022] 1. Circuit devices and oscillators

[0023] Figure 1 This is a structural example of the oscillator 200 and circuit device 100 in this embodiment. The oscillator 200 includes an oscillator 10 and a circuit device 100.

[0024] The oscillator 10 is a component that generates mechanical vibration through an electrical signal. The oscillator 10 can be implemented using a vibrating plate such as a quartz resonator. For example, the oscillator 10 is a tuning fork type quartz resonator. Alternatively, the oscillator 10 can be implemented using a quartz resonator with a shearing cut such as AT cut or SC cut, which allows for thickness shearing vibration. Furthermore, the oscillator 10 of this embodiment can be implemented using various vibrating plates, such as those other than tuning fork type or thickness shearing vibration type, or piezoelectric resonators made of materials other than quartz. For example, the oscillator 10 can also be a SAW resonator, or a MEMS oscillator formed using a silicon substrate as a silicon oscillator. SAW is an abbreviation for Surface Acoustic Wave, and MEMS is an abbreviation for Micro Electro Mechanical Systems.

[0025] The circuit device 100 is electrically connected to the oscillator 10, causing the oscillator 10 to oscillate by driving it. Furthermore, the connection in this embodiment is an electrical connection. An electrical connection is a connection capable of transmitting electrical signals, a connection capable of transmitting information via electrical signals. An electrical connection can also be a connection via active or passive components. In addition, the circuit device 100 performs temperature compensation processing to keep the oscillation frequency of the oscillator 200 constant regardless of temperature. The circuit device 100 is an integrated circuit device called an IC. The circuit device 100 is an IC manufactured using semiconductor technology, which is a semiconductor chip on a semiconductor substrate on which circuit elements are formed.

[0026] The circuit device 100 includes a temperature detection circuit 105, a temperature compensation circuit 135, an adjustment circuit 154, an oscillation circuit 160, and a temperature detection ratio control circuit 190. Furthermore, the oscillator and circuit device are not limited to... Figure 1 The structure can be implemented through various modifications, such as omitting a part of its constituent elements or adding other constituent elements.

[0027] Temperature detection circuit 105 measures the ambient temperature of oscillator 10 and outputs the result as temperature detection data ETD. Temperature detection data ETD is data that monotonically increases or decreases relative to temperature within the operating temperature range of circuit device 100. Temperature detection circuit 105 includes a ring oscillator with a temperature-dependent oscillation frequency and a counter. The counter counts the oscillation signal of the ring oscillator during the enable period specified by the clock signal CLK output by oscillation circuit 160 and outputs the count value as temperature detection data ETD. Alternatively, temperature detection circuit 105 may also include: an analog temperature sensor that outputs a temperature detection voltage based on the temperature dependence of the forward voltage of the PN junction; and an A / D converter that performs A / D conversion on the temperature detection voltage to output temperature detection data ETD. Furthermore, as in... Figure 6 As described later, the temperature detection circuit 105 may also include an arithmetic circuit, which outputs temperature detection data ETD by adjusting the temperature sensitivity of the output data of the counter or the output data of the A / D converter.

[0028] The temperature compensation circuit 135 outputs adjustment data QCL for temperature compensation of the oscillation frequency of the oscillation circuit 160, based on the temperature detection data ETD. The adjustment data QCL is data that eliminates or reduces the temperature characteristic of the oscillation frequency. The temperature compensation circuit 135 uses a lookup table to calculate the adjustment data QCL based on the temperature detection data ETD. Alternatively, the temperature compensation circuit 135 can also calculate the adjustment data QCL based on the temperature detection data ETD by using a polynomial operation approximating the temperature characteristic of the oscillation frequency.

[0029] Adjustment circuit 154 is connected to oscillation circuit 160, adjusting the oscillation frequency of oscillation circuit 160 to an oscillation frequency corresponding to adjustment data QCL. The oscillation frequency is adjusted by using adjustment data QCL, which eliminates or reduces the temperature characteristics of the oscillation frequency, thus controlling the oscillation frequency to be constant regardless of temperature. Adjustment circuit 154 is a capacitor array circuit connected to one or the other end of oscillator 10. Alternatively, adjustment circuit 154 may also include a D / A converter that performs D / A conversion on adjustment data QCL, and a variable capacitance capacitor connected to one or the other end of oscillator 10. The capacitance value of the variable capacitance capacitor is controlled according to the output voltage of the D / A converter.

[0030] Oscillator circuit 160 uses oscillator 10 to generate an oscillation signal. Specifically, oscillator circuit 160 drives oscillator 10 to oscillate, and generates an oscillation signal through this oscillation. An example of oscillator circuit 160 is a Colpitts-type oscillator circuit described later, but it is not limited to this. Various forms of oscillator circuits can be used as long as the oscillation frequency can be adjusted by adjusting circuit 154. In addition, clock signal CLK is output based on the oscillation signal. For example, oscillator circuit 160 may output the oscillation signal as clock signal CLK, or circuit device 100 may include an output circuit that outputs clock signal CLK by buffering or dividing the oscillation signal.

[0031] The temperature detection ratio control circuit 190 calculates the change in temperature detection data ETD and adaptively controls the temperature detection ratio based on this change. The temperature detection ratio is the ratio at which the temperature detection circuit 105 detects the temperature, i.e., the ratio at which the temperature detection circuit 105 updates the temperature detection data ETD. The temperature detection ratio control circuit 190 enables the enable signal ENR with the controlled temperature detection ratio, and the temperature detection circuit 105 detects the temperature when the enable signal ENR is enabled. When n is an integer greater than or equal to 2, the temperature detection ratio can be set to n levels from the 1st ratio to the nth ratio. When k is an integer greater than or equal to 2 and less than n, the kth ratio is a higher ratio than the (k-1)th ratio. When the change in temperature detection data ETD is greater than or equal to the 1st threshold, the temperature detection ratio control circuit 190 sets the temperature detection ratio to the nth ratio; when the change in temperature detection data ETD is less than or equal to the 2nd threshold, the temperature detection ratio is reduced in stages. The 2nd threshold is less than the 1st threshold. In addition, the temperature detection ratio and the enable period of the enable signal ENR are specified based on the frequency or period of the clock signal CLK.

[0032] In this embodiment described above, the circuit device 100 includes: an oscillation circuit 160 that generates an oscillation signal using an oscillator 10; a temperature detection circuit 105 that outputs temperature detection data ETD; a temperature compensation circuit 135; and a temperature detection ratio control circuit 190. The temperature compensation circuit 135 performs temperature compensation on the oscillation frequency of the oscillation signal based on the temperature detection data ETD. The temperature detection ratio control circuit 190 controls the temperature detection ratio performed by the temperature detection circuit 105. At this time, the temperature detection ratio control circuit 190 controls the temperature detection ratio based on changes in the temperature detection data ETD.

[0033] According to this embodiment, when the ambient temperature changes, the temperature detection ratio is controlled based on the change in temperature detection data ETD. This allows temperature compensation to follow temperature changes caused by various factors and timing, thereby maintaining a high-precision oscillation frequency. Furthermore, since the temperature detection ratio can be reduced when temperature changes are absent or minimal, both high oscillation frequency accuracy and low power consumption of the circuit can be achieved.

[0034] 2. Temperature detection ratio control circuit

[0035] Figure 2 This is a detailed structural example of the temperature detection ratio control circuit 190. Figure 3 This is a timing diagram showing the operation of the temperature detection ratio control circuit 190. For example... Figure 2 As shown, the temperature detection ratio control circuit 190 includes a temperature regulation ratio generation counter 191, a selector 192, a ratio control circuit 193, a ratio setting circuit 194, and a temperature variation calculation circuit 195.

[0036] The temperature regulation ratio generator counter 191 divides the clock signal CLK to output a ratio control clock signal CNTQ with the same frequency as the highest temperature regulation ratio. For example... Figure 3 As shown, the ratio control clock signal CNTQ has the same pulse width as the enable signal ENR. Here, a high level of the enable signal ENR indicates enable, and its pulse width is the high level width. Figure 3 This represents an example where the pulse width is set to 7 cycles of the clock signal CLK.

[0037] The temperature variation calculation circuit 195 calculates the variation HNQ based on the temperature detection data ETD. For example... Figure 3As shown, the temperature detection circuit 105 detects the temperature when a pulse of the input enable signal ENR is received, and outputs the temperature detection data ETD as the result. The temperature variation calculation circuit 195 calculates the difference between the temperature detection data ETD and the previously output temperature detection data ETD, as the variation HNQ of the temperature detection data ETD. For example, in the waveform diagram with RTQ=1, when the temperature detection circuit 105 outputs temperature detection data ETD1b following temperature detection data ETD1a, the temperature variation calculation circuit 195 outputs the variation HNQ of the temperature detection data ETD = ETD1b - ETD1a.

[0038] The ratio setting circuit 194 adaptively sets the ratio setting value RTQ based on the variation HNQ of the temperature detection data ETD. Hereinafter, it is assumed that the ratio setting circuit 194 selects a ratio setting value from RTQ = 1, 2, 5, and 10. However, the options for the ratio setting value are not limited to the above options, nor are the number of options limited to 4; any combination of 2 or more is acceptable.

[0039] The ratio control circuit 193 outputs a ratio control signal SEL based on the ratio control clock signal CNTQ and the ratio setpoint RTQ. When the ratio control signal SEL is high, the selector 192 outputs the ratio control clock signal CNTQ as an enable signal ENR; when the ratio control signal SEL is low, it outputs a low-level enable signal ENR. When the pulse ratio of the ratio control clock signal CNTQ is Rmax, the ratio control circuit 193 outputs the ratio control signal SEL, making the pulse ratio of the enable signal ENR Rmax / RTQ.

[0040] Figure 3 These are waveform examples for RTQ=1 and RTQ=2. When RTQ=1, the ratio control circuit 193 keeps the ratio control signal SEL at a high level, and the selector 192 outputs the ratio control clock signal CNTQ as the enable signal ENR. The temperature detection circuit 105 outputs temperature detection data ETD = ETD1a, ETD1b, ETD1c, ETD1d, ... at the temperature detection ratio Rmax. When RTQ=2, the ratio control circuit 193 outputs the ratio control signal SEL at a frequency of Rmax / RTQ = Rmax / 2, and the selector 192 outputs a pulse of the ratio control clock signal CNTQ every two pulses as the enable signal ENR. The temperature detection circuit 105 outputs temperature detection data ETD = ETD2a, ETD2b, ... at the temperature detection ratio Rmax / 2. The same applies to RTQ=5 and 10, with temperature detection ratios of Rmax / 5 and Rmax / 10, respectively.

[0041] Figure 4This is a flowchart of the processing performed by the temperature detection ratio control circuit 190. In step S1, the ratio control circuit 193 sets the ratio setpoint to RTQ = 1. That is, the initial value of the temperature detection ratio is the highest ratio Rmax.

[0042] like Figure 2 As shown, the ratio control circuit 193 includes a ratio control counter 196 that counts the number of pulses of the ratio control clock signal CNTQ. In step S2, the ratio control counter 196 is reset to its count value. Here, the ratio control counter 196 increments by 1, 2, 3, ..., starting with 1 as its initial value.

[0043] In step S3, the ratio control circuit 193 determines whether the count value has reached the ratio setting value RTQ. If the count value is less than the ratio setting value RTQ, in step S4, the ratio control counter 196 increments the count value when a pulse of the ratio control clock signal CNTQ is input. Then, step S3 is executed. If the count value is greater than the ratio setting value RTQ, in step S5, the ratio control counter 196 resets the count value.

[0044] In step S6, temperature compensation is performed. Specifically, the temperature detection ratio control circuit 190 outputs a pulse of the enable signal ENR, the temperature detection circuit 105 detects the temperature, and the temperature compensation circuit 135 outputs adjustment data QCL based on the temperature detection data ETD. Through the above steps S3 to S6, the temperature is detected using the temperature detection ratio Rmax / RTQ, and temperature compensation is performed.

[0045] In step S7, the temperature variation calculation circuit 195 calculates the variation of the temperature detection data ETD. That is, the temperature variation calculation circuit 195 calculates the difference between the temperature detection data ETD detected in step S6 and the temperature detection data ETD detected when step S6 was performed one time prior, and takes this as the variation of the temperature detection data ETD.

[0046] In step S8, the ratio setting circuit 194 determines whether the change in the temperature detection data ETD is greater than or equal to a first threshold. For example, the first threshold is 6 LSB. If the change is greater than or equal to 6 LSB, in step S9, the ratio setting circuit 194 sets the ratio setting value to RTQ = 1. That is, the temperature detection ratio is set to the highest ratio Rmax. Then, step S3 is executed.

[0047] If the change is less than 6 LSB in step S8, in step S10, the ratio setting circuit 194 determines whether the change in the temperature detection data ETD is below a second threshold. For example, the second threshold is 2 LSB. If the change is below 2 LSB, in step S11, the ratio setting circuit 194 reduces the ratio setting by one level. That is, when the ratio setting value is RTQ = 1, 2, and 5, the ratio setting circuit 194 changes RTQ to RTQ = 2, 5, and 10, respectively. Thus, when the temperature detection ratio is Rmax, Rmax / 2, and Rmax / 5, the temperature detection ratio decreases to Rmax / 2, Rmax / 5, and Rmax / 10, respectively. When the ratio setting value is RTQ = 10, RTQ = 10 is maintained.

[0048] If the change in step S10 is greater than 2 LSB, in step S12, the ratio setting circuit 194 maintains the ratio setting value RTQ. Then, step S3 is executed. Through the above steps S7 to S12, the temperature adjustment ratio is adaptively controlled according to the change in the temperature detection data ETD.

[0049] Figure 5 This is a waveform example showing the change in the temperature detection ratio when the ambient temperature of the circuit device 100 changes. Figure 5 The upper segment shows the waveform representing the temperature change over time, and the lower segment shows the waveform of the temperature detection ratio RT and the waveform of the moving average RTave of the temperature detection ratio RT. Here, the waveform is shown when the temperature rises from 25 degrees to 125 degrees, pauses at 125 degrees, and then drops to -50 degrees.

[0050] The temperature starts to rise from 25 degrees Celsius. When the change in the temperature detection data ETD exceeds the first threshold, the temperature detection ratio control circuit 190 sets the temperature detection ratio RT to the highest ratio Rmax. A higher temperature detection ratio results in a shorter update interval for the temperature detection data ETD, thus reducing the difference between the current and previous data (i.e., the change in temperature detection data ETD). When the change in temperature detection data ETD falls below the second threshold, the temperature detection ratio control circuit 190 reduces the temperature detection ratio RT by one level, setting it to Rmax / 2. As the temperature detection ratio decreases, the change in temperature detection data ETD increases, so the temperature detection ratio RT again becomes the highest ratio Rmax, and then the cycle repeats between Rmax and Rmax / 2. The moving average value RTave of the temperature detection ratio RT becomes Rmax and Rmax / 2.

[0051] When the temperature reaches 125 degrees and temperature change stops, the change in the temperature detection data ETD falls below the second threshold. Therefore, the temperature detection ratio control circuit 190 reduces the temperature detection ratio RT by one level each time to the minimum ratio Rmax / 10. Subsequently, the temperature detection ratio control circuit 190 adaptively controls the temperature detection ratio according to temperature changes.

[0052] In this embodiment described above, the temperature detection circuit 105 performs intermittent temperature detection during intermittent temperature detection periods. The temperature detection ratio control circuit 190 controls the temperature detection ratio by controlling the ratio of the intermittent operation.

[0053] exist Figure 3 In this example, the enabling period of the enable signal ENR corresponds to the intermittent temperature detection period, and the temperature detection during each enabling period corresponds to the intermittent operation. Furthermore, the temperature detection ratio control circuit 190 controls the ratio during the enabling period, which corresponds to controlling the ratio of the intermittent operation.

[0054] According to this embodiment, temperature is detected by intermittent operation, thereby performing temperature compensation intermittently. This reduces the power consumption of temperature compensation. Furthermore, by adaptively controlling the ratio of this intermittent operation based on changes in the temperature detection data ETD, both high accuracy of the oscillation frequency and low power consumption of the circuit can be achieved.

[0055] Furthermore, in this embodiment, when the temperature detection data ETD changes to or above a first threshold, the temperature detection ratio control circuit 190 sets the temperature detection ratio to the highest of the nth ratios from the first ratio to the nth ratio. n is an integer greater than or equal to 2.

[0056] exist Figure 4 and Figure 5 In the example, when n=4, the temperature detection ratios Rmax / 10, Rmax / 5, Rmax / 2, and Rmax when the ratio settings RTQ=10, 5, 2, and 1 correspond to the 1st, 2nd, 3rd, and 4th ratios, respectively. At this time, Rmax, as the 4th ratio, is the highest temperature detection ratio.

[0057] According to this embodiment, when a temperature change in the temperature detection data ETD is greater than or equal to the first threshold, i.e., when a sharp temperature change is determined to have occurred, the temperature detection ratio is set to the maximum nth ratio. Therefore, temperature compensation follows the change in oscillation frequency caused by the sharp temperature change, thereby obtaining a high-precision oscillation signal with reduced frequency deviation.

[0058] Furthermore, in this embodiment, when the temperature detection rate control circuit 190 reduces the temperature detection rate from the kth rate among the first rate to the nth rate to the (k-1)th rate when the change in the temperature detection data ETD is less than or equal to the second threshold of the first threshold. k is an integer greater than or equal to 2 and less than or equal to n.

[0059] According to this embodiment, when the temperature change between the previous temperature compensation and the current temperature compensation at the current temperature adjustment ratio is small, i.e., the temperature adjustment ratio is too high relative to the temperature change, the temperature detection ratio decreases by one level. Therefore, within the range where the temperature compensation can follow the oscillation frequency change caused by the temperature change, the temperature adjustment ratio can be set to the lowest possible level.

[0060] In addition, in this embodiment, the initial value of the temperature detection ratio is the nth ratio.

[0061] In the initial state, the variation of the temperature detection data ETD is unknown. Therefore, by setting the nth ratio as the initial value, the consistency of temperature compensation can be ensured from the start of temperature regulation. Furthermore, when the variation of the temperature detection data ETD is small, the temperature regulation ratio is adaptively reduced as described above.

[0062] In addition, in this embodiment, the temperature detection ratio control circuit 190 controls the temperature detection ratio based on the difference between the previous temperature detection data ETD and the current temperature detection data ETD.

[0063] The difference between the previous temperature measurement data ETD and the current temperature measurement data ETD represents the temperature variation that occurred between the previous and current temperature compensations, and is related to the frequency deviation of the oscillation frequency between the two. The temperature regulation ratio is controlled based on this difference to ensure that the frequency deviation of the oscillation frequency between the two temperature compensations is within an appropriate range.

[0064] Furthermore, in this embodiment, the temperature compensation circuit 135 performs temperature compensation based on the temperature detection ratio.

[0065] For example Figure 4 In step S6, temperature compensation is performed together with temperature detection. Furthermore, as described later... Figure 7 The diagram illustrates the situation where the adjustment data QCL is updated when the temperature detection data ETD is updated.

[0066] According to this embodiment, by controlling the temperature detection ratio through the temperature detection ratio control circuit 190, the temperature adjustment ratio, which serves as the temperature compensation ratio, can be controlled. Therefore, the overall ratio of temperature compensation from the point where the temperature detection circuit 105 detects a temperature until the adjustment circuit 154 adjusts the oscillation frequency is controlled, thus reducing the overall power consumption of the circuitry related to temperature compensation when the temperature detection ratio decreases.

[0067] 3. Temperature detection circuit

[0068] Figure 6 This is a detailed structural example of the temperature detection circuit 105. Figure 7 This is a timing diagram illustrating the operation of the temperature detection circuit 105 and the temperature compensation circuit 135. For example... Figure 6 As shown, the temperature detection circuit 105 includes a temperature sensor circuit 110, an arithmetic circuit 120, and a register 170.

[0069] Temperature sensor circuit 110 measures the ambient temperature of oscillator 10 and outputs the result as output data TD. Output data TD is data that monotonically increases or decreases relative to temperature within the operating temperature range of circuit device 100. Temperature sensor circuit 110 includes ring oscillator 112 and counter 113.

[0070] like Figure 7 As shown, the ring oscillator 112 oscillates during the enable period of the enable signal ENR, outputting an oscillation signal RNGQ. The ring oscillator 112 includes, for example, a NAND circuit and an even number of inverters connected in series between the output terminal and the first input terminal of the NAND circuit. The enable signal ENR is input to the second input terminal of the NAND circuit. In this case, a high level corresponds to an active state; the ring oscillator 112 oscillates when the enable signal ENR is high, and the oscillation of the ring oscillator 112 stops when the enable signal ENR is low. Furthermore, the above structure is an example, and the structure of the ring oscillator 112 is not limited to the above structure.

[0071] Counter 113 performs a counting operation based on the oscillation signal RNGQ of the ring oscillator 112, and outputs output data TD based on the count value. Specifically, counter 113 counts the number of pulses of the oscillation signal RNGQ output during the aforementioned enable period, and outputs the count value as output data TD. Figure 7In this circuit, counter 113 outputs output data TD = TDa, TDb, ... in a time sequence for each pulse of the enable signal ENR. Furthermore, counter 113 only needs to perform counting operations based on the oscillation signal RNGQ; for example, it can also count the number of pulses of a signal after frequency division of the oscillation signal RNGQ. Additionally, counter 113 only needs to output output data TD based on the count value; for example, it can also output the output data TD by smoothing the count value.

[0072] The arithmetic circuit 120 is a logic circuit that converts the output data TD from the temperature sensor circuit 110 into temperature detection data ETD. The temperature detection data ETD, like the output data TD, is data that monotonically increases or decreases relative to the temperature. The slope of the temperature detection data ETD corresponds to the temperature range and is obtained by converting the slope of the output data TD. For example... Figure 7 As shown, when the temperature sensor circuit 110 outputs output data TDa, the arithmetic circuit 120 converts TDa into temperature detection data ETDa; when the temperature sensor circuit 110 outputs output data TDb, the arithmetic circuit 120 converts TDb into temperature detection data ETDb. Further details of the conversion process will be described later.

[0073] Register 170 stores the parameters of the conversion performed by the arithmetic circuit 120. When the parameters stored in register 170 are input to the arithmetic circuit 120, the arithmetic circuit 120 converts the output data TD into temperature detection data ETD based on these parameters.

[0074] When the arithmetic circuit 120 outputs temperature detection data ETDa, the temperature compensation circuit 135 outputs adjustment data QCLa based on ETDa; when the arithmetic circuit 120 outputs temperature detection data ETDb, it outputs adjustment data QCLb based on ETDb. Thus, temperature compensation is performed based on the temperature detection ratio, therefore the temperature adjustment ratio is the same as the temperature detection ratio.

[0075] Figure 8 This is an example of a conversion performed by the arithmetic circuit 120. The arithmetic circuit 120 calculates the temperature detection data ETD by multiplying the output data TD by a coefficient and adding an offset. Figure 8 In this circuit, the arithmetic circuit 120 uses temperatures Ta, Tb, and Tc as boundaries to change the coefficient multiplied with the output data TD. This coefficient is less than 1 in the temperature range TRA (below Ta), 1 in the temperature range TRB (above Ta but below Tb), greater than 1 in the temperature range TRC (above Tb but below Tc), and even larger in the temperature range TRD (above Tc). Temperature Ta is set to approximately room temperature (around 25 degrees Celsius). In the temperature range higher than room temperature (25 degrees Celsius), the slope of the temperature detection data ETD increases.

[0076] Figure 9 Examples illustrating frequency sensitivity. Frequency sensitivity is the sensitivity of an oscillation frequency to changes in temperature. Figure 9 In this context, the frequency deviation is represented by the change of 1 LSB in the output data TD or the temperature detection data ETD. FS represents the frequency sensitivity characteristic without temperature data correction by the arithmetic circuit 120, and FScol represents the frequency sensitivity characteristic with temperature data correction by the arithmetic circuit 120.

[0077] Without temperature data correction via the arithmetic circuit 120, the frequency sensitivity is relatively low near or below room temperature. Within this temperature range, the oscillation frequency is unlikely to change even with temperature variations; therefore, from a low-power consumption perspective, a lower temperature regulation ratio is preferable. On the other hand, within a temperature range above room temperature, the higher the temperature, the higher the frequency sensitivity. Within this temperature range, the oscillation frequency is prone to significant changes with temperature variations; therefore, from the perspective of temperature compensation tracking, a higher temperature regulation ratio is preferable.

[0078] but, Figure 8 The slope of the output data TD of the temperature sensor circuit 110 shown is relatively larger in the temperature range below room temperature than in the temperature range above room temperature. Therefore, the output data TD is more prone to variation with temperature changes at low temperatures, and the temperature regulation ratio is relatively higher at low temperatures.

[0079] Therefore, as Figure 8 As shown, the arithmetic circuit 120 adjusts the temperature sensitivity of the temperature detection data ETD so that the slope of the temperature detection data ETD in the temperature range higher than room temperature is relatively greater than the slope of the temperature detection data ETD in the temperature range lower than room temperature. Therefore, at high temperatures, the temperature detection data ETD is more prone to change with temperature variations, and the temperature regulation ratio is relatively more likely to increase. Consequently, near room temperature or in the temperature range lower than room temperature, the temperature regulation ratio becomes lower, and in the temperature range higher than room temperature, the temperature regulation ratio becomes higher, and the temperature compensation's following of frequency variations caused by temperature changes becomes more uniform.

[0080] In other words, the temperature sensitivity of the temperature detection data ETD is adjusted by the processing circuit 120 to make the frequency sensitivity uniform. Figure 9As shown, the frequency sensitivity FScol becomes more uniform when the temperature data is corrected by the arithmetic circuit 120 compared to the frequency sensitivity FS when the temperature data is not corrected by the arithmetic circuit 120. When the temperature data is not corrected by the arithmetic circuit 120, in the high-temperature region where the frequency sensitivity FS is high, the temperature regulation ratio needs to be increased to ensure the follow-up of temperature compensation. In this embodiment, since the frequency sensitivity FScol in the high-temperature region is suppressed by correcting the temperature data using the arithmetic circuit 120, the temperature regulation ratio can be suppressed compared to the case where the temperature data is not corrected by the arithmetic circuit 120. Therefore, the power consumption caused by temperature compensation can be reduced.

[0081] In this embodiment described above, the temperature detection circuit 105 includes: a temperature sensor circuit 110 that performs temperature detection; and an arithmetic circuit 120 that outputs temperature detection data ETD with adjusted temperature sensitivity based on the output data TD of the temperature sensor circuit 110. The temperature detection ratio control circuit 190 controls the temperature detection ratio based on the temperature detection data ETD with adjusted temperature sensitivity by the arithmetic circuit 120.

[0082] The temperature detection ratio control circuit 190 controls the temperature detection ratio based on changes in the temperature detection data ETD. According to this embodiment, the arithmetic circuit 120 adjusts the temperature sensitivity of the temperature detection data ETD to determine at what degree of temperature change is considered a change in the temperature detection data ETD. As described above, by adjusting the temperature sensitivity of the temperature detection data ETD based on frequency sensitivity, the temperature regulation ratio can be increased in temperature regions with high frequency sensitivity and decreased in temperature regions with low frequency sensitivity. This enables high-precision oscillation frequency and low-power temperature compensation.

[0083] Furthermore, in this embodiment, the temperature characteristic of the oscillation frequency has a first sensitivity in a first temperature range, and a second sensitivity that is higher than the first sensitivity in a second temperature range that is either lower or higher than the first temperature range. The arithmetic circuit 120 sets the temperature sensitivity of the temperature detection data ETD to the first temperature sensitivity in the first temperature range, and sets it to the second temperature sensitivity that is higher than the first temperature sensitivity in the second temperature range.

[0084] exist Figure 8 In the example, when the first temperature range is set to any of the temperature ranges TRA, TRB, and TRC, the second temperature range is the temperature range TRD. Additionally, in Figure 9 In the example, the frequency sensitivity FS corresponds to the temperature characteristic of the oscillation frequency, such as... Figure 8 and Figure 9As shown, the frequency sensitivity FS for any temperature range of TRA, TRB, and TRC corresponds to the first sensitivity, and the frequency sensitivity FS for the temperature range TDR corresponds to the second sensitivity, which is higher than the first sensitivity. At this time, as... Figure 8 As shown, the temperature sensitivity of the temperature detection data ETD for any temperature range of TRA, TRB, and TRC corresponds to the first temperature sensitivity, and the temperature sensitivity of the temperature detection data ETD for the temperature range TRD corresponds to the second temperature sensitivity. The second temperature sensitivity is set higher than the first temperature sensitivity. Additionally, in Figure 8 and Figure 9 The example shown is that the second temperature range is higher than the first temperature range, but it is also possible to make the second temperature range lower than the first temperature range based on the temperature characteristics of the oscillation frequency of the oscillator and the oscillation circuit.

[0085] According to this embodiment, the temperature regulation ratio can be increased in the second temperature region with high frequency sensitivity, and decreased in the first temperature region with low frequency sensitivity. Therefore, the temperature compensation tracking accuracy can be improved in the second temperature region with high frequency sensitivity, resulting in high-precision oscillation frequency, and the temperature regulation ratio can be decreased in the first temperature region with low frequency sensitivity, resulting in low power consumption for temperature compensation.

[0086] 4. Operational circuit

[0087] Figure 10 This is a detailed structural example of the arithmetic circuit 120. The arithmetic circuit 120 includes start point setting circuits KSA, KSB, KSC, multiplication circuits MLA, MLB, MLC, and addition circuit 126.

[0088] Start point setting circuit KSA setting Figure 8 The starting temperature Ta of the temperature range TRA. The starting temperature Ta is the boundary between the adjacent temperature ranges TRA and TRB, and is the upper limit of the temperature range TRA. Specifically, the starting temperature Ta is set according to the output data TD = TDa of the temperature sensor circuit 110 corresponding to the starting temperature Ta. The starting point setting circuit KSA outputs differential temperature data KSAQ = TD - TDa when TD ≥ TDa, and outputs differential temperature data KSAQ = 0 when TD < TDa. The multiplication circuit MLA outputs the data MLAQ = -KSAQ × GA = -(TD - TDa) × GA. When TD < TDa, MLAQ = 0.

[0089] Start point setting circuit KSB setting Figure 8The starting temperature Tb of the temperature range TRC is defined as the boundary between adjacent temperature ranges TRB and TRC, and is the lower limit of the temperature range TRC. Specifically, the starting temperature Tb is set based on the output data TD = TDb of the temperature sensor circuit 110 corresponding to the starting temperature Tb. The starting point setting circuit KSB outputs differential temperature data KSBQ = -(TD - TDb) when TD ≤ TDb, and outputs differential temperature data KSBQ = 0 when TD > TDb. The multiplication circuit MLB outputs the data MLBQ = -KSBQ × GB = (TD - TDb) × GB. When TD > TDb, MLBQ = 0.

[0090] Start point setting circuit KSC setting Figure 8 The starting temperature Tc of the temperature range TRD is defined as the boundary between adjacent temperature ranges TRC and TRD, representing the lower limit of the TRD temperature range. Specifically, the starting temperature Tc is set by the output data TD = TDc of the temperature sensor circuit 110 corresponding to Tc. The starting point setting circuit KSC outputs differential temperature data KSCQ = -(TD - TDc) when TD ≤ TDc, and KSCQ = 0 when TD > TDc. The multiplication circuit MLC outputs MLCQ = -KSCQ × GC = (TD - TDc) × GC. The gain GC satisfies GC > 0. MLCQ = 0 when TD > TDc.

[0091] The adder circuit 126 adds the output data TD, output data MLAQ, output data MLBQ, output data MLCQ and offset value EQOF, and outputs the result as the temperature detection data ETD.

[0092] Within the temperature range TRA, ETD = TD - (TD - TDa) × GA + EQOF = (1 - GA) × TD + (TDA × GA + EQOF). The temperature sensitivity of the temperature detection data ETD is lower than the temperature sensitivity of the output data TD of the temperature sensor circuit 110.

[0093] Within the temperature range TRB, ETD = TD + EQOF, and the temperature sensitivity of the temperature detection data ETD is the same as the temperature sensitivity of the output data TD of the temperature sensor circuit 110.

[0094] Within the temperature range TRC, ETD = TD + (TD - TDb) × GB + EQOF = (1 + GB) × TD + (-TDb × GB + EQOF). The temperature sensitivity of the temperature detection data ETD is higher than the temperature sensitivity of the output data TD of the temperature sensor circuit 110.

[0095] Within the temperature range TRD, ETD = TD + (TD - TDb) × GB + (TD - TDc) × GC + EQOF = (1 + GB + GC) × TD + (-TDb × GB - TDc × GC + EQOF). The temperature sensitivity of the temperature detection data ETD is higher than that of the temperature range TRC.

[0096] In addition, the offset value EQOF is set in such a way that the lower limit of the temperature detection data ETD within the operating temperature range is not negative. That is, the offset value EQOF is set so that the lower limit of the temperature detection data ETD is zero or greater than zero.

[0097] Figure 11 This is a detailed structural example of the start-point setting circuit KSA and the multiplication circuit MLA. Furthermore, the structures of the start-point setting circuits KSB and KSC, and the multiplication circuits MLB and MLC are similar.

[0098] The start-point setting circuit KSA includes an adder circuit ADa, a sign inversion circuit SRa1, a selector SLa1, and a ReLU circuit RLa. ReLU is an abbreviation for Rectified Linear Unit.

[0099] The adder circuit ADa adds an offset OFFa to the output data TD of the temperature sensor circuit 110. The sign inversion circuit SRa1 inverts the sign of the output data of the adder circuit ADa. The selector SLa1 selects the output data of the adder circuit ADa when the sign selection signal ISGa is 0, and selects the output data of the sign inversion circuit SRa1 when the sign selection signal ISGa is 1. The ReLU circuit RLa outputs 0 when the output data of the selector SLa1 is less than 0, and directly outputs the data when the output data of the selector SLa1 is greater than 0. In addition, the offset OFFa and the sign selection signal ISGa are stored in register 170.

[0100] exist Figure 8 In the example, the offset OFFa is set to -TDa, and the sign selection signal ISGa is set to 0. At this time, the output data of the adder circuit ADa is TD-TDa, the selector SLa1 selects TD-TDa, and the ReLU circuit RLa outputs KSAQ=TD-TDa when TD-TDa≥0, and KSAQ=0 when TD-TDa<0. The starting temperature Ta of the temperature range RTA is specified by the offset OFFa=-TDa, and the absolute value of the offset OFFa, TDa, becomes the output data of the temperature sensor circuit 110 corresponding to the starting temperature Ta. As described above, this achieves... Figure 10 The operation of the start point setting circuit KSA is described in the text.

[0101] The multiplication circuit MLA includes a bit shift circuit BSa, a sign inversion circuit SRa2, and a selector SLa2.

[0102] The bit shifting circuit BSa shifts the differential temperature data KSAQ from the start-point setting circuit KSA by multiplying the differential temperature data KSAQ by a gain GA. The shift direction and shift amount are specified by the bit shift value GAa. The shift direction is either LSB or MSB, and the shift amount is the number of bits to be shifted. The bit shift gain GA is 2, 4, 8, ... in the MSB direction, and 0.5, 0.25, 0.125, ... in the LSB direction. Additionally, when the shift amount is zero, the bit shift gain is GA = 1. The sign inversion circuit SRa2 inverts the sign of the output data from the bit shifting circuit BSa. The selector SLa2 selects the output data of the bit shifting circuit BSa when the sign selection signal QSGa is 0, and selects the output data of the sign inversion circuit SRa2 when the sign selection signal QSGa is 1. Furthermore, the bit shift value GAa and the sign selection signal QSGa are stored in register 170.

[0103] exist Figure 8 In the example, the shift direction of the bit shift value GAa is set to the LSB direction. That is, the bit shift gain is GA < 1. Additionally, the sign selection signal QSGa is set to 1. At this time, the output data of the bit shift circuit BSa is KSAQ × GA, and the selector SLa2 selects -KSAQ × GA. Therefore, when TD ≥ TDa, the output MLAQ = -(TD - TDa) × GA, and when TD < TDa, the output MLAQ = 0. As described above, this achieves... Figure 11 The operation of the multiplication circuit MLA is explained in the text.

[0104] 5. Temperature compensation circuit, adjustment circuit, and oscillation circuit

[0105] Figure 12 The following is a detailed structural example of the temperature compensation circuit 135 and the adjustment circuit 154, as well as a connection structure example of the oscillator 10, the oscillation circuit 160 and the adjustment circuit 154. Furthermore, it is assumed below that n is an integer greater than or equal to 1, and the temperature detection data ETD is n+1 bits of data ETD[n: 0].

[0106] First, a detailed structural example of the temperature compensation circuit 135 will be described. The temperature compensation circuit 135 includes a storage circuit 130 and an interpolation circuit 152.

[0107] The storage circuit 130 stores a lookup table 131 representing the correspondence between temperature detection data ETD[n:0] and frequency adjustment data. Specifically, the high-order bit ETD[n:i+1] of the temperature detection data ETD[n:0] is input to the storage circuit 130 as the address of the lookup table 131. i is an integer greater than or equal to n. The lookup table 131 stores frequency adjustment data at each address, and the storage circuit 130 outputs the frequency adjustment data CLa at the address specified by the high-order bit ETD[n:i+1] and the frequency adjustment data CLb at the adjacent address. The storage circuit 130 is, for example, a semiconductor memory such as a non-volatile memory or RAM, or a register composed of a latch circuit, etc. The non-volatile memory is, for example, an OTP memory such as a FAMOS memory, but is not limited to this; it can also be an EEPROM such as a MONOS memory or a fuse-type ROM, etc. FAMOS is an abbreviation for Floating Gate Avalanche Injection Metal Oxide Semiconductor. MONOS is an abbreviation for Metal-Oxide-Nitride-Oxide-Silicon.

[0108] The interpolation circuit 152 interpolates the frequency adjustment data CLA and the frequency adjustment data CLb by using the lower bit ETD[i:0] based on the temperature detection data ETD[n:0], and outputs the adjustment data QCL.

[0109] The frequency adjustment data stored in lookup table 131 is data that reduces the temperature dependence of the oscillation frequency of the oscillation circuit 160 and the oscillator 10. By using the frequency adjustment data to adjust the oscillation frequency, the oscillation frequency becomes constant regardless of temperature.

[0110] Next, an example of the connection structure of the oscillator 10, the oscillation circuit 160, and the adjustment circuit 154 will be described.

[0111] One end of the oscillator 10 is connected to terminal TX1, and the other end of the oscillator 10 is connected to terminal TX2. Terminals TX1 and TX2 are terminals of the circuit device 100, such as pads on a semiconductor substrate. One end of capacitor CX1 is connected to terminal TX1, and the other end of capacitor CX1 is connected to a ground node. One end of capacitor CX2 is connected to terminal TX2, and the other end of capacitor CX2 is connected to a ground node. Capacitors CX1 and CX2 are, for example, configured as external components of the circuit device 100.

[0112] The oscillator 10, oscillation circuit 160, and capacitors CX1 and CX2 constitute a so-called Colpitts-type oscillator circuit. The oscillation circuit 160 generates a drive signal SDR by inverting and amplifying the signal SIN, which is input from the other end of the oscillator 10 via terminal TX2, and outputs the drive signal SDR to one end of the oscillator 10 via terminal TX1. The oscillation circuit 160 is, for example, an inverter, with its input node connected to terminal TX2 and its output node connected to terminal TX1. However, the oscillation circuit 160 is not limited to this and can be various amplifier circuits, such as an amplifier circuit using bipolar transistors. The oscillation signal is, for example, the drive signal SDR. The drive signal SDR can be used as... Figure 1 The clock signal CLK is output, and the circuit device 100 may also include an output circuit that outputs the clock signal CLK by buffering or dividing the drive signal SDR.

[0113] Next, a detailed structural example of the adjustment circuit 154 will be described. The adjustment circuit 154 includes capacitor array circuits CAC1 and CAC2.

[0114] Capacitor array circuit CAC1 is connected to terminal TX1, and capacitor array circuit CAC2 is connected to terminal TX2. The following description uses capacitor array circuit CAC1 as an example, but capacitor array circuit CAC2 has the same structure.

[0115] The capacitor array circuit CAC1 includes capacitors 1 through m and switches 1 through m. m is an integer greater than or equal to 2. The j-th capacitor and the j-th switch are connected in series between terminal TX1 and the ground node. j = 1, 2, ..., m. Each switch from the 1st to the mth switch is controlled to be on or off by adjustment data QCL from interpolation circuit 152. Thus, the capacitance value of the capacitor array circuit CAC1 is controlled according to the adjustment data QCL, thereby adjusting the oscillation frequency.

[0116] The circuit arrangement of this embodiment described above includes: an oscillation circuit that generates an oscillation signal using an oscillator; a temperature detection circuit that outputs temperature detection data; a temperature compensation circuit; and a temperature detection ratio control circuit. The temperature compensation circuit performs temperature compensation on the oscillation frequency of the oscillation signal based on the temperature detection data. The temperature detection ratio control circuit controls the temperature detection ratio performed by the temperature detection circuit. The temperature detection ratio control circuit controls the temperature detection ratio based on changes in the temperature detection data.

[0117] According to this embodiment, the temperature detection ratio is controlled based on the changes in temperature detection data when the ambient temperature changes. This allows temperature compensation to follow temperature changes caused by various factors and timing, thereby maintaining a high-precision oscillation frequency. Furthermore, since the temperature detection ratio can be reduced when temperature changes are absent or minimal, both high oscillation frequency accuracy and low power consumption of the circuit can be achieved.

[0118] Alternatively, in this embodiment, the temperature detection circuit may also include: a temperature sensor circuit that performs temperature detection; and an arithmetic circuit that outputs temperature detection data with adjusted temperature sensitivity based on the output data of the temperature sensor circuit. The temperature detection ratio control circuit may also control the temperature detection ratio based on the temperature detection data with adjusted temperature sensitivity obtained by the arithmetic circuit.

[0119] The temperature detection ratio control circuit controls the temperature detection ratio based on changes in the temperature detection data. According to this embodiment, the arithmetic circuit adjusts the temperature sensitivity of the temperature detection data, thereby determining the degree of temperature change required to identify a change in the temperature detection data. By adjusting the temperature sensitivity of the temperature detection data based on frequency sensitivity, the temperature regulation ratio can be increased in temperature regions with high frequency sensitivity and decreased in temperature regions with low frequency sensitivity. This enables high-precision oscillation frequency and low-power temperature compensation.

[0120] Alternatively, in this embodiment, the temperature characteristic of the oscillation frequency may have a first sensitivity in a first temperature range, and a second sensitivity higher than the first sensitivity in a second temperature range that is either lower or higher than the first temperature range. The arithmetic circuit may also set the temperature sensitivity of the temperature detection data to the first temperature sensitivity in the first temperature range, and set it to a second temperature sensitivity higher than the first temperature sensitivity in the second temperature range.

[0121] According to this embodiment, the temperature regulation ratio can be increased in the second temperature region with high frequency sensitivity, and decreased in the first temperature region with low frequency sensitivity. Therefore, the temperature compensation tracking accuracy can be improved in the second temperature region with high frequency sensitivity, resulting in high-precision oscillation frequency, and the temperature regulation ratio can be decreased in the first temperature region with low frequency sensitivity, resulting in low power consumption for temperature compensation.

[0122] In addition, in this embodiment, the temperature detection circuit can also perform intermittent temperature detection during intermittent temperature detection periods. The temperature detection ratio control circuit can also control the temperature detection ratio by controlling the ratio of the intermittent operation.

[0123] According to this embodiment, temperature is detected by intermittent operation, thereby intermittently performing temperature compensation. This reduces the power consumption of temperature compensation. Furthermore, by adaptively controlling the rate of this intermittent operation based on changes in the temperature detection data, both high accuracy of the oscillation frequency and low power consumption of the circuit can be achieved.

[0124] Furthermore, in this embodiment, the temperature detection ratio control circuit may also set the temperature detection ratio to the highest of the nth ratios from the first ratio to the nth ratio when the temperature detection data changes to or above the first threshold. n is an integer greater than or equal to 2.

[0125] According to this embodiment, when a temperature change in the detected temperature data is greater than or equal to a first threshold, i.e., when a rapid temperature change is determined to have occurred, the temperature detection ratio is set to the maximum nth ratio. Therefore, temperature compensation follows the change in oscillation frequency caused by the rapid temperature change, thereby obtaining a high-precision oscillation signal with reduced frequency deviation.

[0126] In addition, in this embodiment, the temperature detection ratio control circuit may also reduce the temperature detection ratio from the kth ratio among the first ratio to the nth ratio to the (k-1)th ratio when the temperature detection data changes to a second threshold less than the first threshold. k is an integer between 2 and n.

[0127] According to this embodiment, when the temperature change between the previous temperature compensation and the current temperature compensation at the current temperature adjustment ratio is small, i.e., the temperature adjustment ratio is too high relative to the temperature change, the temperature detection ratio decreases by one level. Therefore, within the range where the temperature compensation can follow the oscillation frequency change caused by the temperature change, the temperature adjustment ratio can be set to the lowest possible level.

[0128] In addition, in this embodiment, the initial value of the temperature detection ratio can be the nth ratio.

[0129] In the initial state, the variation of temperature detection data is unknown. Therefore, by setting the nth ratio as the initial value, the consistency of temperature compensation can be ensured from the start of temperature regulation. Furthermore, when the variation of temperature detection data is small, the temperature regulation ratio is adaptively reduced as described above.

[0130] In addition, in this embodiment, the temperature detection ratio control circuit can also control the temperature detection ratio based on the difference between the previous temperature detection data and the current temperature detection data.

[0131] The difference between the previous temperature measurement data and the current temperature measurement data represents the temperature change that occurred between the previous and current temperature compensations, and is related to the frequency deviation of the oscillation frequency between the two. By controlling the temperature adjustment ratio based on the difference between the previous and current temperature measurement data, the temperature adjustment ratio is controlled in a way that the frequency deviation of the oscillation frequency between the previous and current temperature compensations is within an appropriate range.

[0132] In addition, in this embodiment, the temperature compensation circuit can also perform temperature compensation based on the temperature detection ratio.

[0133] According to this embodiment, the temperature detection ratio control circuit controls the temperature detection ratio, thereby controlling the temperature adjustment ratio, which is the temperature compensation ratio. Therefore, by controlling the overall temperature compensation ratio from the time the temperature detection circuit detects a temperature until the adjustment circuit adjusts the oscillation frequency, the overall power consumption of the circuit related to temperature compensation decreases when the temperature detection ratio decreases.

[0134] Furthermore, the oscillator of this embodiment includes: an oscillator; and a circuit arrangement. The circuit arrangement includes: an oscillation circuit that generates an oscillation signal using the oscillator; a temperature detection circuit that outputs temperature detection data; a temperature compensation circuit; and a temperature detection ratio control circuit. The temperature compensation circuit performs temperature compensation on the oscillation frequency of the oscillation signal based on the temperature detection data. The temperature detection ratio control circuit controls the temperature detection ratio performed by the temperature detection circuit. The temperature detection ratio control circuit controls the temperature detection ratio based on changes in the temperature detection data.

[0135] Alternatively, in this embodiment, the temperature detection circuit may also include: a temperature sensor circuit that performs temperature detection; and an arithmetic circuit that outputs temperature detection data with adjusted temperature sensitivity based on the output data of the temperature sensor circuit. The temperature detection ratio control circuit may also control the temperature detection ratio based on the temperature detection data with adjusted temperature sensitivity obtained by the arithmetic circuit.

[0136] Furthermore, in this embodiment, the temperature characteristic of the oscillation frequency can also have a first sensitivity in a first temperature range, and a second sensitivity higher than the first sensitivity in a second temperature range that is either lower or higher than the first temperature range. The arithmetic circuit can also set the temperature sensitivity of the temperature detection data to the first temperature sensitivity in the first temperature range, and set it to a second temperature sensitivity higher than the first temperature sensitivity in the second temperature range.

[0137] Furthermore, although this embodiment has been described in detail above, those skilled in the art will readily understand that various modifications can be made without substantially departing from the new aspects and effects of this disclosure. Therefore, all such modifications are included within the scope of this disclosure. For example, in the specification or drawings, any term that is described at least once with a different term that is more general or synonymous can be replaced with that different term anywhere in the specification or drawings. Additionally, all combinations of this embodiment and its modifications are also included within the scope of this disclosure. Furthermore, the structure and operation of circuit devices, oscillators, and other components are not limited to those described in this embodiment, and various modifications can be made.

Claims

1. A circuit arrangement, characterized by The circuit device includes: An oscillating circuit that uses an oscillator to generate an oscillating signal; Temperature detection circuit, which outputs temperature detection data; A temperature compensation circuit, which performs temperature compensation on the oscillation frequency of the oscillation signal based on the temperature detection data; and A temperature detection ratio control circuit controls the temperature detection ratio of the temperature detection circuit. The temperature detection circuit includes: Temperature sensor circuit, which performs the temperature detection; and The processing circuit, based on the output data of the temperature sensor circuit, outputs temperature detection data with adjusted temperature sensitivity. Without calibration of the temperature sensitivity by the computational circuit, the frequency deviation of the oscillation frequency when the output data of the temperature sensor circuit changes by 1 LSB, i.e., the frequency sensitivity, has a first sensitivity in a first temperature range and a second sensitivity higher than the first sensitivity in a second temperature range that is either lower or higher than the first temperature range. The processing circuit sets the temperature sensitivity of the temperature detection data to a first temperature sensitivity in the first temperature range, and sets it to a second temperature sensitivity higher than the first temperature sensitivity in the second temperature range. The temperature detection ratio control circuit, based on the temperature detection data with the temperature sensitivity adjusted by the arithmetic circuit, sets the temperature detection ratio to the highest of the nth ratios (from the 1st ratio to the nth ratio) when the difference between the previous temperature detection data and the current temperature detection data is greater than or equal to a first threshold. Here, n is an integer greater than or equal to 2. When the difference is less than or below a second threshold that is less than the first threshold, the temperature detection ratio is reduced from the kth ratio among the first ratio to the nth ratio to the (k-1)th ratio, where k is an integer greater than 2 and less than n.

2. The circuit device according to claim 1, characterized in that, The temperature detection circuit performs intermittent temperature detection during intermittent temperature detection periods. The temperature detection ratio control circuit controls the temperature detection ratio by controlling the ratio of the intermittent operation.

3. The circuit device according to claim 1 or 2, characterized in that, The initial value of the temperature detection ratio is the nth ratio.

4. The circuit device according to claim 1 or 2, characterized in that, The temperature compensation circuit performs the temperature compensation based on the temperature detection ratio.

5. An oscillator characterized by, This oscillator has: Oscillator; and Circuit device, The circuit device includes: An oscillating circuit that uses the oscillator to generate an oscillating signal; Temperature detection circuit, which outputs temperature detection data; A temperature compensation circuit, which performs temperature compensation on the oscillation frequency of the oscillation signal based on the temperature detection data; and A temperature detection ratio control circuit controls the temperature detection ratio of the temperature detection circuit. The temperature detection circuit includes: Temperature sensor circuit, which performs the temperature detection; and The processing circuit, based on the output data of the temperature sensor circuit, outputs temperature detection data with adjusted temperature sensitivity. Without calibration of the temperature sensitivity by the computational circuit, the frequency deviation of the oscillation frequency when the output data of the temperature sensor circuit changes by 1 LSB, i.e., the frequency sensitivity, has a first sensitivity in a first temperature range and a second sensitivity higher than the first sensitivity in a second temperature range that is either lower or higher than the first temperature range. The processing circuit sets the temperature sensitivity of the temperature detection data to a first temperature sensitivity in the first temperature range, and sets it to a second temperature sensitivity higher than the first temperature sensitivity in the second temperature range. The temperature detection ratio control circuit, based on the temperature detection data with the temperature sensitivity adjusted by the arithmetic circuit, sets the temperature detection ratio to the highest of the nth ratios (from the 1st ratio to the nth ratio) when the difference between the previous temperature detection data and the current temperature detection data is greater than or equal to a first threshold. Here, n is an integer greater than or equal to 2. When the difference is less than or below a second threshold that is less than the first threshold, the temperature detection ratio is reduced from the kth ratio among the first ratio to the nth ratio to the (k-1)th ratio, where k is an integer greater than 2 and less than n.

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