JP2015035706A - Method for controlling oscillation circuit, oscillating circuit, oscillator, electronic apparatus, and mobile body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling an oscillation circuit, an oscillating circuit, an oscillator, an electronic apparatus, and a mobile body which reduce the risk that a supply voltage switching operation will cause an oscillation frequency compensation section to malfunction.SOLUTION: An oscillation circuit 2 includes: a temperature compensation section; an oscillation section compensated by a signal from the temperature compensation section; a power supply section 30 for supplying power to the oscillation section; and a control section 20 for boosting the power supply section 30 upon power application, returning the power supply section 30 to normal after the power supply section 30 is boosted, and operating the temperature compensation section after the power supply section 30 is returned to normal.

Description

  The present invention relates to an oscillation circuit control method, an oscillation circuit, an oscillator, an electronic device, and a moving object.

  Patent Document 1 discloses a piezoelectric reference oscillator that can suppress power consumption by delaying supply of a power supply voltage to a temperature characteristic compensation circuit until operation of the oscillation circuit is stabilized after power supply.

Japanese Patent Laid-Open No. 10-28016

  However, Patent Document 1 does not clearly indicate that the voltage or current supplied to the oscillation circuit is changed in order to increase the oscillation start time of the oscillation circuit. For this reason, when a circuit that accelerates the oscillation start time by changing the voltage or current supplied to the oscillation circuit at startup is added to the piezoelectric reference oscillator described in Patent Document 1, the operation of the temperature characteristic compensation circuit starts. When the switching operation of the voltage or current to be supplied to the oscillation circuit is performed later, there is a risk of malfunction in the adjustment process of the frequency temperature characteristic in the temperature compensation circuit due to the fluctuation of the voltage or current at the time of switching. This problem is not limited to frequency temperature characteristic adjustment processing, but is common to compensation units that perform processing for correcting oscillation frequency fluctuations caused by some environmental change.

  The present invention has been made in view of the above problems, and according to some aspects of the present invention, it is possible to reduce the possibility that the oscillation frequency compensator will malfunction due to the switching operation of the power supply voltage. It is possible to provide an oscillation circuit control method, an oscillation circuit, an oscillator, an electronic device, and a moving body that can perform the above-described operation.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
The oscillation circuit according to this application example includes a compensation unit, an oscillation unit compensated by a signal from the compensation unit, a first power supply unit that supplies power to the oscillation unit, and the first circuit after the power is turned on. The first power supply means is set to the first state, and after the first power supply means is set to the first state, the first power supply means is set to the second state, and the first power supply means is set to the first state. Control means for operating the compensation means after the second state is reached.

  According to the oscillation circuit according to this application example, since the operation of the compensation unit does not overlap with the timing at which the state of the first power supply unit is switched, it is possible to reduce malfunction of the compensation unit due to power supply fluctuation. Accordingly, it is possible to reduce a possibility that the accuracy of the oscillation frequency of the oscillation circuit is lowered.

[Application Example 2]
The oscillation circuit according to the application example further includes a storage unit that stores setting information for setting the first power supply unit to the second state, and the control unit includes the storage unit from the storage unit. The setting information may be read to place the first power supply unit in the second state.

  According to the oscillation circuit according to this application example, for example, by storing optimal setting information in the storage unit, the accuracy of the oscillation frequency of the oscillation circuit when the first power supply unit is in the second state is stored. Can be increased.

[Application Example 3]
In the oscillation circuit according to the application example, after the operation of the compensation unit, the control unit reads the setting information from the storage unit and sets the first power supply unit to the second state; and The operation of the compensation means may be repeated without overlapping in time.

  According to the circuit for oscillation according to this application example, the operation of the compensation unit and the operation of setting the first power supply unit to the second state do not overlap in time, so the first power supply unit is in the second state. Since the fluctuation of the power supply voltage generated by the operation is difficult to affect the operation of the compensation means, it is possible to reduce the malfunction of the compensation means due to the power supply fluctuation. Accordingly, it is possible to reduce a possibility that the accuracy of the oscillation frequency of the oscillation circuit is lowered. Further, since the setting information for setting the first power supply means to the second state is periodically read from the storage means, even if the setting of the second state is changed due to the influence of noise or the like, it is correct. It becomes possible to return to the setting.

[Application Example 4]
In the oscillation circuit according to the application example, in the first state, the power supplied from the first power supply unit to the oscillation unit may be larger than that in the second state.

  According to the oscillation circuit according to this application example, the operation of the compensation unit does not overlap with the state in which the power supplied to the oscillation unit is large. Therefore, when the operation is performed with a large amount of power applied to the oscillation unit. It becomes less susceptible to the influence of the oscillation unit on the compensation unit (for example, the temperature rise of the compensation unit due to heat generation of the oscillation unit). In addition, since the power supplied from the first power supply means to the oscillation means becomes large after the power is turned on, the oscillation means can be quickly brought into a stable state.

[Application Example 5]
The oscillation circuit according to the application example further includes power supply switching means for selecting at least one of a plurality of second power supply means and connecting to the first power supply means, and the first power supply The means may further supply power to the compensation means so that the operation of the compensation means and the operation of the power supply switching means do not overlap.

  According to the oscillation circuit according to this application example, it is possible to reduce the power supply voltage fluctuation during the operation of the compensation unit, and thus it is possible to reduce malfunction of the compensation unit. Accordingly, it is possible to reduce a possibility that the accuracy of the oscillation frequency of the oscillation circuit is lowered.

  In the oscillation circuit according to the application example, the operation of setting the first power supply unit to the second state and the operation of the power supply switching unit may not overlap.

  The oscillation circuit according to the application example further includes a timing unit that generates time information based on a signal output from the oscillation unit, and a timing at which the timing unit updates the time information and the power source switching unit It is possible to prevent the operation from overlapping.

[Application Example 6]
An oscillator according to this application example includes any of the above-described oscillation circuits and a vibrator.

[Application Example 7]
An electronic apparatus according to this application example includes any of the above oscillation circuits or the above oscillator.

[Application Example 8]
The moving body according to this application example includes any one of the above oscillation circuits or the above oscillator.

[Application Example 9]
An oscillation circuit control method according to this application example is an oscillation circuit control method including an oscillation unit to which a vibrator is connected, a power supply unit that supplies power to the oscillation unit, and a compensation unit. After the power is turned on, the power supply unit is set to the first state, and after the power supply unit is set to the first state, the power supply unit is set to the second state, and the power supply unit is set to the second state. Thereafter, the compensation unit is operated.

  For example, the control unit included in the oscillation circuit sets the power supply unit to the first state after power is turned on, sets the power supply unit to the second state after the power supply unit enters the first state, and The control unit may be controlled to operate after the unit is set to the second state.

  According to the control method of the oscillation circuit according to this application example, the operation of the compensation unit does not overlap with the timing at which the state of the power supply unit is switched, so that malfunction of the compensation unit due to power supply fluctuation can be reduced. Accordingly, it is possible to reduce a possibility that the accuracy of the oscillation frequency of the oscillation circuit is lowered.

[Application Example 10]
In the oscillation circuit control method according to the application example, the oscillation circuit further includes a storage unit that stores setting information for setting the power supply unit to the second state, and the power supply unit includes the first power supply unit. After the state is reached, the setting information may be read from the storage unit to put the power supply unit in the second state.

  For example, the control unit included in the oscillation circuit controls so that the setting information is read from the storage unit and the power supply unit is in the second state after the power supply unit is in the first state. May be.

  According to the control method of the oscillation circuit according to this application example, for example, by storing optimal setting information in the storage unit, the accuracy of the oscillation frequency of the oscillation circuit when the power supply unit is in the second state is increased. Can do.

[Application Example 11]
In the oscillation circuit control method according to the application example, after the operation of the compensation unit, the setting information is read from the storage unit and the power supply unit is set to the second state, and the operation of the compensation unit May be repeated without overlapping in time.

  For example, the control unit included in the oscillation circuit includes an operation of setting the power supply unit in the second state by reading the setting information from the storage unit after the operation of the compensation unit and an operation of the compensation unit. You may control so that it may be repeated without overlapping in time.

According to the control method of the oscillation circuit according to this application example, the operation of the compensation unit and the operation of setting the power supply unit to the second state do not overlap in time, and thus the operation occurs to set the power supply unit to the second state. Since power supply voltage fluctuations hardly affect the operation of the compensation unit, malfunctions of the compensation unit due to power supply fluctuations can be reduced. Accordingly, it is possible to reduce a possibility that the accuracy of the oscillation frequency of the oscillation circuit is lowered. In addition, since setting information for setting the power supply unit to the second state is periodically read from the storage unit, even if the setting of the second state is changed due to the influence of noise or the like, the setting is restored to the correct setting. It becomes possible.

[Application Example 12]
In the oscillation circuit control method according to the application example described above, in the first state, power supplied from the power supply unit to the oscillation unit may be larger than that in the second state.

  According to the control method of the oscillation circuit according to this application example, the operation of the compensation unit does not overlap with the state in which the power supplied to the oscillation unit is large. The influence of the oscillation unit on the compensation unit at the time (for example, temperature rise of the compensation unit due to heat generation of the oscillation unit) is less likely to be received. In addition, since the power supplied from the power supply unit to the oscillation unit becomes large after the power is turned on, the oscillation unit can be brought into a stable state quickly.

[Application Example 13]
In the oscillation circuit control method according to the application example, the oscillation circuit further includes a power supply switching unit that selects at least one of a plurality of power supply sources and connects the power supply unit, and the power supply unit further includes: Power may be supplied to the compensation unit so that the operation of the compensation unit and the operation of the power supply switching unit do not overlap.

  For example, the control unit included in the oscillation circuit may perform control so that the operation of the compensation unit and the operation of the power supply switching unit do not overlap.

  According to the control method of the oscillation circuit according to this application example, it is possible to reduce the power supply voltage fluctuation during the operation of the compensation unit, and thus it is possible to reduce malfunction of the compensation unit. Accordingly, it is possible to reduce a possibility that the accuracy of the oscillation frequency of the oscillation circuit is lowered.

  In the method for controlling an oscillation circuit according to the application example described above, the operation of setting the power supply unit to the second state and the operation of the power supply switching unit may not overlap.

  In the method for controlling an oscillation circuit according to the application example, the oscillation circuit further includes a clock unit that generates time information based on a signal output from the oscillation unit, and the clock unit updates the time information. The timing to perform and the operation of the power supply switching unit may not overlap.

The figure which shows the structural example of the real-time clock of this embodiment. The figure which shows the structural example of the temperature compensation oscillation circuit in this embodiment. The figure which shows the structural example of the control part in this embodiment. The flowchart figure which shows an example of the process sequence of the control part in this embodiment. The flowchart figure which shows an example of the procedure of a temperature compensation process. The flowchart figure which shows an example of the procedure of a refresh process. The flowchart figure which shows an example of the procedure of a switch switching process. The timing chart figure which shows an example of the operation | movement at the time of starting of an oscillation circuit. The timing chart figure which shows an example of the operation | movement after starting of an oscillation circuit. The timing chart figure which shows another example of the operation | movement after starting of an oscillation circuit. The detailed timing chart figure of temperature compensation operation | movement and switch switching operation | movement. The figure which shows the structural example of the oscillator of this embodiment. 1 is a functional block diagram of an electronic apparatus according to an embodiment. 1 is a diagram illustrating an example of an appearance of an electronic apparatus according to an embodiment. The figure which shows an example of the mobile body of this embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. Also, not all of the configurations described below are essential constituent requirements of the present invention.

1. Real time clock 1-1. Configuration FIG. 1 is a diagram illustrating a configuration example of a real-time clock according to the present embodiment. The real-time clock 1 of this embodiment includes an oscillation circuit 2 that oscillates the vibrator 3. In addition, the real-time clock 1 according to the present embodiment may include a vibrator 3 or a limiting resistor 6 or a backup power source 5.

  In the present embodiment, the oscillation circuit 2 is realized by one integrated circuit (IC) chip, and has two power supply terminals, a VCC terminal and a VBA terminal. However, the oscillation circuit 2 may be realized by wiring a plurality of IC chips, or a part or all of the configuration of the oscillation circuit 2 may be realized by wiring discrete components.

  A main power supply 4 is connected to the VCC terminal, and power is supplied from the main power supply 4. Further, a CPU (Central Processing Unit) 8 is connected to the VCC terminal. When the CPU 8 does not operate in order to reduce current consumption, power supply from the main power supply 4 to the VCC terminal is cut off. Since the oscillation circuit 2 needs to continue the timing operation even when the power supply from the main power supply is cut off, the backup power supply 5 that can be charged via the limiting resistor 6 for limiting the charging speed is applied to the VBA terminal. (Secondary battery, large-capacity capacitor, etc.) are connected. However, the backup power supply 5 may be replaced with a power supply (primary battery or the like) that cannot be charged.

  In the present embodiment, the oscillation circuit 2 includes a temperature compensated oscillation circuit 10, a control unit 20, a power supply unit 30, a power-on reset circuit 40, a switch 50, a power supply monitoring circuit 60, a timer unit 70, a nonvolatile memory 80, a serial interface ( I / F) circuit 90 is included. However, the oscillation circuit 2 may have a configuration in which some of these elements are omitted or changed, or other elements are added.

  The switch 50 is connected between the VCC terminal and the VBA terminal, and is realized by a PMOS transistor in this embodiment. That is, the switch 50 conducts (turns on) between the source and the drain when the control signal SWCTL input to the gate terminal is at a low level, with the upstream side as the source and the downstream side as the drain with respect to the direction of current flow. When the control signal SWCTL is at a high level, the source and the drain are made non-conductive (off).

  In the present embodiment, the switch 50 is a diode whose drain is connected to the back gate, the source is the anode, and the drain is the cathode between the source and the drain (the direction from the source to the drain is the forward direction). (Body diode) is formed. Accordingly, even when the switch 50 is in the off state, if the source potential is higher than the drain potential, a current flows from the source to the drain (the forward direction of the diode).

The switch 50 is provided so that the VCC terminal side is the source and the VBA terminal side is the drain. Therefore, when the power supply voltage is supplied from the main power supply, the voltage at the VBA terminal is the power supply voltage of the main power supply when the switch 50 is on, and when the switch is off, the voltage of the switch is higher than the power supply voltage of the main power supply. The voltage becomes lower by the forward drop voltage VF of the diode 50 has. Further, when the switch 50 is on, a current flows from the main power source to the backup power source through the channel formed between the source and drain of the switch 50 to charge the backup power source. Even when the switch 50 is off, the switch 50 A current flows from the main power supply to the backup power supply through the diode to charge the backup power supply.

  On the other hand, in a state where the supply of the power supply voltage from the main power supply is interrupted, the voltage at the VBA terminal becomes the power supply voltage of the backup power supply both when the switch 50 is on and off.

  The voltage at the VBA terminal is supplied to each unit as the internal power supply voltage of the oscillation circuit 2. The voltage at the VBA terminal is supplied to the power-on reset circuit 40. The power-on reset circuit 40 follows the voltage increase at the VBA terminal and generates the reset signal POR until the desired voltage is reached. For example, when the power supply voltage of the main power supply 4 is supplied to the VCC terminal while the backup power supply 5 is not charged, the switch 50 is turned on to charge the backup power supply 5 and the voltage at the VBA terminal rises to reset. A signal POR is generated.

  The power supply unit 30 includes a reference power supply circuit 32 and a regulator 34, and generates a power supply voltage to be supplied to the temperature compensated oscillation circuit 10 based on the voltage at the VBA terminal.

  The reference power supply circuit 32 generates a constant reference voltage VREF and a reference current IBIAS regardless of the temperature, and supplies them to the regulator 34. In the present embodiment, the reference voltage VREF can be adjusted within a predetermined range by reference voltage adjustment data BGRD supplied from the control unit 20. Similarly, the reference current IBIAS can be adjusted within a predetermined range by reference current adjustment data IBIASD supplied from the control unit 20. In the present embodiment, the reference power supply circuit 32 includes a temperature sensor 36 that outputs a temperature detection signal T_SENS. Such a reference power supply circuit 32 includes, for example, a circuit that generates a predetermined voltage using a semiconductor band gap voltage, and a temperature sensor 36 that generates a voltage having a temperature characteristic opposite to the temperature characteristic of the band gap voltage. It can be realized by a bandgap reference circuit constituted by a circuit for adding the output voltages of these two circuits.

  The regulator 34 generates and outputs a power supply voltage to be supplied to the temperature compensated oscillation circuit 10 based on the reference voltage VREF and the reference current IBIAS. In the present embodiment, the output voltage of the regulator 34 can be adjusted within a predetermined range by the regulator voltage adjustment data VREGD supplied from the control unit 20.

  The temperature compensated oscillation circuit 10 is a circuit for oscillating the vibrator 3 connected via the GATE terminal and the DRAIN terminal of the oscillation circuit 2, and operates using the output voltage of the regulator 34 as a power supply voltage.

  FIG. 2 is a diagram illustrating a configuration example of the temperature compensated oscillation circuit 10 in the present embodiment. As illustrated in FIG. 2, the temperature compensated oscillation circuit 10 includes an oscillation unit 12 and a temperature compensation unit 14.

  The oscillation unit 12 includes an inverter circuit 121, two resistors 122 and 123, and two variable capacitance circuits 124 and 125. The input terminal of the inverter circuit 121 is connected to the GATE terminal of the oscillation circuit 2, and the output terminal of the inverter circuit 121 is connected to the DRAIN terminal of the oscillation circuit 2 via the resistor 123.

  The resistor 122 is connected between the output terminal and the input terminal of the inverter circuit 121, and the resistor 123 is connected between the output terminal of the inverter circuit 121 and the DRAIN terminal.

The variable capacitance circuit 124 includes a plurality of capacitance elements connected between the input terminal of the inverter circuit 121 (GATE terminal of the oscillation circuit 2) and the ground via each of the plurality of switches. By switching on / off of the switch element, the load capacity of the input terminal of the inverter circuit 121 (GATE terminal of the oscillation circuit 2) can be variably set. Similarly, the variable capacitance circuit 125 includes a plurality of capacitance elements connected between the output terminal of the inverter circuit 121 (DRAIN terminal of the oscillation circuit 2) and the ground via each of the plurality of switches. By switching on / off of these switch elements, the load capacity of the output terminal of the inverter circuit 121 (DRAIN terminal of the oscillation circuit 2) can be variably set. Note that one of the variable capacitance circuits 124 and 125 may be replaced with a circuit having a fixed capacitance value.

  The temperature compensation unit 14 includes a register 142, an arithmetic circuit 144, and an A / D converter 146, and operates when the control signal EN_SENS from the control unit 20 is at a high level. In the present embodiment, the control signal EN_SENS is at a high level for a certain period with a certain period, and the temperature compensation unit 14 operates intermittently.

  The A / D converter 146 A / D converts the temperature detection signal T_SENS and outputs A / D conversion data ADO to the control unit 20. The arithmetic circuit 144 receives temperature compensation data TCOMPD corresponding to the A / D conversion data ADO from the control unit 20, performs temperature correction calculation, and controls on / off control values (high or low) of the switch elements of the variable capacitance circuits 124 and 125. Low) and set in the register 142 as the capacity selection data CAPD. On / off of each switch element of the variable capacitance circuits 124 and 125 is controlled in accordance with the capacitance selection data CAPD.

  The temperature-compensated oscillation circuit 10 configured as described above periodically updates the capacitance selection data CAPD according to the temperature change, and corrects the temperature characteristics of the vibrator 3 so that the vibrator 3 has a desired frequency near the resonance frequency. Oscillate with In this embodiment, the resonance frequency of the vibrator 3 is a frequency around 32.768 kHz, and the temperature compensated oscillation circuit 10 outputs a clock signal clk_32k of 32.768 kHz with a very small frequency deviation in the temperature range in which operation is guaranteed.

  As the resonator 3, for example, a crystal Z cut, a crystal resonator using a cut angle obtained by rotating the crystal Z cut around the X axis by several degrees around the Y axis, an SC cut or AT cut crystal resonator, a SAW (Surface Acoustic Wave) resonator can be used. Further, as the vibrator 3, for example, a piezoelectric vibrator other than a crystal vibrator, a MEMS (Micro Electro Mechanical Systems) vibrator, or the like can be used. As a substrate material of the vibrator 3, a piezoelectric single crystal such as crystal, lithium tantalate, or lithium niobate, a piezoelectric material such as piezoelectric ceramics such as lead zirconate titanate, or a silicon semiconductor material can be used. In addition, as the excitation means of the vibrator 3, a piezoelectric effect may be used, or electrostatic driving using a Coulomb force may be used. Further, as the shape of the vibrator, a flat plate shape, a tuning fork shape, or the like can be used.

  Returning to FIG. 1, the power monitoring circuit 60 includes a comparator 62, a switch circuit 64, and two resistors 66 and 68.

  The switch circuit 64 is turned on when the control signal COMPEN from the control unit 20 is at a high level and turned off when the control signal COMPEN is at a low level.

  The two resistors 66 and 68 are connected in series between the VCC terminal and the ground via the switch circuit 64.

The comparator 62 operates when the control signal COMPEN from the control unit 20 is at a high level, and compares the voltage obtained by dividing the voltage at the VCC terminal by two resistors 66 and 68 with a predetermined voltage. That is, the comparator 62 determines whether the voltage at the VCC terminal is equal to or higher than a desired voltage (threshold voltage). When the voltage at the VCC terminal is equal to or higher than the threshold voltage, the comparator 62 becomes high level. When is lower than the threshold voltage, a signal COMPO that is at a low level is output.

  In the present embodiment, the control signal COMPEN becomes a high level for a certain period at a certain period, and the power supply monitoring circuit 60 operates intermittently. The reason why the switch circuit 64 is turned off when the control signal COMPEN is at a low level is to prevent a current from flowing from the VCC terminal to the ground during a period in which the comparator 62 does not operate, thereby reducing current consumption.

  The clock unit 70 generates time information (information such as year, month, day, hour, minute, second) in synchronization with the 1 Hz clock signal clk1 Hz. In the present embodiment, the timer unit 70 updates the second information at the falling edge of the clock signal clk1 Hz (timing to change from high level to low level).

  The non-volatile memory 80 stores adjustment data for each part of the oscillation circuit 2. For example, a flash memory such as a MONOS (Metal-Oxide-Nitride-Oxide-Silicon) memory or an EEPROM (Electrically Erasable Programmable Read- (Only Memory) or the like. In the present embodiment, the non-volatile memory 80 stores reference voltage adjustment data, reference current adjustment data, regulator voltage adjustment data, temperature compensation data, and the like. For each real-time clock 1, an optimum value of each data may be written in the nonvolatile memory 80 in the inspection process.

The serial I / F circuit 90 is an interface circuit for performing data communication with the CPU 8. For example, the serial I / F circuit 90 may perform data communication using an I ² C communication method via an SCL terminal and an SDA terminal. The CPU 8 can read and write various data to and from the nonvolatile memory 80 via the serial I / F circuit 90 and read time information generated by the time measuring unit 70.

  The control unit 20 is initialized by the reset signal POR, controls the operation of the temperature compensated oscillation circuit 10, the power supply unit 30 and the power supply monitoring circuit 60, controls the on / off of the switch 50, reads / writes various data from / to the nonvolatile memory 80, serial Data communication with the outside through the I / F circuit 90, generation of a clock signal clk1 Hz, and the like are performed.

  FIG. 3 is a diagram illustrating a configuration example of the control unit 20 in the present embodiment. As illustrated in FIG. 3, the control unit 20 includes a frequency dividing circuit 22, a timing generation unit 24, a memory control unit 26, A register unit 28 is provided. When a reset signal POR is input, all these units are initialized.

  The register unit 28 includes various setting registers including setting registers for the reference voltage VREF, the reference current IBIAS, and the output voltage of the regulator 34. When the reset signal POR is generated, each setting register is stored in advance. Initialized to the set value. In particular, in the present embodiment, when the reset signal POR is generated, the respective setting registers are initialized so that the reference current IBIAS, the reference voltage VREF, and the output voltage of the regulator 34 become larger than usual. The power supplied to the oscillation unit 12 of the temperature compensated oscillation circuit 10 becomes larger than that in the normal state. As a result, it is possible to shorten the startup time from when power is supplied to the oscillation circuit 2 until the temperature compensated oscillation circuit 10 is stabilized. For example, if the respective setting registers for the reference voltage VREF, the reference current IBIAS, and the output voltage of the regulator 34 are initialized to the maximum values that can be set, the startup time can be minimized.

The frequency dividing circuit 22 generates a 1.024 kHz clock signal clk_1k obtained by dividing the 32.768 kHz clock signal clk_32k by 32. Further, the frequency dividing circuit 22 divides the clock signal clk_1k by 2 ¹ (= 2) to 2 ¹⁰ (= 1024), respectively, a clock signal clk 512 Hz, a clock signal clk 256 Hz, a clock signal clk 128 Hz, a clock signal clk 64 Hz, a clock signal clk 32 Hz, A clock signal clk16 Hz, a clock signal clk8 Hz, a clock signal clk4 Hz, a clock signal clk2 Hz, and a clock signal clk1 Hz are generated. The clock signal clk 1 Hz is a signal with a period of 1 second, and serves as an operation clock signal for the timer unit 70.

  Further, the 10 clock signals clk512 Hz to clk1 Hz excluding the clock signal clk — 1k constitute a 10-bit count signal cnt [9: 0] in which clk1 Hz is MSB and clk512 Hz is LSB. That is, the count signal cnt [9: 0] is counted up from 0 to 1023 per second.

  When the count signal cnt [9: 0] is 0, the timing generator 24 changes the control signal EN_SENS from the low level to the high level in synchronization with the clock signal clk_32k, and counts a predetermined time with the clock signal clk_32k. Return EN_SENS to low level.

  Further, when the count signal cnt [9: 0] is 64, the timing generation unit 24 changes the control signal COMPEN from the low level to the high level at the falling edge of the clock signal clk_1k, and counts a predetermined time with the clock signal clk_1k. Then, the control signal COMPEN is returned to the low level.

  In addition, the timing generation unit 24 changes the control signal SWCTL from the low level to the high level at the timing of changing the control signal COMPEN from the low level to the high level, and returns the control signal COMPEN to the low level at the timing of changing the control signal COMPEN to the low level. Only when the output signal COMPO is at a high level, the control signal SWCTL is returned to a low level.

  The timing generation unit 24 controls the operation of the memory control unit 26, and the memory control unit 26 reads / writes data from / to the nonvolatile memory 80. In particular, in this embodiment, the timing generator 24 changes the control signal EN_SENS from low level to high level and then counts a predetermined time with the clock signal clk_32k. The temperature compensation data corresponding to the D conversion data ADO (temperature information) is read out.

  In addition, the timing generation unit 24 sends the non-volatile memory 80 to the memory control unit 26 when the predetermined time is counted with the clock signal clk_32k after the reset signal POR is canceled and immediately after the control signal EN_SENS is returned to the low level. The reference voltage adjustment data, the reference current adjustment data, and the regulator voltage adjustment data are read out from the control register, and the setting registers are set.

In the present embodiment, the oscillation circuit 2 is an example of the “oscillation circuit” or “oscillation circuit” in the present invention. The oscillator 12 is an example of the “oscillator” or “oscillator” of the present invention. The configuration comprising the temperature compensation unit 14 or a part of the temperature compensation unit 14 and the control unit 20 (the part that performs processing related to the temperature compensation operation) is an example of the “compensation unit” or “compensation unit” of the present invention. is there. The power supply unit 30 is an example of the “power supply unit” or “first power supply unit” in the present invention. The nonvolatile memory 80 is an example of the “storage unit” or “storage unit” in the present invention. The control unit 20 is an example of the “control unit” in the present invention. The configuration comprising the switch 50 or the switch 50 and the power supply monitoring circuit 60 is an example of the “power supply switching unit” or “power supply switching unit” of the present invention. The main power supply 4 and the backup power supply 5 are examples of the “plurality of power supply sources” or the “plurality of second power supply means” in the present invention. The “boost state” and the “normal state” are examples of the “first state” and the “second state” of the present invention, respectively. The reference voltage adjustment data, reference current adjustment data, and regulator adjustment data stored in the nonvolatile memory 80 are an example of “setting information” in the present invention. The “temperature compensation operation” is an example of the “operation of the compensation unit” or “operation of the compensation means” in the present invention. The “switch switching operation” is an example of the “operation of the power switching unit” or the “operation of the power switching unit” in the present invention.

1-2. Processing Procedure of Control Unit FIG. 4 is a flowchart illustrating an example of a processing procedure of the control unit 20 in the present embodiment. As shown in FIG. 4, in the present embodiment, when the reset signal POR is generated (Y in S10), the control unit 20 first sets the power supply unit 30 to the boost state (S12).

  Next, the control unit 20 sets the power supply unit 30 to a normal state after a lapse of T1 time after the reset signal POR is canceled (Y in S14) (S16). This T1 time is set to be longer than the time necessary for the output signal of the temperature compensated oscillation circuit 10 to become stable.

  Thereafter, when the count signal cnt [9: 0] is 0 or 512 (Y in S18), the control unit 20 performs temperature compensation processing (S20), and after the temperature compensation processing is completed, the register setting of the power supply unit 30 is set. A refresh process is performed (S22). That is, in the present embodiment, the control unit 20 repeatedly performs the temperature compensation process and the refresh process at a cycle of 0.5 seconds.

  In addition, when the count signal cnt [9: 0] is 64 (Y in S24), the control unit 20 performs a switch switching process (S26). That is, in the present embodiment, the control unit 20 repeatedly performs the switch switching process at a cycle of 1 second.

  FIG. 5 is a flowchart showing an example of the procedure of the temperature compensation process (S20) of FIG. As shown in FIG. 5, the control unit 20 first sets the control signal EN_SENS to a high level to cause the temperature compensation unit 14 to start a temperature compensation operation (S100).

  Next, after the elapse of T2 time from the start of the temperature compensation operation (Y in S102), the control unit 20 acquires A / D conversion data ADO from the temperature compensation unit 14 (S104). This T2 time is set to be longer than the time necessary for the A / D conversion operation of the temperature compensation unit 14.

  Next, the control unit 20 reads temperature compensation data corresponding to the A / D conversion data ADO from the nonvolatile memory 80, and outputs the temperature compensation data as temperature compensation data TCOMPD to the temperature compensation unit 14 (S106).

  Finally, after the elapse of T3 time from the start of the temperature compensation operation (Y in S108), the control unit 20 sets the control signal EN_SENS to a low level, and causes the temperature compensation unit 14 to end the temperature compensation operation (S110). Compensation processing ends. This T3 time is set to be longer than the time necessary for completing all the temperature compensation operations of the temperature compensation unit 14.

  FIG. 6 is a flowchart showing an example of the procedure of the refresh process (S22) of FIG. The procedure for setting the power supply unit 30 in FIG. 4 to the normal state (S16) is the same as that in FIG.

As shown in FIG. 6, the control unit 20 first reads the reference voltage adjustment data from the nonvolatile memory 80 and sets it in the register of the register unit 28 (S200).

  Next, the control unit 20 reads the reference current adjustment data from the nonvolatile memory 80 and sets it in the register of the register unit 28 (S202).

  Finally, the control unit 20 reads the regulator voltage adjustment data from the nonvolatile memory 80, sets it in the register of the register unit 28 (S204), and ends the refresh process.

  FIG. 7 is a flowchart showing an example of the procedure of the switch switching process (S26) of FIG. As shown in FIG. 7, the control unit 20 first sets the control signal SWCTL to high level to turn off the switch 50, and sets the control signal COMPEN to high level to turn on the power supply monitoring circuit 60 (S300). Here, the reason why the switch 50 is turned off is to disconnect the VCC terminal from the VBA terminal so that the power supply monitoring circuit 60 can correctly determine the voltage of the VCC terminal.

  Next, the control unit 20 turns off the switch 50 and, after T4 time has elapsed since turning on the power supply monitoring circuit 60 (Y in S302), acquires the output signal COMPO of the power supply monitoring circuit 60 and performs control. The signal COMPEN is set to low level to turn off the power supply monitoring circuit 60 (S304). This T4 time is set to be longer than the time necessary for the output signal COMPO of the power supply monitoring circuit 60 to become stable.

  When the COMPO is at a high level (Y in S306), the control unit 20 returns the control signal SWCTL to a low level and turns on the switch 50. When the COMPO is at a low level (N in S306), The switch 50 is kept off without returning the control signal SWCTL to the low level, and the switch switching process is terminated.

1-3. Operation Timing FIG. 8 is a timing chart showing an example of the operation when the oscillation circuit 2 is activated. As shown in FIG. 8, before the time t ₀ , the power supply from the main power supply 4 to the VCC terminal is cut off, and the backup power supply 5 is not charged, and the voltage at the VCC terminal and the voltage at the VBA terminal are Both voltages are 0V.

The main power supply 4 is connected to the VCC terminal at time t ₀ , and the voltage at the VCC terminal reaches the power supply voltage of the main power supply 4 at time t ₁ . At times t _{0 to} t ₁ , a reset signal POR is generated, and each setting register of the register unit 28 is initialized. As a result, the reference voltage adjustment data BGRD, the reference current adjustment data IBIASD, and the regulator voltage adjustment data VREGD are set to A0, B0, and C0, respectively, and the power supply unit 30 enters the boost state.

  Next, when the oscillation unit 12 of the temperature compensated oscillation circuit 10 starts operation and the clock signal clk_32k is generated, the count-up operation of the count signal cnt [9: 0] starts.

Next, at time _{t 1} from the after T1 time time _t 2 ~t _3, processing is performed to set the power unit 30 in the normal state, at time _{t 3,} the reference voltage adjustment data BGRD, reference current adjustment data IBIASD The regulator voltage adjustment data VREGD is set to A1, B1, and C1, respectively, and the power supply unit 30 enters the normal state.

Next, the count signal cnt [9: 0] is the period from the time _{t 4} when becomes 64 to time _{t 5} after time T4 has elapsed, the control signal COMPEN and the control signal SWCTL switch change operation both at the high level line We, the voltage of the VCC terminal is a higher than the threshold voltage, the control signal SWCTL at time _{t 5} is returned to the low level.

Next, the count signal cnt [9: 0] is the period from time _{t 6} to be 512 until time _{t 7} after time T3 elapses, the control signal EN_SENS temperature compensation operation is performed at a high level, a time _{t 7} The capacity selection data CAPD is updated.

  As described above, in this embodiment, the switch switching operation and the temperature compensation operation are started after the boost state is changed to the normal state.

FIG. 9 is a timing chart showing an example of the operation of the oscillation circuit 2 after the backup power supply 5 is completely charged. In FIG. 9, it is assumed that the power supply voltage of the backup power supply 5 is slightly lower than the power supply voltage of the main power supply 4. Fig As shown in 9, the count signal cnt at time _{t 8} [9: 0] when is 0, the control signal EN_SENS at time _t 8 ~t ₉ the temperature compensation operation is performed at a high level, the time _{t 9} The capacity selection data CAPD is updated from D2 to D3.

Then, immediately after the time _{t 9,} the refresh operation of the adjustment data of the power supply unit 30 is performed, the reference voltage adjustment data BGRD, reference current adjustment data IBIASD, A1 registers setpoint of regulator voltage adjustment data VREGD respectively, B1, Refreshed (overwritten) to C1.

Next, the count signal cnt at time _{t 10} [9: 0] is the becomes 64, the control signal COMPEN and the control signal SWCTL at time _t 10 _{~t 11} switches the switching operation is performed both at the high level. Since the switch 50 is turned off at times t _{10 to} t ₁₁ , the voltage at the VBA terminal becomes the power supply voltage of the backup power supply 5.

Then, the voltage of the VCC terminal is a higher than the threshold voltage, the control signal SWCTL is returned to the low level at time _{t 11,} the switch 50 is turned on, the voltage of the VBA terminal voltage (power supply voltage of the main power supply 4 of the VCC terminal Return to).

Next, the count signal cnt at time _{t 12:} If [9 0] is 512, the control signal EN_SENS at time _t 12 _{~t 13} temperature compensation operation is performed at a high level at time _{t 13,} capacitance selection Data CAPD is updated from D3 to D4.

Then, immediately after the time _{t 13,} the refresh operation of the adjustment data of the power supply unit 30 is performed, the reference voltage adjustment data BGRD, reference current adjustment data IBIASD, A1 registers setpoint of regulator voltage adjustment data VREGD respectively, B1, Refreshed (overwritten) to C1.

Next, the count signal cnt at time _{t 14} [9: 0] when is 0, the control signal EN_SENS at time _t 14 _{~t 15} temperature compensation operation is performed at a high level at time _{t 15,} capacitance selection Data CAPD is updated from D4 to D5.

Then, immediately after the time _{t 15,} the refresh operation of the adjustment data of the power supply unit 30 is performed, the reference voltage adjustment data BGRD, reference current adjustment data IBIASD, A1 registers setpoint of regulator voltage adjustment data VREGD respectively, B1, Refreshed (overwritten) to C1.

Then, at time t _16, and cut off the power supply from the main power supply 4 to the VCC terminal, since the switch 50 is turned on, the voltage of the voltage VBA and VCC pins becomes the power supply voltage of the backup power supply 5 together .

Next, the count signal cnt at time _{t 17} [9: 0] is the becomes 64, the control signal COMPEN and the control signal SWCTL at time _t 17 _{~t 18} switches the switching operation is performed both at the high level. Since the switch 50 is turned off at times t _{17 to} t ₁₈ , the voltage at the VCC terminal becomes 0V.

Then, the voltage of the VCC terminal is lower than the threshold voltage, the control signal SWCTL does not return to remain low at the high level at time t _18, the switch 50 remains off. That is, at time t _18, is switched from the normal mode (mode for operating at a power of the main power supply 4) to the backup mode (operating at a power of the backup power supply 5).

Next, the count signal cnt at time _{t 19} [9: 0] When is 512, the control signal EN_SENS at time _t 19 _{~t 20} temperature compensation operation is performed at a high level at time _{t 20,} capacitance selection Data CAPD is updated from D5 to D6.

Then, immediately after the time _{t 19,} the refresh operation of the adjustment data of the power supply unit 30 is performed, the reference voltage adjustment data BGRD, reference current adjustment data IBIASD, A1 registers setpoint of regulator voltage adjustment data VREGD respectively, B1, Refreshed (overwritten) to C1.

  As described above, in this embodiment, the temperature compensation operation is repeated at a cycle of 0.5 seconds, and the switch switching operation is repeated at a cycle of 1 second.

Figure 10 is a timing chart showing an example of the operation of the time t ₂₀ after the oscillation circuit 2 in FIG. As shown in FIG. 10, the backup mode is set at time t ₂₁ , and the voltage of the VBA terminal is the power supply voltage of the backup power supply 5 because the control signal SWCTL is at a high level.

Count signal cnt at time _{t 21} [9: 0] when is 0, the control signal EN_SENS at time _t 21 _{~t 22} temperature compensation operation is performed at a high level at time _{t 22,} the capacitance selection data CAPD It is updated from D6 to D7.

Then, immediately after the time _{t 22,} the refresh operation of the adjustment data of the power supply unit 30 is performed, the reference voltage adjustment data BGRD, reference current adjustment data IBIASD, A1 registers setpoint of regulator voltage adjustment data VREGD respectively, B1, Refreshed (overwritten) to C1.

Next, the count signal cnt at time _{t 23} [9: 0] is the becomes 64, the control signal COMPEN at time _t 23 _{~t 24} switches the switching operation is performed at a high level. Then, the voltage of the VCC terminal is lower than the threshold voltage, the control signal SWCTL at time t ₂₃ remains at a high level, the switch 50 remains off.

Next, the count signal cnt at time _{t 25:} If [9 0] is 512, the control signal EN_SENS at time _t 25 _{~t 26} temperature compensation operation is performed at a high level at time _{t 26,} capacitance selection Data CAPD is updated from D7 to D8.

Then, immediately after the time _{t 26,} the refresh operation of the adjustment data of the power supply unit 30 is performed, the reference voltage adjustment data BGRD, reference current adjustment data IBIASD, A1 registers setpoint of regulator voltage adjustment data VREGD respectively, B1, Refreshed (overwritten) to C1.

Next, the count signal cnt at time _{t 27:} If [9 0] becomes 0, the control signal EN_SENS at time _t 27 _{~t 28} temperature compensation operation is performed at a high level at time _{t 28,} capacitance selection Data CAPD is updated from D8 to D9.

Next, immediately after time t ₂₈ , the adjustment data refresh operation of the power supply unit 30 is performed, and the register setting values of the reference voltage adjustment data BGRD, the reference current adjustment data IBIASD, and the regulator voltage adjustment data VREGD are respectively A1, B1, Refreshed (overwritten) to C1.

Next, at time t ₂₉ , power supply from the main power supply 4 to the VCC terminal is resumed, but the voltage at the VBA terminal remains the power supply voltage of the backup power supply 5 because the switch 50 is off.

Next, the count signal cnt at time _{t 30} [9: 0] is the becomes 64, the control signal COMPEN at a time _t 30 _{~t 31} switch switching operation is performed at a high level. Then, the voltage of the VCC terminal is a higher than the threshold voltage, the control signal SWCTL is set to a low level at time _{t 31,} the switch 50 is turned on. As a result, the voltage at the VBA terminal becomes the power supply voltage of the main power supply 4. That is, at time _{t 31,} switches from the backup mode to the normal mode.

Next, the count signal cnt at time _{t 32:} If [9 0] is 512, the control signal EN_SENS at time _t 32 _{~t 33} temperature compensation operation is performed at a high level at time _{t 33,} capacitance selection Data CAPD is updated from D9 to D10.

Then, immediately after the time _{t 33,} the refresh operation of the adjustment data of the power supply unit 30 is performed, the reference voltage adjustment data BGRD, reference current adjustment data IBIASD, A1 registers setpoint of regulator voltage adjustment data VREGD respectively, B1, Refreshed (overwritten) to C1.

Figure 11 is a timing chart showing the detailed timing of the temperature compensation operation and the switch switching operation, corresponds to the period from the time t ₈ ~t ₁₁ in FIG.

As shown in FIG. 11, when the control signal EN_SENS becomes high level at time _{t 8,} the temperature compensation operation is started, first, A / D conversion of the temperature detection signal T_SENS is performed after a predetermined time, A / D conversion data ADO is updated. Subsequently, a memory read is performed on the nonvolatile memory 80, and the temperature compensation data TCOMPD is updated from F2 to F3 according to the A / D conversion data ADO. Subsequently, a temperature- compensation operation in accordance with the temperature compensation data TCOMPD, at time _{t 9,} together with the capacitance selection data CAPD is updated from D2 to D3, the control signal EN_SENS is the temperature compensation operation at a low level End To do. Thus, in the present embodiment, the temperature compensation operation includes the A / D conversion operation, the memory read operation, and the temperature correction calculation operation.

Then, the refresh operation of the adjustment data of the power supply unit 30 is started at time _{t 9,} the memory read is performed for the non-volatile memory 80, the reference voltage adjustment data BGRD, reference current adjustment data IBIASD, register regulator voltage adjustment data VREGD The set values are refreshed (overwritten) in order. Thus, in the present embodiment, the refresh operation includes a memory read operation and a register setting operation.

Next, when the control signal COMPEN and the control signal SWCTL is set to the high level together at time _{t 10,} the switch switching operation starts, the switch 50 is switched from ON to OFF, the voltage and the threshold voltage of the VCC terminal by the comparator 62 Is compared.

Then, on at time _{t 11} a sufficient time has elapsed for the output signal COMPO of the comparator 62 is determined, the COMPO depending on whether a high level or low level, returning the control signals STWL the low level (switch 50 Or not) is selected. Here, since COMPO is at a high level, the control signal STWL returns to a low level, and the switch 50 is switched from off to on. Further, the control signal COMPEN switch switching operation is completed at a low level at time _{t 11,} COMPO is returned to the low level. As described above, in the present embodiment, the switch switching operation includes the comparison operation between the voltage at the VCC terminal and the threshold voltage, and the ON / OFF selection operation of the switch 50 according to the comparison result.

  In the present embodiment described above, the temperature compensation operation is performed in synchronization with the maximum frequency of 32.768 kHz, so that the current consumption is very large, and the temperature compensation operation is the boost state where the current consumption is also very large, or If it overlaps with the timing of switching from the boost state in which the power supply voltage fluctuates to the normal state, the temperature compensation data TCOMP may be damaged, and the error may occur in the temperature compensation operation. Therefore, in the present embodiment, the temperature compensation operation is started after the boost state is changed to the normal state. Therefore, according to the present embodiment, it is possible to reduce the possibility that the temperature compensation operation is erroneous, and therefore it is possible to reduce the possibility that the accuracy of the output frequency of the temperature compensated oscillation circuit 10 is lowered.

  In the present embodiment, the refresh operation is performed after the temperature compensation operation, and the temperature compensation operation and the refresh operation do not overlap in time. Therefore, the power supply voltage fluctuation generated in the refresh operation affects the temperature compensation operation. Therefore, the malfunction of the temperature compensation unit 14 due to the power supply voltage fluctuation can be reduced, and the possibility that the accuracy of the output frequency of the temperature compensated oscillation circuit 10 is lowered can be reduced. Further, since the adjustment data of the power supply unit 30 stored in the nonvolatile memory is periodically read out and set in each setting register in the register unit 28, it is ensured that the data in each setting register is damaged. Can be recovered.

In the present embodiment, the temperature compensation operation is performed in synchronization with the maximum frequency of 32.768 kHz, so that the current consumption is very large, and the temperature compensation oscillation circuit 10 (temperature compensation unit 14) of the temperature compensation operation is accompanied by the switch switching operation. If the timing at which the power supply voltage fluctuates (time t ₁₀ , t ₁₁ , t _{17 in} FIG. 9 or time t _{31 in} FIG. 10, etc.) overlaps the temperature compensation operation period, the temperature compensation data TCOMP will be damaged, etc. May cause errors. Therefore, in this embodiment, as shown in FIGS. 8 to 11, the temperature compensation operation period and the switch switching operation period do not overlap each other. That is, according to the present embodiment, since the switch 50 and the power supply monitoring circuit 60 are not operated during the operation of the temperature compensation unit 14, the operation of the temperature compensation unit 14 is the power supply voltage accompanying the operation of the switch 50 and the power supply monitoring circuit 60. Since it is not affected by fluctuations, it is possible to reduce malfunctions of the temperature compensation unit 14 due to fluctuations in the power supply voltage and to reduce the possibility that the accuracy of the output frequency of the temperature compensated oscillation circuit 10 will be lowered.

In the present embodiment, after the oscillation circuit 2 is powered on, the switch switching operation is started when the count signal cnt [9: 0] becomes 64, and then when the count signal cnt [9: 0] becomes 512. Since the temperature compensation operation is started, the temperature compensation operation is performed after the switch switching operation is performed first after the oscillation circuit 2 is started. Therefore, according to the present embodiment, the power supply voltage supplied to the temperature compensation unit 14 before the operation of the temperature compensation unit 14 can be maintained in a more stable state. Therefore, the temperature compensation unit 14 that consumes a large amount of power during operation can be operated in a more stable state, and malfunctions of the temperature compensation unit 14 can be reduced. Therefore, the oscillation circuit 2 with good frequency stability can be configured.

In the present embodiment, the timing at which the time measuring unit 70 updates the time information (at the falling edge of the 1 Hz clock) is such that the circuit operates most, so the through current from the power supply to the ground is maximized. When is switched, there is a possibility that the timer unit 70 or a circuit sharing the power source with the timer unit 70 may cause a malfunction. Therefore, in the present embodiment, the switch switching operation is not performed during the operation of the time measuring unit (time t ₈ and t _{14 in} FIG. 9, time t ₂₁ and t _{27 in} FIG. 10, etc.). Therefore, according to the present embodiment, since the timing unit 70 is not affected by the power supply voltage fluctuation caused by the switch switching operation, it is possible to reduce the possibility of a malfunction of the timing due to the power supply voltage fluctuation. It is possible to reduce the possibility that the accuracy and the like of the time information output from will decrease.

2. Oscillator FIG. 12 is a diagram illustrating a configuration example of the oscillator according to the present embodiment. 12, the same components as those in FIG. 1 are denoted by the same reference numerals. The oscillator 200 according to the present embodiment includes the vibrator 3 and the oscillation circuit 2 that oscillates the vibrator 3. Further, the oscillator 200 of this embodiment may include the limiting resistor 6 and the backup power source 5.

  The configuration of the oscillation circuit 2 is the same as that in FIG. Note that the oscillation circuit 2 may have a configuration in which some of the elements in FIG. 12 are omitted or changed, or other elements are added.

  According to the oscillator 200 of this embodiment, the same effect as that of the real-time clock 1 of the above embodiment can be obtained.

3. Electronic Device FIG. 13 is a functional block diagram of the electronic device of the present embodiment. FIG. 14 is a diagram illustrating an example of the appearance of a smartphone that is an example of the electronic apparatus of the present embodiment.

  The electronic apparatus 300 according to the present embodiment includes a real-time clock 310, a CPU (Central Processing Unit) 320, an operation unit 330, a ROM (Read Only Memory) 340, a RAM (Random Access Memory) 350, a communication unit 360, a display unit 370, a main unit. A power source 380 is included. Note that the electronic device of the present embodiment may be configured such that some of the components (each unit) in FIG. 13 are omitted or changed, or other components are added.

  The real time clock 310 includes an oscillation circuit 312 (an example of an oscillation circuit), a vibrator 314, and a backup power source 316. The oscillation circuit 312 oscillates the vibrator 314 to generate a clock signal, and generates time information based on the clock signal. The backup power supply 316 supplies power to the VBA terminal of the oscillation circuit 312.

  The main power supply 380 supplies power to the VCC terminal of the oscillation circuit 312. The main power supply 380 also supplies power to the CPU 320.

  The oscillation circuit 312 operates using the voltage at the VCC terminal as the power supply voltage when the voltage at the VCC terminal is equal to or higher than the threshold voltage, and the voltage at the VBA terminal when the voltage at the VCC terminal is lower than the threshold voltage. Operates as power supply voltage.

The CPU 320 performs various calculation processes and control processes in accordance with programs stored in the ROM 340 and the like. Specifically, the CPU 320 performs various setting processing for the oscillation circuit 312, processing for reading time information from the oscillation circuit 312, various processing according to an operation signal from the operation unit 330, and data communication with an external device. Processing for controlling the communication unit 360, processing for transmitting a display signal for displaying various types of information (such as time information read from the oscillation circuit 312) on the display unit 370, and the like are performed.

  The operation unit 330 is an input device including operation keys, button switches, and the like, and outputs an operation signal corresponding to an operation by the user to the CPU 320.

  The ROM 340 stores programs, data, and the like for the CPU 320 to perform various calculation processes and control processes.

  The RAM 350 is used as a work area of the CPU 320, and temporarily stores programs and data read from the ROM 340, data input from the operation unit 330, calculation results executed by the CPU 320 according to various programs, and the like.

  The communication unit 360 performs various controls for establishing data communication between the CPU 320 and an external device.

  The display unit 370 is a display device configured by an LCD (Liquid Crystal Display) or the like, and displays various types of information based on a display signal input from the CPU 320. The display unit 370 may be provided with a touch panel that functions as the operation unit 330.

  Realizing a highly reliable electronic device by applying, for example, the real-time clock 1 of the above-described embodiment as the real-time clock 310, or by applying, for example, the oscillation circuit 2 of the above-described embodiment as the oscillation circuit 312. Can do. Note that the electronic device 300 of the present embodiment may use an oscillator instead of the real-time clock 310, and for example, the oscillator 200 of the above-described embodiment can be applied as the oscillator.

  Various electronic devices can be considered as such an electronic device 300, for example, a personal computer (for example, a mobile personal computer, a laptop personal computer, a tablet personal computer), a mobile terminal such as a smartphone or a mobile phone, Digital still cameras, inkjet discharge devices (for example, inkjet printers), storage area network devices such as routers and switches, local area network devices, mobile terminal base station devices, televisions, video cameras, video recorders, car navigation devices, Real-time clock device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game machine, game controller, word processor , Workstations, videophones, crime prevention TV monitors, electronic binoculars, POS terminals, medical equipment (eg, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiogram measuring devices, ultrasonic diagnostic devices, electronic endoscopes), fish detectors, Examples include various measuring devices, instruments (for example, vehicles, aircraft, and ship instruments), flight simulators, head mounted displays, motion traces, motion tracking, motion controllers, PDR (pedestrian position and orientation measurement), and the like.

4). FIG. 15 is a diagram (top view) illustrating an example of the moving object according to the present embodiment. A moving body 400 shown in FIG. 15 includes controllers 420, 430, and 440 that perform various controls such as a real-time clock 410, an engine system, a brake system, and a keyless entry system, a battery 450, and a backup battery 460. . Note that the mobile body of the present embodiment may have a configuration in which some of the components (each unit) in FIG. 15 are omitted or other components are added.

  The real-time clock 410 includes an oscillation circuit (not shown) (an example of an oscillation circuit), and the battery 450 supplies power to the VCC terminal of the oscillation circuit. The backup battery 460 supplies power to the VBA terminal of the oscillation circuit.

  This oscillation circuit outputs the voltage at the VCC terminal to the VOUT terminal when the voltage at the VCC terminal is equal to or higher than the threshold voltage, and the voltage at the VBA terminal when the voltage at the VCC terminal is lower than the threshold voltage. Output to the VOUT terminal.

  Power is supplied to the controllers 420, 430, and 440 from the main power source or the backup power source via the VOUT terminal of the oscillation circuit.

  By applying, for example, the real-time clock 1 of the above-described embodiment as the real-time clock 410, or by applying, for example, the oscillation circuit 2 of the above-described embodiment as an oscillation circuit, a highly reliable moving body can be realized. it can. Note that the moving body 400 of this embodiment may use an oscillator instead of the real-time clock 410, and for example, the oscillator 200 of the above-described embodiment can be applied as the oscillator.

  As such a moving body 400, various moving bodies can be considered, and examples thereof include automobiles (including electric automobiles), aircraft such as jets and helicopters, ships, rockets, and artificial satellites.

5. The present invention is not limited to this embodiment, and various modifications can be made within the scope of the present invention.

  For example, in the above embodiment, after the oscillation circuit 2 is powered on, the switch switching operation is started when the count signal cnt [9: 0] becomes 64, and then the count signal cnt [9: 0] becomes 512. Since the temperature compensation operation is started, the temperature compensation operation is performed after the switch switching operation is performed first after the oscillation circuit 2 is started, but the temperature compensation operation is performed first. After that, it may be modified so that the switch switching operation is performed.

  In the flowchart of FIG. 4, for example, it is determined in step S18 whether the count signal cnt [9: 0] is 100 or 612, and in step S24, it is determined whether the count signal cnt [9: 0] is 164. Thus, after the oscillation circuit 2 is turned on, the temperature compensation operation is started when the count signal cnt [9: 0] becomes 100, and then the count signal cnt [9: 0] becomes 164. Sometimes a switch change operation is started. That is, the switch switching operation is performed after the temperature compensation operation is performed first after the oscillation circuit 2 is started.

  In this way, the output frequency of the temperature compensated oscillation circuit 10 is in a state in which the temperature is compensated before the switch switching operation is performed, and a circuit such as the time measuring unit 70 that operates based on the output signal of the temperature compensated oscillation circuit 10 is provided. The startup time required for stabilization can be shortened.

  Further, for example, in the above embodiment, the cycle of the temperature compensation operation and the refresh operation is fixed to 0.5 seconds, but the cycle of the temperature compensation operation and the refresh operation can be variably set by register setting or the like. Also good. Similarly, in the above embodiment, the cycle of the switch switching operation is fixed to 1 second, but the cycle of the switch switching operation may be variably set by register setting or the like.

  Further, for example, in the above embodiment, the time for one switch switching operation is fixed to 2 ms, but the switch switching operation time may be variably set by register setting or the like.

  Further, for example, in the above embodiment, the oscillation unit 12 of the temperature compensated oscillation circuit 10 includes a variable capacitance element (variable capacitance diode) instead of the variable capacitance circuits 124 and 125, and the temperature compensation unit 14 responds to the temperature detection signal T_SENS. It may be modified to include a circuit for generating a voltage applied to the variable capacitance element (variable capacitance diode).

  Further, for example, in the above embodiment, the temperature compensation operation may be modified so as to include an operation of writing temperature compensation data in the nonvolatile memory 80. For example, the control unit 20 may further perform (refresh) processing for writing the temperature compensation data TCOMPD read from the nonvolatile memory 80 into the nonvolatile memory 80. Further, for example, the control unit 20 may calculate temperature compensation data corresponding to the A / D conversion data ADO and write the temperature compensation data in the nonvolatile memory 80.

  Further, for example, in the above embodiment, the switch 50 and the power supply monitoring circuit 60 select at least one of the main power supply 4 and the backup power supply 5 to control the power supply to the power supply unit 30. You may deform | transform so that the power supply to the power supply part 30 may be controlled by selecting at least one of the above power supplies.

  In the above embodiment, as an example of the “compensation unit” or “compensation unit” in the present invention, the temperature compensation unit 14 that performs the temperature compensation operation of the oscillation unit 12 has been described as an example, but the “compensation unit” in the present invention. Alternatively, the “compensation unit” may perform a compensation operation other than the temperature compensation operation of the oscillation unit 12 or perform a compensation operation of a circuit other than the oscillation unit 12 (for example, a compensation operation of the output voltage of the regulator 34). Also good.

  This embodiment and each modification mentioned above are examples, Comprising: It is not necessarily limited to these. For example, it is also possible to combine this embodiment and each modification suitably.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

1 real time clock, 2 oscillation circuit, 3 oscillator, 4 main power supply, 5 backup power supply, 6 limiting resistor, 8 CPU, 10 temperature compensation oscillation circuit, 12 oscillation unit, 14 temperature compensation unit, 20 control unit, 22 frequency divider circuit , 24 Timing generation unit, 26 Memory control unit, 28 Register unit, 30 Power supply unit, 32 Reference power supply circuit, 34 Regulator, 36 Temperature sensor, 40 Power-on reset circuit, 50 Switch, 60 Power supply monitoring circuit, 62 Comparator, 64 Switch circuit, 66 resistor, 68 resistor, 70
Timekeeping unit, 80 non-volatile memory, 90 serial interface (I / F) circuit, 121 inverter circuit, 123 resistor, 123 resistor, 124 variable capacitance circuit, 125 variable capacitance circuit, 142 register, 144 arithmetic circuit, 146 A / D conversion 200, oscillator, 300 electronic device, 310 real-time clock, 312 oscillation circuit, 314 oscillator, 316 backup power supply, 320 CPU, 330 operation unit, 340
ROM, 350 RAM, 360 communication unit, 370 display unit, 380 main power supply, 4
00 Mobile, 410 Real-time clock, 420, 430, 440 Controller, 450 battery, 460 Backup battery

Claims (13)

Compensation means;
Oscillating means compensated by a signal from the compensating means;
First power supply means for supplying power to the oscillation means;
After the power is turned on, the first power supply means is set to the first state, and after the first power supply means is set to the first state, the first power supply means is set to the second state, and And an oscillating circuit comprising: a control unit that operates the compensation unit after the first power supply unit enters the second state. A storage unit storing setting information for setting the first power supply unit to the second state;
The control means includes
The oscillation circuit according to claim 1, wherein the setting information is read from the storage unit, and the first power supply unit is set to the second state.   After the operation of the compensation unit, the operation of the control unit reading the setting information from the storage unit to bring the first power supply unit into the second state and the operation of the compensation unit overlap in time. 3. The oscillation circuit according to claim 2, wherein the oscillation circuit is repeated instead.   4. The oscillation circuit according to claim 1, wherein in the first state, power supplied from the first power supply unit to the oscillation unit is larger than that in the second state. 5. A power supply switching means for selecting at least one of the plurality of second power supply means and connecting to the first power supply means;
The first power supply means further supplies power to the compensation means,
5. The oscillation circuit according to claim 1, wherein the operation of the compensation unit and the operation of the power supply switching unit do not overlap.   An oscillator comprising the oscillation circuit according to claim 1 and a vibrator.   An electronic device comprising the oscillation circuit according to claim 1 or the oscillator according to claim 6.   A moving body comprising the circuit for oscillation according to any one of claims 1 to 5 or the oscillator according to claim 6. An oscillation circuit control method comprising: an oscillation unit to which an oscillator is connected; a power supply unit that supplies power to the oscillation unit; and a compensation unit.
After turning on the power, the power supply unit is set to the first state,
After the power supply unit is in the first state, the power supply unit is in the second state,
A control method of an oscillation circuit, wherein the compensation unit is operated after the power supply unit is set to the second state. The oscillation circuit further includes a storage unit that stores setting information for setting the power supply unit to the second state,
10. The method of controlling an oscillation circuit according to claim 9, wherein after the power supply unit is in the first state, the setting information is read from the storage unit and the power supply unit is set to the second state. 11.   After the operation of the compensation unit, the setting information is read from the storage unit and the operation of setting the power supply unit in the second state and the operation of the compensation unit are repeated without overlapping in time. The method for controlling an oscillation circuit according to claim 10.   12. The method of controlling an oscillation circuit according to claim 9, wherein in the first state, power supplied from the power supply unit to the oscillation unit is larger than that in the second state. The oscillation circuit is
A power switching unit that selects at least one of a plurality of power supply sources and connects to the power source;
The power supply unit further supplies power to the compensation unit,
The method for controlling an oscillation circuit according to claim 9, wherein the operation of the compensation unit and the operation of the power supply switching unit do not overlap.

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