JP2011166439A - Semiconductor integrated circuit device and temperature correction method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit device and a temperature correction method thereof in which the temperature correction of a reference signal can be performed by a simple constitution. <P>SOLUTION: Values of reference signals outputted from signal generating means 21, 22 of a semiconductor integrated circuit are measured at three different temperatures, at least, and correction control data are determined which are applied to trimming means of the signal generating means for bringing the measured values of the reference signals to a target value. Correction control data at temperatures within a use temperature range of the semiconductor integrated circuit are then calculated from the correction control data which are obtained at the three temperatures to be applied to the trimming means of the signal generating means. The correction control data of the temperatures are stored in a storage means 56 correspondingly to the temperatures, the correction control data to be applied to the trimming means of the signal generating means are read from the storage means in accordance with a temperature detected by a temperature detecting means 23 of the semiconductor integrated circuit, and set to the trimming means of the signal generating means, thereby performing the temperature correction of the reference signals outputted from the signal generating means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor integrated circuit device having signal generation means for outputting a reference signal and a temperature correction method thereof.

  In recent years, a battery pack using a secondary battery such as a lithium ion battery is mounted on a mobile device such as a mobile phone or a digital camera. In general, it is difficult for a lithium ion battery to detect the remaining battery level from its voltage. For this reason, a method has been adopted in which the charge / discharge current of the battery is detected by a microcomputer or the like, and the remaining battery charge is measured by integrating the detected charge / discharge current.

  In this way, the battery monitoring module that measures the remaining battery level of the lithium ion battery in the battery pack includes an analog circuit such as a high-precision A / D conversion circuit and a digital circuit such as a CPU or timer that integrates the measured current value. It is mounted on one semiconductor integrated circuit device.

  The battery monitoring module includes an oscillation circuit that supplies a clock to the digital circuit and a reference voltage circuit that supplies a reference voltage to the analog circuit. When the environmental temperature changes, the oscillation frequency changes in the oscillation circuit, and the reference voltage changes in the reference voltage circuit. In the conventional battery monitoring module, the temperature correction circuit unit is individually designed inside the oscillation circuit and the reference voltage circuit, and the temperature correction of each of the oscillation circuit and the reference voltage circuit is performed.

  In addition, there is known a technique for improving the stability of the oscillation circuit and stabilizing the current consumption by controlling the power supply by following the temperature fluctuation in the oscillation frequency / power supply voltage characteristics of the oscillation means (for example, Patent Document 1).

JP-A 63-169828

  When the oscillation circuit and the reference voltage circuit are mounted on one semiconductor integrated circuit device as in the battery monitoring module, the temperature correction circuit unit is provided with a temperature correction circuit unit in each of the oscillation circuit and the reference voltage circuit. Therefore, it takes time to design each of the oscillation circuit including the reference voltage circuit and the reference voltage circuit including the temperature correction circuit unit, and the temperature correction circuit unit of each of the oscillation circuit and the reference voltage circuit is increased in size.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a semiconductor integrated circuit device capable of correcting the temperature of a reference signal with a simple configuration and a temperature correction method thereof.

A temperature correction method according to an embodiment of the present invention includes:
The value of the reference signal output from the signal generating means (21, 22) of the semiconductor integrated circuit is measured at at least three different temperatures, and the signal generating means (21, 22) is used to set the measured value of the reference signal as a target value. ) To obtain the correction control data to be given to the trimming means (27),
From the correction control data given to the trimming means (27) of the signal generating means (21, 22) obtained at the three temperatures, correction control data for each temperature in the operating temperature range of the semiconductor integrated circuit is calculated, and each temperature is calculated. Is stored in the storage means (56) in association with the temperature,
According to the temperature detected by the temperature detecting means (23) of the semiconductor integrated circuit, correction control data to be given to the trimming means (27) of the signal generating means (21, 22) is read from the storage means (56) and the signal is read. Set to the trimming means (27) of the generating means (21, 22),
The temperature of the reference signal output from the signal generating means (21, 22) is corrected.

  Preferably, the correction control data read from the storage means (56) is periodically set in the trimming means (27) of the signal generating means (21, 22).

  Preferably, the correction control data read from the storage means (56) is set in the trimming means (27) of the signal generation means (21, 22) based on the temperature detected by the temperature detection means (23). When it changes beyond

A semiconductor integrated circuit device according to an embodiment of the present invention includes:
A semiconductor integrated circuit device having signal generating means (21, 22) for outputting a reference signal,
Trimming means (27) of the signal generating means (21, 22) for changing the value of the reference signal output from the signal generating means (21, 22) according to correction control data;
Storage means (56) for storing correction control data to be given to the trimming means (27) of the signal generating means (21, 22) at each temperature in the operating temperature range of the semiconductor integrated circuit in association with the temperature;
Temperature detecting means (23) for detecting the environmental temperature of the semiconductor integrated circuit;
According to the temperature detected by the temperature detecting means (23) of the semiconductor integrated circuit, correction control data to be given to the trimming means (27) of the signal generating means (21, 22) is read from the storage means (56) and the signal is read. Setting means (11) for setting the trimming means (27) of the generating means (21, 22).

  Preferably, the setting means (11) periodically sets the correction control data read from the storage means (56) to the trimming means (27) of the signal generation means (21, 22).

  Preferably, the setting means (11) sets the correction control data read from the storage means (56) in the trimming means (27) of the signal generation means (21, 22) to the temperature detection means (23). This is performed when the temperature detected in step) changes beyond the threshold.

  Preferably, the signal generating means is an oscillation circuit (21), and the value of the reference signal is an oscillation frequency.

  Preferably, the signal generating means is a reference voltage circuit (22), and the value of the reference signal is a reference voltage.

  Note that the reference numerals in the parentheses are given for ease of understanding, are merely examples, and are not limited to the illustrated modes.

  According to the present invention, the temperature correction of the reference signal can be performed with a simple configuration.

It is a block diagram of one Embodiment of a battery pack. It is a circuit block diagram of a part of trimming circuit. FIG. 6 is a reference voltage / temperature characteristic diagram of a reference voltage circuit. It is an oscillation frequency and temperature characteristic diagram of an oscillation circuit. It is a block diagram at the time of registering control data. It is a flowchart of one Embodiment of the control voltage registration process for oscillator circuits. It is a flowchart of one Embodiment of the control voltage registration process for reference voltage circuits. It is a flowchart of one Embodiment of the temperature correction process of an oscillation frequency and a reference voltage. It is a timing chart at the time of power-on.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Battery pack>
FIG. 1 shows a configuration diagram of an embodiment of a battery pack to which a battery monitoring module which is a semiconductor integrated circuit device of the present invention is applied. In FIG. 1, the battery monitoring module 10 is roughly composed of a digital part and an analog part.

  In the digital unit, a CPU 11, a ROM 12, a RAM 13, a nonvolatile memory (EEPROM) 14, a communication interface (I / F) 15, a timer 16, and the like are provided. The CPU 11, ROM 12, RAM 13, nonvolatile memory 14, communication interface (I / F) 15, and timer 16 are connected to each other via an internal bus.

  The analog portion includes an oscillation circuit 21, a reference voltage circuit 22, a temperature detection circuit 23, a voltage detection circuit 24, a current detection circuit 25, a charge / discharge protection circuit 26, a trimming circuit 27, an AD converter (ADC) 28, a power-on A reset circuit 29 and the like are provided.

  The battery monitoring module 10 is housed in a casing together with a lithium ion battery 30, a current detection resistor R1, and MOS transistors M1 and M2 serving as protection switches to form a battery pack 35. The battery pack 35 to which the lithium ion battery 30 is connected is connected to the portable device 40 via the terminals 10 a, 10 b, and 10 c of the battery monitoring module 10, and supplies power to the portable device 40 from the battery pack 35.

  In the battery monitoring module 10, the CPU 11 executes a program stored in the ROM 12 to control the entire battery monitoring module 10, and integrates temperature correction processing, voltage calculation processing, current calculation processing, and battery charge / discharge current. The process for managing the remaining battery level, the charge / discharge control process, etc. are executed. At this time, the RAM 13 is used as a work area. The nonvolatile memory 14 stores control data that is retained even when the power is turned off.

  The communication interface 15 is connected to the portable device 40 via the terminal 10 c and performs communication between the CPU 11 and the CPU of the portable device 40. The timer 16 counts the system clock, and the count value is referred to by the CPU 11.

  The oscillation circuit 21 as a signal generating means is supplied with a control voltage from a trimming circuit 27, and has a VCO (voltage controlled oscillator) that varies the oscillation frequency in accordance with the control voltage. The oscillation circuit 21 generates a clock based on the oscillation frequency of the VCO, supplies it as a reference signal to the CPU 11, the AD converter 28, etc., and outputs it from the terminal 10d.

  The reference voltage circuit 22 as a signal generating means is supplied with a control voltage from the trimming circuit 27, and the reference voltage circuit 22 varies and outputs the reference voltage according to the control voltage. The reference voltage is supplied as a reference signal to the AD converter 28 and the like and is output from the terminal 10e.

  The temperature detection circuit 23 detects the environmental temperature and supplies an analog temperature detection signal to the AD converter 28.

  The voltage detection circuit 24 detects the voltage across the lithium ion battery 30 externally attached to the battery monitoring module 10 and supplies an analog voltage detection signal to the AD converter 28.

  The current detection circuit 25 detects the voltage across the resistor R1 for current detection externally attached to the battery monitoring module 10 and supplies an analog current detection signal to the AD converter 28.

  The AD converter 28 has a built-in multiplexer, and selects analog temperature detection signal, analog voltage detection signal, and analog current detection signal in order, and performs analog / digital conversion to detect temperature detection signal, voltage detection signal, and current detection. Digitize each signal. In this analog / digital conversion, the reference voltage from the reference voltage circuit 22 is used. The temperature detection value, voltage detection value, and current detection value digitized by the AD converter 28 are supplied to the CPU 11.

  The power-on reset circuit 29 detects that the power supplied from the lithium ion battery 30 has started up, generates a reset signal, and supplies the reset signal to each circuit unit in the battery monitoring module 10.

<Trimming circuit>
FIG. 2 shows a partial circuit configuration diagram of the trimming circuit 27. This circuit shows one of a circuit for generating a control voltage for the oscillation circuit 21 and a circuit for generating a control voltage for the reference voltage circuit 22.

  In FIG. 2, an operational amplifier 51 is supplied with a constant voltage V1 from a constant voltage source 52 at an inverting input terminal. The non-inverting input terminal of the operational amplifier 51 is connected to the intermediate terminal of the three-terminal resistor 53. The output of the operational amplifier 51 is output as a control voltage from the terminal 54 and supplied to one end of the three-terminal resistor 53. The other end of the three-terminal resistor 53 is set to a constant potential (for example, ground).

  The three-terminal resistor 53 functions as a three-terminal sliding resistor by changing the connection position (voltage extraction position) of the intermediate terminal according to the correction control data supplied from the trimming register 55. As a result, the voltage fed back from the output terminal of the operational amplifier 51 to the non-inverting input terminal is changed according to the correction control data, and the output voltage from the terminal 54 changes.

  In the nonvolatile memory 56, for example, control data whose value gradually increases is written in advance at addresses 0 to n. In addition, correction control data is written in the nonvolatile memory 56 at an address (address n and later) according to the environmental temperature.

  The nonvolatile memory 56 is supplied with a read address from the CPU 11 via the terminal 57, whereby correction control data read from the nonvolatile memory 56 is set in the trimming register 55 and supplied from the trimming register 55 to the three-terminal resistor 53. Is done. That is, the control voltage output from the terminal 54 is changed by the control from the CPU 11.

<Temperature characteristics>
FIG. 3 is a reference voltage / temperature characteristic diagram of the reference voltage circuit 22. If the control voltage supplied from the trimming circuit 27 is constant, the reference voltage circuit 22 has a maximum value in the vicinity of 10 ° C. The reference voltage decreases as the environmental temperature decreases from 10 ° C. The reference voltage decreases as the temperature rises from 10 ° C., and has a temperature characteristic as shown by a solid line.

  FIG. 4 shows an oscillation frequency / temperature characteristic diagram of the oscillation circuit 21. If the control voltage supplied from the trimming circuit 27 is constant, the oscillation circuit 21 has a higher oscillation frequency as the environmental temperature is lowered, and a lower oscillation frequency as the environmental temperature is raised. have.

<Control voltage registration process>
FIG. 5 shows a configuration diagram when the correction control data is registered in the nonvolatile memory 56 of the trimming circuit 27 in the manufacturing process of the battery pack 35. 5, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. In FIG. 5, the measuring device 60 has a function of measuring a signal frequency and a function of measuring a signal voltage. The measuring device 60 is connected to the terminals 10 d and 10 e of the battery monitoring module 10, and the measuring device 60 and the communication circuit 65 are connected by a communication line 61.

  A clock output from the terminal 10 d of the battery monitoring module 10 is supplied to the measuring device 60, and a reference voltage output from the terminal 10 e of the battery monitoring module 10 is supplied to the measuring device 60. The control instruction output by the measuring device 60 is supplied to the communication interface 15 of the battery monitoring module 10 via the communication circuit 65. A power supply 66 is connected instead of the lithium ion battery 30.

<Registering control voltage for oscillation circuit>
FIG. 6 shows a flowchart of an embodiment of the control voltage registration process for the oscillation circuit. In this process, the environmental temperature of the battery monitoring module 10 is changed n times (n is a number of 3 or more, and the environmental temperature is, for example, −40 ° C., 0 ° C., + 80 ° C.).

  In FIG. 6, in step S <b> 11, the measuring apparatus 60 sets an initial value for the trimming register 55 that controls the oscillation frequency in the CPU 11 via the communication circuit 65 and the communication interface 15. Next, in steps S12 to S13, the process waits until the environmental temperature matches the measured temperature. In step S14, the measuring device 60 measures the oscillation frequency of the output of the oscillation circuit 21 supplied from the terminal 10d, and in FIG. Compared with the target value indicated by the alternate long and short dash line, it is determined whether or not both match. If the oscillation frequency does not match the target value, a change instruction including a difference between the direction in which the oscillation frequency is the target value and the frequency is supplied to the CPU 11 in step S16. Thus, the CPU 11 sets a value corresponding to the change instruction in the trimming register 55, and the changed control voltage is supplied from the trimming circuit 27 to the oscillation circuit 21. If step S16 is performed, it will progress to step S14.

  By repeating the above steps S14 to S16, the oscillation frequency matches the target value. When the oscillation frequency matches the target value, the process proceeds from step S15 to step S17. In step S <b> 17, the measuring device 60 corrects the control data set in the trimming register 55 at this time to the address corresponding to the temperature detection value of the nonvolatile memory 56 of the trimming circuit 27 for the oscillation circuit 21 with respect to the CPU 11. Instructs to write as control data.

  Next, in step S18, it is determined whether or not the environmental temperature has been changed n times. If the environmental temperature has not been changed n times, the environmental temperature is changed in step S19 and the process proceeds to step S13. Repeat S19. If the environmental temperature has already been changed n times, the process proceeds to step S20.

  In step S20, the measurement apparatus 60 instructs the CPU 11 to perform setting processing via the communication circuit 65 and the communication interface 15. From the correction control data for three or more environmental temperatures stored in the nonvolatile memory 56 for the oscillation circuit 21, the CPU 11 shows the operating temperature range (for example, −40 ° C. to + 120 ° C.) of the battery monitoring module 10 in FIG. Correction control data having the oscillation frequency as a target value at each environmental temperature indicated by a one-dot chain line is approximately calculated, and the calculated correction control data at each temperature corresponds to each environmental temperature of the nonvolatile memory 56 for the oscillation circuit 21. Write to the address and end this process.

<Control voltage registration for reference voltage circuit>
FIG. 7 shows a flowchart of an embodiment of the control voltage registration process for the reference voltage circuit. In this process, the environmental temperature of the battery monitoring module 10 is changed n times (n is a number of 3 or more, and the environmental temperature is, for example, −40 ° C., 0 ° C., + 80 ° C.).

  In FIG. 7, in step S <b> 21, the measuring device 60 sets an initial value for the trimming register 55 that controls the reference voltage in the CPU 11 via the communication circuit 65 and the communication interface 15. Next, in steps S22 to S23, the process waits until the ambient temperature matches the measured temperature. In step S24, the measuring device 60 measures the reference voltage supplied from the terminal 10e, and in step S25, the target indicated by the one-dot chain line in FIG. Compare with the value to determine whether or not they match. If the reference voltage does not match the target value, a change instruction including a difference between the direction in which the reference voltage is set as the target value and the voltage is supplied to the CPU 11 in step S26. As a result, the CPU 11 sets a value corresponding to the change instruction in the trimming register 55, and the changed control voltage is supplied from the trimming circuit 27 to the reference voltage circuit 22. If step S26 is performed, it will progress to step S24.

  By repeating the above steps S24 to S26, the reference voltage matches the target value. When the reference voltage matches the target value, the process proceeds from step S25 to step S27. In step S27, the measuring apparatus 60 instructs the CPU 11 to set the control data set in the trimming register 55 at this time to an address corresponding to the temperature detection value of the nonvolatile memory 56 of the trimming circuit 27 for the reference voltage circuit 22. An instruction to write as correction control data is given.

  Next, in step S28, it is determined whether or not the environmental temperature has been changed n times. If the environmental temperature has not been changed n times, the environmental temperature is changed in step S29 and the process proceeds to step S23. Repeat S29. If the environmental temperature has already been changed n times, the process proceeds to step S30.

  In step S20, the measurement apparatus 60 instructs the CPU 11 to perform setting processing via the communication circuit 65 and the communication interface 15. From the correction control data for three or more environmental temperatures stored in the non-volatile memory 56 for the reference voltage circuit 22, the CPU 11 shows the operating temperature range (for example, −40 ° C. to + 120 ° C.) of the battery monitoring module 10 in FIG. The correction control data having the reference voltage as the target value at each environmental temperature indicated by a one-dot chain line is approximately calculated, and the calculated correction control data at each temperature is set to each environmental temperature of the nonvolatile memory 56 for the reference voltage circuit 22. Write to the corresponding address, and the process is terminated.

<Temperature correction>
FIG. 8 shows a flowchart of an embodiment of the temperature correction process of the oscillation frequency and the reference voltage. This process is executed when the power is turned on, for a certain period (for example, several minutes), or when the temperature detection value of the temperature detection circuit 23 changes beyond a preset threshold value.

  In FIG. 8, in step S <b> 31, the CPU 11 reads the temperature detection value detected by the temperature detection circuit 23 and supplied from the AD converter 28. In step S <b> 32, the CPU 11 reads the correction control data from the address corresponding to the detected temperature value in the nonvolatile memory 56 of the trimming circuit 27 for the oscillation circuit 21 and sets it in the trimming register 55 of the trimming circuit 27 for the oscillation circuit 21.

  In step S33, the CPU 11 reads the correction control data from the address corresponding to the detected temperature value in the nonvolatile memory 56 of the trimming circuit 27 for the reference voltage circuit 22 and sets it in the trimming register 55 of the trimming circuit 27 for the reference voltage circuit 22. To do. As a result, the oscillation frequency output from the oscillation circuit 21 becomes a predetermined value after temperature correction, and the reference voltage output from the reference voltage circuit 22 becomes a predetermined value after temperature correction.

<Operation at power-on>
FIG. 9 shows a timing chart when the power is turned on. The power supply shown in FIG. 9A is turned on. As a result, the power-on reset circuit 29 generates a reset signal shown in FIG. 9B that instructs resetting at a high level and reset cancellation at a low level, and supplies the reset signal to each circuit unit of the battery monitoring module 10. Further, when the power is turned on, the oscillation circuit 21 starts oscillation and outputs a clock shown in FIG.

  By releasing the reset, the timer 16 counts the oscillation stabilization period shown in FIG. 9C using the output clock of the oscillation circuit 21. The CPU 11 is notified of the oscillation stabilization period from the timer 16 and executes the processing of FIG. 8 after this oscillation stabilization period. As a result, the oscillation frequency output from the oscillation circuit 21 becomes a predetermined value after temperature correction, and the reference voltage output from the reference voltage circuit 22 becomes a predetermined value after temperature correction.

  In the above embodiment, the nonvolatile memory 56 is provided in the trimming circuit 27. However, the nonvolatile memory 14 may be used instead of the nonvolatile memory 56, and is not limited to the above embodiment.

10 Battery monitoring module 11 CPU
12 ROM
13 RAM
DESCRIPTION OF SYMBOLS 14 Nonvolatile memory 15 Communication interface 16 Timer 21 Oscillation circuit 22 Reference voltage circuit 23 Temperature detection circuit 24 Voltage detection circuit 25 Current detection circuit 26 Charge / discharge protection circuit 27 Trimming circuit 28 AD converter 29 Power-on reset circuit 30 Lithium ion battery 35 Battery Pack 40 Portable device 51 Operational amplifier 52 Constant voltage source 53 Three-terminal resistance 55 Trimming register 56 Non-volatile memory 60 Measuring device 65 Communication circuit

Claims (8)

The correction control data to be applied to the trimming means of the signal generating means for measuring the value of the reference signal output from the signal generating means of the semiconductor integrated circuit at at least three different temperatures and setting the measured value of the reference signal as the target value. Seeking
The correction control data for each temperature in the operating temperature range of the semiconductor integrated circuit is calculated from the correction control data given to the trimming means of the signal generating means obtained at the three temperatures, and the correction control data for each temperature is associated with the temperature. And store it in the storage means,
According to the temperature detected by the temperature detection means of the semiconductor integrated circuit, the correction control data applied to the trimming means of the signal generation means is read from the storage means and set in the trimming means of the signal generation means,
A temperature correction method for a semiconductor integrated circuit, wherein the temperature of the reference signal output from the signal generating means is corrected. The temperature correction method according to claim 1,
Setting of the correction control data read from the storage means to the trimming means of the signal generating means is performed periodically. The temperature correction method according to claim 1,
Setting the correction control data read from the storage means to the trimming means of the signal generating means is performed when the temperature detected by the temperature detecting means changes beyond a threshold value. A semiconductor integrated circuit device having signal generating means for outputting a reference signal,
Trimming means of the signal generating means for changing the value of the reference signal output from the signal generating means according to correction control data;
Storage means for storing correction control data to be given to the trimming means of the signal generating means at each temperature in the operating temperature range of the semiconductor integrated circuit in association with the temperature;
Temperature detecting means for detecting an environmental temperature of the semiconductor integrated circuit;
Setting means for reading correction control data to be applied to the trimming means of the signal generating means from the storage means according to the temperature detected by the temperature detecting means of the semiconductor integrated circuit, and setting the trimming means of the signal generating means;
A semiconductor integrated circuit device comprising: The semiconductor integrated circuit device according to claim 4.
The semiconductor integrated circuit device according to claim 1, wherein the setting means periodically sets the correction control data read from the storage means to the trimming means of the signal generating means. The semiconductor integrated circuit device according to claim 4.
The setting means is configured to set the correction control data read from the storage means to the trimming means of the signal generation means when the temperature detected by the temperature detection means changes beyond a threshold value. Semiconductor integrated circuit device. The semiconductor integrated circuit device according to claim 5 or 6,
The semiconductor integrated circuit device, wherein the signal generating means is an oscillation circuit, and the value of the reference signal is an oscillation frequency. The semiconductor integrated circuit device according to claim 5 or 6,
The semiconductor integrated circuit device, wherein the signal generating means is a reference voltage circuit, and the value of the reference signal is a reference voltage.

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