JP2013201658A - Electronic circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem wherein a prior art has been able to reduce the power consumption of a circuit block in a standby state but unable to reduce the power consumption of an intermediate voltage generation circuit for generating a voltage supplied to the circuit block.SOLUTION: An electronic circuit has an intermediate voltage generation circuit driven by a supply voltage to output an intermediate voltage having a lower absolute value than the supply voltage; a circuit block for performing a predetermined operation; and switch means for controlling the supply of the intermediate voltage to the circuit block, and the intermediate voltage generation circuit also includes operation stopping means coordinated with the switch means. In a standby state, the switch means is turned off to reduce the power consumption of the circuit block and the power consumption of the intermediate voltage generation circuit. This can implement a reduced power consumption of the entire electronic circuit.

Description

  The present invention relates to an electronic circuit that drives a circuit block constituting an electronic circuit with an intermediate voltage generated by an intermediate voltage generation circuit, and more particularly to an electronic circuit that reduces current consumption when the circuit block is in a standby state. .

With the development of electronic devices, there is an increasing demand for low power consumption in built-in electronic circuits.
In response to such a demand, for example, a clock gating technique effective for reducing power during operation of an electronic circuit, and an MTCMOS (Multi-Threshold-Voltage Complementary-Metal Oxide-Semiconductor) technique effective for reducing leakage current. We see many proposals.

  Among them, it is said that a power gating technique that reduces the leakage current of the circuit block when the circuit block constituting the electronic circuit is in a standby state is effective.

  By the way, the standby state means a standby state by stopping the operation of the electronic circuit. Some circuit blocks constituting the electronic circuit and elements constituting the circuit block may be stopped. In any case, the circuit operation is stopped mainly for the purpose of reducing the power consumption due to the convenience of the electronic circuit itself or the electronic device in which the electronic circuit is mounted.

  Stopping circuit operation in an electronic circuit means that the electronic circuit has completely stopped operating due to power-off or the like, and the circuit operation itself that is slightly energized to the extent that the electronic circuit does not perform the specified operation. May be stopped. In the latter case, the operation of some elements or small-scale circuits constituting the electronic circuit is often limited by lowering the voltage of the power supply or reducing the amount of current flow. Such a case is called a substantial circuit operation stop.

  In addition, the substantial stop of the circuit operation is generally made, for example, by making the power supply voltage supplied to the electronic circuit lower than the threshold voltage Vth of the element constituting the electronic circuit. For example, if the power supply voltage of the electronic circuit is 1.5V in absolute value and the threshold voltage Vth of the constituent elements is 0.65V in absolute value, the power supply voltage is about 0.5V in absolute value. is there.

  The power gating technology is a technology for controlling the power supply of the circuit block. For example, the power supply wiring connected to the circuit block is controlled to be opened and closed by a switch such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect-Transistor). In the standby state, the power supply to the circuit block is cut off and the operation is stopped to reduce power consumption.

  With the recent demand for low power consumption, electronic circuits are desired to be driven with a low power supply voltage. However, when the power supply voltage drops to near the threshold voltage Vth of the MOSFETs constituting the circuit block, the operating speed may decrease. In addition, when power gating technology is used, power supply to the circuit block is not possible. There arises a problem such as an increase in leakage current due to the fact that the switch to be cut off cannot be completely turned off.

  In order to solve such a problem, a low Vth MOSFET having a threshold voltage Vth lower than that of a normal MOSFET has begun to be used for a switch used in the power gating technique.

  However, even if such an element is used, the switch for shutting off the power supply to the circuit block cannot be completely turned off at the standby time other than the operation due to the decrease of the threshold voltage Vth of the MOSFET. The leakage current of the circuit block could not be reduced.

  Therefore, a technique for reducing the leakage current in the standby state in the power gating technique has been proposed (see, for example, Patent Document 1).

FIG. 7 is a block diagram for explaining the prior art shown in Patent Document 1, which has been rewritten so that it can be easily explained without departing from the gist.
In FIG. 7, reference numeral 102 denotes a control circuit, 103 denotes a switching circuit constituted by a MOSFET having a low threshold voltage Vth, and 104 denotes a logic circuit constituted by a MOSFET having a low threshold voltage Vth. A device equipped with these is denoted by reference numeral 100. Reference numeral 101 denotes a voltage regulator that supplies a driving voltage to the logic circuit 104.

The prior art disclosed in Patent Document 1 utilizes the feature that the leakage current of the MOSFET becomes the lowest when the voltage Vgs between the gate terminal and the source terminal of the MOSFET is held at a predetermined voltage. Yes.
As shown in FIG. 7, the switching circuit 103 controlled by the control circuit 102 is provided in the supply path of the driving voltage supplied from the voltage regulator 101 to the logic circuit 104, and the logic circuit 104 is controlled by opening and closing the switching circuit 103. It switches the start and stop of the power supply to

  Specifically, when the logic circuit 104 enters the standby state, a voltage having a higher absolute value than the power supply voltage for driving the device 100 (ie, from the voltage regulator 101) is applied to the gate terminal of the MOSFET constituting the switching circuit 103. The drive voltage is applied to the MOSFET constituting the switching circuit 103 in a strong off state, so that the current path is cut off and the leakage current can be reduced even when a MOSFET having a low threshold voltage Vth is used. .

JP 2003-37494 A (page 4, FIG. 1)

  In the prior art disclosed in Patent Document 1, the driving voltage supplied from the voltage regulator 101 to the logic circuit 104 is cut off in the standby state, but the leakage current is reduced because the MOSFET constituting the switching circuit 103 is turned off. The power consumption can be reduced even in the standby state.

  However, even in this state, the voltage regulator 101 itself is not stopped. For this reason, the voltage regulator 101 itself continues to consume power even after the logic circuit 104 is stopped.

  For this reason, when the conventional technique shown in Patent Document 1 is applied to a device with large power consumption, the current consumption of the voltage regulator 101 is relatively small and can be ignored. When applied to an electronic device, the power consumption of the voltage regulator 101 cannot be ignored, and the life of the battery mounted on the small electronic device is significantly shortened.

The present invention is to solve such a problem, and stops a circuit that is operating unnecessarily in a standby state, thereby reducing the power consumption of the entire circuit system.

  In order to solve the above problems, the electronic circuit of the present invention employs the following configuration.

  An electronic circuit according to the present invention includes an intermediate voltage generating circuit that supplies a power supply voltage and outputs an intermediate voltage having an absolute value lower than the power supply voltage, a circuit block that is supplied with the intermediate voltage and performs a predetermined operation, and outputs from a control circuit Switching means for controlling the supply of the intermediate voltage to the circuit block based on the control signal, and the switching means generates an intermediate voltage in an electronic circuit that is controlled to open and close by a potential difference between the intermediate voltage and the control signal. The circuit has an operation stop means for stopping the circuit operation of the intermediate voltage generation circuit based on the control signal.

  As a result, in the standby state, the current supply path to the circuit block is cut off, reducing the power consumption in the circuit block and stopping the intermediate voltage generation circuit itself, thus reducing the overall power consumption of the electronic circuit. It can be.

  The intermediate voltage generation circuit is composed of three circuit parts, a reference voltage generation circuit part, an amplification circuit part, and an output circuit part. The reference voltage generation circuit part generates a predetermined reference voltage and amplifies it based on the reference voltage. An intermediate voltage may be generated and output by the circuit unit and the output circuit unit, and the operation stop unit may stop the supply of the power supply voltage of all three circuit units based on the control signal.

  With such a configuration, the operation of the intermediate voltage generation circuit is completely stopped, so that power consumption can be reduced.

  The intermediate voltage generation circuit is composed of three circuit parts, a reference voltage generation circuit part, an amplification circuit part, and an output circuit part. The reference voltage generation circuit part generates a predetermined reference voltage and amplifies it based on the reference voltage. The circuit unit and the output circuit unit may generate and output an intermediate voltage, and the operation stop unit may stop the supply of the power supply voltage to the amplifier circuit unit and the output circuit unit based on the control signal.

  In such a configuration, since the reference voltage generation circuit unit does not stop operating, the circuit unit consumes power somewhat, but the reference voltage is always generated, and the amplifier circuit unit and the output circuit Since the intermediate voltage can be output as soon as the unit returns from the stop, the startability of the entire electronic circuit can be improved.

  The intermediate voltage generation circuit is composed of three circuit parts, a reference voltage generation circuit part, an amplification circuit part, and an output circuit part. The reference voltage generation circuit part generates a predetermined reference voltage and amplifies it based on the reference voltage. The circuit unit and the output circuit unit may generate and output an intermediate voltage, and the operation stop unit may stop the supply of the power supply voltage to the output circuit unit based on the control signal.

  In such a configuration, since the reference voltage generation circuit unit does not stop its operation, power is consumed somewhat in this circuit unit, but the reference voltage is always generated and the output circuit unit is stopped from stopping. Since the intermediate voltage can be output immediately after returning, the startability of the entire electronic circuit can be improved.

  The intermediate voltage generation circuit is composed of three circuit parts, a reference voltage generation circuit part, an amplification circuit part, and an output circuit part. The reference voltage generation circuit part generates a predetermined reference voltage and amplifies it based on the reference voltage. An intermediate voltage is generated and output by the circuit unit and the output circuit unit, and the operation stop unit amplifies the reference voltage by limiting the amount of current supplied to the reference voltage generation circuit unit based on the control signal to zero. You may make it stop the circuit operation | movement of a circuit part and an output circuit part.

  With such a configuration, the elements constituting each circuit are not compared with the case where the circuit operation is stopped by shutting off the power supply of the three circuit units, that is, the reference voltage generation circuit unit, the amplification circuit unit, and the output circuit unit. Since it does not float, it is less likely to malfunction due to disturbances such as noise.

  The operation stop means may be a MOSFET type switch that is controlled to open and close based on a control signal.

  With such a configuration, in addition to simple switch control with a voltage signal, lower power consumption can be achieved.

  The transistors constituting the circuit block and the intermediate voltage generation circuit and the switch means may have the same threshold value.

  With such a configuration, the power consumption can be further reduced by lowering the threshold values. In addition, since it is not necessary to configure a circuit with elements having a plurality of threshold values, the manufacturing process is not complicated, an electronic circuit can be manufactured in a short time, and the cost can be reduced.

  According to the present invention, by providing an operation stop means for stopping the circuit operation of the intermediate voltage generation circuit itself in the standby state, the power consumption of the circuit block is reduced and the power consumption of the intermediate voltage generation circuit itself is also reduced. Can be reduced.

It is a functional block diagram explaining the outline | summary of the electronic circuit of this invention. FIG. 3 is a circuit diagram illustrating an intermediate voltage generation circuit according to the first embodiment. FIG. 6 is a circuit diagram illustrating an intermediate voltage generation circuit according to a first modification of the first embodiment. FIG. 6 is a circuit diagram illustrating an intermediate voltage generation circuit according to a second modification of the first embodiment. FIG. 6 is a block diagram illustrating an intermediate voltage generation circuit according to a second embodiment. FIG. 6 is a circuit diagram illustrating an intermediate voltage generation circuit according to a second embodiment. It is a block diagram explaining the prior art shown in patent document 1. FIG.

The electronic circuit according to the present invention includes an operation stopping means for stopping the operation of the intermediate voltage generating circuit in the intermediate voltage generating circuit for supplying the power supply voltage to the circuit block.
When the electronic circuit is set to the standby state, the power supply to the circuit block is cut off, and the operation of the intermediate voltage generation circuit is stopped or substantially stopped by the operation stop means.
As a result, the power consumed by the intermediate voltage generation circuit can be reduced, and the power consumption of the electronic circuit can be further reduced.

  By the way, as already explained, there are two concepts for stopping the circuit operation in the electronic circuit. The circuit operation is completely stopped by shutting off the power supply voltage or the like, and the circuit operation is substantially stopped by reducing the power supply voltage or the operating current.

  The same applies to the operation of the intermediate voltage generating circuit being stopped or substantially stopped. In the description of the embodiments described later, an example in which the circuit operation of the intermediate voltage generating circuit is completely stopped in the first embodiment. An example in which the circuit operation of the intermediate voltage generation circuit is substantially stopped in the second embodiment will be described.

Hereinafter, embodiments of the present invention will be described. First, an outline of an electronic circuit will be described, and then Example 1 will be described. The first embodiment includes a first modification and a second modification, and a total of three examples will be described. A second embodiment will be described.
In the description, the drawings are designated while referring to other drawings as appropriate. Further, the same symbols and signs used in the drawings are given to the same components. In the description, specific voltage values and the like are shown, but this is merely an example and does not limit the invention.

[Outline of electronic circuit: Fig. 1]
First, the outline of the electronic circuit will be described with reference to the functional block diagram of FIG.
In FIG. 1, 21 is a circuit block to be operated, 31 is a switch means for controlling power supply to the circuit block 21, and 41 is an intermediate for generating an intermediate voltage VREG for power supply to the switch means 31. This is a voltage generation circuit. Reference numeral 50 denotes an operation stop means for substantially stopping the circuit operation by stopping all or part of the intermediate voltage generation circuit 41. A control circuit 11 generates a control signal CNT for controlling the switch unit 31 and the operation stop unit 50. Reference numeral 90 denotes an electronic circuit composed of these.

  The intermediate voltage generation circuit 41 supplies a power supply voltage VDD as a high level power supply voltage (for example, 0V) and a power supply voltage VSS as a low level power supply voltage (for example, −1.5V) from a power supply wiring (not shown). And outputs an intermediate voltage VREG (for example, -0.8 V). Although this circuit will be described in detail later, it can be composed of a voltage regulator circuit.

  The intermediate voltage generation circuit 41 is provided with operation stop means 50 for stopping or substantially stopping the operation of the intermediate voltage generation circuit 41, and the circuit is operated by a control signal CNT from the control circuit 11.

  The circuit block 21 receives a supply of the power supply voltage VDD and a supply of the intermediate voltage VREG generated by the intermediate voltage generation circuit 41 from a power supply wiring (not shown), and performs a predetermined operation. For example, when the electronic circuit 90 is used in an electronic timepiece, the circuit block 21 corresponds to an oscillation circuit, a frequency dividing circuit, a display means driving circuit, or the like.

  The switch means 31 is provided between the circuit block 21 and the wiring for supplying the intermediate voltage VREG generated by the intermediate voltage generation circuit 41, and is opened and closed by a control signal CNT from the control circuit 11.

  The control circuit 11 stops the circuit block 21 and stops the operation of the intermediate voltage generation circuit 41 in response to a request from the electronic circuit 90 itself, other circuits of the electronic device in which the electronic circuit 90 is mounted, or the system side. Alternatively, it is a circuit that outputs a predetermined control signal CNT for substantially stopping. For example, when the electronic circuit 90 enters a standby state, the control circuit 11 controls the switch unit 31 and the operation stop unit 50 with the control signal CNT to realize it.

  When the electronic circuit 90 is in the standby state, the switch means 31 is strongly turned off by the control signal CNT from the control circuit 11. Thereby, the supply of the intermediate voltage VREG to the circuit block 21 is interrupted. Since there is no current path to the circuit block 21, the circuit block 21 stops operating, and power consumption associated with the circuit operation is eliminated.

  Further, the operation of the intermediate voltage generation circuit 41 is stopped or partially stopped (substantial stop) by the operation stop means 50 that stops or substantially stops the operation of each circuit constituting the intermediate voltage generation circuit 41. ), Power consumption associated with circuit operation is eliminated.

[Description of Configuration of First Embodiment: FIGS. 1 and 2]
The configuration of the first embodiment will be described with reference to FIG. 1 mainly using FIG.
FIG. 2 is a circuit diagram showing details of the intermediate voltage generating circuit 41 constituting the electronic circuit 90 shown in FIG.

  The feature of the first embodiment is that the power consumed in this circuit is reduced by stopping all the circuits constituting the intermediate voltage generating circuit 41 in the standby state.

In FIG. 2A, reference numeral 42 denotes a reference voltage generation circuit unit, 43 denotes an amplification circuit unit that amplifies the reference voltage, and 44 denotes an output circuit unit that outputs the amplified reference voltage.
The reference voltage generation circuit unit 42 includes a current mirror circuit and generates a constant voltage reference voltage VREF. The amplifier circuit unit 43 is a circuit that inputs and amplifies the reference voltage VREF, and is, for example, a 1 × differential amplifier (operational amplifier). The output circuit unit 44 is a circuit that generates an intermediate voltage VREG from the reference voltage VREF.

  These three circuits constitute a voltage regulator circuit. Since these circuits are well-known circuits, detailed description thereof is omitted.

In FIG. 2A, 51 is a switch corresponding to the operation stop means 50 shown in FIG. The switch 51 may be a known mechanical switch or electromagnetic switch that operates by receiving a control signal CNT.
2B to 2D are other configuration examples of the switch 51. FIG. FIG. 2B shows an example using a MOSFET type semiconductor switch. FIG. 2C shows an example using a transmission gate circuit using two MOSFETs. FIG. 2D shows an example using a bipolar transistor type semiconductor switch.

  As described above, the switch 51 constituting the operation stopping means 50 uses any one of the configurations illustrated in FIGS. 2B to 2D in addition to a known mechanical switch or electromagnetic switch. It doesn't matter. This is because the configuration to be selected changes depending on the environment in which the electronic circuit 90 is operated.

  Note that the MOSFET type semiconductor switch shown in FIG. 2B is preferable because it has a simple configuration and low power consumption as a single semiconductor switch. The following description will be made using an example using the configuration shown in FIG.

  The symbol VDD is a high-level power supply voltage (for example, 0 V) supplied to the electronic circuit 90. The symbol VSS is a low-level power supply voltage (for example, −1.5 V). Although not particularly limited, the intermediate voltage VREG is, for example, −0.8V. These voltages are supplied to each element by a power supply wiring (not shown).

  By the way, the elements constituting the circuit block 21 and the intermediate voltage generation circuit 41 including the operation stopping means 50 can be constituted by MOSFETs having a low threshold voltage Vth. In the relation of the power supply voltage described above, for example, if the standard threshold voltage Vth is 0.65V in absolute value, the low threshold voltage is about 0.35V in absolute value.

  As the switch means 31, for example, an n-type MOSFET type semiconductor switch can be used. The control signal CNT is input to the gate terminal, the drain terminal is input to the circuit block 21, and the source terminal is input to the intermediate voltage VREG.

As shown in FIG. 2A, the reference voltage generation circuit unit 42, the amplification circuit unit 43, and the output circuit unit 44 constituting the intermediate voltage generation circuit 41 are supplied with the power supply voltage VDD. A switch 51, which is an operation stop means 50, is connected between these circuits and the power supply wiring for supplying the power supply voltage VSS.

  The switch 51 which is the operation stop means 50 is a MOSFET type semiconductor switch as already described. The control signal CNT is input to the gate terminal, and the drain terminal is connected to the reference voltage generation circuit unit 42, the amplification circuit unit 43, and the output circuit unit 44. The source terminal is supplied with the power supply voltage VSS.

  The control signal CNT from the control circuit 11 is a signal that is at the VDD level during normal operation and at the VSS level in the standby state.

[Description during normal operation]
Next, the operation of the first embodiment will be described with reference to FIGS.
First, the operation during normal operation will be described.
When the electronic circuit 90 is operating normally, the control signal CNT at the power supply voltage VDD level, which is higher than the power supply voltage VSS input to the source terminal, is applied to the gate terminal of the switch 51 which is the operation stop means 50. Is typing. For this reason, the switch 51 is turned on.
Then, the intermediate voltage VREG from the intermediate voltage generation circuit 41 is output.

Similarly, the control signal CNT at the power supply voltage VDD level, which is a voltage higher than the intermediate voltage VREG input to the source terminal, is input to the gate terminal of the switch means 31. For this reason, the switch means 31 is turned on.
Then, the intermediate voltage VREG from the intermediate voltage generation circuit 41 is transmitted to the circuit block 21 as it is, and the intermediate voltage VREG is used as a drive power source for the circuit block 21.

  By the way, depending on the configuration of the intermediate voltage generation circuit 41, when the intermediate voltage VREG is generated, a delay may occur in time after the activation of the intermediate voltage generation circuit 41. This is because it may take several tens of mSec until the intermediate voltage VREG is stably output. When such an intermediate voltage generation circuit 41 is used, in order to supply the intermediate voltage VREG to the circuit block 21 stably, a means for delaying the signal transmission may be provided in the transmission system of the control signal CNT.

That is, by adding a delay circuit for delaying the applied control signal CNT to the gate terminal side of the switch means 31, the operation stop means 50 is turned on first, and the intermediate voltage VREG is stably output. After that, the switch means 31 is turned on. Thereby, a stable intermediate voltage VREG can be applied to the circuit block 21.
Note that the delay circuit can be configured by combining a resistance element and a capacitance element such as a capacitor, and is well known in an electronic circuit, and thus description of the configuration is omitted.

[Description of standby status]
Next, the operation in the standby state will be described.
When the electronic circuit 90 enters the standby state, the control signal CNT from the control circuit 11 becomes the power supply voltage VSS level.
A control signal CNT at the power supply voltage VSS level, which is a voltage lower than the intermediate voltage VREG input to the source terminal, is input to the gate terminal of the switch means 31. For this reason, the switch means 31 is turned off.

Then, the intermediate voltage VREG from the intermediate voltage generation circuit 41 is not transmitted to the circuit block 21, and the circuit block 21 that has lost the drive voltage stops its operation.

  As already described, the switch means 31 uses an n-type MOSFET and can be an element having a low threshold voltage Vth. Then, the state of the switch means 31 at this time is a strong off state. In such a state, since the switch unit 31 is reliably turned off, there is no leakage of the switch unit 31 itself, and the current supply path to the circuit block 21 can be cut off. Therefore, the power consumption of the circuit block 21 itself is almost eliminated.

Similarly, since the gate terminal of the switch 51 which is the operation stop means 50 is the same as the power supply voltage VSS which is the voltage supplied to the source terminal, the operation stop means 50 is turned off.
Then, the intermediate voltage generation circuit 41 stops operating because the power is cut off, and the intermediate voltage VREG is not output. Therefore, the power consumption in the intermediate voltage generation circuit 41 is almost eliminated.

  By the way, the intermediate voltage generation circuit 41 is in a state where the power supply voltage VDD side is applied in a state where the operation is stopped, but the power supply voltage VSS is cut off, so that a predetermined time (for example, several hundred mSec) is taken. After the elapse of time, the intermediate voltage VREG approaches the power supply voltage VDD level. That is, the charge accumulated in the stray capacitance of each element constituting the intermediate voltage generation circuit 41 is discharged and gradually converges to the power supply voltage VDD level of 0V.

  In this case, since the intermediate voltage VREG becomes the power supply voltage VDD level as time passes, the potential difference between the gate terminal and the source terminal of the switch means 31 further increases, and the state of the switch means 31 changes with time. Furthermore, it can be set as a strong OFF state (super cut-off state). If it does so, it will be in the state which the leak of switch means 31 itself does not generate | occur | produce further.

Further, the intermediate voltage generation circuit 41 can immediately set the output of the intermediate voltage VREG to the power supply voltage VDD without stopping the operation and passing through the predetermined time (for example, several hundred mSec).
That is, the switch means linked to the operation stop means 50 is provided between the power supply voltage VDD and the intermediate voltage VREG. If it does in this way, the switch means 31 can be immediately made into the said strong OFF state.

[Summary of Example 1]
As described above, when the electronic circuit 90 enters the standby state, the three circuits of the reference voltage generating circuit unit 42, the amplifying circuit unit 43, and the output circuit unit 44 that constitute the intermediate voltage generating circuit 41 are MOSFET type switches. 51, the supply of the power supply voltage VSS is cut off, and all operations are stopped. Thereby, in the standby state, the intermediate voltage generation circuit 41 does not consume useless power.

[Description of Modification 1 of Embodiment 1: FIGS. 1 and 3]
Next, a first modification of the first embodiment will be described with reference to FIGS. 1 and 3.
FIG. 3 shows details of the intermediate voltage generation circuit 41 constituting the electronic circuit 90 shown in FIG.

  The feature of the first modification of the first embodiment is that the amplification circuit unit 43 and the output circuit unit 44, which are a part of the circuit constituting the intermediate voltage generation circuit 41, are stopped in the standby state by stopping the amplification circuit unit 43 and the output circuit unit 44. The power consumed by one circuit is reduced.

The example shown in FIG. 3 is an example in which the amplifier circuit unit 43 and the output circuit unit 44 are stopped while the reference voltage generation circuit unit 42 is operated. The amplifier circuit unit 43 and the output circuit unit 44 are connected to the power supply voltage VSS. A switch 51, which is an operation stop means 50, is connected between the wiring to be supplied.

  In such a configuration, the operation of the reference voltage generation circuit unit 42 is not stopped, and thus power is consumed somewhat in this circuit unit. However, the reference voltage VREF is always generated, and the amplification circuit unit 43 If the output circuit unit 44 returns from the stop, the intermediate voltage VREG can be output immediately. Therefore, the operation of the circuit block 21 can be started immediately, and the startability of the entire electronic circuit 90 can be improved.

[Description of Modification 2 of Embodiment 1: FIGS. 1 and 4]
Next, a second modification of the first embodiment will be described with reference to FIGS. 1 and 4.
FIG. 4 shows details of the intermediate voltage generation circuit 41 constituting the electronic circuit 90 shown in FIG.

  The feature of the second modification of the first embodiment is that, in the standby state, by stopping only the output circuit unit 44, which is a part of the circuit constituting the intermediate voltage generation circuit 41, the power consumed by this circuit is reduced. It is a point to reduce.

  The example shown in FIG. 4 is an example in which only the output circuit unit 44 is stopped while the reference voltage generation circuit unit 42 and the amplifier circuit unit 43 are operated, and the output circuit unit 44 and the wiring for supplying the power supply voltage VSS are illustrated. A switch 51 which is an operation stop means 50 is connected between them.

  In such a configuration, since the operation of the reference voltage generation circuit unit 42 and the amplification circuit unit 43 is not stopped, power is consumed somewhat in these circuit units, but the reference voltage VREF is always generated. In addition, if the output circuit unit 44 returns from the stop, the intermediate voltage VREG can be output immediately. In addition, since the elements constituting the amplifier circuit unit 43 do not float, there is an advantage that no malfunction occurs.

  The amplifier circuit unit 43 uses a 1 × differential amplifier circuit in the illustrated example. If the differential amplifier circuit malfunctions, the intermediate voltage VREG fluctuates greatly immediately after the intermediate voltage generating circuit 41 is activated, and the circuit block 21 cannot immediately start operating normally.

[Summary of Modification 1 and Modification 2 of Embodiment 1]
Since the reference voltage generation circuit unit 42, the amplification circuit unit 43, and the output circuit unit 44 that constitute the intermediate voltage generation circuit 41 have different circuit configurations and functions, the power consumed by each circuit unit is also different.
Depending on the design and specifications of the intermediate voltage generation circuit 41, or in a large sense, the specifications and usage environment of the electronic circuit 90, it is possible to select whether or not a part of each of the circuit units is stopped by the switch 51.

  As an example, the intermediate voltage generation circuit 41 composed of a MOSFET manufactured by the inventors as a prototype operates normally when the power supply voltage VDD is 0 V, the power supply voltage VSS is -1.5 V, and the intermediate voltage VREG is -0.8 V. Its total current consumption at the time was about 6.4 nA.

  As shown in the first embodiment, the operation stop means 50 is controlled to stop the supply of the power supply voltage VSS to the intermediate voltage generation circuit 41 and stop the operation (standby state). The current was 0.024 nA. This value is so small that it can be called a leakage current of the circuit, and it can be said that almost no current flows.

Since the reference voltage generation circuit section 42 of the intermediate voltage generation circuit 41 must output the reference voltage VREF, a certain amount of current consumption is required. Since the amplification circuit unit 43 is a 1 × differential amplification amplifier that does not amplify the input reference voltage VREF, its power consumption is considerably smaller than that of the reference voltage generation circuit unit 42. On the other hand, since the output circuit unit 44 generates the intermediate voltage VREG from the reference voltage VREF, the power consumption thereof requires a certain amount of current as with the reference voltage generation circuit unit 42.

According to an examination by the inventors, the current consumption of the intermediate voltage generation circuit 41 when only the reference voltage generation circuit unit 42 is operated is about 3.39 nA. The consumption current of the reference voltage generation circuit unit 42 and the amplification circuit unit 43 was about 3.41 nA. The consumption current of the output circuit unit 44 was about 2.99 nA.
From this, it can be seen that the reference voltage generation circuit unit 42 and the output circuit unit 44 occupy most of the current consumption of the intermediate voltage generation circuit 41.

  In the example shown in the first modified example of the first embodiment in which the reference voltage generating circuit unit 42 is operated and the amplifier circuit unit 43 and the output circuit unit 44 are stopped, the intermediate voltage generating circuit is maintained while maintaining the startability already described. The current consumption of 41 can be reduced to about half.

Even in the example shown in the second modification of the first embodiment in which the reference voltage generation circuit unit 42 and the amplification circuit unit 43 are operated and only the output circuit unit 44 is stopped, the current consumed in the amplification circuit unit 43 is small. The current consumption of the intermediate voltage generation circuit 41 can be reduced to about half as in the first modification.
In this example, since the operation of the amplifier circuit unit 43 is not stopped, the potentials of the MOSFETs constituting this circuit are also fixed, and there is an advantage that they do not malfunction.

  From the above, in the first and second modifications of the first embodiment described above, it is significant to reduce the power consumption by stopping the output circuit unit 44. For example 2, it is preferable to use both examples properly for the convenience of operating the electronic circuit 90.

  In the example shown in the first embodiment, the time from when the operation stop means 50 is controlled from the standby state to supply the power supply voltage VSS of the intermediate voltage generating circuit 41 and when the intermediate voltage VREG generates a predetermined voltage. Was about 2.38 mSec. On the other hand, in the example shown in the modification 1 and the modification 2 of Example 1, it was about 1.81 mSec.

That is, it can be seen that the generation of the intermediate voltage VREG is accelerated by operating the reference voltage generation circuit unit 42 and generating the reference voltage VREF.
The difference is slight, about 0.57 mSec, but it can be said that the effect is great in the case of an electronic circuit or the like mounted on a small electronic device such as an electronic timepiece that is desired to start up quickly even with 0.1 mSec.

[Description of Configuration of Second Embodiment: FIGS. 1, 5, and 6]
First, the structure of Example 2 is demonstrated using FIG.5 and FIG.6.
FIG. 5 is a block diagram showing the intermediate voltage generation circuit 41 according to the second embodiment, and reference numeral 52 denotes a switch corresponding to the operation stop means 50 shown in FIG. Reference numeral 91 denotes a p-type MOSFET constituting this switch.

FIG. 6 is a circuit diagram showing a specific configuration of intermediate voltage generating circuit 41 shown in FIG. Reference numerals 71 to 74 are p-type MOSFETs, and reference numerals 81 and 82 are n-type MOSFETs.
The intermediate voltage generation circuit 41 shown in FIG. 6 is the same circuit as the example already described. However, to facilitate the following description, reference numerals 71 to 74 are assigned to some of the p-type MOSFETs of each circuit, and n Reference numerals 81 and 82 are given to a part of the type MOSFET.

  The feature of the second embodiment is that the operation of other circuits is stopped by limiting the energization amount of some circuits in the standby state, and the power consumed by the intermediate voltage generating circuit 41 as a whole is reduced. is there. The intermediate voltage generation circuit 41 is not completely stopped, but is substantially stopped.

Specifically, the energization amount to the reference voltage generation circuit unit 42 constituting the intermediate voltage generation circuit 41 is limited to make the value of the reference voltage VREF zero, and the circuit operation of the amplification circuit unit 43 and the output circuit unit 44 is stopped. It is something to be made.
As already described in the first embodiment, the reference voltage generation circuit unit 42 and the output circuit unit 44 are circuits that consume most of the current consumption of the intermediate voltage generation circuit 41. Therefore, the energization amount of these circuits is limited. Doing so results in lower power consumption.

  In the example shown in FIG. 5, a switch 52 is inserted between the output unit of the reference voltage generation circuit unit 42 and the input unit of the amplification circuit unit 43.

  The switch 52 shows an example in which a p-type MOSFET 91 constitutes a switch. As shown in FIG. 6, the source terminal of the p-type MOSFET 91 is connected to the wiring for supplying the power supply voltage VDD, and the drain terminal is connected to the input unit of the subsequent amplification circuit unit 43 and the reference voltage generation circuit unit 42. It is connected to a connection point (also a connection point to the drain terminal of the n-type MOSFET 82) between the gate terminal and the drain terminal of the p-type MOSFET 72 which is an output unit. A control signal CNT is input to the gate terminal of the p-type MOSFET 91 constituting the switch 52.

[Description during normal operation: FIGS. 1 and 6]
Next, the operation of the second embodiment will be described with reference mainly to FIG.
First, the operation during normal operation will be described.
When the electronic circuit 90 is operating normally, the control signal CNT at the power supply voltage VDD level, which is higher than the power supply voltage VSS, is input to the gate terminal of the switch constituting the switch 52 that is the operation stop means 50. ing. For this reason, the p-type MOSFET 91 is turned off.

  Then, the reference voltage VREF is input to the amplifier circuit unit 43 from the reference voltage generation circuit unit 42, and the intermediate voltage VREG is output from the output circuit unit 44.

Similarly, the control signal CNT at the power supply voltage VDD level, which is a voltage higher than the intermediate voltage VREG input to the source terminal, is input to the gate terminal of the switch means 31. For this reason, the switch means 31 is turned on.
Then, the intermediate voltage VREG from the intermediate voltage generation circuit 41 is transmitted to the circuit block 21 as it is, and the intermediate voltage VREG is used as a drive power source for the circuit block 21.

  In the description of the first embodiment, the example in which the delay circuit for delaying the applied control signal CNT is added to the gate terminal side of the switch unit 31 has been described. However, the delay circuit may be used also in the second embodiment. Of course.

[Description of standby state: FIGS. 1 and 6]
Next, the operation in the standby state will be described.
When the electronic circuit 90 enters the standby state, the control signal CNT from the control circuit 11 becomes the power supply voltage VSS level.
A control signal CNT at the power supply voltage VSS level, which is a voltage lower than the intermediate voltage VREG input to the source terminal, is input to the gate terminal of the switch means 31. For this reason, the switch means 31 is turned off.

  Then, the intermediate voltage VREG from the intermediate voltage generation circuit 41 is not transmitted to the circuit block 21, and the circuit block 21 that has lost the drive voltage stops its operation.

  Similarly, the control signal CNT at the power supply voltage VSS level, which is a voltage lower than the power supply voltage VDD, is applied to the gate terminal of the p-type MOSFET 91 constituting the switch 52 that is the operation stop means 50. For this reason, the p-type MOSFET 91 is turned on.

  Then, a voltage of the power supply voltage VDD level is applied between the gate terminal and the source terminal of the p-type MOSFETs 71 and 72 constituting the reference voltage generation circuit unit 42. As a result, the value of the reference voltage VREF becomes zero (the power supply voltage VDD level, in short, 0 V). Then, almost no drain current flows through these p-type MOSFETs 71 and 72, and almost no drain current flows through the n-type MOSFETs 81 and 82 of the reference voltage generating circuit section 42 as well. That is, there is almost no current consumed by the reference voltage generation circuit unit 42.

Since the p-type MOSFET 91 constituting the switch 52 is turned on, the power supply voltage VDD level is also applied to the gate terminal side of the p-type MOSFETs 73 and 74 constituting the subsequent amplification circuit section 43 and the output circuit section 44, respectively. Is done.
Since the p-type MOSFETs 73 and 74 serve to limit the current flowing through the amplifier circuit unit 43 and the output circuit unit 44, respectively, the power supply voltage VDD level is applied to the gate terminal side and the source terminal side thereof. Then, these two p-type MOSFETs are in an off state.

  Then, no current flows through the amplifier circuit unit 43 and the output circuit unit 44, and these circuit operations are stopped.

  In this state, the reference voltage generation circuit unit 42, the amplification circuit unit 43, and the output circuit unit 44 are energized, but have stopped the circuit operation, and operate by turning off the power supply of these circuits already described. The circuit operation is stopped in the same manner as in the first embodiment. However, even in this state, the reference voltage generation circuit unit 42, the amplification circuit unit 43, and the output circuit unit 44 have an effect of being strong against noise because the respective units do not float electrically.

  In the first and second embodiments described above, the elements such as MOSFETs that constitute the circuit block 21 and the intermediate voltage generation circuit 41 and the semiconductor switches such as MOSFETs that constitute the switch means 31 have the same threshold value. You may do it.

With such a configuration, the power consumption of the electronic circuit 90 can be further reduced by lowering the threshold values.
In this way, since it is not necessary to configure a circuit with elements having a plurality of threshold values, the manufacturing process is not complicated, the electronic circuit can be manufactured in a short time, and the cost can be reduced.

  It is known that such adjustment of the threshold value can be easily changed, for example, by adjusting the impurity concentration of the semiconductor substrate constituting the MOSFET or adjusting the impurity concentration of the channel region, the source region, and the drain region.

[Summary]
As described above, as described in the first and second embodiments, according to the electronic circuit of the present invention, the power consumption of the circuit block 21 and the intermediate voltage generating circuit 41 in the standby state can be reduced.
The specific circuit configuration and power supply voltage used in the embodiments already described are not limited to this, and can be arbitrarily changed without departing from the scope of the present invention. For example, the switch 52 described in the second embodiment may be a transmission gate circuit shown in FIG.

  The present invention is suitable for a small electronic device such as an electronic wristwatch that consumes very little power during operation, and has a demand for extending battery life, extending operation time, and the like. It can also be applied to electronic devices that require electric power.

DESCRIPTION OF SYMBOLS 11 Control circuit 21 Circuit block 31 Switch means 41 Intermediate voltage generation circuit 42 Reference voltage generation circuit part 43 Amplifier circuit part 44 Output circuit part 50 Operation stop means 51, 52 Switch 71-74, 91 p-type MOSFET
81, 82 n-type MOSFET
90 electronic circuit

Claims (7)

An intermediate voltage generating circuit that is supplied with a power supply voltage and outputs an intermediate voltage having an absolute value lower than the power supply voltage;
A circuit block which is supplied with the intermediate voltage and performs a predetermined operation;
Switch means for controlling the supply of the intermediate voltage to the circuit block based on a control signal output from the control circuit;
Have
In the electronic circuit that is controlled to open and close by the potential difference between the intermediate voltage and the control signal,
2. The electronic circuit according to claim 1, wherein the intermediate voltage generating circuit has an operation stopping means for stopping the circuit operation of the intermediate voltage generating circuit based on the control signal. The intermediate voltage generation circuit is composed of three circuit parts including a reference voltage generation circuit part, an amplification circuit part, and an output circuit part,
A predetermined reference voltage is generated in the reference voltage generation circuit unit, and the intermediate voltage is generated and output by the amplification circuit unit and the output circuit unit based on the reference voltage,
2. The electronic circuit according to claim 1, wherein the operation stop unit stops the supply of the power supply voltage to all of the three circuit units based on the control signal. The intermediate voltage generation circuit is composed of three circuit parts including a reference voltage generation circuit part, an amplification circuit part, and an output circuit part,
A predetermined reference voltage is generated in the reference voltage generation circuit unit, and the intermediate voltage is generated and output by the amplification circuit unit and the output circuit unit based on the reference voltage,
The electronic circuit according to claim 1, wherein the operation stop unit stops the supply of the power supply voltage to the amplifier circuit unit and the output circuit unit based on the control signal. The intermediate voltage generation circuit is composed of three circuit parts including a reference voltage generation circuit part, an amplification circuit part, and an output circuit part,
A predetermined reference voltage is generated in the reference voltage generation circuit unit, and the intermediate voltage is generated and output by the amplification circuit unit and the output circuit unit based on the reference voltage,
The electronic circuit according to claim 1, wherein the operation stopping unit stops the supply of the power supply voltage to the output circuit unit based on the control signal. The intermediate voltage generation circuit is composed of three circuit parts including a reference voltage generation circuit part, an amplification circuit part, and an output circuit part,
A predetermined reference voltage is generated in the reference voltage generation circuit unit, and the intermediate voltage is generated and output by the amplification circuit unit and the output circuit unit based on the reference voltage,
The operation stop means limits an energization amount to the reference voltage generation circuit unit based on the control signal, and sets a value of the reference voltage to zero, thereby performing circuit operations of the amplification circuit unit and the output circuit unit. The electronic circuit according to claim 1, wherein the electronic circuit is stopped.   6. The electronic circuit according to claim 1, wherein the operation stop means is a MOSFET type switch that is controlled to open and close based on the control signal.   7. The electronic circuit according to claim 1, wherein the transistors constituting the circuit block and the intermediate voltage generation circuit and the switch means have the same threshold value.

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