JP3525620B2 - Battery save circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] TECHNICAL FIELD The present invention relates to a battery saver.
Circuit, mainly internal power supply circuit in IC for communication etc.
ON / OFF control can be performed by an external signal.
Battery that reduces power consumption to 0 when the internal power supply circuit is off
It relates to a terry save circuit. [0002] 2. Description of the Related Art Pagers, PHS, cordless phones
The communication ICc used for communication devices such as the one shown in FIG.
As shown in FIG.
A sense-type voltage generation circuit is used. This voltage generation circuit
Output voltage is, for example, as a reference voltage or power
The voltage is sent to each part in the IC. Then, the internal power supply circuit a once activated is
As a method of turning off the battery,
There is a method of stopping the application of power supply voltage from terry, or there is
Or an NPN transistor (not shown)
The internal power supply circuit
Of stopping supply of power supply voltage Vcc to path a
Was conventionally adopted. Incidentally, the conventional internal power supply circuit a
Of the supply of the power supply voltage Vcc to the communication IC c
The method of turning off the power supply voltage
If you do this on a computer,
This is a small problem required for portable communication devices.
This is a factor that hinders the development of models and lower prices. [0005] In addition, a power supply voltage off circuit is provided in the communication ICc.
By providing an NPN transistor and turning it on
To stop the supply of the power supply voltage to the internal power supply circuit a.
The internal power supply circuit a is turned off even when the power supply is off.
NPN transistor for source voltage off keeps on
Problem. This is, of course, the power consumption when off
Battery life for portable communication devices
Is a factor that hampers the demand for longer. Therefore, an internal power supply circuit is provided inside ICc.
Can be turned on and off by an external signal, and
New battery that can reduce power consumption by ICc to zero
-A save circuit has been developed, and
Battery saver circuit has been filed by the present applicant in Japanese Patent Application No. Hei 8-
98109. FIGS. 4A and 4B show the battery saver.
(A) is for explaining the battery circuit.
(B) is a schematic diagram of a communication device using the circuit.
It is a circuit block diagram showing a schematic structure. In the drawings, reference numeral 1 denotes a battery saving time.
2 is an internal power supply circuit, 3 is a main part of the internal power supply circuit 2.
Band-gap reference type voltage generation circuit
Is a communication IC incorporating these components, and 5 is a
It is a microcomputer that rolls. Next, the configuration of the battery saving circuit 1 will be described.
Will be described. [0010] The battery save circuit 1 is provided with a power supply voltage transmission.
Series constant-voltage circuit 6 and a power supply
Switch inserted in the path for supplying voltage Vcc
Such as a transistor Q8 as a switching means and resistors R7 and R8.
It is composed of Q4 is a PN for controlling the series-type constant voltage circuit 6.
P-type transistor with emitter connected to power supply terminal (Vcc)
Connected, the collector is connected to the output terminal (Vout)
ing. This output terminal is the band of the switching means 2.
Connects to the power supply terminal of the gap reference voltage generation circuit 3.
Has been continued. Q5 has an emitter connected to the power supply terminal (Vcc).
PNP whose collector is connected to one end of the resistor R5
A transistor whose base is composed of resistors R1 and R2.
Connected to the output point of the
Stably supplies current and generates a predetermined reference voltage to resistor R5.
Let it live. The other end of the resistor R5 is connected to the switching means Q.
8 collectors. Q1 is the output voltage of the battery save circuit 1.
A PNP transistor for detecting Vout.
The output terminal (Vou) of the battery save circuit 1
The base collectors connected to t) and shorted to each other
To the collector of the switching means Q8 via an anti-R3
It is connected. Q6 has a base connected to the transistor Q1.
NPN transistor connected to a connection point with anti-R3, Q
Reference numeral 7 denotes a connection between the transistor Q5 and the resistor R5.
NPN transistors connected to a point
The collector of the switching means Q8 via the resistor R4
It is connected to the. The transistors Q6 and Q7 are
The reference voltage (that is, the connection between the transistor Q5 and the resistor R5).
The output voltage Vout with a transistor
Vf shifted voltage of Q1 (ie, transistor Q1 and
(A potential at a connection point with the resistor R1) to perform differential amplification.
Configure a differential amplifier. Q2 and Q3 are current mirror connected to each other.
PNP transistors, the transistors Q6 and Q7
Make up the load. And the transistor Q3 and the transistor
The base of the control transistor Q4 is connected to the connection point with Q7.
Is connected. The switching means Q8 is an NPN transformer.
The collector is connected to the ground terminal of the constant voltage circuit 6.
The emitter is grounded, and the base is a resistor R
6 is connected to the switching signal input terminal.
You. The input terminal is connected to a power supply from the microcomputer 5.
This is a terminal to which a switching signal (SW) is input.
R7 is connected between the base of transistor Q8 and ground.
Resistance. Next, the operation of the battery save circuit 1 will be described.
Will be described. For switching from a microcomputer
When a signal is input and transistor Q8 goes high
The transistor Q8 is turned on and the constant voltage circuit 6 operates.
It is ready to work. Then, the control transistor Q4
Includes a transistor Q7, a resistor R4, and a transistor Q8.
As a path is formed, a base current flows and the
Transistor Q4 turns on and inputs to battery save circuit 1
Power supply voltage Vcc from the battery is output terminal Vo
band gap reference of internal power supply circuit 2 through
The voltage is transmitted to the sense voltage generator 3. In such a battery saving circuit 1,
The switching signal from the microcomputer 5
When (SW) goes low, transistor Q8 turns off.
You. Then, a base current flows through the control transistor Q4.
Path is cut off by the transistor Q8, and the control
The transistor Q4 is cut off, and the power supply voltage Vcc
Bandgap reference type voltage generation circuit of power supply circuit 2
No transmission to Road 3 is made. Moreover, there is a traffic between the constant voltage circuit 6 and the ground.
Is interrupted by the transistor Q8.
In this case, no current flows and the power consumption becomes zero. Of course
Of course, the transistor Q8 itself is also turned off,
Does not flow, and current is supplied to the resistors R6 and R7.
Battery saving circuit 1
At which the power consumption is completely zero. Therefore, the battery saving circuit 1 is used.
The power consumption of the communication IC 4 when the communication device is off is 0.
Can be In that respect it can be said that it is excellent. [0022] However, the bag shown in FIG.
The battery save circuit includes a control transistor Q4.
Voltage drop from the battery due to the voltage drop
The reduced power supply voltage is the bandgap of the internal power supply circuit 2.
The bandgap applied to the preference-type voltage generation circuit 3
Minimum required for the operation of the gap reference type voltage generation circuit 3.
There is a problem that a necessary power supply voltage becomes high. this is,
Battery voltage as low as 3V, PHS, cord
Items used for portable devices such as wrist phones
Is a serious problem that cannot be overlooked. That is, the battery saving circuit shown in FIG.
Is basically composed of a series constant voltage circuit 6.
Power supply voltage input terminal (Vcc) and output terminal (Vou).
The control transistor Q4 is interposed between the control transistor Q4 and t). Subordinate
Thus, the emitter collector of the transistor Q4 is
Voltage V_CEQ4Voltage drop occurs. This value is
For example, set to about 0.3-0.4V to avoid
(Approximately 0.2 V in the case of saturation).
A voltage [Vcc−
V_CEQ4(= 0.3-0.4V)] is the band gap riff
The voltage is applied to the reference voltage generating circuit 3. Therefore, the power supply voltage Vcc of the battery is
Assuming 3V, the output voltage Vo of the battery save circuit 1
ut is only 2.7-2.6V. Meanwhile, the band
The gap reference type voltage generating circuit 3 generally has a voltage of 1.3.
~ 1.4V (2Vf) output voltage, from which about
A voltage higher than 1.3 to 1.4 V (2 Vf) is referred to as a power supply voltage.
And need. Therefore, when the power supply voltage Vcc is about 3 V
Sometimes so-so bandgap reference voltage generation
Circuit 3 operates normally, but V
If the cc drops only slightly, the band gap reference
Normal operation of the sense-type voltage generation circuit 3 cannot be expected.
It is. The present invention has been developed to solve such a problem.
Provided inside the IC, and
The power supply circuit can be turned on and off by an external signal, and
Battery that can reduce the power consumption of the IC when the power is off
In the power saving circuit, the power supply voltage of the battery is
Band gap reference without loss
The purpose is to be able to apply to the
I do. [0026] SUMMARY OF THE INVENTION The battery saver of the present invention
The circuit comprises a main part for generating a voltage and a battery for the main part.
Current mirror that transmits the power supply voltage received directly from the
Bandgap reference voltage generation circuit
A battery save circuit that controls on / off
Of the bandgap reference voltage generator
Impedance between the emitter and base of the mirror circuit
Path for connecting means and passing current through the impedance means
The current mirror is turned on by an external signal.
-Operate the circuit and operate the bandgap reference type
The switching means that activates the pressure generation circuit is inserted.
It is characterized by having. Therefore, according to the battery saving circuit of the present invention,
If the switching means is off, the switch
Not only does the power consumption of the
Since no current flows through the dance means, the band gap
Emi of the current mirror circuit of the reference voltage generator
No voltage can be generated between the heater and base. Therefore, Karen
No current flows through the Tomirror circuit and the band gap reference
The sense-type voltage generation circuit keeps the operation
One. Then, the band gap reference type
Voltage drop in the path for transmitting the power supply voltage to the
Battery saving circuit because there is no intervening element
Power supply voltage without the risk of
Bandgap riff without any voltage drop
To the reference voltage generator as its power supply voltage.
And become possible. [0029] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Therefore, it will be described in detail. FIG. 1 shows a first embodiment of the battery saving circuit of the present invention.
FIG. 3 is a circuit diagram showing an embodiment of the present invention. In the drawing, 14
Is a communication IC, and 11 is a battery in the communication IC 14.
The save circuit 13 supplies power to each part in the communication IC 14.
Voltage or reference voltage
The bandgap reference type voltage generation circuit
The power supply voltage is transmitted to the section 13a (supply current
) Current mirror circuit 13b. First, the battery saving circuit 11
explain. Q13 is a transistor whose base is grounded,
Via a resistor R13 (for example, a core not shown in FIG. 1).
Control microcomputer).
To turn it on. R14 is the base of the transistor Q13
And a resistor connected between the ground and the ground. Q11 and Q12 have their emitters connected to each other.
Of the transistor Q13 via the resistor R15.
A pair of differential transistors connected to the collector
One of the transistors Q11 has a collector connected to a resistor R16.
To the power supply voltage (Vcc) terminal. other
The transistor Q12 has a collector connected to the power supply voltage (Vc
c) Connected to terminal and base is band gap reference
Current mirror circuit 13b of sense-type voltage generation circuit 13
And the main part 13a. R11 has one end connected to a power supply voltage (Vcc) terminal.
The other end of the connected resistor is
The resistors R12 and R1 are connected to the collector of the
1 is connected to the base of the transistor Q11
Have been. Next, a band gap reference type voltage
The generation circuit 13 will be described. Q15 and Q16 are Emi
Is connected to the power supply voltage (Vcc) terminal,
Are connected to constitute a current mirror circuit 13b.
A P-transistor with a resistor (emitter) between its emitter and base
Impedance means referred to in the claims) R16 is connected
When a current flows through the resistor R16, its terminal
Base-biased by voltage
The main part 13a of the lens type voltage generating circuit 13
Supply equal currents Io, Io. In addition, band gap
The main part 13a of the reference type voltage generation circuit 13 is a general type.
Since there is no difference from the first embodiment, the description is omitted. Next, the operation of the circuit will be described. First, when a control signal is input,
When a base current flows through transistor Q13, it turns off.
State. Then, the resistor R11 and R13 are formed.
A current flows through the bias circuit, and the transistor Q11
And the current flows through the resistor R16. Then,
The rent mirror circuit 13b turns on and the band gap
The current flows through the main part 13a of the preference-type voltage generation circuit 13.
Io, Io, and as a result, output from the main part 13a.
Generates a voltage of 1.3-1.4V. This output voltage is IC
Supply voltage or reference voltage
Sent as At the same time, the transistor Q12
Turn on. The transistors Q11 and Q12 have a differential amplifier.
And a connection to which the base of the transistor Q12 is connected.
When the potential at the connection point a is connected to the base of the transistor Q11.
To the potential of the connection point b between the separated resistors R11 and R12.
Feedback is applied to make them equal, and stable operation
State. That is, the potential of the connection point a is higher than the potential of the connection point b.
Rises, the current in transistor Q12 increases and
The current of the transistor Q11 decreases, and the voltage of the resistor R16 drops.
Decreases. Therefore, the transistors Q15 and Q16
Source bias becomes shallow and the collector-emitter
Pressure V_CEQ15 , V _CEQ16 Goes up. As a result, the connection point a
The level goes down. Conversely, the potential of the connection point a is lower than that of the connection point b.
Then, the level of the connection point a is increased by the differential amplifier.
It takes a return as if. Therefore, connection point a is always a differential
The pump operates so that the potential becomes equal to that of the connection point b.
Position controlled, band gap reference type
The voltage generation circuit 13 operates stably. The resistance R15 is the difference
Specifies the gain of the dynamic amplifier. By the way, no control signal is input.
State, that is, when the signal goes low, the transistor Q13
Turns off. Then, the transistors Q11 and Q12
No current can flow. That is, the transistors Q11 and Q12
Turns off. As a result, a current flows through the resistor R16.
It becomes impossible state. Then, the current mirror circuit 13
b, the transistors Q15 and Q16 are
No voltage is received between the emitter and the
Off. As a result, the bandgap reference voltage
The currents Io and Io are supplied to the main portion 13a of the generation circuit 13.
Will be in a state where the
The operation of the generator circuit 13 is stopped when no power is consumed.
State. Then, for example, the reception system, transmission
The communication system is completely turned off. Also, the battery save circuit 11
By turning off the transistor Q13, the transistors Q11 and Q11 are turned off.
12 not only turns off, but also turns off transistor Q11.
No current flows through the resistors R11 and R12 that are biased.
Therefore, no power is consumed at all. Therefore, the battery saving circuit 11
The bandgap reference type voltage generation circuit 13
ON / OFF control by control signal from
And a bandgap reference voltage generator
Zero power consumption when the raw circuit 13 is off
Can be. Therefore, avoid wasting battery power
Therefore, the service life can be extended. The battery saving circuit 11 is shown in FIG.
In series as shown in the applied battery saving circuit 1 shown in
No power supply voltage Vcc
The signal transmitted to the gap reference type voltage generation circuit 13
There are no circuit elements on the path that cause a voltage drop.
Therefore, the power supply voltage Vcc from the battery is not reduced at all.
No bandgap reference voltage generation
Can be applied to the path 13. That is, the conventional battery
ー Emission by control transistor Q4 of save circuit 1
Collector-collector voltage V_CEQ4Voltage loss
When using portable equipment such as a cordless fan.
Tolerance for battery voltage drop caused by
Can be made wider by that amount. FIG. 2 shows a band gap reference type voltage.
When the generating circuit 13 is turned off and its output voltage becomes 0V
The operation stops and the power consumption becomes completely zero.
FIG. 3 is a circuit diagram illustrating one specific example of a circuit. This circuit is not a new circuit, but
I do not give a detailed explanation because there is no essence of the invention
But I will explain briefly. Bandgap reference type voltage generation
When a reference voltage is generated from the path 13,
, The transistor Qa turns on, and as a result, the transistor
The transistor Qb is turned on. Then, the transistor Qc,
Qd is turned on, the input main signal Vin is amplified, and the output signal is amplified.
Vout. However, a battery not shown in FIG.
The bandgap reference type
Voltage generation circuit 13 does not generate a reference voltage
Then, the transistor Qa turns off and the transistor Qb
Is turned off, so that the transistors Qc and Qd
Turn off. Then, an amplifier circuit for amplifying the input main signal Vin
No current can flow through the device, and the operation stops in the state of no current consumption
You. Therefore, the power consumption in the IC can be reduced to zero. [0046] According to the battery saving circuit of the present invention,
When the switching means is off, the switching means
Not only does it not consume power itself, but also
Since no current flows through the means, the band gap reference
Emitter of the current mirror circuit of the
No voltage can be generated between the bases. Therefore, the current Mira
-No current flows in the circuit, band gap reference type
The voltage generation circuit keeps the operation stopped at zero power consumption. Then, the band gap reference type
Voltage drop in the path for transmitting the power supply voltage to the
Battery saving circuit because there is no intervening means
There is no danger of lowering the power supply voltage,
Bandgap without any drop in battery voltage
Supply voltage to the reference voltage generation circuit
It becomes possible to give.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing a first embodiment of a battery save circuit according to the present invention. FIG. 2 shows a specific example of a transmission or reception circuit in which a band gap reference type voltage generation circuit receives an output voltage as a reference voltage by the battery save circuit shown in FIG. 1 and the power consumption becomes 0 when the voltage becomes 0V. It is a circuit diagram. FIG. 3 is a circuit block diagram illustrating a schematic configuration of a conventional example of a communication device. 4A and 4B are diagrams for explaining a battery save circuit that has already been developed and applied for, and FIG. 4A is a circuit diagram of the battery save circuit, and FIG. FIG. 2 is a circuit block diagram illustrating a schematic configuration of a device (communication device). [Description of Signs] 11 ... Battery save circuit, 13 ... Band gap reference type voltage generation circuit, 13a ... Main part, 13b ... Current mirror circuit for transmitting power supply voltage to the main part, Q13 ..Switching means, R16
.Impedance means

Claims (1)

(57) [Claims] [Claim 1] A main part for generating a voltage and the main part
Current transmitting power supply voltage received directly from battery
Bandgap reference voltage consisting of a mirror circuit
A battery save circuit that controls the generation circuit on and off
An impedance means connected between an emitter and a base of a current mirror circuit for transmitting a power supply voltage from a battery to a main part of the band gap reference type voltage generation circuit; Inserted,
A switching means that is turned on by an external signal to activate the current mirror circuit and activate the band gap reference voltage generation circuit.