JPH0563547A - Reference voltage revision circuit - Google Patents

Abstract

PURPOSE:To make power of a differential logic circuit zero by adding the reference voltage revision circuit to an ECL, connecting the circuit to a reference voltage of a constant current source of an internal differential logic circuit and a termination voltage of an emitter follower so as to change a signal of an internal cell. CONSTITUTION:The reference voltage revision circuit 9 is added to a conventional ECL. The circuit 9 consists a constant current source reference voltage revision circuit and an emitter follower (EF) termination voltage revision circuit and they are respectively connected to a constant current source reference voltage of a differential logic circuit of a specific operation circuit block 7 and a termination voltage of the EF. Through the constitution above, when a control terminal 12 is set to an H level, the output voltage of the circuit 9 is made equal to a voltage at an EF termination power supply terminal 3 and a constant current source reference voltage output terminal 5 and the circuit 7 is operated similarly as a normal operation circuit block 8. When the terminal 12 is set to an L level, the circuit 9 outputs a voltage at which the circuit 7 is not in operation to make the current of the constant current source and the EF zero.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reference voltage changing circuit for changing the reference voltage of an emitter-coupled logic circuit (hereinafter referred to as ECL).

[0002]

2. Description of the Related Art FIG. 6 is a circuit diagram showing a general ECL circuit having a conventional reference voltage changing circuit. This circuit
High-side power supply terminal 1, low-side power supply terminal 2, emitter
A follower (hereinafter referred to as EF) terminal power supply terminal 3, a reference voltage generation circuit 4 using the higher power supply terminal 1 and the lower power supply terminal 2 as input power supplies, and a constant current source reference voltage output from the reference voltage generation circuit 4. Output terminal 5, the reference voltage output terminal 6, the high-side power supply terminal 1, the low-side power supply terminal 2, the constant current source reference voltage output terminal 5, and the reference voltage output terminal 6 as the input power supply circuit block 7 And a normal operation circuit block 8. The specific operation circuit block 7 has an input terminal T1 and an output terminal T2 in addition to the input terminal T1 and the output terminal T2 in order to explain the operation principle.
The buffer circuit includes transistors Q1 to Q4 and resistors R1 to R3.

In this conventional circuit, even if the specific operation circuit block 7 does not have to operate, the specific operation circuit block 7 is always operating in the same manner as the normal operation circuit block 8 and consumes power. is doing.

FIG. 7 is a circuit diagram showing another conventional reference voltage changing circuit. This circuit includes a high-side power supply terminal 1, a high-side power supply terminal 1a, a low-side power supply terminal 2, an EF termination power supply terminal 3, and a reference voltage using the high-side power supply terminal 1a and the low-side power supply terminal 2 as input power supplies. A generation circuit 4; a constant current source reference voltage output terminal 5a output from the reference voltage generation circuit 4;
Similarly, a specific operation circuit block 7 that uses the reference voltage output terminal 6a, the high-side power supply terminal 1, the low-side power supply terminal 2, the constant current source reference voltage output terminal 5a, and the reference voltage output terminal 6a as input power sources, and the high-side power supply. A reference voltage generation circuit 10 using the terminals 1 and the low-side power supply terminal 2 as input power sources, a constant current source reference voltage output terminal 5 output from the reference voltage generation circuit 10, a reference voltage output terminal 6, and a high-side power supply. It is provided with a terminal 1, a low-potential side power supply terminal 2, a constant current source reference voltage output terminal 5 and a reference voltage output terminal 6 as a normal operation circuit block 8 using the input power supply. However, the reference voltage generation circuit 4 and the reference voltage generation circuit 10 have the same circuit configuration. Further, the specific operation circuit block 7 has an input terminal T1, an output terminal T2, transistors Q1 to Q4, and resistors R1 to R3 in order to explain the operation principle.
And a buffer circuit.

When the specific operation circuit block 7 is operated, the same voltage as that of the high-potential power supply terminal 1 is applied to the high-potential power supply terminal 1a. As a result, the specific operation circuit block 7 operates similarly to the normal operation circuit block 8.

When the specific operation circuit block 7 is not operated, the same voltage as that of the lower power supply terminal 2 is applied to the higher power supply terminal 1a. At this time, there is no difference between the voltage of the reference voltage generation circuit 4 and the voltage of the low potential side power supply terminal 2, and both are low potential side voltages. Further, the voltages of the constant current source reference voltage output terminal 5a and the reference voltage output terminal 6a, which are the outputs of the reference voltage generation circuit 4, are also low-side voltages. As a result, the base-emitter voltage of the constant current source transistor Q3 in the specific operation circuit block 7 becomes 0, so that the transistor Q3
Is always off and the power is zero. Therefore, the transistors Q1 and Q2 forming the differential amplifier are both turned off and the power becomes zero.

FIG. 8 is a circuit diagram showing still another conventional technique of the present invention.

This circuit includes a high-potential power supply terminal 1, a low-potential power supply terminal 2, an EF termination power supply terminal 3, and a reference voltage generation circuit 4 using the high-potential power supply terminal 1 and the low-potential power supply terminal 2 as input power supplies. , A control terminal 11 for a control signal input to the reference voltage generation circuit 4, a constant current source reference voltage output terminal 5a output from the reference voltage generation circuit 4, a reference voltage output terminal 6a, and a high potential side power supply terminal. 1, a low-side power supply terminal 2, a constant current source reference voltage output terminal 5a and a reference voltage output terminal 6a as input power supply, a specific operation circuit block 7, and a high-side power supply terminal 1 and a low-side power supply terminal 2 as input power supplies. Reference voltage generation circuit 10 and reference voltage generation circuit 10
A constant current source reference voltage output terminal 5, a reference voltage output terminal 6, a high-side power supply terminal 1, a low-side power supply terminal 2, a constant current source reference output terminal 5, and a reference voltage output terminal 6.
And a normal operation circuit block 8 which uses as a power source.
The specific operation circuit block 7 has an input terminal T1, an output terminal T2, and transistors Q1 to Q in order to explain its operation principle.
4 and resistors R1 to R3.

As shown in FIG. 9, the reference voltage generating circuit 4 is configured to change the voltage of the constant current source reference voltage output terminal 5 by the control terminal 11. This circuit includes transistors Q41 to Q45, resistors R41 to R47, a diode D41 and a voltage adjustment / compensation feedback circuit 13.
It is composed by.

When operating the specific operation circuit 7, an L level is input to the control terminal 11. At this time, since all the current flowing through the resistor R47 flows through the diode D41, the base current flowing through the transistor Q43 becomes 0, and the transistors Q43, Q44, Q45 are all turned off. Therefore, the voltage of the constant current source reference voltage output terminal 5a becomes a normal voltage, and the specific operation circuit block 7 operates similarly to the normal operation circuit block 8.

When the specific operation circuit block 7 is not operated, the H level is input to the control terminal 11. At this time, the current flowing through the resistor R47 flows into the base of the transistor Q43. As a result, the transistor Q44 is turned on and the emitter current of the transistor Q44 begins to flow into the resistor R41, so that the base voltages of the transistors Q41 and Q42 drop and the voltage of the constant current source reference voltage output terminal 5 drops. Since this voltage is set so that the current of the constant current source composed of the transistor Q3 and the resistor R2 of the specific operation circuit block 7 becomes 0, the transistor Q3 is turned off and the power becomes 0. Therefore, the transistors Q1 and Q2 forming the differential amplifier are both turned off and the power becomes zero.

[0012]

However, the above-mentioned conventional reference voltage changing circuit has the following drawbacks.
In the first conventional example shown in FIG. 6, the ECL logic circuit irrespective of logic, a current always flows through the differential logic circuit composed of the transistors Q1 and Q2 by the constant current source composed of the transistor Q3 and the resistor R2. Because of that, it always consumes power. The EF transistor also consumes power regardless of the H level or the L level. For this reason, there is a drawback that power is always consumed even in a circuit section that does not have to operate under certain conditions.

In the second conventional example shown in FIG. 7, it is possible to reduce the electric power of the circuit portion which does not need to be operated under certain conditions to 0, as compared with the first conventional example. An external power supply terminal is additionally required because the voltage switches on / off the operation of the circuit section. Further, since the power supply line for control is wired in the internal cell, the number of power supply lines increases. Furthermore, when switching on / off the operation of a plurality of circuit units, a plurality of reference power supply generation circuits are required, and the number of reference voltage generation circuits increases, so that the power of the entire chip increases,
Further, there is a drawback that the element area increases. Also, EF
There is a drawback that the power of the transistor part cannot be reduced to zero.

In the third conventional example shown in FIG. 8, the electric power can be reduced to 0 in the circuit portion which does not have to operate under certain conditions as compared with the first conventional example.
Since the control terminal is not inside the internal cell, it is necessary to lead the wiring of the control terminal into the internal cell when switching on / off the operation of the circuit section under a certain condition. Furthermore, when switching on / off the operation of a plurality of circuit parts, a plurality of reference power supply generation circuits are required, and the number of reference voltage generation circuits increases, so that the power of the entire chip increases.
Further, there is a drawback that the element area increases. Also, EF
There is also a drawback that the power of the transistor part cannot be reduced to zero.

The present invention has been made in view of the above problems, and even when the operation of a plurality of circuit parts is switched on / off, the operation is performed by an internal logical value without increasing the reference voltage generation circuit. (EN) Provided is a reference voltage changing circuit which can be turned on / off, can be turned on / off in a circuit portion without increasing the number of power supply terminals and without placing a burden on arrangement / wiring, and preventing waste of power. The purpose is to

[0016]

A reference voltage changing circuit according to the present invention is a reference voltage changing circuit for changing a voltage generated in a reference voltage generating circuit to an arbitrary voltage set by a signal value of an internal cell, It is connected to the reference voltage of the constant current source and the termination voltage of the emitter follower of the internal differential logic circuit, and has means for making the current value of the constant current source and the emitter follower zero by changing the signal value of the internal cell. It is characterized by

[0017]

In the present invention, by changing the signal value of the internal cell, the current value of the constant current source and the emitter follower is set to 0, and the power of the differential logic circuit is set to 0.

[0018]

Embodiments of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a circuit diagram of a reference voltage changing circuit according to the first embodiment of the present invention. It has a high potential side power supply terminal 1, a low potential side power supply terminal 2 and an EF termination power supply terminal 3, and the reference voltage generation circuit 4 uses the high potential side power supply terminal 1 and the low potential side power supply terminal 2 as input power supplies. The reference voltage generation circuit 4 outputs a reference voltage via a constant current source reference voltage output terminal 5 and a reference voltage output terminal 6.

The reference voltage changing circuit 9 uses the high-side power supply terminal 1, the low-side power supply terminal 2, the EF termination power supply terminal 3, and the constant current source reference voltage output terminal 5 as input power supplies, and the control terminal 1
An input signal is input from 2. This reference voltage changing circuit 9
Is output to the EF terminal power supply terminal 3a and the constant current source reference voltage output terminal 5a.

The specific operation circuit block 7 uses the high power supply terminal 1, the low power supply terminal 2, the EF termination power supply terminal 3a, the constant current source reference voltage output terminal 5a, and the reference voltage output terminal 6 as input power supplies.

The normal operation circuit block 8 uses the high-potential power supply terminal 1, the low-potential power supply terminal 2, the EF termination power supply terminal 5 and the reference output terminal 6 as input voltages.

The specific operation circuit block 7 includes four transistors Q1, Q2 and Q3. The buffer circuit has Q4. The collector of this transistor Q1 is connected to the high-potential side power supply terminal 1, and the base is connected to the input terminal T1. The collector of the transistor Q2 is connected to the high potential side power supply terminal 1 through the resistor R1, the base is connected to the reference voltage output terminal 6, and the emitter is connected to the emitter of the transistor Q1. Transistor Q3
Has its collector connected to the emitter of the transistor Q1, its base connected to the constant current source reference voltage output terminal 5a, and its emitter connected to the lower power supply terminal 2 via the resistor R2. The transistor Q4 has a collector connected to the high-potential side power supply terminal 1 and a base connected to the transistor Q2.
Of the EF terminal power supply terminal 3a through the resistor R3 while the emitter is connected to the output terminal T2.
It is connected to the. Although the specific operation circuit block 7 is used as a buffer circuit for explanation of operation, any ECL logic circuit may be used.

The reference voltage changing circuit 9 comprises the constant current reference voltage changing circuit shown in FIG. 2 and the EF termination voltage changing circuit shown in FIG.

FIG. 2 is a circuit diagram of the constant current source reference voltage changing circuit. In this constant current source reference voltage changing circuit,
The transistor Q11 has its emitter connected to the high-potential side power supply terminal 1 via the resistor R11, its base connected to the constant current source reference voltage output terminal 5, and its collector connected to the low-potential side power supply terminal 2.
It is connected to the. The collector of the transistor Q12 is connected to the high potential side power supply terminal 1, and the base is connected to the control terminal 12. The transistor Q13 has a collector connected to the high-potential side power supply terminal 1 and a base connected to the reference voltage output terminal 6. The diode D11 has its anode connected to the emitter of the transistor Q12, the diode D12 has its anode connected to the cathode of the diode D11, and the diode D13 has its anode connected to the emitter of the transistor Q13 and the diode D14.
Has its anode connected to the cathode of diode D13. The transistor Q14 has its collector connected to the high-potential power supply terminal 1, its base connected to the cathode of the diode D12, and also connected to the low-potential power supply terminal 2 via the resistor R12, and its emitter connected to the resistor R14. It is connected to the low-potential side power supply terminal 2 through. The transistor Q15 has a collector connected to the emitter of the transistor Q11, a base connected to the cathode of the diode D14, a resistor R13 connected to the lower power supply terminal 2, and an emitter connected to the emitter of the transistor Q14. There is. The transistor Q16 has a collector connected to the high-potential power supply terminal 1, a base connected to the emitter of the transistor Q11, and an emitter connected to the constant current source reference voltage output terminal 5a.
And the low-potential side power supply terminal 2 via a resistor R15.

FIG. 3 is a circuit diagram of the EF termination voltage changing circuit. In this EF termination voltage changing circuit, the transistor Q21 has its collector connected to the high potential side power supply terminal 1, its base connected to the EF termination power supply terminal 3, and its emitter connected to the low potential side power supply terminal 2 via the resistor R21. It is provided. Further, the transistor Q22 has a collector connected to the high-potential side power supply terminal 1 and an emitter connected to the transistor Q22.
Connected to 21 emitters. Transistor Q23 is
The collector is connected to the higher power supply terminal 1 via the resistor R22, the base is connected to the control terminal 12, and the emitter is connected to the lower power supply terminal 2 via the resistor R23. The collector of the transistor Q24 is the high-side power supply terminal 1
And the base is connected to the reference voltage output terminal 6,
The emitter is connected to the emitter of transistor Q23. The collector of the transistor Q25 is the high-side power supply terminal 1
, The base is connected to the collector of the transistor Q23, the emitter is connected to the base of the transistor Q22, and the low-side power supply terminal 2 is connected via the resistor R24. The transistor Q26 has an emitter connected to the EF terminal power supply terminal 3a and a high-side power supply terminal 1 via a resistor R25, and a base connected to the transistor Q21.
Is connected to the low-side power supply terminal 2.

Next, the first aspect of the present invention constructed as described above
The operation of the embodiment circuit will be described.

First, the case where the control terminal 12 is at the H level will be described. In FIG. 2, the transistor Q
14 is on and transistor Q15 is off. Since only the emitter current of the transistor Q11 flows through the resistor R11, the base voltage VB18 of the transistor Q16 is represented by the following formula 1 when the voltage of the constant current source reference voltage output terminal 5 is VCS.
Given in.

[0029]

[Equation 1] VB16 = VCS + VBE11

However, VBE11 is the base-emitter voltage of the transistor Q11. From this, the voltage VCS ′ at the constant current source reference voltage output terminal 5a is expressed by the following mathematical formula 2.

[0031]

## EQU2 ## VCS '= VB16-VBE16 = VCS + (VBE11-VBE16)

However, VBE16 is the base-emitter voltage of the transistor Q16. This equation 2 is expressed by the following equation 3 when the base-emitter voltages of the transistors Q11 and Q12 are equal and VBE.

[0033]

[Formula 3] VCS ′ = VCS

In FIG. 3, the transistor Q23 is on and the transistor Q24 is off. Resistance R
Since the emitter current IE23 of the transistor Q23 flows through the transistor 22, the base voltage B25 of the transistor Q25 is represented by the following formula 4 when the internal H level voltage is VH.

[0035]

[Equation 4] IE23 = (VH-VBE23-VEE) / R23 VB25 = VGND-R22 IE23 = VGND-R22 (VH-VBE23-VEE) / R23

However, VGND is the voltage of the high-potential side power supply terminal 1,
VEE is the voltage of the lower power supply terminal 2, and VBE23 is the base-emitter voltage of the transistor Q23. According to this equation 4, the base voltage VB22 of the transistor Q22 is given by the following equation 5
It is represented by.

[0037]

[Formula 5] VB22 = VB25-VBE25 = VGND-R22 (VH-VBE23-VEE) / R23-VBE25

However, VBE25 is the base-emitter voltage of the transistor Q25. At this time, the transistor Q2
1 is a differential amplifier composed of Q22, and transistor Q21
Is on and the transistor Q22 is off, the base voltage of the transistor Q22 is set as shown in the following equation 6 when the voltage at the EF termination voltage output terminal 3 is VT.

[0039]

[Equation 6] VB22 <VT

From the condition of the equation 6, the transistor Q26
The base voltage VB26 of is expressed by the following formula 7.

[0041]

[Equation 7] VB21 = VT-VBE21

However, VBE21 is the base-emitter voltage of the transistor Q21. From this equation 7, the voltage VT 'at the EF termination voltage output terminal 3a is expressed by the following equation 8.

[0043]

(8) VT '= VB21 + VBE26 = VT + (VBE26-VBE21)

However, VBE26 is the base-emitter voltage of the transistor Q26. This equation 8 is represented by the following equation 9 when the base-emitter voltages of the transistors Q21 and Q26 are equal to VBE.

[0045]

[Equation 9] VT '= VT

From the above, the output voltage of the reference voltage changing circuit in FIG.
Since the terminal power supply terminal 3 and the constant current source reference voltage output terminal 5 are the same, the specific operation circuit block 7 operates similarly to the normal operation circuit block 8.

Next, the case where the control terminal 12 is at the L level will be described. In FIG. 2, the transistor Q
14 is in the off state and transistor Q15 is in the on state. As a result, the emitter current IE11 of the transistor Q11 and the emitter current IE15 of the transistor Q15 flow through the resistor R11. The emitter currents IE11 and IE15 are expressed by the following formula 1 respectively.
It is given by 0 and 11.

[0048]

[Equation 10] IE11 = (VGND-VBE11-VCS) / R11

[0049]

IE15 = (VR1-VBE13-VBE15-VF13-VF14-VEE) / R14

However, VR1 is the voltage of the reference voltage output terminal 6,
VBE11 is the base-emitter voltage of the transistor Q11,
VBE13 is the base-emitter voltage of the transistor Q13,
VBE15 is the base-emitter voltage of transistor Q15,
VF13 is the cathode-anode voltage of the diode D13,
VF14 is the cathode-anode voltage of the diode D14. From equations 10 and 11, the base voltage VB16 of the transistor Q16 is represented by the following equation 12.

[0051]

[Equation 12] VB16 = VGND-R11 (IE11 + IE15)

However, the base voltage VB1 of the transistor Q16
6 is set so as to satisfy the condition expressed by the following formula 13.

[0053]

[Equation 13] VB16 <VCS + VBE11

From equations 10 to 12, the voltage VCS 'of the constant current source reference voltage output terminal 5a is represented by the following equation 14.

[0055]

## EQU14 ## VCS '= VB16-VBE11 = VCS + VBE11-VBE16-R11 (VR1-VBE13-VBE15-VF13-VF14-VEE) / R14

From the equation (14), assuming that the base-emitter voltage of the transistor and the cathode-anode voltage of the diode are equal and VBE, the voltage VCS 'of the constant current source reference voltage output terminal 5a is expressed by the following equation (15). To be done.

[0057]

## EQU15 ## VCS '= VCS-R11 (VR1-4VBE-VEE) / R14

In FIG. 3, the transistor Q23 is off and the transistor Q24 is on. Resistance R
Since almost no current flows through 22, transistor Q25
The base voltage VB25 of is expressed by the following formula 16.

[0059]

[Formula 16] VB25 = VGND

From this equation 16, the base voltage VB22 of the transistor Q22 is represented by the following equation 17.

[0061]

[Expression 17] VB22 = VGND -VBE25

At this time, the transistor Q21 is turned off,
In order to turn on the transistor Q22, the base voltage of the transistor Q22 is set as in the following formula 18.

[0063]

[Equation 18] VB22> VT

From equations 17 and 18, the base voltage of the transistor Q22 is represented by the following equation 19.

[0065]

## EQU19 ## VB26 = VB22-VBE22 = VGND-VBE22-VBE25

However, VBE22 is the base-emitter voltage of the transistor Q22. From the equation (19), the voltage VT 'at the EF termination voltage output terminal 3a is expressed by the following equation (20).

[0067]

(20) VT '= VB26 + VBE26 = VGND-VBE22-VBE25 + VBE26

This equation 20 shows that the transistors Q22 and Q2
If the base-emitter voltages of 5 and Q26 are equal to VBE, the following formula 21 is given.

[0069]

[Equation 21] VT '= VGND-VBE

Here, in FIG. 1, in order for the current value of the constant current source circuit composed of the transistor Q3 and the resistor R2 of the specific operation circuit block 7 to become 0, the condition of the following formula 22 is necessary.

[0071]

[Equation 22] VCS ′ = VBE + VEE

However, VBE2 is the base-emitter voltage of the transistor Q2. From the equations (15) and (22), if the base-emitter voltage of the transistor Q2 is also VBE, the following equation (23) is established.

[0073]

## EQU23 ## R11 / R14 = (VCS-VBE-VEE) / (VR1-4VBE-VEE)

By setting the resistors R11 and R14 so as to meet the condition of Expression 23, the current and power of the constant current source circuit are set to 0.
become. Further, as a result, the power of the differential amplifier circuit composed of the transistors Q1 and Q2 also becomes zero. Further, since the current flowing through the resistor R1 becomes 0, the base voltage VB4 of the transistor Q4 is represented by the following formula 24.

[0075]

[Equation 24] VB4 = VGND

At this time, in order that the current flowing through the resistor R3 becomes 0 and the power of the EF transistor portion also becomes 0, the following formula 25 must be established.

[0077]

(25) VT '= VB4-VBE4 = VGND-VBE4

However, VBE4 is the base-emitter voltage of the transistor Q4. Equation 25 is the transistor Q
Similarly, if the base-emitter voltage of 4 is also VBE, the power of the EF transistor portion becomes 0 because it is equal to the equation 21.

From the above, when the control terminal 12 is at the L level, the output voltage of the reference voltage changing circuit outputs a voltage at which the specific operation circuit 7 does not operate, and the operation becomes zero. Next, the operation of the circuit of the first embodiment is performed by setting VGND of the higher power supply terminal 1 to 0V and VEE of the lower power supply terminal 2 to -4.5.
VH of V and H level voltage value is -0.8V, VCS of constant current source reference voltage output terminal 5 is -3.1V, VR1 of reference voltage output terminal 6 is -1.1V, VT of EF termination power supply terminal 3 -
The condition of each resistance value in the case of designing 2.0 V and the base-emitter voltage of all transistors as 0.8 V will be described. From Equations 5 and 6, the resistances R22 and R23 satisfy the conditions represented by the following equations.

[0080]

[Equation 26] R22 / R23> 12/29

From equations 10 to 13, the resistances R11 and R14 satisfy the following equations.

[0082]

[Equation 27] R11 / R14> 0

Equation 18 is established from Equations 17 and 18. From the equation 23, the resistors R11 and R14 satisfy the condition of the following equation 28.

[0084]

[Equation 28] R11 = 3R14

As described above, the resistors R11, R14, R22, R
By setting 23, the specific operation circuit block 7 operates when the control terminal 12 is at the H level and does not operate when the control terminal 12 is at the L level, and the electric power is 0. Can be configured.

In the present embodiment, even when the operation of a plurality of circuit parts is switched on / off, the operation is turned on / off by an internal logical value without increasing the reference voltage generating circuit.
It can be switched off. In addition, without increasing the number of power terminals, that is, without placing a burden on arrangement and wiring,
It is possible to switch on / off of the circuit unit, and it is possible to prevent power consumption. Furthermore, not only the differential logic circuit section,
The power of the EF transistor section can also be zero.

Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is different from the circuit of the first embodiment shown in FIG. 1 in that there is no EF termination power supply terminal 3 and
That is, the F termination voltage is used as the lower power supply terminal 2, the EF termination voltage changing circuit is configured as shown in FIG. 5 instead of that of FIG. 3, and the input voltage of the reference voltage changing circuit is the EF termination power supply terminal 3.

The reference voltage changing circuit 9 is composed of the constant current source reference voltage changing circuit shown in FIG. 2 and the EF termination voltage changing circuit shown in FIG.

FIG. 5 is a circuit diagram of the EF termination voltage changing circuit. In this EF termination voltage conversion circuit, the transistor Q31 has a collector connected to the high-potential side power supply terminal 1 and a base connected to the control terminal 12. The transistor Q32 has a collector connected to the high-potential power supply terminal 1 and a base connected to the reference voltage output terminal 6. The transistor Q33 has a collector connected to the high potential side power supply terminal 1 via the resistor R33, a base connected to the low potential side power supply terminal 2 via the resistor R31, and an emitter connected to the low potential side power supply terminal 2 via the resistor R34. Has been done. Transistor Q34
Has a collector connected to the higher power supply terminal 1, a base connected to the lower power supply terminal 2 through a resistor R32, and an emitter connected to the emitter of the transistor Q33. The anode of the diode D31 is connected to the emitter of the transistor Q31, the anode of the diode D32 is connected to the cathode of the diode D31, and the cathode of the diode D32 is connected to the base of the transistor Q33. The diode D34 is connected to the emitter of the transistor Q32, the anode is connected to the cathode of the diode D33, and the cathode is connected to the base of the transistor Q34. Furthermore, the transistor Q
35, the emitter is connected to the collector of the transistor Q33 via the resistor R35, and the base and collector are connected to the low potential side power supply terminal 2. The transistor Q36 has a collector connected to the higher power supply terminal 1, a base connected to the collector of the transistor Q33, an emitter connected to the EF terminal power supply terminal 3a, and a lower power supply terminal 2 via the resistor R36. Has been done.

Next, the operation of the circuit of the second embodiment will be described.

First, the case where the control terminal 12 is at the H level will be described. The constant current source reference voltage changing circuit of FIG. 2 operates similarly to the circuit of the first embodiment.
In the EF termination voltage changing circuit of FIG. 5, the transistor Q33 is on and the transistor Q34 is off.
An emitter current IE33 of the transistor Q33 represented by the following formula 29 flows through the resistor R33.

[0092]

[Equation 29] IE31 = (VR1-VF31-VF32-VBE31-VBE33-VEE) / R34

Here, VBE31 is the base-emitter voltage of the transistor Q31, VBE33 is the base-emitter voltage of the transistor Q33, VF31 is the cathode-anode voltage of the diode D31, and VF32 is the cathode-anode voltage of the diode D32. ..

As a result, the base potential VB36 of the transistor Q36 is expressed by the following equation 30.

[0095]

[Expression 30] VB36 = VGND-R33 IE31 = VGND-R33 (VR1-VF31-VF32-VBE31-VBE33-VEE) / R34

At this time, in order to set the current of the resistor R35 to 0, the following equation 31 is set.

[0097]

[Equation 31] VB36 = VEE + VBE35

However, VBE35 is the base-emitter voltage of the transistor Q35. From the equations 30 and 31, when the base-emitter voltage of the transistors Q31, Q33, Q35 and the cathode-anode voltage of the diodes D31, D32 are equal to VBE, the following equation 32 is obtained.

[0099]

[Expression 32] R33 / R34 = (VGND-VBE-VEE) / (VR1-4VBE-VEE)

By setting the resistors R33 and R34 as in Expression 32, the voltage of VT 'at the EF terminal power supply output terminal 3a is expressed by Expression 33 below.

[0101]

(33) VT '= VEE + VBE35-VBE36

From the equation 33, if the base-emitter voltage of the transistor Q36 is also VBE, the EF termination power supply terminal 3a is represented by the following equation 34.

[0103]

[Expression 34] VT '= VEE

From the above, in FIG. 4, the output terminal of the reference voltage changing circuit is equal to the constant current source reference voltage output terminal 5 of the reference voltage generating circuit according to the equations 3 and 34, and therefore is specified similarly to the normal operation circuit block 8. The operation circuit block 7 operates.

Next, the case where the control terminal 12 is at the L level will be described. The constant current source reference voltage changing circuit shown in FIG. 2 performs the same operation as that of the first embodiment circuit. In the EF termination voltage changing circuit shown in FIG. 5, the transistor Q33 is off and the transistor Q34 is on. Since almost no current flows through the resistor R33, the base voltage of the transistor Q36 is given by the following formula 35.

[0106]

[Formula 35] VB36 = VGND

From this equation 35, the EF termination power supply terminal 3a
VT 'is represented by the following formula 36.

[0108]

(36) VT '= VGND-VBE36

In FIG. 4, assuming that the base-emitter voltage of the transistor Q36 is also VBE, the formula 37 is equal to the formula 25, so that the electric power of the EF transistor portion becomes 0.

As described above, when the control terminal 12 is at the L level, the output voltage of the reference voltage changing circuit outputs a voltage at which the specific operation circuit 7 does not operate, and the power becomes 0.

The constant current source reference voltage changing circuit shown in FIG. 2 and the EF termination voltage changing circuit shown in FIGS. 3 and 5 are described as one embodiment, and are described in the claims of the present invention. Various changes and modifications may be made as long as the circuit performs the same operation within the above range.

[0112]

As described above, according to the present invention, even when the operation of a plurality of circuit parts is switched on / off, the operation is switched on / off by an internal logic value without increasing the reference voltage generating circuit. be able to. Further, the circuit section can be switched on / off without increasing the number of power supply terminals, that is, without placing a burden on the arrangement and wiring, and it is possible to prevent unnecessary power consumption.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an entire reference voltage changing circuit according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a constant current source reference voltage changing circuit which also constitutes the reference voltage changing circuit of the present embodiment.

FIG. 3 is a circuit diagram showing an EF termination voltage changing circuit which also constitutes the reference voltage changing circuit of the present embodiment.

FIG. 4 is a circuit diagram showing an entire reference voltage changing circuit according to a second embodiment of the present invention.

FIG. 5 is a circuit diagram showing an EF termination voltage changing circuit which also constitutes the reference voltage changing circuit of the present embodiment.

FIG. 6 is an overall circuit diagram of a first conventional example.

FIG. 7 is an overall circuit diagram of a second conventional example.

FIG. 8 is an overall circuit diagram of a third conventional example.

FIG. 9 is a circuit diagram showing a reference voltage generating circuit of a third conventional example.

[Explanation of symbols]

1; High-side power supply terminal 2; Low-side power supply terminal 3, 3a; EF termination voltage output terminal 4, 10: Reference voltage generation circuit 5, 5a; Constant current source reference voltage output terminal 6; Reference voltage output terminal 7; Specific operation Circuit block 8; Normal operation circuit block 9; Reference voltage changing circuit 11; Control terminals Q1 to Q4, Q11 to Q16, Q21 to Q26, Q31 to Q36, Q
41 to Q45; Transistors R1 to R3, R11 to R15, R21 to R25, R31 to R36, R
41 to R47; resistors D11 to D14, D31 to D34, D41; diode T1; input terminal T2; output terminal

Claims (1)

[Claims] 1. The voltage generated by the reference voltage generating circuit is
In the reference voltage change circuit that changes to the arbitrary voltage set by the signal value of the internal cell, it is connected to the reference voltage of the constant current source of the internal differential logic circuit and the termination voltage of the emitter follower to change the signal value of the internal cell. A reference voltage changing circuit having means for reducing the current values of the constant current source and the emitter follower to 0 by performing the above.