JPS61294527A - Generating circuit for reference voltage - Google Patents

Abstract

PURPOSE:To compensate the variance of the output voltage against the production variance of a resistance by constituting a generating circuit for reference voltage after the resistance value ratio of each resistance is set at a prescribed level. CONSTITUTION:A generating circuit for reference voltage consists of a constant current circuit part and a reference voltage generating part.. The constant current circuit part includes a resistance connected to a power supply VEE at the low potential side through an end and a transistor TR connected to the other end of the resistance. While the base of the TR is connected to a constant voltage source for extraction of a constant current. Then the reference voltage generating part includes a parallel connection matter of a series matter of a diode D connected to a power supply VCC at the high potential side and the 2nd resistance RS and another series matter of the 3rd and 4th resistances R1 and R2. Here the resistance of the constant current circuit part contains a parallel connection matter of the 5th resistance R4 produced by the same manufacturing process as the resistance RS and the 6th resistance R5 produced by the same manufacturing process as the 2nd and 3rd resistances R1 and R2. Thus each resistance value ratio can be set at a prescribed level. Then the variance of the output voltage VR can be compensated against the production variance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reference voltage generation circuit used in an integrated circuit having a bipolar circuit.

[Conventional technology]

Traditionally, the circuit used as a reference voltage generation circuit is
There is a circuit that generates a reference voltage by dividing the forward voltage Vs of the diode according to the ratio of resistors connected in parallel to a Schottky-barrier diode (hereinafter simply referred to as a diode).

FIG. 2 is a circuit diagram of an example of a conventional reference voltage generating circuit.

Resistors R1 and R are connected in parallel to the diode D and its series resistance Rs.
2 is connected, and in order to flow a constant current, a constant voltage is applied to the base of T so as to produce a constant voltage drop across the resistor B3 connected to the emitter of the transistor Tr.The reference voltage vR is equal to Divide (head direction voltage Vf of diode D) ten (potential drop of resistor Rs) by the ratio of R2, and calculate V
Take out the output voltage based on cc. Output voltage VR is expressed by the following equation.

Here, although the current flowing through the diode D changes due to variations in the resistance value, the amount of change in the forward voltage (Vf) with respect to the change in current density is small. Therefore, the variation in vR is small if the ratios of Rt, Rs, Has, and BS are correctly calculated and forgotten.

[Problem that the invention seeks to solve]

However, Rs is the resistance of the semiconductor region forming the shield barrier diode, and is a resistor hole conveniently used in the IC! ~ R3 is often manufactured using a different manufacturing process. For this reason, 几S and 几l.

几2. In R3, the resistance value is unrelated and varies. If the variation in Rs is α (%), and the variation in R1, Rz, and R3 is β (%), then the variation ΔvR in V+a is as follows (5). From formula (5), (Rs+Rz): Rs=+ Rt: Rs-Rt/E
, s −−(6), that is, 几3=几l+Rz ・・・−・−(7
) If the resistance value is selected to satisfy the relationship ΔVR=O, it is possible to compensate for the variation in output voltage for the variation in resistance.

However, if the resistance value is determined as in the force equation, equation (2).

From equation (3), Rs=Q or l2=0, which contradicts reality. That is, by taking the ratio of the resistances.

It is not possible to guarantee variations in Va. For that reason,
vR sometimes varied greatly depending on the manufacturing loft.

As described above, the conventional S has a problem in that it is extremely difficult to compensate for variations in reference voltage for manufacturing variations in resistance value.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reference voltage generation circuit that can compensate for variations in output voltage even with manufacturing variations in two types of resistors manufactured in different manufacturing processes.

[Means for solving problems]

The reference potential generation circuit of the present invention includes a first resistor whose one end is connected to a low potential side power source, an emitter connected to the other end of the first resistor, a base connected to a constant voltage source, and a base connected to a constant voltage source. a constant current circuit section including a transistor that takes out a constant current, a diode whose anode is connected to a high potential side power supply, a second resistor connected between the cathode of the diode and the collector of the transistor, and the a reference voltage generating circuit including a third resistor and a fourth resistor connected in series between a high potential side power supply and a collector of the transistor; The first resistor is configured by a parallel connection of a fifth resistor made in the same manufacturing process as the second resistor and a sixth resistor made in the same manufacturing process as the second and third resistors. Let the number of hours be the number of hours.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a circuit diagram of an embodiment of the present invention.

In this embodiment, a first resistor has one end connected to the source VEE on the low potential side, an emitter is connected to the other end of this first resistor R3, and a base is connected to a constant voltage source. A constant current circuit section including a transistor Tr for extracting current, a diode D whose anode is connected to the high potential side power supply Vcc, a cathode of this diode, and a transistor T.
A configuration including a second resistance hole S connected between the collector of r and a resistor R1 of Wc3 and a fourth resistance hole 2 connected in series between the high potential side power supply VCC and the collector of the transistor Tr. In the reference voltage generating circuit, the first resistor includes a fifth resistor R4 made in the same manufacturing process as the second resistor Rs, and second and third resistors R1 and Rs. It is configured in parallel connection with a sixth resistor Rs made in the same manufacturing process.

That is, the resistor R4 is made in the same manufacturing process as the diode series resistor Rs, and the resistor Rs is made in the same manufacturing process as the resistor 5. Therefore, the resistors R1, R2, R1 are R
4. This is a resistor manufactured in a different manufacturing process from R8.

The output voltage vn of this reference voltage generation circuit is as follows. However, the combined resistance value of R4 and R1 is R of the conventional circuit (Fig. 2).
Set it to the same value as 3. It is.

Here, let us consider variations in the output voltage when R11, R4, Rx, Rv, and Rs vary unrelatedly due to manufacturing variations.

Rs, 几4 variation to α (%), Rx, Rz.

When the variation in R5 is β (%), the variation ΔVn in the output voltage vR is as follows (10). It can be seen that if the resistor is selected to take the ratio according to equation (10), ΔVR=0, and the variation in the output voltage VR can be compensated for by the variation in the resistance. Also, when the resistance is selected to take the ratio of equation (11), the resistance value can be determined without contradicting reality.

In other words, in the circuit configuration shown in Figure 1, by taking the ratio of each resistor, the output voltage V
It is possible to compensate for variations in a.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a reference voltage generation circuit that can compensate for variations in output voltage due to manufacturing variations in two types of resistors that are manufactured in different manufacturing processes.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is a circuit diagram of an example of a conventional reference voltage generation circuit. D・・・・・・Shotki barrier diode, R1
゜Rz, R3, R4, Rs, Rs...Resistor, Tr...Transistor. Also ゛'', 4' V. Fig. 1 VEε Fig. 2

Claims (1)

[Claims] It is configured to include a first resistor whose one end is connected to a low potential side power source, and a transistor whose emitter is connected to the other end of the first resistor, whose base is connected to a constant voltage source, and which extracts a constant current from the collector. a constant current circuit section, a diode whose anode is connected to a high potential power supply, a second resistor connected between the cathode of the diode and the collector of the transistor, and between the high potential power supply and the collector of the transistor; and a reference voltage generating section including a third resistor and a fourth resistor connected in series, the first resistor being manufactured in the same manufacturing process as the second resistor. 1. A reference voltage generation circuit comprising a fifth resistor and a sixth resistor manufactured in the same manufacturing process as the second and third resistors connected in parallel.