JPS62100129A - Voltage source circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a power supply circuit technology and a technology that is particularly effective when applied to a reference voltage source circuit in a semiconductor integrated circuit.
It relates to a technology that is effective for use in CL (emitter-coupled logic)-RAM (random access memory), ECL gate arrays, and the like.

[Background technology]

For example, bipolar CMO8 type circuit ECL-
In a semiconductor integrated circuit device such as a RAM or an ECL gate array, a reference voltage source for providing an operating reference voltage for the ECL is formed in the semiconductor integrated circuit device along with a logic circuit such as an ECL.

This reference voltage source is described in 1, for example, "Integrated Circuit Engineering (2)" published by Corona Co., Ltd., co-authored by Daiyoshi Yanai and Kiyoshi Nagata, published June 20, 1971, pages 23 and 24 (Bandgap reference voltage circuit). It consists of a reference voltage generation circuit and an output circuit.

FIG. 4 shows the configuration of a reference voltage source circuit studied prior to the present invention.

The reference voltage source circuit 1 shown in the figure is formed in a semiconductor integrated circuit device such as an ECL-RAM or a bipolar CMO8-type RAM, and is connected to power supplies Vcc and Vee supplied from power lines /3 and 4. It includes a reference voltage generation circuit 11 that generates a constant reference voltage, and an output circuit 13 that outputs the voltage generated by the reference voltage generation circuit 11. ℃, bipolar transistors Ql, Q2, Q3, and resistors R1, R2, R3.

R4, R5 and capacitor Co constitute a so-called band gap type reference voltage generation circuit 11. Bipolar transistors Q4, Q5, Q6, Q7 and resistor R6 constitute a level shift circuit 12 that shifts the output potential of the reference voltage generating circuit 11 by a certain amount. Bipolar transistor QB and resistor R7 constitute an emitter follower type output circuit 13, which amplifies the reference voltage input through the level shift circuit 12 and outputs the amplified current.

The reference voltage vbb output from the reference voltage source circuit 1 is distributed as a reference bias voltage to the ECL 2 in the semiconductor integrated circuit device. ECL2 has collector load resistances R11 and R12, respectively, as partially shown in FIG.
a pair of bipolar transistors Qll connected to
The emitters of Q12 are commonly connected, and this common connection point is connected to the negative power supply Vee via a constant current circuit 21.

In this case, the operating characteristics of ECL2, in particular its logic input threshold, depend on the reference voltage vbb applied to the base of one bipolar transistor Q12. Therefore, the reference voltage vbb is required to always remain stable at a constant level regardless of voltage fluctuations of the power supplies Vcc and Vee.

However, the inventors have found that when the reference voltage source circuit 11 described above is formed, for example, in the semiconductor integrated circuit device, the following problem occurs.

That is, in the semiconductor integrated circuit device, the operating power supplies Vcc and Vee of the reference voltage source circuit 11 are supplied in common with the operating power supplies of the ECL or Bi-CMO8 type O8 circuit. Therefore, if the power supply current in the semiconductor integrated circuit device increases instantaneously due to the ECL or Bi-CMO8 type O8 circuit, the voltages of the operating power supplies Vcc and Vee of the reference voltage source circuit 11 will instantaneously increase. It may change. This instantaneous power supply voltage fluctuation is caused by, for example, resistance and inductance parasitic in wiring within a semiconductor integrated circuit device made of aluminum or the like. When such an instantaneous fluctuation in the power supply voltage occurs, the reference voltage vbb outputted from the reference voltage source circuit 11 also instantaneously fluctuates accordingly. This variation in the reference voltage vbb causes the operating characteristics of a logic circuit such as an ECL to vary, particularly its input threshold value, and as a result, problems such as malfunctions are likely to occur.

[Purpose of the invention]

An object of the present invention is to provide a technique that can stabilize a reference voltage output from a reference voltage source without being affected by instantaneous fluctuations in the power supply voltage.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief description of typical inventions disclosed in this application is as follows.

That is, the reference voltage from the reference voltage generation circuit is amplified and outputted by the output circuit, and a capacitor is inserted in parallel between the input side of the output circuit and the power supply, so that the reference voltage is output from the output circuit. The purpose of this invention is to stabilize the reference voltage regardless of instantaneous fluctuations in the power supply.

〔Example〕

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

In the drawings, the same reference numerals indicate the same or corresponding parts.

FIG. 1 shows an embodiment of a reference voltage source circuit according to the present invention.

The reference voltage source circuit 11 shown in the figure is basically the same as that shown in FIG. That is, the reference voltage source circuit 11 shown in the figure is an ECL-RAM or a bipolar-C
A reference voltage generation circuit 11 that is formed in a semiconductor integrated circuit device such as an MO8 type O8M and generates a constant reference voltage from power supplies Vcc and vee supplied from power supply lines 3 and 4; The output circuit 13 includes an output circuit 13 that outputs the voltage generated by the voltage generation circuit 11.

In the figure, bipolar transistors Q11Q2 .
Q3, resistors R1, R2, R3, R4°R5, and capacitor Co constitute a so-called band gap type reference voltage generating circuit 11. Bipolar transistor Q4
, C5, C6, C7 and resistor R6 constitute a level shift circuit 12 that shifts the output voltage of the reference voltage generating circuit 11 by a certain amount. Bipolar transistor Q
8 and resistor R7 are emitter 7 lower type output circuit 13.
The reference voltage input through the level shift circuit 12 is current-amplified and outputted. The reference voltage vbb outputted from the reference voltage source circuit l is distributed to the ECL2 in the semiconductor integrated circuit device as a reference bias voltage. As part of the ECL2 is shown in FIG. 4, the emitters of a pair of bipolar transistors Qll and Q12, each connected to a collector load resistor R11 and R12, are commonly connected, and this common connection point is a constant current. It is connected to the negative power supply V ee via the circuit 21 .

Here, in the reference voltage source circuit 11 shown in FIG. 1, in addition to the above configuration, there is a Capacitors CI and C2 are inserted in parallel, respectively. One of the capacitors CI and C2 (C1) is connected between the input side of the output circuit 13 and the positive side of the power supply, that is, Vcc, and the other (C2) is connected between the input side of the output circuit 13 and the negative side of the power supply. That is, V
ee are connected in parallel with each other. In this embodiment, the capacitance values of the capacitors C1 and C2 are approximately the same.

As described above, when the capacitors CI and C2 are inserted in parallel between the input side of the output circuit 130 and the power supplies Vcc and Vee, the instantaneous fluctuations in the power supplies Vcc and Vee are caused by the parallel capacitor CI.

The voltage is averaged by the charging/discharging operation of C2, thereby suppressing fluctuations in the reference voltage vbb output from the output circuit 13. What should be noted at this time is that the capacitors CI and C2 are connected to the input side of the output circuit 13, not the output side. The output side of the output circuit 13 has low impedance in order to distribute the reference voltage vbb to many logic circuits. However, the input side has a relatively high impedance due to the amplification effect of the output circuit 13. Therefore, the above capacitor C1
, C2 has a high impedance, that is, even if its capacitance value is small, by connecting it to the input side of the output circuit 130, the instantaneous fluctuation in the input voltage Min of the output circuit 130 can be suppressed to a sufficiently small value. You will be able to do this. This makes it possible to effectively stabilize the reference voltage vbb that is amplified and appears on the output side.

Furthermore, in the reference voltage source circuit 11 of the embodiment shown in FIG. 1, the input side of the output circuit 130 is connected to two capacitors C.
It is connected to both the positive side (Vcc) and negative side (Vee) of the power supply by I and C2. As a result, the instantaneous voltage fluctuations that occur in both the positive and negative power supplies Vcc and Vee are absorbed by the two capacitors CI and C.
2, that is, at the input side of the output circuit 130, they cancel each other out. Therefore, both power supplies Vcc and Ve
The effects of voltage fluctuations in opposite directions that occur together on e are:
It can be suppressed even more efficiently.

Figures 2(a) and 2(b) show how the fluctuation states of both the plus and minus power supply voltages (Vcc and Vee) caused by an instantaneous increase in the power supply current in a semiconductor integrated circuit device correspond to each other in time. Shown. Also, the same figure (C)
shows the fluctuation state of the output reference voltage vbb when the capacitors C1 and C2 are connected. Furthermore, the figure (d) is for comparison, and the above capacitors CI, C2
This shows the fluctuation state of the output reference voltage vbb when not connected. As shown in the figure, both power supply voltages (Vcc and Ve
e) fluctuate in opposite directions, but these fluctuations are canceled out by the capacitors C1 and C2, so that the fluctuation range ΔV of the output reference voltage vbb can be suppressed to a small value. In this case, two capacitors CI.

C2 is set so that its capacity ratio is 1=1. The closer this capacitance ratio is to 1:1, the more the above-mentioned canceling effect appears.

FIG. 3 shows the size p of the capacitance C (C=CI=02) of the capacitors CI and C2 in the circuit shown in FIG.
F) and the fluctuation width △V of the output reference voltage vbb. m
V). As shown in the figure, the capacitors CI and C2 have a remarkable effect even with a small capacitance value of several pF or less. Therefore, even with a capacitor having a small capacitance value that can be easily formed within a semiconductor integrated circuit device, fluctuations in the output reference voltage vbb can be reliably suppressed to a point where there is no practical problem.

〔effect〕

(1) The reference voltage from the reference voltage generation circuit is amplified and outputted by the output circuit, and a capacitor is inserted in parallel between the input side of the output circuit and the power supply to generate the output from the output circuit. This has the effect that the reference voltage that is used can be stabilized regardless of instantaneous fluctuations in the power supply.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that this invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, part or all of the bipolar transistors forming the reference voltage generation source circuit may be formed from MOS transistors.

[Application field]

The invention described above is applied to the technology of reference voltage source circuits in semiconductor integrated circuit devices, which is the background field of application of the invention, but the invention is not limited to this, for example. It can also be applied to technology for power supply arrangement made up of individual parts.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an example of the reference voltage source circuit according to the present invention, and FIGS. 2(a) to (d) are waveform charts for explaining the operation of the reference voltage source according to the present invention. , FIG. 3 is a graph showing an example of the relationship between capacitance value and operating characteristics of a capacitor, and FIG. 4 is a circuit diagram showing a reference voltage circuit studied before the present invention. 1... Reference voltage source circuit, 11... Reference voltage generation circuit 13... Output circuit (emitter follower type output circuit) V
cc, Vee...power supply, vbb...output reference voltage,
CI, C2... Capacitor. ′ Electric “i ~ Tongue θ Electric ■ River θ too

Claims (1)

[Claims] 1. A voltage source circuit comprising a voltage generating circuit that generates a constant voltage from a power source supplied from a power line, and an output circuit that outputs the voltage generated by the voltage generating circuit. A voltage source circuit characterized in that a capacitor is inserted in parallel between the input side of the output circuit and a power supply line. 2. The voltage source circuit according to claim 1, wherein capacitors are inserted in parallel to the input side of the output circuit and to the positive and negative sides of the power source, respectively. 3. The voltage source circuit according to claim 1 or 2, wherein the output circuit is constituted by an emitter follower.