JPS6331309A - Differentiation circuit - Google Patents

Abstract

PURPOSE:To attain the inputting of two signals of a differential input, by sharing one constant current by two pairs of pair of transistors. CONSTITUTION:Transistors Q1 and Q2 constitute a first differential pair, and transistors Q3 and Q4 constitute a second differential pair, and these two differential pairs share a constant current source Io, and have two differential inputs V1 and V2. Assuming that the base voltage of transistors are set as VB1-VB4, the collector of the transistor Q1 is connected to that of the transistor Q2, and the collectors of the transistors Q3 and Q4 are connected to each other, and it is set as VB3=VB4:1/2(VB1+VB2), the current of collector current (Ic3+Ic4) and that of collector current (Ic1+ Ic2) become two multiple waves having negative phases mutually to the input V.

Description

[Detailed description of the invention] Industrial applications The present invention relates to differential circuits.

Conventional Technology Conventional technology uses three transistors as shown in Figure 7 in one constant current source! /) There is a circuit that does J.

Problems to be Solved by the Invention However, the conventional circuit described above
Since the bases of each number are used as inputs, there is a drawback that it is not possible to receive two numbers by differential input.

The present invention has been made in view of the above-mentioned conventional situation,
Accordingly, an object of the present invention is to provide a novel difference υ1 circuit which makes it possible to eliminate the above-mentioned drawbacks inherent in the conventional technology.

Means for Solving the Problems In order to achieve the above object, the differential circuit according to the present invention has two
It is configured to include a pair of transistors and one constant current source.

Embodiment Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is a circuit configuration diagram showing a first embodiment of the present invention.

Referring to FIG. 1, transistor Q1. Q2 is the first
The transistors Q3 and Q4 constitute a second differential pair, and the two differential pairs share a constant current source IO. As shown in FIG. 1, two differential inputs V1. V2
have.

FIG. 2 shows a second embodiment of the present invention, and is an example of a circuit in which an emitter resistor is inserted into each transistor in FIG. 1 to reduce the influence of the gain of each differential pair and the input offset between each transistor. .

Now, in FIGS. 1 and 2, the base voltages of each transistor are set as vB, , vB, , VBs, and VB, and the collector of transistor Ql and the collector of transistor 02 are connected.

Connect the collectors of transistors Q3 and Q4.

VB3 = VB4 = 1/2 (VBI + VB
), then the collector current Ic3+ for the input V□
The current of Ic and the current of IC1+IC4 have double waveforms with mutually opposite phases.

FIG. 3 shows a circuit diagram at this time, and FIG. 4 shows waveforms.

FIG. 5 is an example of an application circuit of the present invention, and shows an example of a multiplier circuit.

FIG. 6 shows the output characteristics as R1=R, R,=n, and R,=R.

As described in detail, according to the present invention, two pairs of transistors share one constant current, thereby achieving the effect that two differential input signals can be input.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing a first embodiment of the present invention, FIG. 2 is a circuit configuration diagram showing a second embodiment of the invention as an example in which an emitter resistor is inserted, and FIG. 3 is a circuit diagram showing a second embodiment of the invention. is a circuit diagram illustrating a double multiplier circuit as an example of an application of the present invention, FIG. 4 is a characteristic diagram of FIG. 3, and FIG. 5 is a circuit diagram illustrating a multiplier circuit as an example of an application of the invention. FIG. 6 is a diagram showing the input/output characteristics of FIG. 5, and FIG. 7 is a diagram showing an example of a conventional circuit.

Claims (1)

[Claims] A differential circuit characterized by two pairs of transistors having one constant current source.