SU1356197A1 - Current generator - Google Patents

Abstract

This invention relates to microelectronics. The purpose of the invention is to reduce the power dissipation and increase the temperature stability of the output current I. The current generator contains transistors 1.2 and 3 n resistors 4 and 5, the voltage at the base of transistor 2 is determined by the voltage drop at the base-emitter junction of transistor 3 due to current flowing through the circuit: resistor 5, base-emitter junction of transistor 3 and power supply bus. If transistor 2 is in active mode, then transistor 3 is open and full. The goal is achieved by introducing a transistor 3, allowing ush; it is possible to choose a smaller current-setting resistor 4, 1 sludge.

Description

The invention relates to microelectronics and can be used in the construction of integrated circuits.

The purpose of the invention is to reduce the power dissipation and increase the temperature stability of the output current.

The drawing shows the electrical circuit of the current generator.

The current generator contains the first 1 and second 2 transistors, an additional transistor 3, the first 4 and second 5 resistors.

The current generator operates as follows.

The voltage at the base of the second transistor 2 is determined by the voltage drop at the base-emitter transition of the additional transistor 3 due to the current flowing through the circuit: the second resistor 5, the base-emitter transition of the additional transistor 3, the power supply bus. This voltage consists of two components:

6.3

de Ugjj

 537

CI4

Uc +

BE2

and

KIZ

the voltage drop across the base-emitter junction of the additional transistor 3;

the voltage drop across the base-emitter junction of the second transistor 2; voltage drop between the collector and the emitter of the additional transistor 3.

If the second transistor 2 is in active mode, then the additional transistor 3 is open and saturated.

The voltage on the saturated transistor is

and

kn

/ 3

Editor H, Kistoulinets

Compiled by I. Water Khina

Tehred M. Didyk Proof-reader A. Zimokosov

Order 5810/53 Circulation 900 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Rauschska nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

where U -r is the temperature potential;

/ 3- is the inverse gain of the transistor.

In this case, the temperature coefficient of voltage variation U i is not more than 0.15 mV / degree, i.e. an order of magnitude less than for individual transitions.

The voltage on the basis of the second transistor 2 with respect to the power supply bus is distributed between the base-emitter junction of the first transistor 1 and the voltage drop across the first resistor 4.

The current generator output current is determined by

about ikne.,

where R is the first resistor 4.

Thus, a lower value than the first value of the first resistor 4 and an increase in the temperature stability of the output current is provided.

ka

Claims (1)

Invention Formula The current generator containing the first transistor having one structure, the collector of which is the output of the current generator, the emitter of the first transistor through the first resistor is connected to the power supply bus, the base is connected to the base of the second transistor having the same structure, and a second terminal of which is an input of a current generator, characterized in that, in order to reduce the power dissipation p thirty 35 40 45 temperature stability of the output current, an additional transistor, having the same structure, is inserted, the emitter of which is connected to the power supply bus, and the collector and base are connected respectively to the emitter and base of the second transistor, the collector of which is connected to the second output of the second resistor.