SU1259229A1 - Reference-voltage source - Google Patents

Abstract

The invention relates to a secondary power supply of electronic equipment. The aim of the invention is to increase the stabilization factor of the source of the reference voltage and expand the range of its adjustment. Bipolar transistor 1 and operational amplifier 7 realize a logarithmic amplifier. At the output of the amplifier 7, the voltage is equal to the voltage of the emitter - the base of the transistor 1. Transistor 2 with a divider on resistors 5 and 6 and an operational amplifier 9 form the second logarithmic amplifier. The amplifier 8 performs the function of equalizing the potentials at the output of the amplifier 7 and the midpoint of the resistive divider. By selecting the resistance values of the resistors 5 and 6, a voltage can be obtained at the output, equal to the band gap in silicon, at which self-stabilization of the parameters of bipolar transistors I and 2 is most pronounced. 1 Il. with IS (l you eat so you tc with

Description

The invention relates to electrical engineering and can be used to power a precision instrument.

The purpose of the invention is to increase the stabilization factor and expand the range of output voltage adjustment.

The circuit diagram of the reference voltage source is shown in principle.

The device contains the first I and second 2 bipolar transistors, the first 3, the second 4, the third 5 and the fourth 6 resistors, the first 7, the 8 and the third 9 operational amplifiers, the output terminal 10, the common bus 11.

The bases of the first 1 and second 2 bipolar transistors are connected to a common power bus, the emitter of transistor 1 is connected to the inverting input of amplifier 8, the emitter of transistor 2 to the resistor 5 of the voltage divider on resistors 5 and 6, the midpoint of which is connected to a non-inverting input the amplifier 8, and the output of the resistor 6 - with the output of the amplifier 9 and the output output 10 of the device. The collector of transistor 1 is connected to the inverting input of the amplifier 7, and the collector of the transistor 2 is the inverting input of the amplifier 9, and the non-inverting inputs of the amplifiers 7 and 9 are connected to the common bus 11, and the inverting inputs of the amplifiers 7 and 9

through current-setting resistors with amplifier output 8.

3 and 4 The device operates as follows.

A bipolar transistor I and an operational amplifier 7 realize a logarithmic amplifier. The current 1 through the transistor 1 is determined by the value of the resistance of the current-carrying resistor 3. At the output of the amplifier 7, the voltage is equal to the emitter-base voltage V, of the transistor 1. The bipolar transistor 2 with a resistive voltage divider on resistors 5 and 6 and the operational amplifier 9 form second logarithmic amplifier. The current 1 through the transistor 2 is determined by the value of the resistor 4. Operational amplifier 8 performs the function of equalizing the potentials on a 595992

during amplifier 7 and in the middle: point of resistive voltage divider Vb. V ,, +1 R, - (1) The output voltage of the device 5 is equal to

(2)

ten

15

20

25

thirty

35

40

VftM ... her (

Substituting in the formula (2) the value for the current Ij from () we get

 z. + (,) (+ + Re / Rs) (3)

In order to provide Vfg using current-supplying resistors 3 and 7, the following relationship is established between the currents of bipolar transistors 1 and 2

I, / I2 const 10 (A)

The feedback from the output of the amplifier 8 to the non-inverting inputs of the amplifiers 7 and 8 ensures that the condition (4) is met. By selecting resistance values 5 and 6, the output voltage Ygy 1.25 V, equal to the width of the forbidden zone in silicon, at which self-stabilization (drift self-compensation) of the parameters of bipolar transistors 1 and 2 are most pronounced, can be obtained. Since the temperature errors of the reference voltage taken from the device output are not high, it is possible to obtain higher values of the output voltages by selecting resistors 5 and 6.

The proposed device in comparison with the known one has a higher stability and a wide range of output voltage regulation,

Claims (1)

Invention Formula The source of the reference voltage contains the first and second bipolar transistors, the first, second, the third and fourth resistors, the first and second operational amplifiers, the bases of the transistors are combined, the collectors of the first and second transistors are connected via the first and second resistors to the output of the second amplifier, the collector of the first transistor is connected to the inverting input of the first amplifier, the third and fourth resistors are connected in series, with the extreme terminal of the third resistor connected to the emitter of the second transistor, 312592294 characterized in that, with the average output of the divider naps, the aim is to increase the coefficient of aging, non-inverting perblization levels and extending the range of the first and third amplifiers and base output voltage goulling, vtransistors are connected to common power supply, the third one- to 5 is additionally introduced, the collector of the second transistor the radio amplifier, while the output is connected to the inverting input of the first amplifier connected to the emitting amplifier, the output of which is connected with the power of the first transistor and inverted to the extreme terminal of the fourth with the tamping input of the second amplifier, resistor, and with the output terminal is-. non-inverting input of which connector.