SU1504785A1 - Amplifying stage - Google Patents

Abstract

This invention relates to radio engineering and can be used in integrated power devices. The purpose of the invention is to increase temperature stability. The amplifier cascade contains N first and N second transistors 1, 2, N composite transistors made on transistors 3,4, N resistors 6, N first and N second generators 7.8 current, current generator 9, and power and signal outputs 10 and 11. The goal is achieved by introducing N additional transistors 5. The currents I _{8I of} sources 7 are selected so that the voltage drops to resp. N resistors 6 from the flow of current I _8I did not exceed 1-2 mV. If the temperature of the I -th element of the amplifier cascade increases for any reason, then ϕ _{T is the} temperature potential of pn-junctions of transistors 3.5 respectively. element proportional to the absolute temperature also increases. The current gain is independent of the parameters of the transistors and is determined by R6, N (N is the ratio of the emitter areas of the transistors 3 and 5). 1 il.

Description

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3150

The invention relates to radio engineering and can be used in high-power integrated devices.

The purpose of the invention is to increase the temperature stability.

The drawing shows a circuit diagram of an amplifier foot, on a cascade.

The amplifier cascade contains N first transistors 1, N second transistors 2, N components; Transistors made on transistors 3, 4, N additional transistors 5, Ы resistors 6, N first current generators 7, N second current generators 8, third current generator 9, as well as power and signaling conclusions 10 and P.

Amplification cascade works as follows.

The currents 1, the current sources 7 are chosen such that the voltage drop across the corresponding N resistors 6 from the flow of current I does not exceed

1-2 mV. Then, neglecting the base currents of the i-ro transistor 3, for the current 14 i transistor 4 can be recorded (if the transistors of the amplifier stage are made on the same chip according to the same technology and are located next to each other)

I,; (l8i-I,;) (URci / 4) V)

where ikg (18r1g;), (2) i. - i-ro second collector current

transistor; C is the temperature potential of the p-junction;

n is the ratio of the emitter areas of transistors 3 and 5. If the voltages on resistors R6 are not equal, for example, Uj,; 7Unjj, then the voltage difference emitter — base of transistors li and Ij, transistor I is closed, Ij is unlocked, and currents Ij , - and I, j. changed so that U, | i4 ,.

Then according to (1) and (2) (Ig |

v) and

Thus, the currents N of the transistor

Ditch 4 is equalized, the load current flowing between terminals 10 and 11 is evenly distributed.

If the temperature of the i-ro element of the amplifier stage increases for any reason, then q; (The temperature potential of the pn junctions of the transistors 3, 5 of the corresponding element, proportional to the absolute temperature) also increases. Then, since it remains equal to Ujjg of the remaining elements of the amplifier cascade, then according to (1), it will decrease. Thus, in the amplifier stage, there is no positive temperature feedback.

The maximum current 1. is limited and equal (at I2.)

l4; MOKc Igi exp (l8; R6 / if). (3)

Thus, by limiting the currents 1., you can limit the load current. The current gain is independent of the parameters of the transistors and is determined by R6, p.

Claims (1)

Invention Formula An amplifier stage containing N first, N second, N composite transistors, N first, S second and third current generators, and N resistors whose first terminals are connected and are the signal output of the amplifier cascade, and the second terminals are connected to the emitters of the corresponding N first transistors, the bases of which are connected and connected to the output T15 of its current generator and to the emitters of N second transistors, the bases of which are connected to the collectors of the corresponding N first transistors and the outputs of the corresponding N first current generators, and the collectors N of the composite transistors are connected and are the power output of the amplifier stage, and the bases are connected to the outputs of the corresponding second current generators and the collectors of the corresponding N second transistors, characterized in that, in order to increase the temperature stability, N additional transistors are inserted, the collectors of which are connected by bases corresponding N composite transistors, emitters with the second terminals of the corresponding N resistors, and bases with the emitters of the input transistors corresponding to N These transistors, with the emitters of the N composite transistors connected to the first terminals of the N resistors.