SU1580441A1 - Reading amplifier - Google Patents

Abstract

The invention relates to microelectronics and can be used to create integrated circuits. The purpose of the invention is to increase speed. This goal is accomplished by reducing the capacitance in the most stressed amplifier nodes to which the collectors of the current source transistors are connected, and reducing the logical difference at its output. 1 il.

Description

The invention relates to microelectronics and can be used to create integrated circuits.

The purpose of the invention is to increase the speed of the amplifier.

The drawing shows a circuit diagram of an amplifier.

The amplifier contains the first and second emitter followers on transistors 1 and 2 and the first 3 and second 4 current supply elements on resistors, the first and second current generators on transistors 5 and 6 with a stabilizing element 7 on a resistor, the differential cascade on transistors 8, 9 and first 10 and the second 11 load elements on resistors, the first 12 and second 13 limiting elements on transistors and the third limiting element 14 on the resistor, the first 15 and second 16 information inputs of the amplifier, the first 17, the second 18, the steppe 19 and the fourth 2 0 information inputs of the amplifier, power bus 21 and bus 22 of the zero potential of the amplifier.

The amplifier works as follows.

When the input 15 is logical 1 and the input 16 is logical O, the current in both arms of the amplifier is determined by the current source on elements 1, 5 and element 3. In this case, the output 17 is logical 1, and since element 11 is also turned on, at the exit

19 will be a logical O due to the flow of current through the element 10. At the output 18 logical O, and the output

20 logical 1, because element 9 is turned off. When the input influences change, the conditions at the outputs change to prohibitive. The ratio of the ratings of the elements 13 and 7 are chosen so that on the element 13 the voltage drop is less than the logical difference at the input, thereby decreasing by the same value

Gain differential at the output due to Boost logic level About emitters of elements 12 and 13. For normal operation of an amplifier, it is necessary that the ratings of elements 3 and 4 be equal. Element 7 is necessary to set the current in the emitter of elements 11 and 9 sufficient for them to work at elements 10 and 11, serves to set the current to the element 13, as well as to dissolve the excess current without elements 5 and 6 when switching.

Depending on the specific application of the amplifier, the output signal is removed either from outputs 17 and 18, or from outputs 19 and 20. The logic level 1 at outputs 17 and 18 is equal to the sum of the voltage drops on the base of emitter junctions of transistors 5 and 11 or-6 and 9 accordingly, the level of logic O is less by the amount of voltage drop on element 14, which, in order to increase speed, is chosen to be very small, minimum required for operation (with a small margin) of elements 11 and 9. Logical level 1 at outputs 19 and 20 is less than the supply voltageby the amount of voltage drop on element 14, which is very small, and the logic level 0m is less than logic level 1 by the amount of voltage drop on elements 10 and 11, respectively.

A further increase in speed is obtained due to the fact that, compared to a known amplifier, the nodes where outputs 17 and 18 are connected have reduced capacity by eliminating the capacity of emitters of limiting transistors, which are now connected to emitters of elements 1 and 2, and are much faster than in a known amplifier, they switch to the logical state, since this process is not slowed down by elements 3 and 4, respectively.

The decrease in the output differential due to the internal embedded source of the reference voltage in the emitter circuit of elements 1 and 2, and the decrease in capacitance at the most stressed nodes due to this, significantly improves the performance of the read amplifier.

five

five

0

five

0

five

50

five

Claims (1)

Claims. A read amplifier containing the first and second emitter followers, each made of a transistor and a current-carrying element on a resistor, a differential cascade on the first and second transistors, the first and second current generators on transistors with a stabilizing element on a resistor, the first output of which is connected to the bus zero potential of the amplifier and the combined emitters of the transistors of the current generators, the bases of the transistors of which are connected to the second output of the resistor of the stabilizing element and Differential cascade transistor emitters whose transistor bases are combined respectively with the collectors of the first and second current sources and connected respectively to the "first terminals of the first and second current supply elements and are respectively the first and second information outputs of the amplifier; differential collectors of the transistors are connected respectively to the first terminals of the resistors of the first and second load elements and are respectively the third and the fourth information outputs of the amplifier, the collectors of the transistors of the first and second emitter followers are connected to the power supply bus of the amplifier, the bases are the first and second information inputs of the amplifier, respectively, and the emitters are connected to the second terminals of the first and second current supply elements, respectively, in that in order to increase speed, the first and second limiting elements on the transistors and the third limiting element on the resistor, the first pin of which It is connected to the second terminals of the load element resistors and the combined bases of the transistors of the limiting elements, the collectors of which are connected to the power supply bus of the amplifier, and the emitters are connected respectively to the emitters of the transistors of the first and second emitter followers. U o / 7о 022