SU1401564A1 - Current amplifier - Google Patents

Abstract

The invention relates to measuring and computing. The purpose of the invention is to increase the gain at low input currents and preserve the operating frequency band. The current amplifier contains leakage current sources 1 and 1, inflow current source 2, additional leakage current source 3 introduced, and inflow current sources 4 and 4, source 5 of the initial bias current. Sources 1, 1, and 3 are filled with reflectors 6 and 7 of the current, and sources 2, 4, and 4 are filled with reflectors 8 and 9 of the current. The device also contains power supply bus 10 and 11. Since the execution of the blocks is identical, the currents in the initial conditions at their inputs and outputs can be considered the same. The sameness condition is satisfied with the accuracy of the current transfer coefficients oi. current transistors. The displacement currents of the subsequent stages are the displacement currents of the preceding ones, amplified with a coefficient. amplification of current reflectors used. In case the coefficient the gain of the first current reflector is equal to one, the bias currents of all the cascade are the same and are close to the source current 5. I Il. SS (L

Description

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The invention relates to measuring and computing techniques and can be used in the construction of current amplifiers based on matched transistor pairs in integrated technology.

The purpose of the invention is to increase the gain at low input currents and to preserve the frequency band.

The drawing shows a structural electrical circuit current amplifier.

The current amplifier contains sources 1 and 1, a flowing current, a source of 2 flowing current, an additional source 3 of a flowing current, additional sources 4 "and 4 2 of a flowing current, a source 5 of the initial bias current, and sources 1 and 1 of a flowing current and an additional source 3 of a flowing the current is made on the first and second reflectors 6 and 7 of the current, the source 2 of the flowing current and additional sources 4, and 4, the flowing current are made on the first 8 and second 9 current reflectors, as well as the first 10 and second 11 power supply buses.

The current amplifier operates as follows.

Amplified input current I is fed to the input of an additional source 4 ,. The bias current IC / M specified by the source 5 from its second output flows through the input of the additional source 4, into the second reflector 9 of the additional source 4, through a common output of which day-1 current flows into the negative second bus 11 of the power supply.

Displacement current I set by source) L

NICOM 5 from its first output, flows through the input of source 1, and the supply current flows from the positive first bus 10 of the power supply to the common output of source 1,,

The currents flowing into the first and second outputs of the additional source 4, are summed with one another and with the current flowing from the second output of source 1 ,. Since the execution of these blocks is identical, the currents in the initial conditions at the inputs and their outputs can be considered identical. The condition of sameness is fulfilled with the accuracy of the current transfer coefficients of the current entering the current reflectors of the transistors.

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Therefore, the current flowing into the second output of the additional source 4 is equal to the current flowing from the second output of the source, and when summed up, they are compensated.

The residual residual current, equal to the current flowing into the first output of the additional source 4, is supplied as a bias current IcmjHa to the input of the additional source 3.

The current flowing from the first output of source 1 ,, is supplied as a bias current to the input of source 2.

Similarly, the bias currents 1. and I cm-e inputs, respectively, of the additional source 4 and the source 12 are formed. Thus, the bias currents of the subsequent stages are the bias currents of the previous ones, amplified with the gain current reflectors used. If the gain of the first current reflector is one, the bias currents of all the stages are the same and close to the current of source 5.

The current of the input signal passes through the chain of additional sources of 4, 3, 42 currents, the gain of each of which is (1 + K,) (1 + K) - 11,

where K and K are the current gain factors of the first and second current reflectors 8 and 9, respectively, and 6 and 7. Through compensating sources - 1 ,, 2 ,, l, etc. input current does not flow.

Claims (1)

Invention Formula The current amplifier containing the source of the initial bias current, N sources of flowing current, where N, 3, ..., each of which contains the first and second current reflectors made on transistors of the same structure, and the common terminal of the first current reflector is connected to the input of the second reflector current, the common output of which is the common output of the source of the outgoing current and is connected to the first power supply terminal, the input of the first current reflector is in the output of the current source, the first and second outputs of which are the outputs corresponding to etstvenno far the second and second current reflectors, N sources of incoming current, made on transistors of a different structure, similar to N sources of flowing current, common terminals of N sources of flowing current are connected to the second power supply bus, the input of the first source of flowing current is connected to the first output source of the initial bias current, which differs . With the aim of increasing the gain at low input currents and preserving the operating frequency band, N additional sources of flowing current and N additional sources have been introduced. chnikov influent current eponymous N identical current sources effluent and influent N current sources, wherein the first and second outputs of the i-ro complement ten 20 01564 the main source of the flowing current is combined and connected to the second output, the i-ro source of the flowing current and the input i-ro of the additional source of the flowing current, the first and second outputs of which are combined and connected to the second output of the i-ro source of the flowing current and the input of the additional source of the flowing current, the first output of the i-ro source of the flowing current is connected to the input of the i-ro source of the flowing current, and the first output of the i-ro source of the flowing current is connected to the input of the i + 1 th source of the flowing current, and the second output of the source The initial bias current is connected to the input of the first auxiliary source of the flowing current, which is the input of the current amplifier. 15