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Buffer Amplifier

IP.com Disclosure Number: IPCOM000061383D
Original Publication Date: 1986-Jun-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Gibson, BD: AUTHOR

Abstract

A transistor buffered voltage-mode amplifier is disclosed. This amplifier operates well when high output load current, at close to rail voltages, is required.

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Buffer Amplifier

A transistor buffered voltage-mode amplifier is disclosed. This amplifier operates well when high output load current, at close to rail voltages, is required.

When the output voltage of operational amplifier 10 approaches the rail voltage of #12 volts, the current through the operative one of the bias resistors 11 and 12 decreases to the point where the base current of the operative one of the transistors 13 and 14 is equal to that of its bias resistor curr Output current 15 is then limited by the transistor's base current times the gain of the transistor.

Bootstrap capacitor 16 operates when more base current is required than the base biasing resistor can supply. Operational amplifier 10 then supplies additional base current via the bootstrap capacitor. The circuit works especially well when current pulses at high voltages are required (i.e., current pulses to an inductive load such as an actuator or voice coil).

This circuit increases both voltage and peak pulsed current outputs, requires a minimum of additional circuitry, and eliminates the need for additional gain stages.

Disclosed anonymously.

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