Title: Transistor amplifier

Abstract: A differential amplifier stage, suitable for use as the first stage in an operational amplifier with a single power supply, has the capability of its input terminals being operated over a range including one of the supply potentials. The differential amplifier stage includes a pair of emitter-coupled transistors of a first conductivity type having their base electrodes connected to input signal terminals. These transistors are each provided with an active collector load by grounded-emitter transistors of the second conductivity type connected collector-to-collector therewith. Commonmode feedback from these collector-to-collector connections to the base electrode of the grounded-emitter transistors is used to regulate the emitter-to-collector potentials of these grounded-emitter transistors to a lower value than their emitter-to-base potentials, but to a value larger enough to avoid saturation.

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Inventors: Leidich, Arthur John (Flemington, NJ, US)

Application Number: 486243
Filing Date: 1974-07-05
Publication_date: 1976-03-23
Assignee: RCA Corporation (New York, NY)
Primary Class(es): 330/258
Other Classes:
US Patent Ref:

3564439	Feb, 1971	Rao	330/30.
3760288	Sep, 1973	Leonard	330/30.
R27351	May, 1972	McGraw et al.	330/69.

Other Refs:
Primary Examiner: Rolinec, R. V.
Assistant Examiner: Dahl, Lawrence J.
Attorney: Christoffersen; H., Cohen; S., Limberg; A. L.