The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 24, 1992
Filed:
Sep. 18, 1991
Hiroshi Koga, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An amplifier circuit configured to be selectively brought into an active condition or in an inactive condition by a control signal, comprises an input differential circuit stage having a pair of input terminals and one output node, and an output emitter follower stage having a driving NPN transistor having a base connected to the output node and a collector connected to a high voltage Vcc. An emitter of the driving NPN transistor is connected to an output terminal and a collector of an active load NPN transistor having an emitter connected to a low voltage Vss. A control circuit is connected to a base of the active load NPN transistor and is controlled by the control signal so as to turn on the active load NPN transistor in response to an active control signal and to turn off the active load NPN transistor in response to an inactive control signal. Another control circuit is connected to the base of the driving transistor and controlled by the control signal so as to cut off a base current of the driving transistor in synchronism with the inactive control signal.