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:
Feb. 04, 1997
Filed:
Feb. 03, 1995
Thomas F Uhling, Monument, CO (US);
Keith C Griggs, Colorado Springs, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A first amplifier channel between an input and output includes an input transistor emitter and a first output transistor emitter connected together to form a first emitter pair. A current source is connected to the emitter pair via a transistor which is controlled by a latch. Programming the latch permits the channel to be turned on or off. The emitter pair is connected to a positive voltage through a resistor and to ground through a diode to force it to a controlled off voltage, which prevents signals from passing when the channel is off. There is a output driver amplifier in a feedback circuit. An outdisable circuit controls the voltage and current of the output driver amplifier to place the output in a state in which it appears electrically as an open circuit when the channel is off. Multiple programmable amplifiers can be combined to make a multiplexer, a selectable gain circuit, or a selectable attenuation circuit, all with high band width and high signal integrity.