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:
Jan. 24, 1989
Filed:
Jan. 25, 1988
Keith A Taylor, Portland, OR (US);
Tektronix, Inc., Beaverton, OR (US);
Abstract
A pin driver circuit for driving a digital integrated circuit is capable of producing symmetrical rise and fall characteristics, yet is suitable for implementation in monolithic bipolar integrated circuits. This circuit includes a pair of matched transconductance amplifiers, one at each end of an output resistor, connected between a voltage source and a return voltage. Each amplifier has one of a pair of equal resistors between its input terminal and high output terminal to develop an equal swing voltage on alternate ends of the output resistor when a swing voltage current source is switched between the two input resistors by a control signal. The output is taken from the junction between the output resistor and the low output terminal of the amplifier at the high end of the output resistor. An additional current source is connected to the input resistor of the amplifier at the low end of the divider to provide a current which may be adjusted to allow the standing current in the output resistor to be reduced to a satisfactory minimum. Additional circuitry can be added to allow the output to be put in a high impedance condition. In a preferred embodiment, the high level of the output, the swing voltage, and the standing current may all be controlled.