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:
Oct. 16, 1984
Filed:
Mar. 29, 1982
John J Moser, Jr, Essex Junction, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
This describes a tristate driver circuit designed such that it will not be destroyed by excessive high voltage conditions when two such drivers are connected to a bus at the same time. The circuit accomplishes this with parallel high current, low impedance and low current, high impedance output devices, coupled to means for causing the high current, low impedance devices to supply, to the circuit output, only the initial high currents required without inhibiting the low current, high impedance devices from maintaining the steady state conditions needed to clamp the output at the desired output level. The circuit is arranged to cause both high and low current output devices to be initially conductive to charge the output terminal to the desired level, but to subsequently shut off the high current, low impedance device while keeping the low current, high impedance device in a condition to clamp the output at the desired level. This result is achieved by providing the high current output devices with means for automatically terminating once the initially required high current has been supplied to the output.