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. 21, 2006
Filed:
Feb. 12, 2004
Wayne T. Holcombe, Mountain View, CA (US);
Matthijs D. Pardoen, Mountain View, CA (US);
Wayne T. Holcombe, Mountain View, CA (US);
Matthijs D. Pardoen, Mountain View, CA (US);
Integration Associates, Inc., Mountain View, CA (US);
Abstract
A hook switch circuit is shown wherein two high-voltage bipolar transistors, a PNP transistor Qand a NPN transistor Q. that are connected in a regenerative feedback manner to form a bi-stable latch. The regenerative structure permits the use of low beta transistors that may be turned on with a low control current, but still conduct a sufficient off-hook current. Also shown is a polarity steering regenerative switch (MP, MP) that provides a power supply voltage from a telephone line pair and may be adapted for a polarity signal and can be combined with a current mirror (MP) to produce a current signal proportional to the line voltage (LV).