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:
Jun. 11, 2002
Filed:
Mar. 27, 2000
Raymond J. Grover, Manchester, GB;
Franciscus ACM Schoofs, Valkenwaard, NL;
Pieter G. Blanken, Nuenen, NL;
Koninklijke Philips Electronics N.V., New York, NY (US);
Abstract
A switch circuit for battery-powered equipment, for example a mobile telephone or a portable computer, comprises a 4-terminal bi-directional semiconductor switch (M ) and a protection diode (Dbg). The switch (M ) has a control-gate terminal (g) for applying a control signal (Vg) to form a conduction channel ( ) in a body region ( ) of the switch, for turning the switch (M ) on and off between a battery (B) and a power line ( ) of the equipment. The switch (M ) also has a back-gate terminal (b; bg) in a bias path that serves for applying a bias potential (Vmin) to the body region ( ). The protection diode (Dbg) has a diode path in series with the back-gate terminal (b; bg) so as to provide in the bias path a rectifying barrier ( ′) that blocks current flow between the body region ( ) and the gate-bias terminal (b, bg) in the event of a reverse voltage polarity across the switch (M ), for example when recharging the battery (B). Preferably the protection diode (Dbg) is integrated with a semiconductor device body ( ) of the switch (M ), with a p-n junction ( ′) or Schottky barrier ( ) forming its rectifying barrier in the bias path between the body region ( ) and the gate-bias terminal (bg).