US 7,321,201 B2
Basic halogen convertor IC
Peter Green, Redondo Beach, Calif. (US); and Iulia Rusu, Redondo Beach, Calif. (US)
Assigned to International Rectifier Corporation, El Segundo, Calif. (US)
Filed on May 21, 2003, as Appl. No. 10/443,525.
Application 10/443525 is a continuation of application No. PCT/US02/41836, filed on Dec. 30, 2002.
Claims priority of provisional application 60/343236, filed on Dec. 31, 2001.
Claims priority of provisional application 60/398298, filed on Jul. 22, 2002.
Prior Publication US 2004/0012346 A1, Jan. 22, 2004
Int. Cl. H05B 37/02 (2006.01)
U.S. Cl. 315—224  [315/291; 315/307; 315/247; 315/209 R] 7 Claims
OG exemplary drawing
 
1. A control circuit implemented in an integrated circuit for providing a control signal to a power semiconductor device for providing power to a filament lamp, said control circuit comprising:
an oscillator for generating said control signal; and
a shutdown circuit for shutting down said oscillator in response to a fault condition including both overload and short circuit conditions,
wherein said control circuit senses load current as a feedback voltage on a resistor connected to said power semiconductor device and feeds back said voltage to detect both short circuit and overload conditions,
wherein said control circuit detects a short circuit by determining whether said feedback voltage exceeds a first threshold, and detects an overload by determining whether said feedback voltage exceeds a second threshold, said first threshold being higher than said second threshold, and
wherein said control circuit shuts down the oscillator if the feedback voltage exceeds the first threshold for a first time, or exceeds the second threshold for a second time, said first time being shorter than said second time.