Amir A Asvadi

US Patent:

20090079408, Mar 26, 2009

Filed:

Apr 23, 2008

Appl. No.:

12/107968

Inventors:

Chongming Qiao - Irvine CA, US
Reza Amirani - Dana Point CA, US
Vincent Condito - San Jose CA, US
Amir Asvadi - Laguna Hills CA, US

Assignee:

NEXEM, INC. - Irvine CA

International Classification:

G05F 1/46

US Classification:

323283

Abstract:

A voltage controller and method providing multiple modes of operation. Embodiments include pulse-width modulation (PWM), feed-forward (FF), pulse-frequency modulation (PFM) and skip operation (PWM-FF-PFM/SKIP). Controller embodiments have integrated MOSFET components, comparator hysteresis, oscillator feed-forward, fixed gain, and error amplifier (EA) limits thereby providing improved efficiency and noise immunity.

US Patent:

7254000, Aug 7, 2007

Filed:

Jun 20, 2005

Appl. No.:

11/156767

Inventors:

Mark Smith - Irvine CA, US
Chongming Qiao - Irvine CA, US
Vincent Condido - Palo Alto CA, US
Amir Asvadi - Laguna Hills CA, US

Assignee:

Nexem, Inc. - Irvine CA

International Classification:

H02H 9/00

US Classification:

361 56, 323224

Abstract:

An over voltage protection circuit for single phase and multiphase buck converters. According to one embodiment, upon the occurrence of an over voltage condition, the high side switch is turned Off and the low side switch is On. As the output voltage drops below a lower threshold, the low side switch is turned Off thereby reducing or eliminating negative spikes on the voltage output.