Chong K Choi

US Patent:

20090195318, Aug 6, 2009

Filed:

Feb 5, 2008

Appl. No.:

12/026394

Inventors:

Li-Hung Kang - Gilbert AZ, US
Chong W. Choi - Gilbert AZ, US

Assignee:

FREESCALE SEMICONDUCTOR, INC. - Austin TX

International Classification:

H03F 3/04
G05F 3/02
G05F 3/16

US Classification:

330296, 327538

Abstract:

A disclosed self regulating biasing circuit (SRBC) includes an unregulated node that couples to an unregulated power supply that produces a supply voltage. An impedance element of the SRBC carries an unregulated current having a nominal component and a variance component between an unregulated node and a regulated node. A detection circuit connected between the unregulated node and a third node detects a variance component of a supply voltage and generates a detection current based on the variance component. A compensation circuit connected to the third node draws a compensation current, based on the detection current, from the regulated node. The SRBC is designed wherein the compensation current is approximately equal to the variance component of the unregulated current. The regulated node may be connected to a control terminal of a transistor to be biased.