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:
Dec. 29, 2009
Filed:
Sep. 12, 2007
Hao Yu, Fremont, CA (US);
Sing Chin, Alameda, CA (US);
Bill Wong, Milpitas, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A reference voltage buffer circuit () includes first and second transistors (M, M) and first and second resistors (R, R) connected in series between positive and negative power supply voltages and providing a positive reference voltage (Vrp) and a negative reference voltage (Vrn) at the first current handling terminals of the first and second transistors, respectively. A first control voltage (Vg) for driving the first transistor is generated by a first feedback loop and using a positive boosted voltage. A second control voltage (Vg) for driving the second transistor is generated by a second feedback loop and using a negative boosted voltage. The first and second feedback loops establish the first and second control voltages while the positive and negative boosted voltages ensure sufficient drives are provided to the first and second transistors. The reference voltage buffer is capable of fast settling while maintaining a wide reference voltage range.