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.

Date of Patent:
Aug. 29, 2000

Filed:

Jan. 14, 1999
Applicant:
Inventors:

Jayendar Rajagopalan, Santa Clara, CA (US);

Christopher Falvey, Santa Clara, CA (US);

Douglas Robert Farrenkopf, Campbell, CA (US);

Assignee:

National Semiconductor Corporation, Santa Clara, CA (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
327137 ; 327131 ; 327134 ;
Abstract

A circuit having multiple channels for generating multiple ramped voltage signals (preferably of a type useful in an interleaved PWM dc/dc converter) such that each ramped voltage signal has a different phase, and all the ramped voltage signals have a uniform controlled maximum amplitude. The circuit can be implemented as an integrated circuit (or portion of an integrated circuit) which generates the multiple ramped voltage signals with uniform maximum amplitude in a manner independent of process and temperature variations in implementing and operating such integrated circuit. In preferred embodiments, the circuit includes a single amplifier having an input coupled to receive a reference signal (indicative of a preselected maximum ramped voltage amplitude) and an output which is coupled (in time-division-multiplexed fashion) to each of the ramped voltage generation channels, thus implementing time-division-multiplexed negative feedback loops which control the maximum amplitude of the ramped voltage signal generated by each channel. The input offset voltage error of the amplifier is applied across all channels equally. Preferably, the ramped voltage signal generating circuit also includes circuitry for generating clock signals for controlling generation of the ramped voltage signals. Another aspect of the invention is a method for generating multiple ramped voltage signals (preferably those of a type useful in an interleaved PWM dc/dc converter) such that each ramped signal has a different phase and a uniform, controlled maximum amplitude.


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