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:
Oct. 21, 2003
Filed:
Nov. 30, 2001
Gang Liu, Novi, MI (US);
Analog Technologies, Inc., Sunnyvale, CA (US);
Abstract
A pulse width modulation (PWM) circuit has a PWM output signal that features accurate timing even in the face of interference imposed upon the control signal representative of the desired PWM duty cycle. The PWM circuit includes or has a first or switching section and a second or analog section. The second section has an operational amplifier with a summing circuit that sums two input signals, namely a triangular wave signal and the control input signal, and then amplifies the summed signal to produce a trapezoidal waveform output delivered to the second section. The first section features a two-input comparator that produces a PWM signal output with a fast transition in response to trapezoidal output fed as an input and compared to a stable reference signal. Due to the speed of the op amp, timing errors on the PWM output signal due to interference on the control signal are minimized.