07045993 is referenced by 39 patents and cites 3 patents.

A current mode PWM buck regulator is provided. The regulator includes a top-side transistor, a bottom-side transistor, an inductor, a sample-and-hold circuit, a ramp generator, a PWM comparator, an error amplifier, and a current sense amplifier. A current through the low-side transistor is sensed by the current sense amplifier. Also, a current sense voltage provided by the current sense amplifier is sampled when the low-side transistor is on, and held when the low-side transistor is off. The ramp generator is arranged to generate a voltage ramp that emulates the upslope of the inductor current. Additionally, the sampled low-side transistor current is combined with the voltage ramp. The PWM comparator is arranged to provide a PWM signal by comparing the voltage ramp to a comparison signal provided by the error amplifier.

Title
Apparatus and method for step-down switching voltage regulation
Application Number
10/835616
Publication Number
7045993 (B1)
Application Date
April 29, 2004
Publication Date
May 16, 2006
Inventor
Kenji Tomiyoshi
Cupertino
CA, US
Agent
Matthew M Gaffney
Darby & Darby PC
Assignee
National Semiconductor Corporation
CA, US
IPC
G05F 1/613
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