Texas Instruments Corporation

Cirrus Logic Inc.

Jiandong Jiang

John L Melanson

Johann Guy Gaboriau

Lingli Zhang

Paul T Bennett

Sang Yong Lee

Robert Kenneth Oppen

Robert Henry Bell

DC to DC converters and PWM controllers are presented in which a slope compensation ramp signal is provided for current control operation via a frequency adaptive compensation circuit with a phase locked loop that provides a control output signal having an amplitude generally proportional to the frequency of a clock signal, and a slope generator circuit generating the slope compensation ramp signal with an amplitude generally proportional to the control output signal amplitude.

DC to DC converter and PWM controller with adaptive compensation circuit

A pre-charge apparatus and method for controlling startup transients in a capacitively-coupled switching power stage provide lower cost and improved startup transient performance in Class D amplifiers, as well as in other AC power converter applications. A charging source is activated at startup to control the charging of an external capacitor from a single power supply rail to an operating point voltage equal to the average DC output of the switching circuit, while a control circuit disables the output power stage of the switching converter. The current source may be a constant-current source and/or may be controlled via feedback from the voltage or current at the output terminal of the converter to taper the current level to more accurately control the charging. A discharge circuit can also be provided to discharge the output terminal to an opposite power supply rail before commencing the controlled charging.

Pre-charge apparatus and method for controlling startup transients in a capacitively-coupled switching power stage

Disclosed are methods and apparatus for over-current detection in PWM power stages. Disclosed methods and apparatus provide over-current detection with adaptive filtering according to the pulse width of the PWM input signal. Methods and apparatus for their implementation are described for detecting the pulse width of a PWM signal in the PWM circuit. According to the detected pulse width, a digital delay less than the pulse width of the PWM signal is selected from among a plurality of available digital delays. Further, an over-current condition in the PWM power stage is detected. The detected over-current signal is filtered by means of the selected digital delay and an over-current detection result is output.

Adaptive over-current detection

Growing community of inventors

The Colony, TX, United States of America

Jiandong Jiang