Richtek Technology Corporation

Ricktek Technology Corporation

Kuo-Ping Liu

Liang-Pin Tai

Jian-Rong Huang

Ko-Cheng Wang

Kent Huang

Yu-Fan Liao

Hung-I Wang

Cheng-Hsuan Fan

Chung-Sheng Cheng

Kent Hwang

Chih-Wei Tseng

Po-Chin Fan

When the switching frequency of a constant on-time power converter decreases to a threshold, the power converter is switched from the original operation of triggering a constant on-time of a high-side switch responsive to the output voltage of the power converter reaching a valley point to the operation of triggering a constant off-time of the high-side switch responsive to the output voltage reaching a peak point, to thereby prevent the power converter from operating in an audio frequency range.

Audio-skipping of a constant on-time power converter

A PWM controller and control method for a DC-DC voltage converter filter the high-frequency component of the voltage at the phase node between high-side and low-side elements of the voltage converter to generate a signal synchronous and in phase or out-of-phase with the inductor current of the voltage converter, to achieve a low-ripple output voltage and stable loop control.

PWM controller and control method for a DC-DC voltage converter

A control circuit provides a control signal for a constant on-time PWM switching converter to produce an output voltage, such that the converter operates with a constant on-time at a first state and operates with a variable on-time at a second state, so as to decrease the switching frequency and thereby the switching loss, to increase the efficiency of the converter, to improve the transient response, and to reduce the recovery time of the output voltage.

Control circuit and method for a constant on-time PWM switching converter

A DC-to-DC converter comprises a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a first current and to generate a second current in response to a load transient, a charging circuit connected with the first current to generate a charging voltage, a driver to compare the charging voltage with two reference signals to generate a pair of low-side and high-side driving signals, and a fast response circuit to compare a load transient signal corresponding to the second current with a third reference signal to generate a bypass signal to drive the output stage of the converter in the load transient.

DC-to-DC converter with fast load transient response and method thereof

In a noise sensitivity improved switching system and method thereof, comprised sensing the output voltage of the switching system to generate a feedback signal, respectively amplifying the feedback signal by two gains to generate two signals in phase or out of phase, filtering one of the two amplified signals, and summing or comparing the filtered signal and the other one, thereby reducing the noise interference to the switching system.

Apparatus and method for noise sensitivity improvement to a switching system

A pulse width modulator includes an amplifier module, a comparator module, and a filter module. The amplifier module receives a feedback voltage signal from a passive network, and generates first and second non-inverted voltage signals and first and second inverted voltage signals in response to the feedback voltage signal. The comparator module receives the first and second non-inverted voltage signals and the first and second inverted voltage signals, and provides first and second differential voltage signals corresponding to the first and second non-inverted voltage signals and the first and second inverted voltage signals. The filter module is coupled between the amplifier module and the comparator module, and is operable so as to attenuate high frequency components of the first and second non-inverted voltage signals. As such, the presence of noise in the feedback voltage signal does not affect differential operation of the comparator module.

Noise-resistant pulse width modulator

A delta-sigma DC-to-DC converter comprises a pair of high-side and low-side switches switched to convert an input voltage to an output voltage, a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a differential current, a charging circuit connected with the differential current to generate a charging voltage, and a driver to compare the charging voltage with two reference signals to generate the pair of low-side and high-side driving signals.

Growing community of inventors

Hsinchu, Taiwan

Kuo-Ping Liu