Richtek Technology Corporation

Richtek Technology Corporation, R.o.c

Tzu-Huan Chiu

Kwan-Jen Chu

Chien-Ping Lu

Nien-Hui Kung

Wei-Hsin Wei

Hung-Yu Cheng

Chun-Tsung Chen

Chieh-Min Lo

Chien-Sheng Chen

Shuo-Wen Chang

A control circuit of a power converter includes: an error detection circuit, configured to operably generate an error signal according to a reference signal and a feedback signal when coupling with an external feedback node of an external feedback circuit; an output signal detecting circuit, positioned inside the control circuit, configured to operably receive and detect an output signal of the power converter to generate a representative signal; an on time deciding circuit, coupled with the output signal detecting circuit, configured to operably generate an on time signal according to the representative signal; and a control signal generating circuit, coupled with the error detection circuit and the on time deciding circuit, configured to operably control on time of one or more power switches of the power converter according to the error signal and the on time signal.

Control circuit of power converter

The present invention discloses a rail-to-rail comparator. The rail-to-rail comparator includes: a positive voltage rail providing a positive supply voltage, a ground voltage rail providing a ground voltage, an input stage, and an output stage. The input stage includes: a positive and a negative input terminals for receiving a first input signal and a second input signal; a first differential amplifier circuit, which includes a pair of depletion NMOS transistors to generate a first pair of differential currents; and a second differential amplifier circuit, which includes a pair of native NMOS transistors to generate a second pair of differential currents. The output stage is coupled to the first differential amplifier circuit and the second differential amplifier circuit, and generates an output signal related to a difference between the first input signal and the second input signal.

Rail-to-rail comparator

Methods are proposed for a buck boost voltage regulator to monitor the output voltage or both the inductor current and the output voltage of the buck boost voltage regulator to control the buck boost voltage regulator to reduce the switching times of the power switches of the buck boost voltage regulator to improve the light load efficiency of the buck boost voltage regulator.

Methods for light load efficiency improvement of a buck boost voltage regulator

The present invention discloses a buck-boost switching regulator, and a control circuit and a method therefor, to convert an input voltage to an output voltage. The control method comprises: obtaining a feedback signal relating to the output voltage; comparing the feedback signal with a reference voltage to generate an error amplified signal; when the error amplified signal is between a first voltage (V) and a second voltage (V), causing the switching regulator to operate in a buck conversion mode; when the error amplified signal is between a third voltage (V) and a fourth voltage (V), causing the switching regulator to operate in a boost conversion mode; and when the error amplified signal is between the second voltage and the third voltage, causing the switching regulator to operate in a buck-boost conversion mode in which each power switch operates according to a respective predetermined pulse width, wherein V&#x3c;V&#x3c;V&#x3c;V

Buck-boost switching regulator and control circuit and method therefor

A LED driver is disclosed for providing a current for LED lighting. The LED driver includes an inductor and a controller having a power switch, and the inductor, the power switch and a LED to be driven are configured to be an asynchronous boost converter. Because the driven LED serves as a rectifier diode of the asynchronous boost converter, the controller may have fewer components and requires smaller die area.

Boost converter LED driver and controller thereof

The present invention discloses a power system with temperature compensation control, for selectively supplying power from an external power source or a battery to a load, or charging the battery from the external power source, the power system comprising a buck converter electrically connected between the external power source and the load, and a temperature compensation control circuit for adjusting an output voltage of the buck converter according to a sensed temperature.

Power system with temperature compensation control

The present invention discloses a dual power switch and a voltage regulator using the dual power switch. The dual power switch comprises a PMOS power switch and an NMOS power switch connected in parallel and operating according to corresponding predetermined conditions, respectively.

Dual power switch with activation control and voltage regulator using same

The present invention discloses a boost driver circuit which converts an input voltage to an output voltage and supplies it to a load, the boost driver circuit comprising: a power transistor electrically connected with a node between the input voltage and the output voltage; a pulse width modulation driver circuit for controlling the operation of the power transistor; an output node electrically connected with the output voltage; a feedback node electrically connected with the load; a low voltage transistor electrically connected with the feedback node; and a clamp and fast discharge circuit electrically connected with the feedback node for discharging the feedback node when the voltage at the feedback node is higher than a predetermined voltage.

Boost driver circuit with fast discharging function

A switching regulator includes a low-side switch having a body diode. During the low-side switch is on, a zero-current sense circuit monitors the inductor current of the switching regulator and triggers a signal to turn off the low-side switch when the inductor current falls down to a zero-current threshold, to prevent reverse inductor current from the output terminal of the switching regulator. A body-diode turn-on time controller monitors the turn-on time of the body diode and adjusts the zero-current threshold according thereto, and the turn-on time of the body diode can be reduced to an optimal interval subsequently. The self-adjustable zero-current threshold is adaptive according to the application conditions, such as the inductor size, input voltage and output voltage of the switching regulator.

Adaptive zero current sense apparatus and method for a switching regulator

The present invention provides a power path control circuit comprising: an input node for receiving an external power; a first power transistor electrically connected between the input node and a first node, for controlling power supplied from the input node to the first node; a second power transistor electrically connected between the first node and a battery, for controlling power supplied from the battery to the first node; an error amplifier including an output electrically connected with a gate of the second power transistor, a first input terminal electrically connected with the first node, and a second input terminal electrically connected with the battery, wherein a voltage difference is allocated between the two input terminals.

Power path control circuit

A quick response switching regulator comprises a power stage having a pair of high-side switch and low-side switch and an inductor connected together by a switching node, a feedback circuit for producing a feedback signal, and a control circuit producing control signals with reference to the feedback signal to control the pair of high-side switch and low-side switch. The feedback circuit is connected to the switching node to shorten the feedback path and speed up the response. The control circuit further monitors the current flowing through the inductor to keep the low-side switch off before the peak of the inductor current becomes higher than a value.

Growing community of inventors

Jhubei, Taiwan

Tzu-Huan Chiu