Richtek Technology Corporation

Winbond Electronics Corporation

Richtek Technology Corporation, R.o.c

Windbond Electronics Corp.

Richtek Technology Company Ltd

An-Tung Chen

Isaac Y Chen

Chih-Hao Yang

Chien-Fu Tang

Jo-Yu Wang

Li-Wen Fang

Jing-Meng Liu

Hung-Der Su

Shao-Hung Lu

Yung-Peng Hwang

Kuo-Chung Lee

Pao-Chuan Lin

Ting-Jung Tai

Chi-Hua Lin

Wei-Hsu Chang

Nien-Hui Kung

Shui-Mu Lin

Liang-Pin Tai

Wei-Hsin Wei

Kuang-Fu Chang

Hsin-Yi Wu

Ping-Ching Huang

Jen-Hung Chi

Cheng-Kuang Lin

Fu-Shiang Lai

Hsin-Mei Chen

Shiueshr Jiang

Jun-Yao Huang

Fu-Yuan Shih

Jo Yu Wang

Ching-Wei Hsueh

Chien-Liang Kuo

Yu-Chiao Hsieh

Jong Ping Lee

A multi-phase motor control method controls a multi-phase motor which includes multiple nodes respectively receiving a corresponding number of driving voltage signals to control a rotation of a rotor. The motor control method includes: sensing a signal phase of a current signal corresponding to at least one node, for example by sensing a zero-crossing point of the current signal; determining a reference phase for the current signal; calculating a phase difference between the signal phase and the reference phase; and controlling a phase switching frequency of the stator according to the phase difference, such that the signal phase is close to or in phase with the reference phase, to thereby obtain an optimum rotation speed of the rotor corresponding to a given driving voltage. The present invention also provides a multi-phase motor control device using the motor control method.

Multi-phase motor control method and device using the same

The present invention discloses a flyback power supply circuit with a programmable function and a control method thereof. The flyback power supply circuit includes: a transformer circuit, a power switch circuit, a primary side control circuit, an opto-coupler circuit, and a secondary side control circuit. The primary side control circuit determines whether an over voltage condition occurs, and further determines whether to generate an over voltage protection signal to turn OFF a power switch of the power switch circuit according to a rate of increase of a feedback signal and a control level, or according to the rate of increase of the feedback signal and a rate of change of a target control signal.

Flyback power supply circuit with programmable function and control method thereof

An over-voltage protection circuit is applied to a switching voltage converting circuit. The switching voltage converting circuit manipulates an upper bridge power switch in the circuit, so as to convert an input voltage into an output voltage by an inductor. A channel of the upper bridge power switch and the inductor are coupled to a phase end. The over-voltage protection circuit includes: a comparator, coupled to the switching voltage converting circuit, wherein when a voltage of the phase end is higher than a voltage limiting threshold, an output end of the comparator outputs a first voltage level; and a pulse width detection unit, coupled to the output end of the comparator, wherein when the output end of the comparator remains the first voltage level for a time period longer than a protection period, the pulse width detection unit outputs an over-voltage protection activation signal.

Over-voltage protection circuit and over-voltage protection method

A voltage converting controller is applied to a switching voltage converting circuit, in which the voltage converting controller periodically operates a high-side power switch and a low-side power switch in the switching voltage converting circuit with a high-side control signal and a low-side control signal, respectively, so as to convert an input voltage into an output voltage via an inductor. Defining an ideal duty cycle as the rating value of the output voltage divided by the value of the input voltage, when the ideal duty cycle is less than one threshold duty cycle, then the period of the high-side control signal is a constant; and when the ideal duty cycle is greater than the threshold duty cycle, the period of the high-side control signal and the period of the ideal duty cycle are positively correlated.

Voltage converting controller and method of voltage converting control

A power off delay circuit includes a switch connected between an external power input terminal and an internal power supply terminal, a capacitor connected to the internal power supply terminal, and a hysteresis comparator to switch the switch according to the voltages of the external power input terminal and the internal power supply terminal. During on-time of the switch, the external power input terminal is connected to the internal power supply terminal and the capacitor can be charged by the external power source. When the switch is off, the capacitor provides electric power for an internal circuit. Application of the power off delay circuit to an audio system may eliminate the turn-off pops of the audio system.

Power off delay circuit and method, and audio system with power off delay

A control circuit of a switching regulator includes a control pin for coupling with an external resistor; a resistor detecting circuit for detecting a resistance of the external resistor; a current generating module for generating a corresponding control current according to a detection result of the resistor detecting circuit; an oscillating circuit for generating a clock signal; and a mode-switching circuit. When the mode-switching circuit configures the oscillating circuit to operate in a resistor-controlled mode, the oscillating circuit generates the clock signal according to the control current so that the clock signal has a frequency corresponding to the resistance of the external resistor. When the mode-switching circuit configures the oscillating circuit to operate in a signal-controlled mode, the oscillating circuit generates the clock signal according to an external synchronous signal coupled with the control pin so that the clock signal is synchronized with the external synchronous signal.

Switching regulator control circuit with multiple clock frequency setting modes

The present invention discloses an adaptive phase-shifted synchronization clock generation circuit and a method for generating phase-shifted synchronization clock. The adaptive phase-shifted synchronization clock generation circuit includes: a current source generating a current which flows through a node to generate a node voltage on the node; a reverse-proportional voltage generator coupled to the node for generating a voltage which is reverse-proportional to the node voltage; a ramp generator receiving a synchronization input signal and generating a ramp signal; a comparator comparing the reverse-proportional voltage to the ramp signal; and a pulse generator for generating a clock signal according to an output from the comparator.

Adaptive phase-shifted synchronization clock generation circuit and method for generating phase-shifted synchronization clock

A level shifter includes an input stage circuit, a latch circuit and a transient speed-up circuit. The input stage circuit receives an input signal. The latch circuit is coupled to the input stage circuit through a first output terminal and a second output terminal, and determining steady-state levels of the first and the second output terminals according to the input signal. The transient speed-up circuit is coupled to the first and the second output terminals. When the transient speed-up circuit determines the first and the second output terminals are at the same logic level, the transient speed-up circuit accelerates the positive edge transition of the first or the second terminals.

Level shifter

A hysteretic mode LED driver for providing a driving current for an LED includes a hysteretic comparing circuit and a feedback loop. The hysteretic comparing circuit compares a driving current related sensing signal with a reference signal to control the average value of the driving current. The feedback loop senses the error between the average value of the driving current and a target value to adjust the reference signal or the offset of the hysteretic comparing circuit to adjust the average value of the driving current.

Hysteretic mode LED driver with precise average current

The present invention discloses a fuse circuit for final test trimming of an integrated circuit (IC) chip. The fuse circuit includes at least one electrical fuse, at least one control switch corresponding to the electrical fuse, and a resistant device. The electrical fuse is connected with the control switch in series between a predetermined pin and a grounding pin. The control switch receives a control signal to determine whether a predetermined current flows through the corresponding electrical fuse and breaks the electrical fuse. The resistant device is coupled between a bulk terminal and a source terminal to increase a resistance of a parasitic channel, such that an electrostatic discharge (ESD) protection is enhanced, and errors of final test trimming of an IC chip are avoided.

Fuse circuit for final test trimming of integrated circuit chip

A control circuit of a switching DC-DC power supply includes a feedback circuit detecting an output voltage of the power supply to generate a feedback signal, an error comparator detecting an error between the output voltage and a design value of the output voltage, a control logic circuit generating a control signal according to the error for regulating the output voltage, and an offset and delay cancellation circuit generating an offset adjust signal according to the feedback signal and a second reference voltage for adjusting an offset of the error comparator to pull the output voltage toward the design value.

Offset and delay cancellation circuit for a switching DC-DC power supply

A feedback loop is used to optimize a zero current threshold for a switching regulator. After the low side power switch of the switching regulator turns off, the switching node state is monitored to adjust the zero current threshold in a real time and thus the low-side power switch is prevented from turning off too early or too late. Thereby the efficiency in green mode is optimized.

Real time adjustable zero current detection for a switching regulator

An auto-zero amplifier is disclosed, having an amplifying circuit, a switch, and a difference signal generating circuit. The amplifying circuit receives a first input signal for generating a first output signal, and receives a second input signal for generating a second output signal. The switch is coupled between the amplifying circuit and a capacitor. The switch is conducted for charging or discharging the capacitor to a voltage with the first output signal, and the switch is not conducted for keeping the capacitor at the voltage. The difference signal generating circuit is coupled with the amplifying circuit and the capacitor for generating a difference signal of the first output signal and the second output signal, a multiple of the difference signal, a part of the difference signal, and/or a digital output value for the difference signal.

Auto-zero amplifier and sensor module using same

For a system to avoid abnormal operation caused by a shorted parameter setting pin of an integrated circuit, a protection apparatus and method apply a buffered reference voltage to the parameter setting pin to define an internal parameter of the integrated circuit by the buffered reference voltage and an external element connected to the parameter setting pin, and detect the rapid variation of the internal parameter to trigger a shutdown signal or slow down the speed of the variation of the internal parameter reflected to an adjustable signal of the integrated circuit.

Protection to avoid abnormal operation caused by a shorted parameter setting pin of an integrated circuit

A constant frequency ON-time control system applied to a voltage regulator is disclosed. The voltage regulator determines a time length of an input voltage inputted thereto according to an ON-time and thereby regulates an output voltage. The constant frequency ON-time control system includes a constant frequency ON-time control circuit for computing the ON-time according to a system duty cycle of the voltage regulator and a frequency setting parameter and a frequency setting parameter adjusting circuit for generating a frequency setting parameter adjust value according to an OFF-time corresponding to the ON-time and taking a result of operation between the frequency setting parameter adjust value and a preset frequency setting parameter as the frequency setting parameter. The frequency setting parameter adjusting circuit uses the frequency setting parameter adjust value to change the result of operation for varying the frequency setting parameter when the OFF-time is shorter than a reference value.

Growing community of inventors

Pingzhen, Taiwan

An-Tung Chen