Richtek Technology Corporation

Other

Richtek Technology Corporation, R.o.c

Shui-Mu Lin

Tsung-Wei Huang

Jien-Sheng Chen

Huan-Chien Yang

Wei-Jen Huang

Ti-Ti Liu

Kwan-Jen Chu

Nien-Hui Kung

Wei-Hsin Wei

Chueh-Kuei Jan

Chao-Hsuan Chuang

Shei-Chie Yang

Der-Jiunn Wang

Chien-Sheng Chen

Yung-Chun Chuang

Chin-Chiang Yeh

Chien-Hua Lin

Chin-Tsung Chen

Yiu-I Lin

Nang-Ching Yeung

Ta-Yung Yang

Jing-Meng Liu

Wei-Hsu Chang

Yu-Chang Chen

An-Tung Chen

Cheng-Hsuan Fan

Hung-Che Chou

Ching-Hsiang Yang

Chih-Hao Yang

Chin-Hui Wang

Ching-Yu Chen

Chih-Ping Tan

Pao-Hsun Yu

Ying-Hsin Hsing

Hsien-Chih She

Shun-Yu Huang

Chih-Hua Hou

Chun-I Lin

Ming-Yu Lin

Chuan-Yo Hsiao

Fu-Yuan Shih

Shih Chung Wang

Fan Ho

Hui-Wen Cheng

Chien-Yuan Cheng

Teng-Cheng Chen

Jun-Sheng Cheng

Hsien-Chih Shen

A multi-mode power system includes a battery module, a first conversion circuit, and a second conversion circuit. The battery module includes a battery path switch and a battery group. The first conversion circuit includes switches and a first capacitor, wherein the switches include the battery path switch. The multi-mode power system operates in one of plural operation mode combinations, wherein when the first conversion circuit operates in a first outgoing mode or a first bypass mode, the second conversion circuit operates in a second incoming mode, a second outgoing mode, or a second bypass mode; when the first conversion circuit operates in a first incoming mode, the second conversion circuit operates in the second incoming mode or the second bypass mode.

Multi-mode power system and power conversion circuit thereof

A control circuit for controlling a power supply circuit to provide power to a system device which includes a communication circuit includes: a pulse width modulation (PWM) controller configured to switch a transformer of the power supply circuit to generate a first output voltage; and a switched capacitor converter configured to generate a second output voltage according to the first output voltage. The second output voltage provides power to the communication circuit, wherein the communication circuit generates a power saving signal to control the PWM controller and the switched capacitor converter. When the power saving signal is enabled, the first output voltage is decreased and a duty ratio of the switched capacitor converter is increased.

Control circuit having power saving mode for use in power supply circuit

A power conversion circuit includes an N-level PWM power converter and a switching capacitor power converter. The N-level PWM power converter includes shared switches shared with the switching capacitor power converter, and PWM switches. In an N-level PWM mode, the shared switches and the PWM switches periodically switch an inductor and a capacitor, to execute power conversion between a first power and a second power by N-level PWM switching operation. The switching capacitor power converter includes the shared switches and auxiliary switches. In a capacitive conversion mode, the shared switches and the auxiliary switches periodically switch the capacitor, to execute power conversion between the first power and the second power by capacitive power conversion operation. In the capacitive conversion mode, a portion of the plural PWM switches are always OFF such that one end of the inductor is floating.

Charging system, power supply system and dual mode power conversion circuit thereof

A switched capacitor converter includes plural switch units. The switch units are configured to switch a coupling relationship of a capacitor between a first power and a second power, wherein at least one of the switch units includes a switch circuit. The switch circuit includes a first switch, a second switch, and a switch driving circuit, wherein the conduction resistance of the first switch is greater than the conduction resistance of the second switch, and the parasitic capacitance of the first switch is less than the parasitic capacitance of the second switch. The switch driving circuit turns on the first switch before the second switch is turned on and/or turns off the first switch after the second switch is turned off, such that the switching loss of the switch circuit is less than a predetermined target value.

Switched capacitor converter and switch circuit and switch thereof

A switching power conversion circuit includes a conversion capacitor, a capacitive power conversion circuit, an inductor, an inductive power conversion circuit and a switching control circuit. The capacitive power conversion circuit includes plural switching devices for generating an intermediate voltage which is in a predetermined proportional relationship to the input voltage. The inductive power conversion circuit includes plural switching devices for converting the intermediate voltage to an output voltage. The plural switching devices of the capacitive power conversion circuit and the inductive power conversion circuit switch the conversion capacitor and the inductor periodically according to the duty ratio of the switching control signal generated by the switching control circuit. The capacitive power conversion circuit and the inductive power conversion circuit share one of the plural switching devices.

Switching power conversion circuit and switching circuit

A charger circuit which supplies a charging power to charge a battery circuit, includes: a conversion switch circuit, at least one capacitor and a conversion control circuit. The conversion switch circuit is coupled between a charging power and a ground level and includes conversion switches connected in series. The conversion switch circuit has battery voltage balancing nodes electrically connected to the battery circuit, such that each battery is electrically connected between two of the battery voltage balancing nodes. The conversion control circuit is coupled to the conversion switch circuit and provides operation signals to the conversion switch circuit, to respectively control the corresponding conversion switches, so that the capacitor is periodically connected in parallel to each battery of the battery circuit, thereby balancing the battery voltages of the batteries.

Charger circuit and charging control method

A light emitting device driver circuit includes: a power conversion circuit, an error amplifier circuit, a sample-and-hold circuit, a load current generation circuit and a feed-forward capacitor. When the light emitting device driver circuit is in a disable phase, the sample-and-hold circuit connects a feedback signal with a second reference voltage and the sample-and-hold circuit disconnects the feedback signal from a load node, whereby the feed-forward capacitor samples a sample voltage and holds it after the disable phase transits to an enable phase. In the enable phase, the sample-and-hold circuit disconnects the feedback signal from the second reference voltage and the sample-and-hold circuit connects the feedback signal with the load node, so that during a predetermined period following the transition, there is a sufficient difference between two input terminals of the error amplifier circuit so that the load current is raised to a desired current level within the predetermined period.

Driver circuit for driving light emitting device

A charger circuit for providing a charging current and voltage to a battery includes a power delivery unit, a capacitive power conversion circuit and a reverse blocking switch circuit. The power delivery unit converts an input power to a DC voltage and current. The capacitive power conversion circuit includes a conversion switch circuit including plural conversion switches coupled with one or more conversion capacitors, and a conversion control circuit. The DC current is regulated to a predetermined DC current level, and the conversion control circuit controls the connections of the plural conversion capacitors such that the charging current is scaled-up of the predetermined DC current level substantially by a current scale-up factor. The reverse blocking switch circuit is coupled in series with the capacitive power conversion circuit. The body diode of the reverse blocking switch is reversely coupled to the body diode of the conversion switch.

Charger circuit and capacitive power conversion circuit and reverse blocking switch circuit thereof

A charging circuit for providing a charging current to a battery includes a power delivery unit and a capacitive power conversion circuit. The power delivery unit converts an input power to a DC output voltage and current, and regulates the DC output current to a predetermined output current level. The capacitive power conversion circuit includes a conversion switch circuit including plural conversion switches coupled to one or more capacitors, and a conversion control circuit which operates the plural conversion switches in plural conversion periods to connect the one or more capacitors between a pair of nodes selected from plural voltage division nodes, the DC output voltage, and a ground node periodically, so that the level of the charging current is scaled-up of the predetermined output current level.

Charging circuit and capacitive power conversion circuit and charging control method thereof

A power management unit, adapted to a wireless power system, includes: a rectifier, converts an AC power received by an input port thereof to a direct-current (DC) voltage outputted by a rectifying output terminal thereof; a first switch, wherein a first protecting capacitor is coupled between one terminal of the input port and a channel thereof; a second switch, wherein a second protecting capacitor is coupled between the other terminal of the input port and a channel thereof; a reference voltage terminal, for providing a reference voltage; and, a comparator, including two input terminals coupled to the rectifying output terminal and the reference voltage terminal respectively, and including an output terminal coupled to both the control terminals of the first switch and the second switch.

Power management unit and wireless power system using the same

A wireless power receiver includes a power receiving circuit wirelessly receiving power transmitted from a wireless power transmitter so as to generate an induced current, and a rectifying-and-modulating circuit including first to eighth switches and a control unit. The control unit is operable to control operation of each of the first to eighth switches between conduction and non-conduction. Accordingly, the first to fourth switches cooperatively constitute a full-bridge rectifier for rectifying the induced current generated by the power receiving circuit, and each of the fifth to eighth switches is operable to switch synchronously with a respective one of the first to fourth switches or to became non-conducting, thereby changing an amplitude of the induced current.

Rectifying-and-modulating circuit and wireless power receiver incorporating the same

A light emitting diode driver includes: a serial-to-parallel conversion unit converting, based on a reference clock signal, a serial input signal carrying a number (N) of M-bit gray codes into a parallel input signal carrying the M-bit gray codes; a counting unit counting an output control signal to output a counting value; a data buffer unit storing, based on a latch signal, the M-bit gray codes carried by the parallel input signal, and outputting, based on the counting value and the M-bit gray codes, an N-bit signal consisting of N bits, each of which is an ione of M bits of a respective M-bit gray code, where i is associated with the counting value; and an output unit generating a number (N) of driving current signals based on at least the N-bit signal.

Light emitting diode driver

A control circuit of a power converter includes: a zero current detection circuit for detecting a current flowing between an inductor and a voltage output terminal of the power converter to generate a zero current detection signal; an adjusting circuit for generating an adjustment signal according to the zero current detection signal; a clock signal generating circuit for adjusting a frequency of a clock signal according to the adjustment signal; a periodical signal generating circuit for generating a periodical signal according to the clock signal; an error detection circuit for generating an error signal; and a control signal generating circuit for generating a control signal to control operations of a power switch. If the and amount of pulses generated by the zero current detection circuit satisfy a predetermined condition, the adjusting circuit switches the power converter's operation mode from DCM to CCM.

Control circuit for power converter and related control method

The present invention discloses a light emitting device array billboard and a control method thereof. The light emitting device array billboard includes a light emitting device array circuit, plural line switch circuits, plural channel switch circuits, plural ghost image compensation switch circuits, and a control circuit. The control circuit operates the line switch circuits and the channel switch circuit to turn ON a selected light emitting device for a duty period in a lighting period, and operates the plural ghost image compensation switch circuits to electrically connect a channel node corresponding to the selected light emitting device to a ghost image compensation voltage after the lighting period. The control circuit further adjusts a channel operation signal according to a gray scale compensation signal, to turn ON the selected light emitting device for a gray scale compensation period in addition to the duty period.

Light emitting device array billboard and control method thereof

A LED driver using a PWM signal for dimming control includes a power converter and a current regulator. The power converter provides an output voltage and a load current for a plurality of LEDs. The current regulator provides a load current dependent signal for the power converter to speed up load transient response caused by variation of the load current, to reduce the ripple of the output voltage, and thereby to avoid audio noise during PWM dimming.

Avoid audio noise of a LED driver during PWM dimming

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Taichung, Taiwan

Shui-Mu Lin