Richtek Technology Corporation

Other

Jien-Sheng Chen

Shui-Mu Lin

Tsung-Wei Huang

Kwan-Jen Chu

Nien-Hui Kung

Chao-Hsuan Chuang

Wei-Hsin Wei

Der-Jiunn Wang

Yiu-I Lin

Pao-Hsun Yu

Yun-Chi Chiang

The present invention discloses a single-wire transmission interface, and a method of transmission through single-wire. The method comprises: providing a single-wire signal through a single-wire; and transmitting information only in a transmission period defined by a fixed first time period starting from one of a rising or a falling edge of the single-wire signal.

Single-wire transmission interface and method of transmission through single-wire

A charge pump regulator has a charge pump to establish a charge path and a discharge path alternately, so as to produce a regulated voltage on an output terminal. The charge pump has at least a current control element on the charge path or the discharge path to control the current flowing therethrough according to an output-dependent feedback signal.

Charge pump regulator and method of producing a regulated voltage

A current regulator includes a first current source to provide a reference current varying with a dimming step, and a second current source to generate a drive current for a white LED according to the reference current. The reference current and the dimming step have a relationship identical to or approximating a relationship between luminance and lightness perceived by human eyes. Thus, the white LED is controlled to have a linear variation of the luminance perceived by human eyes when the dimming step is changed.

Perceptually linear LED brightness control

The phase node voltage or the PWM signal in an asynchronous boost converter is monitored to detect a phase node voltage ringing. When a phase node voltage ringing is detected, a detection signal is asserted to establish a bypass path to bypass the inductor of the converter. A charge bypass circuit is shunt to the inductor, and controlled by the detection signal to establish the bypass path. Due to the bypass path, the phase node voltage is maintained at a constant, and the phase node voltage radiation and input/output noise are eliminated.

Anti-ring asynchronous boost converter and anti-ring method for an asynchronous boost converter

For efficiency improvement of a LED display system including a charge pump and a LED connected to either the voltage input terminal or the voltage output terminal of the charge pump, either one or both of two current regulators are enabled according to a voltage detected from the LED, for establishing a driving current for the LED. When the detected voltage is higher than a threshold, the first one of the current sources is enabled sole. When the detected voltage is lower than the threshold, the second one of the current sources is enabled sole, or both the current sources are enabled, or the current sources are alternatively enabled.

Current regulator and method for efficiency improvement of a LED display system

A non-synchronous boost converter includes a low-voltage device connected between the input voltage terminal and the output voltage terminal of the converter. When the converter is shutdown, the low-voltage device disconnects the output voltage terminal and the input voltage terminal. Since it is a low-voltage device used in the converter for load disconnection, the efficiency of the converter is improved with lower cost.

Non-synchronous boost converter including low-voltage device for load disconnection

A single-ended operational amplifier includes an output stage, a first transconductance amplifier and a second transconductance amplifier. In an offset cancellation mode, two inputs of the first transconductance amplifier are supplied with a reference voltage to sink two currents from two inputs of the output stage respectively, the output stage generates a third current according to the difference between the two currents to charge a capacitor, and the second transconductance amplifier generates two currents according to the voltage in the capacitor to make currents in the two inputs of the output stage equal to each other, thereby canceling the offset of the single-ended operational amplifier.

Offset cancellation of a single-ended operational amplifier

The present invention discloses a charge pump down circuit which comprises three capacitors operating in three time phases. In the first time phase, the total of the voltages across the three capacitors is equal to an input voltage; in the second time phase, the voltage across the second capacitor is equal to the voltage across the third capacitor; in the third time phase, the difference between the voltages across the first and the second capacitors is equal to the voltage across the third capacitor, wherein the voltage across the third capacitor is the output voltage of the charge pump down circuit.

Charge pump down circuit and method for the same

An apparatus and method are provided for suppressing the input current inrush for a voltage converter in a pre-charge stage. The voltage converter comprises a power input for receiving an input current, a power output for supplying an output voltage for a load, and an output capacitor connected to the power output. In a pre-charge stage, a current limiting device is connected between the power input and the output capacitor to limit the input current to flow therethrough, and a variable current limiting control circuit provides a control signal to the current limiting device to determine a variable maximum value for the input current.

Apparatus and method for suppressing the input current inrush for a voltage converter in a pre-charge stage

A control device, which controls a power-converting module that is coupled to a light-emitting component, includes a duration detecting unit and a control signal generator. The duration detecting unit compares the duration of a predetermined logic state of a pulsating input dim control signal with a reference time period. The control signal generator is enabled by the duration detecting unit so as to generate a control signal that enables the power-converting module to generate a drive voltage for driving the light-emitting component when the duration of the predetermined logic state is not longer than the reference time period. The duration detecting unit disables the control signal generator to disable the power-converting module when the duration of the predetermined logic state is longer than the reference time period.

Control method and device for a power-converting module that drives a light-emitting component

A low noise multiphase charge pump comprises a plurality of capacitors and a plurality of switches configured as a network, the switches are so switched that the charge pump operates in at least three phases by turns, and the operational durations and the operational currents of the phases are preferably balanced, so as to reduce the noise of the charge pump.

Growing community of inventors

Miaoli County, Taiwan

Jien-Sheng Chen