Richtek Technology Corporation

Hung-Yu Cheng

Wan-Hsuan Yang

Chen-Lin Hsu

Kuo-Chun Wu

Keng-Hong Chu

Tsung-Han Yu

Chia-Chun Li

Chen-Pin Huang

Chung-Lung Pai

Chien-Ping Lu

Tzu-Huan Chiu

Po-Yu Chiang

Tzu Huan Chiu

Li-Chen Cheng

Shuo-Wen Chang

Chi-Hsun Wu

A conversion control circuit is configured to generate a PWM (pulse width modulation) signal to control a power switch for switching an inductor to convert an input voltage to an output voltage. The steps of generating the PWM signal includes: enabling the PWM signal at a rising edge of a clock signal to turn on the power switch; disabling the PWM signal to turn off the power switch when an on-time exceeds a predetermined minimum on-time and the output voltage has reached an output level; triggering a next rising edge of the clock signal when the off-time exceeds a predetermined minimum off-time, the output voltage has not reached the output level, and a present cycle period of the clock signal has reached a predetermined cycle period.

Switching power converter circuit and conversion control circuit and method thereof

A constant time buck-boost switching converter includes: a power switch circuit for switching a first terminal of an inductor between an input voltage and a ground, and for switching a second terminal of the inductor between an output voltage and the ground; and a modulation control circuit for generating a buck ramp signal and a boost ramp signal and for controlling the inductor according to comparisons of these two ramp signals with an error amplification signal, so as to convert the input voltage to the output voltage. The average levels of the buck ramp signal and the boost ramp signal are both equal to a product of the output voltage multiplied by a predetermined ratio. The upper limit of the buck ramp signal and the lower limit of the boost ramp signal are both equal to a product of the input voltage multiplied by the predetermined ratio.

Constant time buck-boost switching converter and modulation control circuit and control method thereof

A switching power converter includes: a power stage circuit, including at least one transistor which is configured to operably switch an inductor to convert an input power to an output power; and an active EMI filter circuit, including at least one amplifier, wherein the at least one amplifier is configured to operably sense a noise input signal which is related to a switching noise caused by the switching of the power stage circuit, and amplify the noise input signal to generate a noise cancelling signal, wherein the noise cancelling signal is injected into an input node of the switching power converter, so as to suppress the switching noise and thus reducing EMI, wherein the input power is provided through the input node to the power stage circuit.

Switching power converter and active EMI filter circuit thereof

A multi-loop error amplifier circuit for generating an error amplification signal includes: a first operational transconductance amplifier (OTA) including a first current output stage which generates a first transconductance amplification current in a predetermined current direction according to a first voltage difference between a positive terminal and a negative input terminal of the first OTA; a second OTA including a second current output stage which generates a second transconductance amplification current in the predetermined current direction according to a second voltage difference between a positive terminal and a negative input terminal of the second OTA. The first and the second current output stages are coupled in series to generate a first error output current. The error amplification signal is generated according to the first error output current which is equal to the smaller one of the first and the second transconductance amplification currents.

Multi-loop power converter and multi-loop error amplifier circuit and control method thereof

A switching power converter includes: a power stage circuit, including at least one transistor which is configured to operably switch an inductor to convert an input power to an output power; and an active EMI filter circuit, including at least one amplifier, wherein the at least one amplifier is configured to operably sense a noise input signal which is related to a switching noise caused by the switching of the power stage circuit, and amplify the noise input signal to generate a noise canceling signal, wherein the noise canceling signal is injected into an input node of the switching power converter, so as to suppress the switching noise and thus reducing EMI, wherein the input power is provided through the input node to the power stage circuit.

A switching regulator having a low start-up voltage includes a power stage and a switch control circuit. The switch control circuit includes a power control switch. The power control switch is formed by a low threshold voltage transistor having a first conductivity type in a semiconductor substrate. The low threshold voltage transistor having the first conductivity type includes a first lightly doped region having a second conductivity type which forms a channel region of the low threshold voltage transistor having the first conductivity type. The semiconductor substrate includes a second lightly doped region having the second conductivity type which is formed by a same manufacturing process as the first lightly doped region having the second conductivity type. The second lightly doped region having the second conductivity type forms adrift region of a high-voltage transistor having the second conductivity type in the semiconductor substrate.

Switching regulator having low start-up voltage and switch control circuit thereof

When a ramp signal intersects a feedback related signal, a constant time switching regulator enters a first state and maintains in the first state for a constant time, and after the constant time ends, when the ramp signal exceeds the feedback related signal, the switching regulator enters a second state, while when the ramp signal does not exceed the feedback related signal, the switching regulator enters a third state. In the first state, the first end of an inductor is connected to input voltage and the second end of the inductor is connected to output voltage; in the second state, the first end is connected to ground and the second end is connected to output voltage; and in the third state, the first end is connected to input voltage and the second end is connected to ground.

Constant-time buck-boost switching regulator and control circuit and control method thereof

A dual constant time switching regulator includes: a power circuit including an inductor and at least a power switch for converting an input power to an output power, and a switching control circuit for generating a switch control signal to control the power switch, wherein the switching control circuit includes a comparison circuit for comparing an error amplified signal and a triangle wave signal to generate a comparison result, and a time determining circuit for generating the switch control signal according to the comparison result, wherein after the power switch turns ON, it keeps ON for at least a minimum ON time until the triangle wave signal is higher than the error amplified signal, and wherein after the power switch turns OFF, it keeps OFF for at least a minimum OFF time and until the triangle wave signal is lower than the error amplified signal.

Dual constant time switching regulator and switching control circuit and method thereof

The present invention provides a dual constant time buck-boost switching regulator, and a control circuit and a method thereof. The buck-boost switching regulator converts an input voltage to an output voltage and it includes a buck circuit and a boost circuit. The buck circuit includes an inductor, a buck power switch and a buck power device. The boost circuit includes the inductor, a boost power switch and a boost power device. The present invention controls the buck power switch to be OFF by a constant OFF time in the buck conversion mode, and controls the boost power switch to be ON by a constant ON time in the boost conversion mode. An offset signal ensures that the buck-boost regulator operates only in pure buck conversion mode and pure boost conversion mode, but does not need to operate in a buck-boost conversion mode.

Dual-constant-time buck-boost switching regulator and control circuit and method thereof

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

A power converting circuit includes an upper gate switch, a transistor, a current source circuit, a comparator circuit, a delay circuit, and a pulse width modulation signal generating circuit. The transistor and the current source circuit provide a reference signal. The comparator circuit generates a comparing signal according to the reference signal and an output signal provided by the upper gate switch. The delay circuit generates a delay signal according to the comparing signal and a clock signal. The pulse width modulation signal generating circuit generates a control signal for the upper gate switch according to the delay signal and the clock signal for configuring the conduction status of the upper gate switch. The power converting circuit adjusts the conduction time of the upper gate switch according to the reference signal and the output signal.

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Taipei, Taiwan

Hung-Yu Cheng