Silergy Semiconductor Technology (hangzhou) Ltd

Longqi Wang

Jianxin Wang

Jin Jin

Hongxing Wang

Qi'an Zeng

A detection circuit for a switching converter, whereby: the detection circuit is coupled in parallel with an output capacitor of the switching converter, and is configured to provide a detection branch coupled in parallel with the output capacitor during a first period of a switching cycle, in order to detect an output voltage of the switching converter; and an output voltage detection signal is generated according to the detected output voltage during a second period of the switching cycle. A switching converter can include the detection circuit and an integrated circuit.

Detection circuit and switching converter

A control circuit for controlling an AC-DC power supply, can include: a pulse-width modulation (PWM) signal generating circuit configured to generate a PWM signal in accordance with a reference voltage and a current sampling signal representing an inductor current flowing through an inductor of the AC-DC power supply, and to control a power stage circuit of the AC-DC power supply in accordance with the PWM signal; and a reference voltage generating circuit configured to generate the reference voltage based on an input voltage of the AC-DC power supply.

Control method and control circuit for an AC-DC power supply

A dimming signal generation circuit configured for an LED driver can include: a voltage-type dimmer configured to generate a dimming voltage; a dimming control circuit comprising a transformer and a power switch coupled in series between a first voltage and ground; where a secondary side of the transformer is coupled to the voltage-type dimmer is configured to receive the dimming voltage; where a primary side of the transformer is configured to receive the first voltage; and where a dimming reference signal is generated at the primary side of the transformer in accordance with the dimming voltage.

Dimming signal generation circuit, dimming signal generation method and LED driver

A dimming control circuit for an LED driver, can include: an adjusting circuit configured to generate an adjusting signal in accordance with a PWM dimming signal; and where a switching state of a power transistor of the LED driver is adjusted in accordance with the adjusting signal and a constant current control signal. A dimming control method for an LED driver, can include: determining a first threshold in accordance with a frequency of the PWM dimming signal and a frequency range of audio noise; generating an adjusting signal having a first duty cycle when a duty cycle of a PWM dimming signal is not greater than the first threshold; and controlling, by the adjusting signal, a switching state of a power transistor in the LED driver, where the first duty cycle is greater than the duty cycle of the PWM dimming signal.

Dimming control circuit, dimming control method and LED driver thereof

A leakage protection circuit can include: a pull-down current generation circuit coupled between output terminals of a rectifier circuit; and a control circuit configured to control the pull-down current generation circuit to generate a pull-down current during a predetermined time interval, and to determine whether leakage occurs in accordance with a voltage detection signal that is representative of an output voltage of the rectifier circuit.

Leakage protection circuit, leakage protection method and load driving circuit

A method of reducing THD can include: acquiring a first average inductor current during a first conduction time of a main power transistor of a power converter in a switching cycle; acquiring a second average inductor current during a second conduction time and an off time of the main power transistor in the switching cycle; and adjusting the second conduction time of the main power transistor in accordance with a difference between the first and second average inductor currents, where the first and second conduction times are successive.

Control system and control method for reducing total harmonic distortion

An LED dimming control circuit can include: a detection circuit configured to receive a dimming control signal, and to generate a detection signal for characterizing a type of the dimming control signal; and a dimming signal generation circuit configured to generate a dimming signal according to the detection signal and the dimming control signal, where a duty cycle of the dimming signal corresponds to the dimming control signal. A dimming control method can include: receiving a dimming control signal; detecting a number of rising or falling edges of the dimming control signal within a period of time to generate a detection signal; and determining a type of the dimming control signal in accordance with the detection signal.

LED dimming control circuit, dimming control method and LED power system thereof

An apparatus for an LED driver with a silicon-controlled dimmer, can include: a bleeder circuit coupled to a DC bus of the LED driver, and being configured to draw a bleeder current from the DC bus; and a controller configured to adjust the bleeder current to decrease in accordance with a first current sampling signal that represents a drive current flowing through an LED load after the silicon-controlled dimmer transitions from an off state to an on state. A method of controlling an LED driver can include: drawing a bleeder current from a DC bus of the LED driver; and controlling the bleeder current in accordance with a first current sampling signal representing a drive current flowing through an LED load to decrease after the silicon-controlled dimmer transitions from an off state to an on state.

LED driver with silicon controlled dimmer, apparatus and control method thereof

A method of controlling an LED driver can include: generating a sinusoidal half-wave signal having the same frequency and phase as an AC input voltage by utilizing a phase-locked loop; generating a sampling signal of a peak value of an inductor current in a power stage circuit of the LED driver; generating a loop compensation signal in accordance with the sinusoidal half wave signal and a signal representing an output current of the power stage circuit; and generating a switching control signal for controlling the power stage circuit in accordance with the sampling signal and the loop compensation signal.

Control circuit, control method and LED driver thereof

A dimming signal conversion method can include: converting a dimming voltage to a PWM signal; adjusting a corresponding relationship between the dimming voltage and a duty cycle of the PWM signal according to brightness requirements of a LED light source; and generating a drive current of an LED driver based on the corresponding relationship.

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Hangzhou, China

Longqi Wang