Hangzhou Silan Microelectronics Co., Ltd.

Yunlong Yao

Jianxing Wu

Xianming Tang

Weijiang Zhou

The disclosure relates to an error amplification apparatus and a driving circuit including the error amplification apparatus. In the error amplification apparatus according to the disclosure, a pulse generating circuit generates a first pulse and a second pulse in accordance with an output voltage of an error amplification unit, a counting unit being coupled to the pulse generating circuit counts the first pulse and the second pulse, and generates a loop control signal representing a compensation voltage based on the count. The disclosure utilizes the counting unit to digitize the compensation voltage, and the counter value can reflect the compensation voltage, so that the variation of the loop control signal in the AC cycle of 50 Hz or 60 Hz is controlled to be little, thereby filtering out the ripple of AC of 50 Hz or 60 Hz. In this manner, the capacitance of the compensation capacitor is reduced so that the compensation capacitor can be integrated inside the IC chip, thereby simplifying the peripheral design, and eliminating the influence on the loop by the electrical leakage current due to moisture.

Error amplification apparatus and driving circuit including the same

A switch-mode power supply control apparatus includes a PWM controller for outputting a driving signal and a short-circuit protection module coupled to a detection terminal. The detection terminal receives a zero-crossing detection voltage. If the time that the detection voltage input to the detection terminal is lower than a first reference voltage exceeds a predetermined time period, the short-circuit protection module determines that a short-circuit abnormal situation occurs, the short-circuit protection module outputs a short-circuit signal to the PWM controller, and the driving signal output by the PWM controller becomes a turn-off signal. If the short-circuit protection module does not detect the short-circuit abnormal situation, the PWM controller operates normally. A flyback switch-mode power supply includes the switch-mode power supply control apparatus. The flyback switch-mode power supply has a low power consumption when a short-circuit protection is taking place.

Switch-mode power supply control apparatus and flyback switch-mode power supply including the control apparatus

The present invention discloses a primary-side controlled switch-mode power supply controller for driving LED with constant current and method thereof as well as an apparatus for controlling switch-mode power supply having the switch-mode power supply controller. The switch-mode power supply controller includes an input dimming phase detection circuit, a multiplier, a turn-on signal control circuit, a zero-crossing detection circuit, a comparator, a trigger and a driving circuit. The circuit controls to drive LED with constant current by means of a primary-side controlled method. The circuit realizes the triac dimming function, ensures a constant output current regardless of a high voltage or a low voltage, and obtains a high power factor. The direct use of the isolation transformer improves the safety of the circuit, and simplifies the peripheral circuit, thereby reducing the cost of the circuit and minimizing the size of the PCB layout, which is favorable in minimizing the product.

Primary-side controlled switch-mode power supply controller for driving LED with constant current and method thereof

The present invention is to provide a frequency jitter circuit and a method for generating frequency jitter. The frequency jitter circuit, comprising: an oscillating circuit, configured to generate an oscillating frequency output signal; a decoding circuit, configured to be controlled by said oscillating frequency output signal for generating several pulse output signals; a delay circuit, through which said oscillating frequency output signal is passed for generating a frequency jitter output signal that is delayed a period of time compared to said oscillating frequency output signal. Application of the invention into switched-mode power supply might reduce EMI average noise in the switched-mode power supply, and smooth energy spectrum density.

Circuit and method of frequency jitter, and application thereof in switched-mode power supply (SMPS)

A switch-mode power supply (SMPS) is provided. When the switch power of the SMPS turns on, the inductor current of the SMPS may flow through an inductor current sensing circuit which then provides a sensing voltage. An apparatus for compensating the inductor current peak receives a reference voltage and the sensing voltage as inputs and outputs a compensation voltage. The compensation voltage is combined with the reference voltage and/or the sensing voltage and is provided to a first comparator. The result keep 7as 7is provided to the logic control circuit coupled to the gate of the power switch after being driven by a driver circuit. The actual inductor current peak is kept identical with the reference current, which effectively controls the inductor current peak, thereby protecting the SMPS.

Growing community of inventors

Hangzhou, China

Yunlong Yao