Contact: Nie Zhihui 13632552696 WeChat: 13632552696

Overview

PT4212A is a high-precision step-down LED constant current control chip with active power factor correction, suitable for non-isolated LED constant current power supply with full voltage input range of 85Vac-265Vac. The controller integrates an active power factor correction circuit, which can achieve high power factor and low total harmonic distortion. Due to the working quasi-resonant mode, the power MOS tube is in a zero-current turn-on state, the switching loss is reduced, and the utilization rate of the transformer is also high.

PT4212A adopts a unique current sampling and constant current control mechanism, which can achieve high batch consistency of output current. The chip integrates line voltage, load voltage and temperature compensation circuit, which can achieve excellent line voltage regulation rate and load regulation of output current. rate and temperature characteristics.

PT4212A provides PWM and analog dimming functions, and the LED output current can be smoothly adjusted by adding a PWM signal or an analog signal to the DIM pin.

PT4212A provides complete protection functions: including LED open circuit protection, LED short circuit protection, chip power supply overvoltage protection, undervoltage protection, input undervoltage protection, cycle-by-cycle current limiting protection, transformer winding short-circuit protection, over-temperature protection, etc., all protection states All have automatic restart function. In addition, the chip has a built-in soft-start circuit, which can effectively reduce the power-on stress of the switch tube and LED lamp beads.

PT4212A features:

Fixed on-time, high PF value (>0.9)

Quasi-resonant control mode

More than 90% conversion efficiency

±3%_LED output current accuracy

Excellent line and load regulation

Excellent current temperature compensation characteristics

PWM/Analog dimming (10%~100%)

Soft start function

LED short/open protection

Input undervoltage protection (optional)

Chip power supply over-voltage/under-voltage protection

Inductor winding short circuit protection

Cycle-by-Cycle Current Limit

Over temperature protection

PT4212A is available in SOP-8 package

PT4212A application:

LED bulbs, spotlights

LED PAR30, PAR38 lamps

LED fluorescent light

Other LED lighting