MT7638 is a controller for removing the 100/120Hz LED current ripple on high PF pre-driver circuit. The adaptive technology of MT7638 ensures minimum power dissipation while removing LED current ripple.
MT7638 integrates 150V power MOSFET. It clamps the input voltage on VDD pin by 15V, and clamps the internal maximum current by 15mA. Only one resistor is connected between VDD and Vin+, when the clamping current is too high, which is caused by large input voltage (exceeding 15V). MT7638 can flexibly adjust LED peak current by the sensing resistor between the CS pin and ground, which avoids the LED and the MOSFET damaged when LED short connected or hot plug.
With built-in temperature compensation, the system automatically adjusts the current ripple at high temperature to reduce MOSFET power dissipation and ensures system reliability.