Main description:

S9271B is a high precision off-line non-isolated LED constant current switch chip. Non-isolated step-down LED constant current drive power supply suitable for high constant current precision requirements.

S9271B adopts the patented zero-current detection method, and the critical quasi-resonant working mode realizes the high efficiency of the system. Smaller size inductors can be used, there is no reverse recovery problem of freewheeling diodes, and no compensation circuit is required; the built-in line voltage compensation can meet the current accuracy of ±3% without adding a current compensation circuit. S9271S has a built-in 500V withstand voltage power tube, and integrates high-voltage self-power supply technology, without VCC capacitors and power supply resistors, and easily achieves full-range input voltage. It greatly simplifies the periphery of the system and reduces the area of the PCB, which can effectively reduce the cost of the system. Guaranteed the service life of the whole lamp.

S9271B also integrates a variety of protection functions: under-voltage lockout, leading edge blanking, LED open circuit protection, overcurrent protection, loop open circuit protection, LED short circuit protection, which greatly increases the stability of the system.

The S9271B is available in SOP-7 and DIP-7 packages.

Features:

? No VCC capacitor, no start-up resistor

? Integrated self-powered technology

? Efficient critical work mode

? Patented zero current detection

? Wide input voltage

? ±3% output constant current accuracy

? Built-in 500V power tube

? Output OVP adjustable

? LED open/short circuit protection

? Compatible with switch toning Enable function