CN2770 is a 40V synchronous constant current buck LED driver, with 55mΩ High-Side and 20mΩ Low-Side MOSFETs integrated, minimal external component requirement and high efficiency, ideal for car lamp applications.Adjustable Output Current up to 3.5A with ±3% accuracy. RISEN resistor is used to set the output current.No external  compensation component needed. 135kHz switching frequency with jitter function improves EMI performance. Internal thermal regulation prevents the chip from overheating without shutting down the output.Input under voltage lock-out protection disable the chip when input voltage lower than 7V.

The constant current regulator is based on special technology and regulates current over a wide voltage range. It is designed with a negative temperature coefficient to protect LEDs from thermal runaway at extreme voltages and currents.
The constant current regulator turns on immediately  with only 0.3 V Vak. It requires two resistor to be designed as a high or low side regulator. The high anode-cathode voltage rating withstands surges common in Automotive, Industrial and Commercial Signage applications. One resistor is supply the power to IC and protect the circle without Shorter or Spike impact, and the other Resistor was used to set the current over the LED.