Product Description
The HW6650 is a high efficiency, constant current, step-down DC/DC converter, designed to deliver constant current to high power LED with only 4 external components. The HW6650 is specifically designed with hysteretic PFM control scheme to enhance the efficiency up to 93%. Output current of the HW6650 can be programmed by an external resistor, and LED dimming can be controlled via pulse width modulation (PWM) through DIM pin. In addition, the embedded soft start function eliminates the inrush current while the power is on. The HW6650 also features under voltage lock out (UVLO), over temperature protection, LED open-circuit protection and LED short-circuit protection to protect IC from being damaged.
Additionally, to ensure the system reliability, the HW6650 is built with the thermal protection (TP) function and a thermal pad. The TP function protects IC from over temperature (140°C). Also, the thermal pad enhances the power dissipation. As a result, a large amount of current can be handled safely in one package.

Features
 1.2A Constant Output Current
 93% Efficiency @ input voltage 13V, 350mA, 3-LED
 9~30V Input Voltage Range
 Hysteretic PFM Improves Efficiency at Light Loads
 Settable Output Current
 Integrated Power Switch
 Full Protection: Thermal/UVLO/Soft Start/LED Open-/Short- Circuit
 Only 4 External Components Required

Applications
 Signage and Decorative LED Lighting
 Automotive LED Lighting
 High Power LED Lighting
 Constant Current Source