AF1503 Datasheet | Alfa-MOS

Description AF1503 is a step down LED driver that is designed to meet least 2A continuous output current for high power LED application, and utilizes PWM control scheme that switches with 150Khz fixed frequency. The input voltage range of AF1503 is from 4.2V to 40V. It is suitable for series-parallel 1W, 3W, or 5W high power LED application due to the high operation voltage and output capability. At 24V input voltage, this device can drive up to 30pcs 1W LED (6S-5P) with constant 350m A LED current. The PWM control circuit is able to very the duty ratio linearly from 0 up to 100%. This device also contains an error amplifier circuit as well as a soft-start circuit that prevents overshoot at startup. An enable function, an over current protect function and a short circuit protect function are built inside, and when OCP or SCP happens, the operation frequency will be reduced from 150KHz to 30KHz. Also, an internal pensation block is built in to minimum external ponent count. The package is available in a standard SOP-8P. Features Input voltage: 4.2V to 40V. Low Feedback Voltage 0.21V. Driving up to 30 LEDs (1W 6S-5P) at 24VIN Oscillation frequency: 150KHz typ. Soft-start, Current limit, Enable function Great Output Capability PWM or Analog Dimming Control Thermal Shutdown function Built-in internal P-channel MOS SOP-8P Package. Application High Power LED Driver Backlight Application General Lighting Solution Constant Current Source Pin Define ( SOP-8P ) Marking Information ©Alfa-MOS Technology Corp. Rev.B July 2011 .alfa-mos. Page 1 Alfa-MOS Technology Typical Application Circuit 150KHz, 2A / 40V Step-Down LED Driver Pin Description Pin VC VIN Output GND Symbol 1 3 4 5Ε6 7Ε8 Description Feedback pin Connect to a resistor to set LED current by following formula : ILED= 0.23V/RFB Enable / Disable pin H: Normal operation mode. (Step-down operation) L: Shutdown mode. (All circuits deactivated) Add an external capacitor to VIN. It’s voltage is set...