AF1502A Datasheet | Alfa-MOS

Description AF1502A is a step down LED driver that is designed to meet maximum 2A constant current for high power LED application, and utilizes PWM control scheme that switches with 300Khz fixed frequency. The input voltage range of AF1502A is from 4.2V to 23V. It is suitable for series-parallel 1W, 3W, or 5W high power LED application due to the high operation voltage and output capability. At 12V input voltage, this device can drive up to 15pcs 1W LED (3S-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 300KHz to 60KHz. 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 23V. Low Feedback Voltage 0.2V. Driving up to 15 LEDs (1W 3S-5P) at 12VIN Oscillation frequency: 300KHz 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 Typical Application Circuit ©Alfa-MOS Technology Corp. Rev.B May 2011 .alfa-mos. Page 1 Alfa-MOS Technology 300KHz, 2A / 23V Step-Down LED Driver Pin Description Pin OCSET VIN Output GND Symbol 1 3 4 5Ε6 7Ε8 Description Feedback pin Connect to a resistor to set LED current by following formula : ILED= 0.21V/RFB Enable / Disable pin H: Normal operation mode. (Step-down operation) L: Shutdown mode. (All circuits deactivated) Add an external resistor to set max output current. IC...