A Product Line of Diodes Incorporated PAM2863 2A LED DRIVER with INTERNAL SWITCH Description Pin Assignments The PAM2863 is a continuous mode inductive step-down converter, designed for driving single or multiple series connected LEDs efficiently from a voltage source higher than the LED voltage. The device operates from an input supply between 4.5V and 40V and provides an externally adjustable output current of up to 2A. Depending upon supply voltage and external components, this can provide up to 30 watts of output power. The PAM2863 includes the output switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal average output current. Output current can be adjusted below the set value, by applying an external control signal to the VSET pin. The VSET pin will accept either a DC voltage or a PWM waveform. The soft-start time can be increased using an external capacitor from the VSET pin to ground. Applying a voltage of 0.2V or lower to the VSET pin turns the output off and switches the device into a low current standby state. Applications High End LED Flashlight Features LED Light Bar Simple Low Parts Count Internal 40V NDMOS Switch 2A Output Current Single Pin On/Off and Brightness Control Using DC Voltage or PWM Soft-Start High Efficiency (up to 97%) Wide Input Voltage Range: 4.5V to 40V Output Shutdown Open LED Protection Short LED Protection Up to 1MHz Switching Frequency Typical 5% Output Current Accuracy Pb-Free SOP-8(EP) Packages 1 of 11 October 2012 PAM2863 Diodes Incorporated www.diodes.com Document number: DSxxxxx Rev. 1 - 0 A Product Line of Diodes Incorporated PAM2863 Typical Applications Circuit Pin Descriptions Pin Pin Function Number Name 5, 6 LX Drain of NDMOS switch. 3, 7, 8 GND Ground (0V) Multi-function On/Off and brightness control pin: Leave floating for normal operation. Drive to voltage below 0.2V to turn off output current Drive with DC voltage (0.3V < VSET< 2.5V) to adjust output current from 12% to 100% of I OUTnom 4 VSET Drive with PWM signal from open-collector or open-drain transistor, to adjust output current. Adjustment range 1% to 100% of I for f < 500Hz OUTnom Connect a capacitor from this pin to ground to increase soft-start time. (Default soft-start time = 0.1ms. Additional soft-start time is approx.1.5ms/1nF) 2 ISENSE Connect resistor RS from this pin to VIN to define nominal average output current IOUTnom = 0.1/Rs 1 VIN Input voltage (6V to 40V). Decouple to ground with 10 F or higher X7R ceramic capacitor close to device. 2 of 11 October 2012 PAM2863 Diodes Incorporated www.diodes.com Document number: DSxxxxx Rev. 1 - 0