PAM2861

Description

The PAM2861 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 6V and 40V and provides an externally adjustable output current of up to 1A. Depending upon supply voltage and external components, this can provide up to 30 watts of output power. The PAM2861 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.

Feature(s)

• Simple Low Parts Count
• Internal 40V NDMOS Switch
• 1A 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: 6V to 40V
• Output Shutdown
• Open LED Protection
• Short LED Protection
• Up to 1MHz Switching Frequency
• Inherent Open-Circuit LED Protection
• Typical 5% Output Current Accuracy
• Pb-free TSOT25 and SOT89-5 Packages

Application(s)

• Low voltage halogen replacement LEDs
• Low voltage industrial lighting
• LED back-side lighting
• Illuminated signs