The LM3414 and LM3414HV are 1-A 60-W(1) common anode-capable constant current buck LED drivers. They are suitable for driving single string of 3-W HBLED with up to 96% efficiency. They accept input voltages from 4.5 VDC to 65 VDC and deliver up to 1-A average LED current with ±3% accuracy. The integrated low-side N-channel power MOSFET and current sensing element realize simple and low component count circuitry, as no bootstrapping capacitor and external current-sensing resistor are required. An external small-signal resistor to ground provides very fine LED current adjustment, analog dimming, and thermal fold-back functions.
Constant switching frequency operation eases EMI. No external loop compensation network is needed. The proprietary Pulse-Level-Modulation (PLM) control method benefits in high conversion efficiency and true average LED current regulation. Fast response time realizes fine LED current pulse fulfilling the 240 Hz 256-step dimming resolution requirement for general lighting.
The LM3414 and LM3414HV are available in SOIC-8 and 3 mm × 3 mm WSON-8 packages.