CL8800

CL8800 Sequential Linear LED Driver Features Minimal component count (base config: CL8800 + 6 resistors + diode bridge) No magnetics, no capacitors Up to 7.5W output (13W w/ heat sink) >110Lm/W using efficient LEDs 85% typical electrical efficiency >0.95 power factor <20% THD line current Low conducted EMI w/o filters 85% LED luminous utilization Phase dimmer compatible with an RC network Applications Fluorescent tube retrofit Incandescent & CFL bulb replacement General LED lighting Description CL8800 is designed to drive a long string of inexpensive, low-current LEDs directly from the AC mains. A basic driver circuit consists of CL8800, six resistors, and a bridge rectifier. Two to four additional components are optional for various levels of transient protection. No capacitors, EMI filters, or power factor correction circuits are needed. A string of series/parallel LEDs is tapped at six locations. Six linear current regulators sink current at each tap and are sequentially turned on and off. Thereby tracking the input sine wave voltage. Voltage across each regulator is minimized when conducting, providing high efficiency. Output current at each tap is individually resistor-adjustable. Cross-regulation, as the CL8800 switches from one regulator to another, provides smooth transitions. The current waveform can be tailored to optimize for input voltage range, line/load regulation, output power/current, efficiency, power factor, THD, dimmer compatibil...