The CL8801 is designed to drive a long string of inexpensive, low current LEDs directly from the AC mains. A basic driver circuit consists of the CL8801, four 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 four locations. Fourlinear current regulators sink current at each tap and are sequentially turned on and off, 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 CL8801 switches from one regulator to the next, 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 compatibility, and LED utilization.With the addition of an RC network, the driver is compatible with phase dimming.

  Minimal component count (base config: CL8801 + 4 resistors + diode bridge)

  No magnetics, no capacitors

  Up to 7.5W output (13W w/ heat sink)

  >110Lm/W using efficient LEDs

  85% electrical efficiency

  >0.95 power factor

  Low conducted EMI w/o filters

  85% LED luminous utilization

  Phase dimmer compatible with an RC network