The CL8800 is designed to drive a long string of inexpensive, low current LEDs directly from the AC mains. A basic driver circuit consists of the 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, 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 compatibility, and LED utilization. With the addition of an RC network, the driver is compatible with phase dimming.
Additional 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
The CL8800 is designed to drive a long string of inexpensive, low current LEDs directly from the AC mains. A basic driver circuit consists of the 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, 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 compatibility, and LED utilization. With the addition of an RC network, the driver is compatible with phase dimming.
Additional 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
