- Minimal component count
- No magnetics, no capacitors
- Low conducted EMI w/o filters
- 80-90% LED utilization
- Phase dimmer compatible
with RC network
- Up to 13W output
- Typical electrical efficiency: 85-90%
- >115Lm/W using efficient LEDs
- > 0.9 power factor
- < 10% THD line current (CL8800) or
< 30% THD line current (CL8801)
- Fluorescent tube retrofit
- Incandescent and CFL
- General LED lighting
Microchip CL880x Sequential Linear LED Drivers
Microchip CL880x Sequential Linear LED Drivers are designed to drive long strings of low cost, low current LEDs in solid-state replacements for fluorescent tubes, incandescent bulbs, and CFL bulbs. Both ICs minimize driver circuit component counts, requiring just four or six resistors and a diode bridge in addition to the IC. Two to four additional components in the circuit provide transient protection, and neither capacitors nor magnetic components are required. Because the ICs are multi-stage linear current regulators, there are no high frequency switching currents and, thus, no need for a front-end EMI filter. CL8800 is intended for 230VAC input, while CL8801 is for 120VAC input. Luminous efficiencies of greater than 115lm/W are achievable with both Microchip CL880x Sequential Linear LED Drivers.
CL8800 has six current regulator outputs and CL8801 has four. These outputs tap a string of series/parallel LEDs, and the regulators sink current at each tap and are sequentially turned on and off automatically, tracking the input sine wave voltage. The voltage across each regulator is minimized when conducting, providing typical efficiency of greater than 90%. Output current at each tap is individually resistor-adjustable. Cross regulation provides smooth transitions as the IC switches from one regulator to another. The current waveforms of both ICs can be tailored to optimize for input voltage range, line/load regulation, output power/current, efficiency, power factor, THD, dimmer compatibility, and LED utilization. Both ICs are compatible with phase dimming with the addition of an RC network.
CL8800 and CL8801 deliver easy retrofit solutions for designers looking to replace existing fluorescent tubes or incandescent bulbs with more energy efficient solid-state lighting fixtures. The minimal component count required for both devices, as well as their efficient operation, make them an extremely attractive solution in terms of cost and performance. CL8800 and CL8801 are available in 40-lead QFN packages and are RoHS compliant.