Diodes: Wide PWM Dimming Extends LED Lamp Dimming Range
The AL8807B is an enhancement of Diodes’ low EMI buck high brightness LED driver AL8807.
The AL8807B provides protection against a number of potential faults within a lamp:
- Over-temperature condition: switches itself off
- Open-LEDs: automatically stops switching
- Short-LEDs: continues switching but at reduced duty cycle minimising power dissipation.
The AL8807B can operate at up to 1MHz – reducing the size of external components. The small MSOP-8EP package size (same footprint as AL8806/7) coupled with the need for only 4 external components produces a small solution footprint.
The accuracy, temperature range, cost and PWM dimming range make it ideally suited to dimmable LED lighting applications.
The Diodes Advantage:
The AL8807B provides a simple wide PWM dimming range solution for Low Voltage general illumination LED lamps.
Simple PWM dimming
- Provides a simple solution for varying LED lamps’ brightness with higher accuracy and range than analog dimming
Reduced switching noise and ringing
- Reduces EMI issues – especially in non-optimised layout PCBs
Open-LED, short-LED and Over-Temperature Protection Open-LED
- automatically stops switching, Short-LED
- fSW & duty cycle reduces, TJ > 155ºC
- Thermal trip
Small footprint, low thermal impedance packages – MSOP-8EP
- High power density small PCB footprint solution
5% initial average LED current accuracy
- Meets accuracy requirements of most lighting applications at cost effective price and improves inter-channel matching.
Applications:
- General illumination
- Multi-substrate LED driving
- Driving of parallel LED chains
- Wide Analog Dimming LED lamps
- 12VAC/DC and 24VAC/DC lighting
- SELV lighting
