ISL1903
Dimmable Buck LED Driver - AC Mains or DC Input LED Driver
Key Features
- Excellent LED current regulation over line, load, and temperature
- 0 - 100% dimming with leading-edge (triac) and trailing-edge dimmers
- Power factor correction for up to 0.995 power factor and less than 20% harmonic content
- Critical conduction mode (CrCM) operation for quasi-resonant high efficiency performance
- Supports Universal AC Mains Input
- Configurable for PWM or DC current dimming control of LEDs
- Monitors FET switching current for load regulation
- Supports isolated and non-isolated buck topologies
- Closed loop soft-start for no overshoot
- OFFREF feature to set dimming off-point to improve fixture performance matching
- -40°C to +125°C operation
- Pb-free (RoHS compliant)
Description
The ISL1903 is a high-performance, critical conduction mode (CrCM), single-ended buck LED driver controller. It may be used with DC input converters, but also supports single-stage conversion of the AC mains to a constant current source with power factor correction (PFC). The ISL1903 supports buck converter topologies, such as isolated forward converters or non-isolated source return buck converters. Operation in CrCM allows near zero-voltage switching (ZVS) for improved efficiency while maximizing magnetic core utilization.
The ISL1903 is compatible with both leading and trailing edge modulated AC mains dimmers. It provides all of the features required for high-performance dimmable LED ballast designs.
Applications
- Industrial and commercial LED lighting
- Retrofit LED lamps with triac dimming
- Universal AC mains input LED retrofit lamps
- AC or DC input LED ballasts
