DESCRIPTION

· The LYTSwitch™-3 family is designed for single-stage power factor corrected constant current LED bulbs and downlighters.

· Each device includes a high-voltage power MOSFET and a discontinuous mode, variable frequency variable on-time controller.

· The controller provides cycle-by-cycle current limit, output OVP, line overvoltage, comprehensive protection features, and advanced thermal management circuitry.

· Built-in TRIAC detector distinguishes between leading-edge and trailing-edge dimmers, regulating bleeder current during each switching cycle.

· The controller disables the bleeder circuit if no dimmer is detected, significantly increasing efficiency.

· Low-side switching topology, cooling via electronically quiet SOURCE pins, and frequency jitter ensure extremely low EMI.

FEATURES

· Combined Single-Stage PFC + Accurate CC Output with less than ±3% CC regulation over line and load.

· Power Factor >0.9 and ensures monotonic VA reduction with TRIAC phase angle.

· Low THD, 15% typical for dimmable bulbs, as low as 7% in optimized designs.

· Advanced Integrated TRIAC Dimmer Detection with selectable dimming profile for increased design flexibility.

· Fast turn-on (<500 ms), low pop-on and dead-travel, and active bleeder drive for widest dimmer compatibility.

· Supports buck, buck-boost, tapped buck-boost, boost, isolated and non-isolated flyback topologies with up to 20 W output.

· Highest reliability with no electrolytic bulk capacitors or optoisolators for increased lifetime.

· Comprehensive protection features including input and output overvoltage, output short-circuit and open-loop protection, and advanced thermal control.

APPLICATIONS

· Ideal for single-stage power factor corrected constant current LED bulbs and downlighters.

· Suitable for designs requiring high efficiency and reliability in both isolated and non-isolated topologies.

· Can be used in applications requiring advanced TRIAC dimming compatibility and low THD.