Product Highlights

Accurate CC Regulation, Meets ±3 in a Typical

Design1

Controller Automatically Compensates For:

? Transformer inductance variation

? External component changes with temperature

? Input line voltage variations

This enhances production yield

Cost-Effective, Small Size Designs

? Eliminates the optocoupler and secondary CC control circuitry

? Eliminates control loop compensation circuitry

? Frequency-jitter greatly reduces EMI filter cost

? Programmable switching frequency reduces transformer size

? 725 V switching power MOSFET enables clampless flyback designs

Advanced Protection/Safety Features

? Auto-restart protection reduces power delivered by >90 for output

short-circuit and control loop faults (open and short-circuit components)

? Hysteretic thermal shutdown – with automatic recovery

? Meets high-voltage creepage requirements between DRAIN and all

other pins both on the PCB and at the package

EcoSmart?– Energy Efficient

? No-load consumption <30 mW1

? No current sense resistors – maximizes efficiency

Green Package

? All parts are halogen free and RoHS compliant

Applications

? LED bulbs, down lights, luminaires, ballasts and T8 tubes

Description

The LYTSwitch?-2 family of ICs dramatically simplifies low power CC

LED drivers by eliminating the optocoupler and secondary control

circuitry. The family introduces a revolutionary control technique which

provides accurate output current regulation, compensating for

transformer and external component variations, and device parameter

tolerances as well as input voltage variations.

The device incorporates a high-voltage switching MOSFET, an ON/OFF

control state-machine, a high-voltage switched current source for

self-biasing, frequency jitter to reduce EMI, cycle-by-cycle current limit

and hysteretic thermal shutdown circuitry into a monolithic IC. This high

level of integration enables cost-effective designs with very few

external components, reducing solution cost and driver size.