LYTSwitch-2

Description

LYTSwitch-2 dramatically simplifies low power CC LED drivers by eliminating the optocoupler and secondary control circuitry. The family introduces a revolutionary control technique to provide very tight output current regulation, compensating for transformer and external component variations, and device parameter tolerances as well as input voltage variations.

The device incorporates a 725 V power MOSFET, a novel 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.

Product Highlights

Accurate CC Regulation (< ±3% typical)

• Transformer inductance variation
• External component changes with temperature
• Input line voltage variations – this ensures accurate regulation in production

Highly Reliable, Small Size Designs

• Eliminates the optocoupler and secondary CC control circuitry
• Eliminates control loop compensation circuitry
• Frequency jittering greatly reduces EMI filter cost
• Programmable switching frequency reduces transformer size
• 725 V Switching 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
• Reduced field returns
• 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

• Halogen free and RoHS compliant package

Applications

• LED bulbs, downlights, luminaires, ballasts and T8 tubes