Single-Stage LED Driver IC with Combined PFC and Constant Current Output in Isolated and Non-Isolated Topologies

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Product Details


The LYTSwitch™-5 family is ideal for single-stage power factor corrected constant current LED applications – bulbs, tubes and ballasts.

Each device incorporates a high-voltage power MOSFET and discontinuous mode, variable frequency, variable on-time controller. The controller also provides fast (cycle-by-cycle) current limit, input and output OVP, plus advanced thermal management circuitry.

The combination of a low-side switching topology, cooling via electronically quiet SOURCE pins and frequency jitter ensures extremely low EMI. This reduces the size of the input filter components – greatly reducing audible noise.

The part numbers shown in Table 1 describe 3 different power levels and two MOSFET voltage options to cost-optimize designs, while EcoSmart™ switching technology ensures maximum efficiency for each device size and load condition.

Product Highlights

Combined Single-Stage PFC + Accurate CC Output

  • Accurate CC, better than ±3%
  • Power Factor >0.9
  • Low THD, <10% with typical input and output conditions
  • >90% efficient in optimized designs
  • High switching frequency and DCM allow compact magnetics

Design Flexibility

  • Supports buck, buck-boost, tapped-buck, boost, isolated and non-isolated flyback topologies
  • 2 MOSFET voltage options and 3 power levels for optimum device selection

Highest Reliability

  • No electrolytic bulk capacitors or optoisolators for increased lifetime
  • Comprehensive protection features
    • Input and output overvoltage
    • Open-loop protection
  • Advanced thermal control
    • Thermal foldback allows output light delivery at abnormally high ambient temperatures
    • Hysteretic shutdown provides protection during fault conditions


Power Table

Output Power Table
Product2 Output Power1
90-308 VAC
LYT5225D 9 W
LYT5216D, LYT5226D 16 W
LYT5218D, LYT5228D 25 W


  1. Maximum practical continuous power in an open frame design with adequate heat sinking, measured at 50˚C ambient (see Key Applications Considerations for more information).
  2. Package: D: SO-16B.

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