SSL5031BTS/1 - Compact High Power Factor / Low THD Buck LED driver IC


  • Driving LED strings from a rectified mains supply, high power factor/low-THD
  • Small electronic Bill of Materials (BOM) enabling a compact solution and a small,
  • single layer Printed-Circuit Board (PCB) footprint
  • Excellent line and load regulation and LED output current accuracy
  • Efficient BCM operation with:

Minimal reverse recovery losses in freewheel diode

Zero Current Switching (ZCS) and valley switching for switch turn-on

Minimal inductance value and size required

High efficiency (up to 91 %)

Ultra low IC current during operation (< 150 mA)

  • Auto-recovery protections:

UnderVoltage LockOut (UVLO)

Cycle-by-cycle OverCurrent Protection (OCP)

Internal OverTemperature Protection (OTP)

Output OverVoltage Protection (OVP)

Output Short Protection (OSP)

Thermal foldback protection via a single PTC or NTC resistor

  • Compatible with wall switches with built-in standby indicator lights (Hotaru switch)
  • Extended IC lifetime

Typical Application


The SSL5031BTS is a highly integrated, high-precision, non-isolated buck controller with

external MOSFET. It is intended to drive LED lamps in universal mains non-dimmable

lighting applications up to 25 W. The SSL5031BTS is designed for high power

factor/low-THD applications.


The SSL5031BTS operates in Boundary Conduction Mode (BCM) with on-time regulation.

Operating in BCM provides a constant output current control with high accuracy. Adaptive

switching frequency gives freedom to choose the inductor, which enables the optimization

of inductor size, efficiency and EMI.


The SSL5031BTS starts up and operates in switching mode directly from an external

resistor without dV/dt supply or auxiliary supply. This feature simplifies the VCC supply. It

allows a low-cost off-the-shelf inductor to be used, providing flexibility in application



The SSL5031BTS comes in a compact SOT23-6 package.


The SL5021BTS is suitable for Low-ripple applications. The SSL5031CTS is best for high

power factor/Low-THD applications without high temperature foldback function.


The SSL5031BTS is intended for low-cost, non-isolated LED lighting applications with accurate fixed current output up to 25W for single mains or universal mains voltage (90 to 277 V (AC)).