SSL5257TE - Mains dimmable buck-boost LED driver IC 10 Ohm/700 V


  • Integrated MOSFET (10 Ω/700 V)
  • Supports most available dimming solutions
  • Deep dimming level
  • Flicker-free dimming
  • Low component count ensuring a compact solution and small, single layer Printed-Circuit Board (PCB) footprint
  • Excellent line regulation and load regulation and good LED output current accuracy
  • Hotaru current control
  • Internal thermal foldback
  • Efficient BCM operation with:
    • Minimal recovery losses in freewheel diode
    • Zero Current Switching (ZCS) and Valley switching for turn-on of switch
    • Minimum inductance value and size required
    • High efficiency (up to 90 %)
    • Ultra low IC current during operation (< 200 μA)
  • Auto-recovery protections:
    • UnderVoltage LockOut (UVLO)
    • Cycle-by-cycle OverCurrent Protection (OCP)
    • Internal OverTemperature Protection (OTP)
    • Output OverVoltage Protection (OVP)
    • Output Short Protection (OSP)
  • Extended IC lifetime

Typical Application


The SSL5257TE is a highly integrated, high-precision buck-boost controller with an internal MOSFET. It is intended to drive low-cost compact dimmable LED lamps up to 10 W. The SSL5257TE is designed to achieve high power factor, phase-dimmable applications.

The SSL5257TE operates in Boundary Conduction Mode (BCM) with on-time control. It regulates a constant output current over line and load variations. The wide switching frequency range makes it possible to choose an inductor, which enables the optimization of inductor size, efficiency and EMI.

The SSL5257TE can start up and operate in switching mode directly from the rectified mains. To provide a low-cost driver design, an off-the-shelf inductor can be used, which provides flexibility in application design.


The SSL5257TE is intended for low-cost, non-isolated dimmable lighting applications that work from single mains voltage.