The KTD257M is a versatile constant current LED driver with a high efficiency DC-DC step up “boost” converter architecture. The low-side power MOSFET is integrated in the device, minimizing the total number of external components. Unique technology and high 0.9A current limit allow KTD257M to drive up to 39V output (10 LEDs in series). Alternatively, KTD257M can deliver 160mA total current with 3 series LEDs per string. It can also maximize the current capability while achieving high conversion efficiency. The optimized 900kHz switching frequency results in small external component size. The driver allows wide range of PWM dimming frequency through EN pin. Various protection features are built into the KTD257M, including cycle-by-cycle input current limit protection, LED open-circuit (output over voltage) protection and thermal shutdown protection. The leakage current in shutdown mode is less than 1μA.

The KTD257M is available in a RoHS and Green compliant 6-lead TSOT23 package.


  • Wide output range: up to 10 series LEDs
  • Integrated 40V high current switch (0.9A limit)
  • VIN: 2.7V to 5.5V
  • High efficiency PWM converter (up to 90%)
  • Low 200mV feedback voltage
  • LED open-circuit (OVP) protection
    • KTD257M: 39V
  • High switching frequency
    • KTD257M: 900kHz
  • PWM dimming frequency: 100Hz~200kHz
  • Simple, small solution size
  • Integrated Softstart
  • < 1 μA shutdown current
  • Small TSOT23-6 Package
  • RoHS and Green compliant
  • -40°C to +85°C Temperature Range


  • LED backlighting
  • Mobile Phones
  • Handheld Devices
  • Digital Photo Frames
  • Automotive Navigation

Packaging Information

Package Dimensions Bumps Package Code
TSOT23-6 2.90mm x 2.80mm x 0.85mm 6 HD

Technical Documentation

Description Documents Type
Package Outline DrawingTSOT23-6 HD PODPDF


Part Number Marking Operating Temperature Package
KTD257MEHD-TR EDYWZ -40°C to +85°C TSOT23-6

Purchase Options Coming Soon