The KTD2037/2037B is a fully programmable, constant current RGB LED driver with a flexible control interface. The device is ideally powered from one-cell lithium ion/polymer, 3-cell NiCd/NiMH/Alkaline batteries, or systems with 3.3V or 5V supplies. It provides three independent programmable constant current sinks without requiring any external components.

With an on-chip timing control unit, LED blink rate, fade-in and fade-out are user-adjustable resulting in unique color lighting patterns.

Ten internal registers are programmed via the I2C control interface with a built-in decoder allowing individual control of the LED channels’ On/Off state and current level. A total of 191 current levels are available for each channel from 0.125mA to 24mA with a 0.125mA step.

An AutoBlinQ mode automatically turns on and off LED1 (on D1 pin) at 8mA every 2s after EN pin goes high. In this mode, a phone with a discharged battery connected to a charger can have LED1 blink to notify that the battery is charging.

In shutdown mode, the quiescent current is reduced to less than 1μA.

The device is available in a low profile 8-pin 1.5mm x 1.5mm x 0.5mm Ultra-Thin DFN package. The package is Pb-free and RoHS compliant.


  • Ultra low dropout regulated 3-channel current sinks
    • 40mV typ. at 10mA per channel
  • Programmable LED setting by I2C compatible interface
  • Individual channel control
    • On/Off Interval Time Control
    • Dimming Up/Down Time
    • RGB LED Color Control
  • 191 current level setting
  • AutoBlinQ LED1 (D1 pin) mode
    • Blinking period: 2s
    • Current setting: 8mA
  • Fast, smooth start-up
  • VIN Range: 2.7V to 5.5V
  • 0.1 μA Shutdown Current
  • Pb-free Package: UTDFN-8 1.5×1.5mm
  • -40°C to +85°C Temperature Range


  • RGB indicator LEDs
  • Mobile Phones
  • Handheld Devices
  • Digital Cameras

Packaging Information

Package Dimensions Bumps Package Code
UTDFN-8 1.5mm x 1.5mm x 0.5mm 8 WE


Vin (min)  Vin (max)  Number of LEDs/ Channels LED Channels Brightness Control Max Current (A) Accuracy Dropout
2.7V 5.5V 1 4 I2C 24mA ±5% 40mV

Technical Documentation

Description Documents Type
Package Outline DrawingUDFN-8 WE PODPDF


Part Number Marking Operating Temperature Package
KTD2037EWE-TR IJYYZ -40°C to +85°C UTDFN1.5×1.5-8
KTD2037BEWE-TR HWYYZ -40°C to +85°C UTDFN1.5×1.5-8
Purchase Options
Buy from Digi-Key
Buy from Mouser