New Industry Products

High-Side Constant Current Regulators for LED Lighting Systems

June 28, 2019 by Scott McMahan

The TSCR400 & TSCR402 from Taiwan Semiconductor are high-side constant current regulators (CCR) for linear LED driving. TSCR400 and TSCR402 regulate with presets of 0.1mA and 20mA nominal (respectively) that are adjustable with an external resistor up to 65mA.

Taiwan Semiconductor designed them to drive LEDs in strings, and they will reduce current at increasing temperatures to self-protect.

Typical applications for the CCRs include automotive interior lighting, architectural LED lighting, signage, advertising, decorative lighting, and emergency lighting (e.g. steps lighting, exit way signs etc.), as well as retail lighting in fridges, freezer cases, and vending machines.

Typical application circuit (Click on image to enlarge)

As a series linear CCR for controlling LED string current, it can be used in multiple applications so long as a maximum supply voltage of the device is <40V.

The reduced output current at higher temperatures is the result of the negative temperature coefficient of -0.07%/°C of the LED driver.

(Click on chart to enlarge)


  • LED drive current preset:
  • TSCR400CX6: 0.1mA
  • TSCR402CX6: 20mA
  • Continuous output current up to 65mA with an external resistor
  • Easy paralleling of drivers to increase current
  • Supply voltage up to 40V
  • Good temperature coefficient vs. output current
  • Compliant to RoHS Directive 2011/65/EU and in accordance to WEEE 2002/96/EC.
  • Halogen-Free according to IEC 61249-2-21