Diodes Menu Close
Diodes Pericom: A product line of Diodes Incorporated


he BCR420U/BCR421U monolithically integrates a transistor, diodes and resistors to function as a Constant Current Regulator (CCR) for linear LED driving. The device regulates with a preset 10mA nominal that can be adjusted with external resistor up to 350mA. It is designed for driving LEDs in strings and will reduce current at increasing temperatures to self-protect. Operating as a series linear CCR for LED string current control, it can be used in multiple applications, as long as the maximum supply voltage to the device < 40V.

With the low-side control, the BCR421U has an Enable (EN) pin which can be pulse-width modulated (PWM) up to 10 kHz by a micro controller for LED dimming.

With no need for additional external components, this CCR is fully integrated into a SOT26 minimizing PCB area and component count.


Constant Current Regulation (CCR) in:
  • Automotive Interior Lighting
  • Emergency Lighting
  • Signage, Advertising, Decorative and Architectural Lighting
  • Retail Lighting in Fridges, Freezer Cases and Vending Machines


  • LED Constant Current Regulator using NPN Emitter-Follower with Emitter Resistor to Current Limit
  • Iout = 10mA ± 10% Constant Current (Preset)
  • Iout up to 350mA adjustable with an External Resistor
  • Vout = 40V Supply Voltage
  • Pd up to 1W in SOT26 (SC-74)
  • Negative temperature coefficient (NTC) reduces IOUT with increasing temperature
  • Parallel Devices to Increase Regulated Current
  • Totally Lead-Free & Fully RoHS Compliant
  • Halogen and Antimony Free. “Green” Device
  • Qualified to AEC-Q101 Standards for High Reliability

Product Specifications

Product Parameters

Qualified to AECQ10x Yes
Automotive Compliant PPAP BCR421UW6Q
Topology Linear LED Driver
Minimum Supply Voltage 1.4 V
Maximum Supply Voltage 40 V
Maximum VOUT 40 V
Number of Channels 1
LED Current Sense Voltage 700 mV
Output Current 350 mA
LED Current 10 Preset mA
Accuracy 10 %
Dimming PWM
Temperature Range -55 to 150 °C

Related Content

SOT26 (SC74R)

Quality & Reliability

Technical Documents



Recommended Soldering Techniques
Orderable Part Number Authorized Distributor Quantity Inventory Date Buy Online Region
BCR421UW6-7 Arrow Electronics Central EU 3000 7/22/2019 Buy Now Europe, Middle East, Africa
BCR421UW6-7 Digi-Key Electronics 2175 7/22/2019 Buy Now Americas
BCR421UW6-7 Mouser Electronics Inc. 70748 7/22/2019 Buy Now Americas
BCR421UW6Q-7 Arrow Electronics 1 7/22/2019 Buy Now Americas
BCR421UW6Q-7 Arrow Electronics Central EU 3000 7/22/2019 Buy Now Europe, Middle East, Africa
BCR421UW6Q-7 Digi-Key Electronics 85934 7/22/2019 Buy Now Americas
BCR421UW6Q-7 Mouser Electronics Inc. 18196 7/22/2019 Buy Now Americas
BCR421UW6Q-7 Rutronik GmbH 3000 7/21/2019 Buy Now Europe, Middle East, Africa