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The 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 BCR420UW6Q
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 by external transistor
Temperature Range -55 to 150 °C

Related Content

SOT26 (SC74R)

Technical Documents



Recommended Soldering Techniques



Orderable Part Number Authorized Distributor Quantity Inventory Date Buy Online Region
BCR420UW6-7 Avnet EU 75000 8/8/2020 Buy Now Germany
BCR420UW6-7 Arrow Electronics Central EU 3000 8/8/2020 Buy Now Germany
BCR420UW6-7 Digi-Key Electronics 615710 8/8/2020 Buy Now United States
BCR420UW6-7 Mouser Electronics Inc. 122705 8/8/2020 Buy Now United States
BCR420UW6-7 Future Electronics 87000 8/7/2020 Buy Now Canada
BCR420UW6-7 Future Electronics - Europe 111000 8/7/2020 England
BCR420UW6Q-7 Avnet EU 102000 8/8/2020 Buy Now Germany
BCR420UW6Q-7 Arrow/Components Agent Ltd. 81000 8/8/2020 Buy Now Hong Kong
BCR420UW6Q-7 Digi-Key Electronics 13922 8/8/2020 Buy Now United States
BCR420UW6Q-7 Mouser Electronics Inc. 59890 8/8/2020 Buy Now United States
BCR420UW6Q-7 Rutronik GmbH 120000 8/7/2020 Buy Now Germany


Product Change Notices

PCN # Issue Date Subject
PCN-2456 2020-05-29 Qualification of Internal "Diodes Technology (Cheng Du) Company Limited" (CAT) as an Additional Assembly & Test Site Using Copper or Palladium Coated Copper Bond Wire with Standardization of Assembly Bill of Materials, Or as an Additional Wafer Plating, Back Grinding and Back Metal Process Source, and Qualification of Additional Wafer Source for Select Discrete Products.