BCR420UW6 Datasheet, PDF (1/13 Pages) Diodes Incorporated – LINEAR LED CONSTANT CURRENT REGULATOR IN SOT26

BCR420UW6 / BCR421UW6
LINEAR LED CONSTANT CURRENT REGULATOR IN SOT26
Description
The BCR420U and BCR421U monolithically integrate transistors,
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 an 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 is < 40V.
With the low-side control, the BCR421U has an Enable (EN) pin
which can be pulse-width modulated (PWM) up to 25kHz by a micro-
controller for LED dimming.
With no need for additional external components, this CCR is fully
integrated into an SOT26 / SC74R minimizing PCB area and
component count.
Applications
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
Features
 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 / SC74R
 Low-Side Control Enabling PWM Input < 25kHz (BCR421U)
 Negative Temperature Coefficient (NTC) Reduces IOUT with
Increasing Temperature
 Parallel Devices to Increase Regulated Current
 Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
 Halogen and Antimony Free. “Green” Device (Note 3)
 Qualified to AEC-Q101 Standards for High Reliability
 Automotive-Compliant Parts are Available Under Separate
Datasheet (BCR420UW6Q/BCR421UW6Q)
Mechanical Data
 Case: SOT26 / SC74R
 Case Material: Molded Plastic. ―Green‖ Molding Compound.
UL Flammability Rating 94V-0
 Moisture Sensitivity: Level 1 per J-STD-020
 Terminals: Finish - Matte Tin Plated Leads. Solderable per MIL-
STD-202, Method 208
 Weight: 0.018 grams (Approximate)
SOT26 / SC74R
EN
OUT
Top View
EN
REXT
RREeXxTt
(⁽O^Opp^ttⁱi^ooⁿn^aa^l)l)
GND
Internal Device
Schematic
OUT
OUT
OUT
GND
Top View
Pin-Out
Pin Name
OUT
EN
REXT
GND
Pin Function
Regulated Output Current
Enable for Biasing
Transistor
External Resistor for
Adjusting Output Current
Power Ground
Ordering Information (Note 4)
Product
BCR420UW6-7
BCR421UW6-7
Compliance
AEC-Q101
AEC-Q101
Marking
420
421
Reel Size (inches)
7
7
Tape Width (mm)
8
8
Quantity per Reel
3,000
3,000
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
and Lead-free.
3. Halogen- and Antimony-free "Green‖ products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
4. For packaging details, go to our website at http://www.diodes.com/products/packages.html.
BCR420UW6 / BCR421UW6
Document number: DS37667 Rev. 4 - 2
1 of 13
www.diodes.com
June 2016
© Diodes Incorporated