BCR420U / BCR421U
LED Driver
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LED Driver
1.1
Features
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LED drive current preset to 10 mA
Continuous output current up to 150 mA with an external resistor
Easy paralleling of drivers to increase current
Supply voltage up to 40 V
Low side current control
Digital PWM input up to 10 kHz frequency (BCR421U)
Up to 1 W power dissipation in a small SC74 package
Negative thermal coefficient of -0.2 %/K reduces output current at higher temperatures
RoHS compliant (Pb-free) package
Automotive qualified according AEC Q101
SC74-3D
1.2
Applications
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Architectural LED lighting
Channel letters for advertising, LED strips for decorative lighting
Retail lighting in fridge, freezer case and vending machines
Emergency lighting (e.g. steps lighting, exit way signs etc.)
1.3
General Description
The BCR420U / BCR421U provides a low-cost solution for driving 0.25 W LEDs with a typical LED current of
75 mA to 150 mA. Internal breakdown voltage is higher than 40 V which is the maximum voltage the LED driver
can sustain when the output is directly connected to supply voltage.
The BCR420U / BCR421U can be operated with a supply voltage of more than 40 V considering the voltage drop
of the LED load which reduces the output voltage to the maximum rating of the driver.
The enable pin of BCR420U can withstand a maximum voltage of 40 V which can be increased adding a series
resistor in front of the enable pin reducing the voltage at the enable pin below 40 V.
The digital input pin of BCR421U allows dimming via a micro controller with frequencies up to 10 kHz.
A reduction of the output current at higher temperatures is the result of the negative temperature coefficient of -
0.2 %/K of the LED driver.
With no need for additional external components like inductors, capacitors and free wheeling diodes, the
BCR420U / BCR421U LED drivers are a cost-efficient and PCB-area saving solution for driving 0.25 W LEDs.
Datasheet
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Revision 2.0, 2012-05-04