2009-07-31

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BCR402U

LED Driver

Features

• LED drive current of 20mA

• Output current adjustable up to 65mA with external resistor

• Supply voltage up to 40V

• Easy paralleling of drivers to increase current

• Low voltage overhead of 1.4V

• High current accuracy at supply voltage variation

• No EMI

• High power dissipation of 750mW

• Reduced output current at higher temperatures - Negative thermal coefficient of -0.2% / K

• RoHS compliant (pb-free) small and robust SC-74 package

• Qualified according to AEC Q101

Applications

• Channel letters for advertising, LED strips for decorative lighting

• Aircraft, train, ship illumination

• Retrofits for general lighting, white goods like refrigerator lighting

• Medical lighting

• Automotive applications like CHMSL and rear combination lights

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General Description

The BCR402U is a cost efficient LED driver to drive low power LED’s. The advantages

towards resistor biasing are:

• homogenous light output despite varying forward voltages in different LED strings

• homogenous light output of LED’s despite voltage drop across long supply lines

• homogenous light output independent from supply voltage variations

• longer lifetime of the LED’s due to reduced output current at higher temperatures

(negative thermal coefficient)

The advantages towards discrete solutions are:

• lower assembly cost

• smaller form factor

• better quality due to less soldering points

• higher output current accuracy due to pretested LED drivers

Dimming is possible by using an external digital transistor at the ground pin.

The BCR402U can be operated at higher supply voltages by putting LED’s between the

power supply +VS and the power supply pin of the LED driver. You can find further details

in the application note AN097.

The BCR402U is a perfect fit for numerous low power LED applications by combining small

form factor with low cost. These LED drivers offer several advantages to resistors like

significantly higher current control at very low voltage drop ensuring high lifetime of LED’s.