BCR402 Datasheet, PDF (2/8 Pages) Infineon Technologies AG – Light Emitting Diode (LED) Driver IC Provides Constant LED Current Independent of Supply Voltage Variation

is also found in the BCR402R datasheet. Two
cases are shown: “open”, e.g. R1 is omitted (no
R1 used), showing nominal current to be 20mA,
and R1=68Ω, yielding 30mA. For current up to
60mA, R1 will take on values less than 68Ω, and
R1 can be determined experimentally. Note that
in all cases,
1. BCR402R output current should be
limited to 60mA
2. Total power dissipation of BCR402R
should be limited to less than 330 mW
for device soldering point temperatures
(T_S) equal to or less than 87 °C.
The power dissipation is simply calculated by
multiplying the voltage drop across the device
(e.g. voltage between pins 2 and 3) times the
device current. A good general reference for
use when determining if a given circuit design
falls within device power dissipation guidelines
may be found at [1].
Applications Note No. 066
Silicon Discretes
Figure 3. BCR402R Output Current vs.
Supply Voltage for external resistor = OPEN
and external resistor = 68Ω.
Figure 2. Nominal Output Currents of
Devices in the Infineon LED Driver Family.
Current can be adjusted from these nominal
values via use of a single external resistor.
AN 066 Rev D
2. Application Circuit
The application circuit is designed to
demonstrate the difference between stabilizing
LED current using an Infineon LED driver IC,
versus using a series resistance to stabilize
current. This particular circuit has been
initially set up to operate over a supply
voltage range of 9V to 16V. The switch may
be used to easily toggle between BCR402R
mode and “resistor” mode. Please refer to
Figure 4.
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16-Jan-2004