BCR401UE6327_15 Datasheet, PDF (16/19 Pages) Infineon Technologies AG – LED Driver

4
Application hints
BCR 401U E6327
Application hints
4
+V _S
V_S
R_ext
6 ^{(optional )}
Rext
Vdrop
GND 1 OUT 2,3,5
I_S
I _out
Figure 4-1 Application Circuit: Stand alone current source
4
+V _S
V_S
R_ext
6 ^{(optional )}
Vdrop
Rext
I LED
GND 1 OUT 2,3,5
I _out
R₁
I_S
R₂
Figure 4-2 Application Circuit: Boost mode current source with external power transistor
Application hints
BCR 401U E6327 serves as an easy to use constant current source for LEDs. In stand alone application an
external resistor R_ext can be connected to adjust the current between 10 mA and 65 mA. R_ext can be determined
by using Figure 3-8. Connecting a low tolerance resistor R_ext will improve the overall accuracy of the current sense
resistance formed by the parallel connection of R_int and R_ext leading to an improved current accuracy. Please take
into account that the resulting output currents will be slightly lower due to the self heating of the component and
the negative thermal coefficient.
In boost mode configuration the LED current can be extended to drive high power LEDs. Please visit our web site
www.infineon.com/lowcostleddriver for detailed application notes.
Datasheet
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Revision 2.1, 2015-01-28