BCR401W_12 Datasheet, PDF (14/17 Pages) Infineon Technologies AG – LED Driver

4
Application hints
BCR401W
Application hints
3
+V _S
V_S
R_ext
4 ^{(optional )}
Rext
Vdrop
GND 1 I_out 2
I_S
I _out
Figure 4-1 Application Circuit: Stand alone current source
+V _S
3
VS
R_ext
4 ^{(optional )}
R_ext
I_S + I_out
V_drop
GND 1 I_out 2
I_S
I _out
Figure 4-2 Application Circuit: Supply voltages > 18 V
Application hints
BCR401W 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 60 mA. R_ext can be determined by using
Figure 3-6. 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.
Please visit our web site www.infineon.com/lowcostleddriver for detailed application notes.
Datasheet
14
Revision 2.0, 2012-04-12