Data Sheet

WLMDU9456001JT / 172946001
MagI
3
C Power Module
LDHM - LED Step Down High Current Module
We-online.com Würth Elektronik eiSos GmbH & Co. KG – Data Sheet Rev. 1.0
© May 2016 20/35
Example. In the following table two possible external voltage sources and the required resistors are shown. In both cases a
LED current from 300mA to 450mA can be adjusted
V
ADIM
range [V]
R
ADIM
[kΩ]
R
IADJ
[kΩ]
0 to 3.3 18.48 (18.7 closest value 1% series) 2.67
0 to 5 28.00 2.55
The picture below shows how the LED current varies according to the analog dimming voltage, using the above mentioned
resistors.
Since the color temperature of the LED depends on the current flowing through the LED, the analog dimming does not allow
to keep constant the color of the emitted light. For applications where the color of the emitted light plays a crucial role, a
PWM (following section) is strongly recommended.
300
350
400
450
0 1 2 3 4 5
LED current [mA]
Analog dimming voltage ADIM [V]
LED current variation through the analog dimming