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 10/35
BLOCK DIAGRAM
LED-
DIM
47µH
Power Module
Voltage
Regulator
1
2
3
7
Switch Control
& Logic
LED+
V
IN
Current
mirror
VCC
-
+
1.25V
VCC
1 λF
0.33µF
AGND
EP
IFIX
LED+
4
5
6
Vref
PGND
Rsense
3kΩ
GND
C
IN
C
OUT
ISET
High Power LED array
Error
Amplifier
CIRCUIT DESCRIPTION
The MagI³C Power Module 172946001 is based on a non-synchronous floating buck regulator (simplified schematic below)
with integrated MOSFET, integrated diode and a power inductor. Note that in a floating buck topology the load (LEDs) is not
connected to GND. The control loop is based on a current mode control scheme with fixed switching frequency, assuring
accurate constant current regulation and good EMI performance. High speed dimming is implemented by direct control of
the PWM signal.
LED-
LED+
LED+
V
IN
controller
C
IN
C
OUT
R
sense
PGND
Floating buck