Datasheet

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© May 2016
Würth Elektronik eiSos GmbH & Co. KG - Data Sheet - REV 1.0
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WPMDU1251501 / 171021501
MagI³C Power Module
VDRM - Variable Step Down Regulator Module
BLOCK DIAGRAM
INTSS
RT/CLK
PG
FB
SS/TR
SW
EN/UVLO
VOUT
PGND
PWM Controller
Driver
Protection Circuitry
BOOT
RCCOMP
INTR
RT
AGND
COMP
29
2 3
1
27
35
C
OUT
R
SET
V
OUT
AGND
PGND
Linear
Regulator
VIN
UVLO
C
IN
V
IN
PGND
RSET INT
36
C
boot
25
4.9µH
VIN
26
2 µA
V
R EF
AGND PGND
28 3130
10-15, 39
6, 7, 21-24, 38, 41
0.8V
Power Module
Error Amplifier
10kΩ
CIRCUIT DESCRIPTION
The MagI³C Power Module WPMDU1251501 is based on a non synchronous step down regulator with integrated
MOSFET, schottky diode and a power inductor. The control scheme is based on a Current Mode (CM) regulation loop.
The V
OUT
of the regulator is divided with the feedback resistor network R
SET
and an internal 10KΩ resistor and fed into the
error amplifier which compares this signal with the internal 0.8V reference V
REF
. The error signal is amplified and controls
the on-time of a fixed frequency pulse with generator. This signal drives the power MOSFET.
The Current Mode architecture features a constant frequency during load steps. Only the on-time is modulated. It is
internally compensated and stable with low ESR output capacitors and requires no external compensation network.
This architecture supports fast transient response and very small output ripple values (less than 10mV) are achieved.