Datasheet

we-online.com
© May 2016
Würth Elektronik eiSos GmbH & Co. KG - Data Sheet - REV 1.0
23/46
WPMDU1251501 / 171021501
MagI³C Power Module
VDRM - Variable Step Down Regulator Module
For output voltages of 5 V or less, the soft-start capacitance built into the MagI³C Power Module is sufficient for a turn-on
ramp rate that does not induce large surge currents while charging the output capacitors. For output voltages higher than
5 V, an additional soft-start capacitance is recommended. For 12 V to 15 V output voltages, a 22 nF capacitor should be
connected between the SS/TRK pin (Pin 28) and AGND, while connecting the INTSS pin (Pin 29) to AGND as well. Figure 4
shows an external SS capacitor connected to the SS pin and the INTSS pin connected to AGND. See Table 3 below for
SS capacitor values and timing interval.
SS/TRK
AGNDINTSS
C
SS opt
28
29
Figure 4. Soft-Start Capacitor Css and INTSS connection
Soft-Start Time t
SS
Capacitor C
SS
5ms
Open
7ms
4.7nF
10ms
10nF
13ms
15nF
17ms
22nF
Table 3: Recommended Soft-Start Capacitors for typical Start times