Datasheet

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© May 2016
Würth Elektronik eiSos GmbH & Co. KG - Data Sheet - REV 1.0
25/46
WPMDU1251501 / 171021501
MagI³C Power Module
VDRM - Variable Step Down Regulator Module
The V
ON
UVLO threshold must be set to at least (V
OUT
+ 3 V) or 6.5 V whichever is higher to insure proper startup and
reduce current surges on the host input supply as the voltage rises. If possible, it is recommended to set the UVLO
threshold to approximately 80% to 85% of the minimum expected input voltage.
V
OFF
should be selected to be at least 500 mV less than V
ON
.
Use equation 6 and 7 to calculate the values of R
UVLO1
and R
UVLO2
.







  


(10)






 


  



(11)
Table 4 lists standard resistor values for R
UVLO1
and R
UVLO2
for adjusting the V
ON
UVLO threshold for several input voltages.
V
ON Threshold
R
UVLO1
R
UVLO2
6.5V
174kΩ
40.2kΩ
10V
24.3kΩ
15V
15.8kΩ
20V
11.5kΩ
25V
9.09kΩ
30V
7.5kΩ
35V
6.34kΩ
40V
5.62kΩ
45V
4.99kΩ
Table 4: Standard V
ON Threshold
Values