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
For other output voltages the value of R
SET
can be calculated using the following formula.
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
  



 
The MagI³C Power Module operates over the input voltage range of 7 V to 50 V. For reliable start-up and operation at light
loads, the minimum input voltage depends on the output voltage (see table below).
Output voltage range
Condition
Input voltage
V
OUT
≤ 12V
7V ≤ V
IN
≤ 50V
V
INmin
≥ V
OUT
+ 3V
V
INmax
≤ V
OUT
*15
V
OUT
> 12V
V
INmin
≥ V
OUT
*1.33
V
INmax
≤ V
OUT
*15
Although the device can safely handle input surge voltages up to 65 V, sustained operation at input voltages above 50 V
is not recommended. See the Step 6 (Undervoltage Lockout (UVLO) Threshold section) for more information.
V
OUT
36
R
SET
10kΩ
AGND
R
SET INT
1
FB
Step 2 Setting the operating frequency (f
SW
)
Nominal switching frequency of the MagI³C Power Module is set from the factory at 400 kHz. This switching frequency is
optimized for output voltages below 5 V. For output voltages of 5 V and above, better operating performance can be
obtained by raising the operating frequency. This is easily done by adding a resistor, R
RT
from the RT/CLK pin (Pin 31) to
the AGND pin (Pin 30). Raising the operating frequency reduces output voltage ripple, lowers the load current threshold
where pulse skipping begins, and improves transient response. The recommended switching frequency for typical output
voltages is listed in Table 2.
For the maximum recommended output voltage value of 15 V, the switching frequency computes to 1 MHz. Operation
above 1 MHz is not recommended.
V
OUT
f
SW
R
RT
2.5V
400kHz
Open
3.3V
400kHz
Open
5V
500kHz
1,1MΩ
9V
700kHz
365kΩ
12V
800kHz
267kΩ
15V
1MHz
178kΩ
Table 2: Standard Switching Frequencies