Datasheet

WPMDB1400362Q / 171040302
MagI
3
C Power Module
VDRM – Variable Step Down Regulator Module
we-online.com Würth Elektronik eiSos GmbH & Co. KG – Data Sheet Rev. 1.0
© May 2016 34/48
PROTECTIVE FEATURES
Over temperature protection (OTP)
The junction temperature of the MagI³C Power Module should not be allowed to exceed its maximum ratings. Thermal
protection is implemented by an internal thermal shutdown circuit which activates at 175°C (typ) causing the device to enter
a low power standby state. In this state the main MOSFET remains off causing V
OUT
to fall, and additionally the C
SS
capacitor is discharged to ground. Thermal protection helps prevent catastrophic failures due to accidental device
overheating. When the junction temperature falls below 160°C the SS pin is released, V
OUT
rises smoothly, and normal
operation resumes. Applications requiring maximum output current, especially those at high input voltages, may require
additional derating at elevated temperatures.
Over current protection (OCP)
For protection against load faults, the MagI³C Power Module incorporates cycle-by-cycle current limiting (see I
OCP
in
“Electrical Specification” on page 7). During an overcurrent condition the output current is limited and the output voltage is
reduced. As the output voltage drops more than 9% below the set point, the PG signal is pulled low. If the output voltage
drops more than 25%, the switching frequency is reduced to reduce power dissipation within the device. When the
overcurrent condition is removed, the output voltage returns to the nominal voltage.
Short circuit protection (SCP)
The short circuit protection is realized the cycle-by-cycle current limiting. The short circuit protection is continuous with a
recovery at the following switching cycle if the short circuit condition is removed.
Output overvoltage protection (OVP)
The device incorporates an overvoltage protection to minimize output voltage overshoot when recovering from output fault
conditions. When the output voltage reaches the upper trip point of 109% of the voltage programmed with the feedback
resistor divider, the high-side MOSFET is disabled to prevent further output voltage rise caused by the module itself. When
the output voltages reaches the lower trip point of 105% of the programmed output voltage, the high-side MOSFET will be
turned on again at the next switching cycle.