Datasheet

IFX8117
Application Hints
Data Sheet 17 Rev. 1.01, 2010-07-02
6.2 Protection Diodes
Figure 7 IFX8117MEV with Protection Diode
In normal operating conditions, no diodes are needed for protection of the device.
In case the input is shorted to GND and the output capacitor is still charged, a peak current can flow from the output
to the input of the regulator. This peak current depends on the size and the equivalent series resistor (ESR) of the
output capacitor. When the input is instantaneously shorted to GND, and with a large output capacitor with low
ESR, the regulator risks to be damaged. For this environment it is recommended to add an external diode between
the output and the input to protect the regulator as shown in Figure 7.
IFX 8117 MEV
Protection_Diode.vsd
V
I
V
Q
ADJ
R
1
R
2
1N4001
(optional )