CD00000444 Datasheet, PDF (34/58 Pages) STMicroelectronics – Positive voltage regulator ICs

Application information
Positive voltage regulator ICs
Figure 27. Protection against input short-circuit with high capacitance loads
Note:
Application with high capacitance loads and an output voltage greater than 6 volts need an
external diode (see Figure 22 on page 31) to protect the device against input short circuit. In
this case the input voltage falls rapidly while the output voltage decrease slowly. The
capacitance discharges by means of the base-emitter junction of the series pass transistor
in the regulator. If the energy is sufficiently high, the transistor may be destroyed. The
external diode by-passes the current from the IC to ground.
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