Typical performance
L78xx - L78xxC
Figure 37. Protection against input short-circuit with high capacitance loads
1. Application with high capacitance loads and an output voltage greater than 6 volts need an external diode
(see
Figure 32 on page 36)
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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STMICROELECTRONICS [ STMICROELECTRONICS ]
