L7809C STMicroelectronics, L7809C Datasheet - Page 36

• Manufacturer Part Number: L7809C
• Description: Positive voltage regulators
• Manufacturer: STMicroelectronics

Application information
Figure 28. Protection against input short-circuit with high capacitance loads
Note:
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Application with high capacitance loads and an output voltage greater than 6 volts need an
external diode (see
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.
Figure 23 on page
Doc ID 2143 Rev 26
34) to protect the device against input short circuit. In
L78xx, L78xxC, L78xxAB, L78xxAC