Voltage Regulator Application Note
Various protection circuits are built into Ricoh voltage regulators.
Fold-back Protection Circuit
The Fold-back Protection Circuit shown in the blue ellipse as "Current Limit" protects the voltage regulator from damage by overcurrent if the output pin (VOUT) and the ground pin (GND) are shorted.
It consists of the overcurrent protection circuit and the short current protection circuit.
In the typical characteristics, the overcurrent protection activities are shown by the blue line on the "Output Voltage vs. Output Current" graph, and the short current protection activities are shown by the blue circle on the same graph.
The limiting current value of the overcurrent protection is not defined in the datasheet. Please refer to the graph of the typical characteristics.
The limiting current value of the short current protection is defined in the datasheet as short current limit (lSC). In Ricoh voltage regulators, this is usually set within a range of about 30mA to 250mA.
The Fold-back Protection Circuit is built in all voltage regulators except for Rx5RL Series.