How does overcurrent protection work in an LDO regulator?

Figure 1 Example of foldback characteristics
Figure 1 Example of foldback characteristics

In the event of an overcurrent condition, our LDO regulators are protected by foldback.

The term “foldback” is derived from the shape of the output current (IOUT)-vs-output voltage (VOUT) curve that folds back as shown in Figure 1 during protection operation.

Under a short-circuited load condition, foldback reduces IOUT as VOUT decreases. When VOUT has dropped to zero, it keeps the output current at a limited constant level.

When the overcurrent condition has disappeared, VOUT returns to the normal level automatically.

If an output capacitor or a capacitive load is connected to the output pin, VOUT increases while IOUT is limited by foldback.

For LDO’s overcurrent protection, please refer to

For other LDO regulators, visit the main web page of LDO regulators at:

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