How does the overcurrent protection of a low-voltage IPD work?

Low-voltage IPDs incorporate an overcurrent protection circuit, which uses one of the three methods described below. Some IPDs achieve overcurrent protection by combining multiple methods.

See technical datasheets for information about the overcurrent protection circuit used in each IPD.

Overcurrent protection is designed for temporary protection of the IPD. Be sure to shut down a system in the event of the overcurrent protection circuit being enabled.

Intermittent control (self-excited oscillation)
Figure 1 Intermittent control (self-excited oscillation)

In the event of overcurrent detection, an internal timer starts to control the output intermittently for current limiting.

The output turns back on automatically when the overcurrent condition disappears.

Current limiting
Figure 2 Current limiting

In the event of overcurrent detection, the output current is limited to the programmed value.

The output turns back on automatically when the overcurrent condition disappears.

Latch-off
Figure 3. Latch-off

In the event of overcurrent detection, the output is turned off, and output off-state is latched.

To release the latch, apply a "L" level signal to the input terminal.

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