The AP2331TD from Diodes Incorporated is a single-channel, current-limited, integrated, high-side power switcher optimized for hot-swap applications. The devices have fast short-circuit response time for improved overall system robustness and provide a complete protection solution for applications subject to heavy capacitive loads and the prospect of short-circuit. It offers reverse-current blocking, overcurrent, overtemperature, and short-circuit protection, as well as controlled rise time and undervoltage lockout functionality.

Reverse-Current Protection

The USB specification does not allow an output device to source current back into the USB port. In a normal MOSFET switch, the current will flow in a reverse direction (from the output side to the input side) when the output side voltage is higher than the input side. A reverse current limit feature is implemented in the AP2331TD to limit such back currents. Reverse-current limit is always active in the AP2331TD.

Current Limit Protection

The AP2331TD limits the max current to avoid damage of load and during overload conditions.

Short Circuit Protection

The AP2331 senses the short circuit and immediately clamps output current to a certain safe level.

Discharge Function

When input voltage falls below UVLO, the discharge function is active. The output capacitor is discharged through an internal NMOS with a discharge resistance of 1.8 kΩ. Hence, the output voltage drops down. The internal discharge NMOS is turned off right away to avoid leakage current from output. The transient output discharge feature makes it suitable for HDMI or display port applications.