The TPS25947xx is an eFuse with integrated power path that is used to ensure safe power delivery in a system. The device starts its operation by monitoring the IN bus. When the input supply voltage (VIN) exceeds the Undervoltage Protection threshold (VUVP), the device samples the EN/UVLO pin. A high level (> VUVLO) on this pin enables the internal power path (BFET+HFET) to start conducting and allow current to flow from IN to OUT. When EN/UVLO is held low (< VUVLO), the internal power path is turned off. In case of reverse voltages appearing at the input, the power path remains OFF thereby protecting the output load.

After a successful start-up sequence, the device now actively monitors its load current and input voltage, and controls the internal HFET to ensure that the user adjustable overcurrent limit threshold (I_LIM) is not exceeded and overvoltage spikes are either safely clamped to the selected threshold voltage (V_OVC) or cut-off after they cross the user adjustable overvoltage lockout threshold (V_OVLO). The device also provides fast protection against severe overcurrent during short-circuit events. This keeps the system safe from harmful levels of voltage and current. At the same time, a user adjustable overcurrent blanking timer allows the system to pass moderate transient peaks in the load current profile without tripping the eFuse. This ensures a robust protection solution against real faults which is also immune to transients, thereby ensuring maximum system uptime.

The device has integrated reverse current blocking FET (BFET) which operates like an ideal diode. The BFET is linearly regulated to maintain a small constant forward drop (V_FWD) in forward conduction mode and turned off completely to block reverse current if output voltage exceeds the input voltage.

The device also has a built-in thermal sensor based shutdown mechanism to protect itself in case the device temperature (T_J) exceeds the recommended operating conditions.