SNOSDC0A October 2020 – December 2020 LM7310
The LM73100 is an integrated ideal diode 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(R)) 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 pin is held low (< VUVLO(F)), 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 fast-trip threshold (IFT) is not exceeded and overvoltage spikes are cut-off once they cross the user adjustable overvoltage lockout threshold (VOVLO). This helps to keep the system safe from harmful levels of voltage and current.
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 (VFWD) in forward conduction mode and turned off completely to block reverse current from OUT to IN 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 (TJ) exceeds the recommended operating conditions.