Power switch reverse current protection systems

A power supply system comprising:

• an input stage configured to provide a power current in response to an input voltage;
• an output stage configured to provide the power current to a load;
• a power transistor coupled between the input stage and the output stage;
• a power switch control system configured to control the power transistor, the power switch control system comprising:
• a first monitoring terminal coupled to a first terminal of the power transistor;
• a second monitoring terminal coupled to a second terminal of the power transistor, wherein the power transistor and the power switch control system form an ideal diode between the first monitoring terminal and the second monitoring terminal, in which the first monitoring terminal is configured as an anode of the ideal diode and the second monitoring terminal is configured as a cathode of the ideal diode;
• and
• a reverse current controller coupled to the first monitoring terminal and the second monitoring terminal and being configured to control activation of the power transistor in response to a reverse voltage at the second monitoring terminal being greater than a voltage at the first monitoring terminal, the reverse current controller including:
• an anode regulation transistor coupled between an input of the power transistor and the first monitoring terminal, the anode regulation transistor being activated in response to the reverse voltage being approximately equal to a threshold amplitude;
• a cathode regulation transistor coupled between the input of the power transistor and the second monitoring terminal, the cathode regulation transistor being activated in response to the reverse voltage being approximately equal to the threshold amplitude;
• and
• a Zener diode stack coupled to an input of the anode regulation transistor and an input of the cathode regulation transistor, the Zener diode stack being configured to set the threshold amplitude, and to activate the anode regulation transistor and the cathode regulation transistor in response to the reverse voltage being approximately equal to the threshold amplitude, causing a reverse current to flow.

An integrated circuit (IC) comprising:

• a Zener diode stack having an input coupled to a first monitoring terminal and an output coupled to a second monitoring terminal, the first and second monitoring terminals being coupled to receive a first terminal of a power transistor and a second terminal of the power transistor, respectively;
• an anode regulation transistor having an input coupled to the Zener diode stack, having a first terminal coupled to the first monitoring terminal and a second terminal coupled to receive an input of the power transistor;
• and
• a cathode regulation transistor having an input coupled to the Zener diode stack, having a first terminal coupled to receive the input of the power transistor and a second terminal coupled to the second monitoring terminal.