Power supply over-voltage protection system

A power supply over-voltage protection (OVP) system, comprising:

• a low voltage monitor circuit configured to connect between a power supply output terminal of a power supply and a system load, the low voltage monitor circuit being a first voltage detector with a first threshold voltage, the low voltage monitor circuit configured to monitor a power supply output voltage at the power supply output terminal and provide a load voltage to the system load, the load voltage determined by a level of the power supply output voltage relative to a first threshold voltage level;
• and
• a high voltage monitor circuit configured to be connected between the power supply output terminal of the power supply and a control circuit within the power supply, the high voltage monitor circuit being a second voltage detector with a second threshold voltage that is higher than the first threshold voltage, the high voltage monitor circuit configured to monitor the power supply output voltage at the power supply output terminal and turn off the power supply output voltage via the control circuit within the power supply when the power supply output voltage is equal to or greater than a second threshold voltage level;
• wherein the low voltage monitor circuit comprises a transistor, the transistor having:
• a source terminal configured to connect to the power supply output terminal of the power supply;
• a drain terminal configured to connect to the system load;
• and
• a body diode forward voltage drop between the source terminal and the drain terminal;
• wherein the low voltage monitor circuit,
• upon determining the power supply output voltage to be less than the first threshold voltage level, provides a gate control signal to a gate terminal of the transistor to keep the transistor on;
• upon determining the power supply output voltage to be equal to or greater than the first threshold voltage level and less than a second threshold voltage level, provides a gate control signal to the gate terminal of the transistor to turn the transistor off.

A power supply over-voltage protection (OVP) system, comprising:

• a power supply;
• a low voltage monitor circuit connected between a power supply output terminal of the power supply and a system load terminal, the low voltage monitor circuit being a first voltage detector with a first threshold voltage, the low voltage monitor circuit configured to monitor a power supply output voltage at the power supply output terminal and provide a load voltage to the system load terminal, the load voltage determined by a level of the power supply output voltage relative to a first threshold voltage level;
• and
• a high voltage monitor circuit connected between the power supply output terminal of the power supply and a control circuit within the power supply, the high voltage monitor circuit being a second voltage detector with a second threshold voltage that is higher than the first threshold voltage, the high voltage monitor circuit configured to monitor the power supply output voltage at the power supply output terminal and turn off the power supply output voltage via the control circuit within the power supply when the power supply output voltage is equal to or greater than a second threshold voltage level;
• wherein the low voltage monitor circuit comprises a transistor, the transistor having:
• a source terminal connected to the power supply output terminal of the power supply;
• a drain terminal connected to the system load terminal;
• and
• a body diode forward voltage drop between the source terminal and the drain terminal;
• wherein the low voltage monitor circuit,
• upon determining the power supply output voltage to be less than the first threshold voltage level, provides a gate control signal to a gate terminal of the transistor to keep the transistor on;
• upon determining the power supply output voltage to be equal to or greater than the first threshold voltage level and less than a second threshold voltage level, provides a gate control signal to the gate terminal of the transistor to turn the transistor off.

A power supply over-voltage protection (OVP) system, comprising:

• a transistor having:
• a source terminal;
• a drain terminal;
• and
• a body diode;
• a first voltage detector with a first threshold voltage, the first voltage detector being configured to monitor a source voltage at the source terminal and provide a gate control signal to a gate terminal, the gate control signal determined by the source voltage;
• and
• a second voltage detector with a second threshold voltage that is higher than the first threshold voltage, the second voltage detector being configured to monitor the source voltage at the source terminal and provide a power supply control signal to a power supply, the power supply control signal being determined by the source voltage;
• wherein the first voltage detector,
• upon determining the source voltage to be below a first threshold voltage level, causes the gate control signal to keep the transistor on;
• and
• upon determining the source voltage to be equal to or greater than the first threshold voltage level and less than a second threshold voltage level, causes the gate control signal to turn the transistor off;
• and
• wherein, the second voltage detector, upon determining the source voltage to be equal to or greater than the second threshold voltage level, causes a control circuit within the power supply to turn off power delivered to a power supply output terminal.