Circuit for monitoring and disabling power supply signals to a microprocessor in a computer system utilizing secondary voltage regulators

A computer system, comprising:

• a main power supply providing at least one primary supply voltage signal;
• a DC--DC converter circuit receiving at least one of said primary supply voltage signal(s) and providing at least one secondary supply voltage signal to a microprocessor;
• comparator means for sensing and comparing the secondary supply voltage signal with a reference voltage level, said comparator means for sensing providing a fault signal indicating by a first fault signal level that said secondary supply voltage signal is within a predetermined range of satisfactory power supply voltage values, and indicating by a second fault signal level that said secondary supply voltage signal is outside said predetermined range of satisfactory power supply voltage values;
• and
• an electronic switch connected to receive said fault signal, said electronic switch being connected between a primary supply voltage line and ground, said switch being non-conductive when said fault signal is at said first fault signal level, said switch effectively coupling said primary supply voltage line to ground when said fault signal is at said second fault signal level.

A circuit for monitoring and disabling power supply signals to a microprocessor used in a computer system which includes a main power supply providing primary supply voltages and a DC--DC converter circuit which provides secondary supply voltages for use by the microprocessor, the circuit comprising:

• comparator means responsive to a first secondary supply voltage for providing a first fault signal line;
• comparator means responsive to a second secondary supply voltage for providing a second fault signal line;
• a first transistor having a gate connected to said first fault signal line, a drain connected to one of said primary supply voltages, and a source connected to ground;
• and
• a second transistor having a gate connected to said second fault signal line, a drain connected to one of said primary supply voltages, and a source connected to ground.

A computer system, comprising:

• a main power supply providing at least one primary supply voltage signal;
• a DC--DC converter circuit receiving at least one of said primary supply voltage signal(s) and providing at least one secondary supply voltage signal to a microprocessor;
• a comparator circuit configured to compare the secondary supply voltage signal with at least one voltage fault threshold level, said comparator circuit providing a fault signal indicating by a first fault signal level that said secondary supply voltage signal is within a predetermined range of satisfactory power supply voltage values, and indicating by a second fault signal level that said secondary supply voltage signal is outside said predetermined range of satisfactory power supply voltage values;
• and
• an electronic switch connected to receive said fault signal, said electronic switch being connected between a primary supply voltage line and ground, said switch being non-conductive when said fault signal is at said first fault signal level, said switch effectively coupling said primary supply voltage line to ground when said fault signal is at said second fault signal level.