Maximum voltage selector circuit having adaptive current bias generator

A voltage selector circuit, comprising:

• a voltage comparator, comprising:
• a first voltage comparator current path extending between a first input voltage terminal and a ground terminal, and having a first voltage comparator output node between the first input voltage terminal and the ground terminal and having a first voltage comparator current element between the first voltage comparator output node and the ground terminal;
• a second voltage comparator current path extending between a second input voltage terminal and the ground terminal, and having a second voltage comparator output node between the second input voltage terminal and the ground terminal and having a second voltage comparator current element between the second voltage comparator output node and the ground terminal;
• and
• an adaptive current bias generator having a first input terminal coupled to the first input voltage terminal and a second input terminal coupled to the second input voltage terminal, and having an output coupled to the first voltage comparator current element and the second voltage comparator current element.

A Direct Current (DC)-to-DC converter system, comprising:

• a power supply configured to provide a first voltage;
• a load configured to operate on a second voltage that differs from the first voltage;
• a current path coupling the power supply to the load;
• an isolation device arranged on the current path between the power supply and the load, the isolation device including a first body bias switch coupled between a body of the isolation device and the power supply and a second body bias switch coupled between the body of the isolation device and the load;
• and
• a voltage selector circuit including a first input coupled to the power supply and a second input coupled to the load, the voltage selector circuit configured to select a larger of the first voltage and the second voltage in time and to provide a first control signal to the first body bias switch and a second control signal to the second body bias switch based on whether the first voltage or the second voltage is larger.