Four-terminal power MOSFET switch having reduced threshold voltage and on-resistance

A power MOSFET switch for switching a current to a load, the power MOSFET switch comprising:

• a four-terminal MOSFET having first, second gate and body terminals, no one of the terminals being shorted to any of the other terminals;
• a first switch connected between the first and gate terminals;
• a second switch connected between the first and body terminals;
• wherein the first and second switches are ganged together, the first switch passing a voltage V.sub.G (on) to the gate terminal and the second switch passing a voltage V.sub.B to the body terminal when the first and second switches are in a first position, the first switch passing a voltage V.sub.G (off) to the gate terminal and the second switch removing the voltage V.sub.B from the body terminal when the first and second switches are in a second position.

A power MOSFET switch arrangement comprising:

• a four-terminal power MOSFET having source, drain, gate and body terminals, no one of the terminals being shorted to any of the other terminals;
• a resistor connected between the gate and body terminals;
• and
• a depletion-mode MOSFET connected between the source and body of the power MOSFET, the depletion-mode MOSFET having source and body terminals shorted together and a gate terminal connected to the gate of the power MOSFET.

A power MOSFET switch arrangement comprising:

• a power MOSFET having source, drain, gate and body terminals, no one of the terminals being shorted to any of the other terminals;
• a voltage supply line;
• a first inverter having an output terminal connected to the gate terminal and a power input terminal connected to the voltage supply line;
• and
• a second inverter having an output terminal connected to the body terminal and a power input terminal connected through a resistor to the voltage supply line.

A power MOSFET switch arrangement comprising:

• a power MOSFET having source, drain, gate and body terminals, no one of the terminals being shorted to any of the other terminals;
• a voltage supply line;
• a first inverter having an output terminal connected to the gate terminal and a power input terminal connected to the voltage supply line;
• a second inverter having an output terminal connected to an input terminal of the first inverter and a power input terminal connected to the voltage supply line;
• and
• third and fourth MOSFETs connected in series between the voltage supply line and ground, a common node between the third and fourth MOSFETs being connected to the body terminal of the power MOSFET, the output terminal of the first inverter being connected to the gate of the third MOSFET and the output terminal of the second inverter being connected to the gate of the fourth MOSFET.

A power MOSFET switch arrangement comprising:

• a power MOSFET having source, drain, gate and body terminals, no one of the terminals being shorted to any of the other terminals;
• a voltage supply line;
• a first inverter having an output terminal connected to the gate terminal and a power input terminal connected to the voltage supply line;
• a second inverter having an output terminal connected to the body terminal;
• and
• a voltage divider connected to the voltage supply line, a midpoint of the voltage divider being connected to a power input terminal of the second inverter.

A power MOSFET switch arrangement comprising:

• a power MOSFET having source, drain, gate and body terminals, no one of the terminals being shorted to any of the other terminals;
• a voltage supply line;
• a first inverter having an output terminal connected to the gate terminal and a power input terminal connected to the voltage supply line;
• a second inverter having an output terminal connected to the body terminal;
• and
• a linear regulator connected to the voltage supply line, an output terminal of the linear regulator being connected to a power input terminal of the second inverter.