Transistor circuits for switching high voltages and currents without causing snapback or breakdown

A high voltage switching circuit, comprising:

• a plurality of cross-coupled high voltage inverters, wherein each of said cross-coupled high voltage inverters is comprised of a first plurality of n-channel series-connected transistors and a second plurality of p-channel series-connected transistors, each of said series-connected transistors having a gate biased to an increasing voltage such that a voltage difference across said first or second plurality of series-connected transistors is shared across two or more of the transistors comprising said plurality;
• and
• one or more switching transistors, each of said one or more switching transistors connected in series with any one of said plurality of series-connected transistors allowing a high voltage to be switched without snapback or breakdown.

A method for switching high voltages on a semiconductor circuit comprised of a first set of transistors, wherein transistors of said first set of transistors are connected in series and include a plurality of transistors for switching a high voltage without inducing snapback or breakdown, and a second set of transistors, said second set including one or more transistors for switching a high current and connected in parallel with said first set of series-connected transistors, and wherein said transistors within said second set of transistors are connected in series if said second set of transistors comprises two or more transistors, wherein said method comprises the steps of:

• charging a load from a high voltage source through said first set of transistors, whereby a total voltage difference across said first set of transistors is shared across two or more of the transistors comprising said first set;
• and
• enabling said second set of transistors when said total voltage difference is less than a predetermined value to form a high current path through said second set of transistors.

A method for avoiding snapback and for increasing the off-state breakdown voltage on a semiconductor circuit comprised of a plurality of series-connected first transistors, a series-connected switching transistor and a series-connected protection transistor, wherein said switching transistor is connected to said plurality of series-connected first transistors and said protection transistor is connected between said switching transistor and an output, said method comprising the step of:

• biasing a gate of each of said series-connected first transistors with increasing voltages such that a voltage difference across said plurality of series-connected first transistors is shared across two or more of said series-connected first transistors;
• and
• biasing the gate of said protection transistor with a voltage to increase the breakdown of said protection transistor.