US 2015/0311777 A1 · Bidirectional Two-Base Bipolar Junction Transistor Devices, Operation, Circuits, and Systems with Collector-Side Base Driven, Diode-Mode Turn-On, Double Base Short at Initial Turn-Off, and Two Base Junctions Clamped By Default

Abstract

Methods, systems, circuits, and devices for power-packet-switching power converters using bidirectional bipolar transistors (BTRANs) for switching. Four-terminal three-layer BTRANs provide substantially identical operation in either direction with forward voltages of less than a diode drop. BTRANs are fully symmetric merged double-base bidirectional bipolar opposite-faced devices which operate under conditions of high non-equilibrium carrier concentration, and which can have surprising synergies when used as bidirectional switches for power-packet-switching power converters. BTRANs are driven into a state of high carrier concentration, making the on-state voltage drop very low.

Claims21

Dependent claims

1-91. (canceled)

A method for switching a power semiconductor device which includes both an n-type emitter/collector region, and also a p-type base contact region, on both first and second surfaces of a p-type semiconductor die, comprising:

at turn-on, shorting the more positive one of the emitter/collector regions together with the base contact region on the same one of the surfaces, to thereby conduct current with a diode voltage drop;
and thereafter
in the ON state, flowing base current through the base contact region which is nearer the more positive one of the emitter/collector regions, without flowing base current through the other of the base contact regions;
during transition to the OFF state,
temporarily shorting the base contact region on the first surface to the emitter/collector region on the first surface, while also shorting the base contact region on the second surface to the emitter/collector region on the second surface, and thereafter
floating at least the base contact region on the first surface;
in the OFF state, automatically enabling both a first clamp circuit which clamps forward bias across the junction between the base contact region on the first surface and the emitter/collector region on the first surface to less than a diode drop, and also a second clamp circuit which clamps forward bias across the junction between the base contact region on the second surface and the emitter/collector region on the second surface to less than a diode drop, regardless of the voltage between the emitter/collector regions on the first and second surfaces;
wherein the base contact region on the first surface is not electrically connected to the base contact region on the second surface, except through the semiconductor die itself;
and wherein the emitter/collector region on the first surface is not electrically connected to the emitter/collector region on the second surface;
whereby bidirectional switching is achieved with low on-state voltage drop and reliable turn-off.

7 more elements

A method for switching a power semiconductor device which includes first emitter/collector and base contact regions on a first surface of a semiconductor die, and second emitter/collector and base contact regions on a second surface of the die;

wherein the emitter/collector regions both have a first conductivity type, and the base contact regions and the semiconductor die all have a second conductivity type;
comprising:
at turn-on, when the applied voltage polarity is such that the emitter/collector region on the first of said surfaces can act as the collector of a vertical bipolar transistor while the emitter/collector region on the second of said surfaces acts as the emitter of the same vertical bipolar transistor,
beginning turn-on by shorting the base contact and emitter/collector regions on the first surface together, without driving the base contact region on the second surface, to thereby conduct current as a diode without external base current power;
and thereafter
in the ON state, flowing base current through the first base contact region, but substantially not through the second base contact region;
beginning turn-off by temporarily connecting the base contact and emitter/collector regions on the first surface together, while separately connecting the base contact and emitter/collector regions on the second surface together, without connecting the base contact region on the first surface to the base contact region on the second surface;
and then
floating one, but not both, of the base contact regions;
in the OFF state, automatically enabling a respective clamp circuit on each said surface between the respective base contact and emitter/collector regions;
wherein each said clamp circuit comprises a voltage-limiting element and a normally-on switch in series, such that the anode of the voltage-limiting element is connected to the p side of a p-n junction between the respective base contact and emitter/collector regions, and the cathode is connected to the n side of the respective junction;
wherein said voltage-limiting elements limit forward voltage on the respective junction to less than a diode drop;
whereby leakage currents are not amplified when the control circuit is inactive, and breakdown voltage is not degraded by amplification of leakage currents;
and
whereby bidirectional switching is achieved with low on-state voltage drop and reliable turn-off.

12 more elements

A method for switching a power semiconductor device which includes distinct first and second first-conductivity-type emitter/collector regions which are not electrically connected together, and also includes distinct first and second second-conductivity-type base contact regions which are not electrically connected together, the emitter/collector regions and the base contact regions all lying within a common semiconductor die, comprising:

at turn-on, when the applied voltage polarity is such that the emitter/collector region on the first of said surfaces can act as the collector of a vertical bipolar transistor while the emitter/collector region on the second of said surfaces acts as the emitter of the same vertical bipolar transistor,
beginning turn-on by shorting the first base contact and first emitter/collector regions together, to thereby conduct current between the first and second emitter/collector regions as a diode without external base current;
and thereafter
in the ON state, driving the first base contact toward a voltage different from the first emitter/collector region by flowing base current through the first base contact region, while NOT flowing base current through the second base contact region;
beginning turn-off by temporarily connecting the base contact and emitter/collector regions on the first surface together, while separately connecting the base contact and emitter/collector regions on the second surface together, without connecting the base contact region on the first surface to the base contact region on the second surface;
and then
floating one, but not both, of the base contact regions, while not applying external current to either of the base contact regions;
in the OFF state, automatically enabling a clamp circuit between each said emitter/collector region and the respective base contact region to thereby limit forward voltage on a junction between the respective base contact and emitter/collector regions to less than a diode drop;
whereby bidirectional switching is achieved with low on-state voltage drop and reliable turn-off.

6 more elements

A method for switching a power semiconductor device which includes both a respective p-type emitter/collector region, and also a respective n-type base contact region, on both first and second surfaces of an n-type semiconductor die, comprising:

in active OFF mode, when the emitter/collector region on the first surface is more positive than the emitter/collector region on the second surface, connecting the emitter/collector and base contact regions on the first surface together, while floating the base contact region on the second surface;
and thereafter, when the polarity of applied voltage reverses, keeping the emitter/collector and base contact regions on the first surface connected, to thereby conduct current with a diode voltage drop;
and thereafter
in the ON state, flowing base current through the base contact region which is nearer the more negative one of the emitter/collector regions, without flowing base current through the other of the base contact regions;
during transition to the OFF state,
temporarily shorting the base contact region on the first surface to the emitter/collector region on the first surface, while also shorting the base contact region on the second surface to the emitter/collector region on the second surface, and thereafter
floating the base contact region on the first surface, but not the base contact region on the second surface;
in the OFF state,
automatically enabling clamp circuits on said first and second surfaces, each including a diode and a normally-on switch in series, with the anode of the diode operatively connected to the respective p-type emitter/collector region, and the cathode operatively connected to the respective n-type base contact region;
wherein the base contact region on the first surface is not electrically connected to the base contact region on the second surface, except through the semiconductor die itself;
and wherein the emitter/collector region on the first surface is not electrically connected to the emitter/collector region on the second surface;
whereby bidirectional switching is achieved with low on-state voltage drop and reliable turn-off.

9 more elements

Dependencies are inferred from the claim text.

Bidirectional Two-Base Bipolar Junction Transistor Devices, Operation, Circuits, and Systems with Collector-Side Base Driven, Diode-Mode Turn-On, Double Base Short at Initial Turn-Off, and Two Base Junctions Clamped By Default

Life of this patent

Bidirectional Two-Base Bipolar Junction Transistor Devices, Operation, Circuits, and Systems with Collector-Side Base Driven, Diode-Mode Turn-On, Double Base Short at Initial Turn-Off, and Two Base Junctions Clamped By Default

Life of this patent

Abstract

Claims21