Circuits, methods, and systems with optimized operation of double-base bipolar junction transistors
The present application teaches, inter alia, methods and circuits for operating a B-TRAN (double-base bidirectional bipolar junction transistor). Exemplary base drive circuits provide high-impedance drive to the base contact region on the side of the device instantaneously operating as the collector. (The B-TRAN is controlled by applied voltage rather than applied current.) Current signals operate preferred implementations of drive circuits to provide diode-mode turn-on and pre-turnoff operation, as well as a hard ON state with low voltage drop (the “transistor-ON” state). In some preferred embodiments, self-synchronizing rectifier circuits provide adjustable low voltage for gate drive circuits. In some preferred embodiments, the base drive voltage used to drive the c-base region (on the collector side) is varied while base current at that terminal is monitored, so no more base current than necessary is applied. This solves the difficult challenge of optimizing base drive in a B-TRAN.
1. A system for power switching, comprising:
a bidirectional bipolar transistor which has two first-conductivity-type emitter/collector regions separated by a bulk second-conductivity-type base region, and two distinct second-conductivity-type base contact regions which connect to the bulk base region in mutually separate locations; and
first and second transistor-mode drive circuits, separately connected to the first and second base contact regions respectively; wherein each transistor-mode drive circuit is configured, as a voltage source, to selectively apply an adjustable voltage between the corresponding base contact region and the emitter/collector region which is nearest to that base contact region; and
first and second diode-mode drive circuits, separately connected to the first and second base contact regions respectively; wherein each diode-mode drive circuit is configured to selectively connect the corresponding base contact region to the emitter/collector region which is nearest to that base contact region.
2. The system of claim 1 , wherein the first conductivity type is n-type.
3. The system of claim 1 , further comprising two additional drive circuits, respectively connected in parallel with the transistor-mode drive circuits, and each comprising a Schottky diode in series with a normally-off switch.
4. A system for power switching, comprising:
a bidirectional bipolar transistor which has two first-conductivity-type emitter/collector regions separated by a bulk second-conductivity-type base region, and two distinct second-conductivity-type base contact regions which connect to the bulk base region in mutually separate locations; and
a pair of transistor-mode drive circuits, separately connected to the first and second base contact regions respectively, wherein each transistor-mode drive circuit is a voltage-mode drive circuit; and
a pair of diode-mode drive circuits, separately connected to the first and second base contact regions respectively; wherein each diode-mode drive circuit is configured to selectively connect the corresponding base contact region to the emitter/collector region which is nearest to that base contact region.
5. The system of claim 4 , wherein the first conductivity type is n-type.
6. The system of claim 4 , further comprising two additional drive circuits, respectively connected in parallel with the transistor-mode drive circuits, and each comprising a Schottky diode in series with a normally-off switch.
7. A system for power switching, comprising:
a bidirectional bipolar transistor which has two first-conductivity-type emitter/collector regions separated by a bulk second-conductivity-type base region, and two distinct second-conductivity-type base contact regions which connect to the bulk base region in mutually separate locations; and
a pair of transistor-mode drive circuits, separately connected to the first and second base contact regions respectively; wherein each transistor-mode drive circuit is configured, as a voltage source, to selectively apply an adjustable voltage at a selectable value between the corresponding base contact region and the emitter/collector region which is nearest to that base contact region.
8. The system of claim 7 , wherein the first conductivity type is n-type.
9. The system of claim 7 , further comprising two additional drive circuits, respectively connected in parallel with the transistor-mode drive circuits, and each comprising a Schottky diode in series with a normally-off switch.