Trigger circuitry for fast, low-power state transitions

Circuitry comprising a trigger circuit, wherein the trigger circuit comprises:

• an n-type transistor having a base, a collector, and an emitter and characterized by a turn-on threshold voltage;
• a p-type transistor having a base, a collector, and an emitter and characterized by a turn-on threshold voltage, wherein the collector and emitter of the n-type transistor are connected in series with the collector and emitter of the p-type transistor such that, when the two transistors are turned on, current flows from the collector of the n-type transistor to the collector of the p-type transistor;
• and
• a positive-feedback capacitor connected between the collector of a first of the two transistors and the base of a second of the two transistors, wherein:
• the trigger circuit is configured such that (i) the two transistors turn on together when the voltage at the base of the n-type transistor exceeds the voltage at the base of the p-type transistor by at least the sum of the turn-on threshold voltages of the two transistors and (i) the two transistors turn off together when the voltage at the base of the n-type transistor fails to exceed the voltage at the base of the p-type transistor by at least the sum of the turn-on threshold voltages of the two transistors;
• and
• the positive-feedback capacitor ensures that the two transistors turn fully on and off together.