Patent ID: 6268756
Filing Date: 2001-07-31
Classification: H03K

Abstract:
A fast high side switch, for fast switching, from a high impedance non-conductive state to a low impedance conductive state, between two terminals, the switch comprising:a control circuit for turning the switch on and off at a fast speed, said control circuit including a first input terminal and a second input terminal;a first npn transistor, said first npn transistor being turned on when a first input terminal is high;a second npn transistor, the collector of said second npn transistor coupled to a first of the two terminals, the emitter of said second npn transistor coupled to a second of the two terminals;a resistor, said resistor coupled between the emitter of said first npn transistor, and the base of said second npn transistor,wherein said second npn transistor turns on after said first npn transistor goes into saturation, thereby closing the switch and providing a connection between the two terminals; anda capacitor, coupled to the emitter of said first npn transistor and the emitter of said second npn transistor,wherein the emitter current of said first npn transistor is divided between the base current of said second npn transistor and said capacitor.