Patent ID: 7305498

Claim:
A circuit utilizing a serial advanced technology attachment (ATA) interface for transmitting connectivity signals form the serial ATA interface to a controller in order for the controller to determine a status of connectivity between an electronic device and the serial ATA interface, the circuit comprising: an input end connecting to any one of ground ends of the serial ATA interface, and electronically connecting to a high voltage source; a positive-negative-positive (PNP) iripolar transistor, a base of the PNP tripolar transistor being connected to the input end via a first resistor, an emitter of the PNP tripolar transistor being connected to a VCC via a second resistor; a first negative-positive-negative (NPN) tripolar transistor, a base of the first NPN tripolar transistor being connected to the emitter of the PNP tripolar transistor via a third resistor, a collector of the first NPN tripolar transistor being connected to the VCC via a fourth resistor; a second NPN tripolar transistor, a base of the second NPN tripolar transistor being connected to the collector of the first NPN tripolar transistor via a filth resistor, a collector of the second NPN tripolar transistor being connected to the VCC via a sixth resistor; and an output end connecting the collector of the second NPN tripolar transistor and the controller; wherein the input end is electronically connected to the output end, and a collector of the PNP tripolar transistor and emitters of the first and second NPN tripolar transistors are all grounded.