Patent ID: 6958631

Claim:
A high-speed current switch circuit, comprising: an output transistor which switches and outputs a current and has an input terminal, an output terminal, and a source terminal; and a control circuit for controlling said output transistor, said control circuit comprising a source follower circuit and a first switch which is connected between said source follower circuit and a power supply; said source follower circuit comprising a second transistor having an output terminal, and a current source circuit connected between the output terminal of said second transistor and a constant voltage, and the output terminal of said second transistor connected to the input terminal of said output transistor; wherein said source follower circuit determines a voltage level at said input terminal of said output transistor in a state where said first switch is closed and said voltage level causes said output current to flow, and in another state where said first switch is open and said output current does not flow; and the source terminal of said output transistor is connected to said constant voltage.