High-speed current switch circuit

摘要

A high-speed current switch circuit of this invention has an n-type MOS transistor Q11 which switches and outputs a current, and a control circuit 11 which performs switching control of the MOS transistor Q11. In the control circuit 11, a source follower is formed by an N-type MOS transistor Q12 and a constant current source I2 which is a load on this transistor. A switch SW11 is connected to the MOS transistor Q12 to perform switching control of a current flowing through the MOS transistor Q12. The control circuit 11 includes a switch SW12 capable of grounding the gate of the MOS transistor 11. The source of the MOS transistor Q12 is connected to the gate of the MOS transistor Q11. Thus, even if a large current is caused to flow through the output transistor, the output transistor can be made to operate for switching at a high speed.