High voltage tolerant electrostatic discharge protection circuit
An electrostatic discharge (ESD) protection circuit includes an NPN transistor having a collector terminal connected to a voltage source and an emitter terminal connected to the ground via a diode. The NPN transistor includes a base terminal for receiving a base current to turn on the NPN transistor to allow an electrostatic discharge at the voltage source to flow through the NPN transistor to the ground. The ESD protection circuit further includes a PMOS transistor having a source terminal coupled to the voltage source and a drain terminal coupled to the base terminal of the NPN transistor. The PMOS transistor includes a gate terminal for receiving a first and a second gate voltage. The ESD protection circuit further includes an R-C circuit coupled between the source voltage and the ground. The R-C circuit is configured to supply the first gate voltage to the PMOS transistor when there is no electrostatic discharge to turn off the PMOS transistor and the second gate voltage responsive to the electrostatic discharge to turn on the PMOS transistor for a predetermined time period. The ESD protection circuit further includes a voltage divider circuit coupled between the voltage source and the ground and coupled to the R-C circuit.
Mindspeed Technologies, Inc.
H
H02H
inventional
Xiaoming
Li