Patent ID: 7760476

Claim:
An electrostatic discharge protection circuit, comprising: a shunt device coupled between a power supply terminal and ground, the shunt device capable of shunting current from the power supply terminal to ground in response to a trigger signal received at a shunt device input; a latch coupled to the shunt device input, the latch capable of latching the trigger signal received at a latch input; a buffer coupled to the latch input, the buffer capable of receiving the trigger signal at a buffer input; a comparator coupled between the power supply terminal, ground, and the buffer input, the comparator capable of responding to an electrostatic discharge event and producing the trigger signal at a comparator output, wherein the comparator comprises: a first current mirror comprising a first sense device coupled to the power supply terminal and a first mirror device coupled between the comparator output and the power supply terminal; a plurality of bias devices coupled to the first sense device, at least two of the plurality of bias devices coupled in series at a bias output line; a transconductance device comprising an input coupled to the power supply terminal and a control input coupled to the bias output line; a second current mirror comprising a second sense device coupled between the transconductance device and ground and a second mirror device coupled between the comparator output and ground, the second mirror device coupled in series with the first mirror device; and a compensating device coupled between the plurality of bias devices and ground.