ESD protection circuit and structure

An electrostatic discharge (ESD) protection circuit for protecting a core circuit, comprising:

• a first PNP bipolar junction transistor (BJT) comprising a first base, a first emitter, and a first collector, wherein the first emitter is coupled to a first power pad, and the first collector is coupled to a second power pad;
• a first resistor coupled between the first power pad and the first base;
• a second PNP BJT comprising a second base, a second emitter, and a second collector, wherein the second emitter is coupled to the second power pad, and the second collector is coupled to a third power pad;
• a diode comprising a cathode and an anode, wherein the cathode is coupled to the first power pad and the second base, and the anode is coupled to the third power pad;
• a specific BJT coupled between the first and second power pads;
• and
• a second resistor coupled between an emitter and a base of the specific BJT,
• wherein in response to an ESD event occurring, the first PNP BJT and the specific BJT are turned on so that an ESD current passes through the first PNP BJT and the specific BJT.