Patent ID: 7952844

Claim:
An electrostatic discharge immunizing circuit without area penalty comprising: at least one secondary electrostatic discharge immunizing circuit disposed under a core power ring formed between a core circuit and a main electrostatic discharge immunizing circuit, the secondary electrostatic discharge immunizing circuit comprising: a first power clamp having a first terminal coupled to a first voltage source, and a second terminal coupled to a first ground; at least one first current limiter connected in parallel with each other, wherein the current limiter has a positive bias terminal coupled to a signal input terminal, and has a negative bias terminal coupled to the first voltage source; and at least one second current limiter connected in parallel with each other, wherein the second current limiter has a positive bias terminal coupled to the first ground, and has a negative bias terminal coupled to a signal output terminal; wherein the core circuit has a first terminal coupled to the first voltage source and a second terminal coupled to the first ground.