Abstract: A chip includes a core circuit, a main electrostatic discharge immunizing circuit, and a secondary electrostatic discharge immunizing circuit. The secondary electrostatic discharge immunizing circuit is disposed beneath a core power ring formed between the core circuit and the main electrostatic discharge immunizing circuit for reaching the aim of protecting the core circuit from damage by electrostatic discharges without area penalty of the chip. Both the main electrostatic discharge immunizing circuit and the secondary electrostatic discharge immunizing circuit include a power clamp and a plurality of current limiters, and keep electrostatic currents from reaching the core circuit with the aid of the power clamp.

Abstract: A chip includes a core circuit, a main electrostatic discharge immunizing circuit, and a secondary electrostatic discharge immunizing circuit. The secondary electrostatic discharge immunizing circuit is disposed beneath a core power ring formed between the core circuit and the main electrostatic discharge immunizing circuit for reaching the aim of protecting the core circuit from damage by electrostatic discharges without area penalty of the chip. Both the main electrostatic discharge immunizing circuit and the secondary electrostatic discharge immunizing circuit include a power clamp and a plurality of current limiters, and keep electrostatic currents from reaching the core circuit with the aid of the power clamp.

Abstract: An integrated circuit (IC) having an electrostatic discharge (ESD) protection circuit therein is provided. The IC comprises a plurality of bonding pads, a plurality of ESD units, a first ESD bus and a second ESD bus. The first ESD bus has no direct connection with any power pad of the IC. Each ESD unit comprises a first diode, a second diode and an ESD clamping device. Due to the one-to-one correspondent of each bonding pad with an ESD unit, the present invention ensures ESD continuity through a continuous charge dissipation path no matter what kind of pin-to-pin ESD test the IC is undergoing or how many power sources the IC has. In addition, a bonding pad over active circuitry (BOAC) structure can also be deployed in the present invention to provide a better ESD protection for the whole IC chip.