Abstract: An input/output circuit (I/O circuit) includes the following elements. An input/output pad (I/O pad) has a plurality of operation mode, including an output mode, a normal input mode and a tolerance mode of an input mode. A first control circuit provides a first control signal in response to a pad voltage of the I/O pad and a supply voltage. A first P-type transistor has a first body region to receive a first control signal. A second P-type transistor has a second body region to receive the first control signal. In the input mode, when the pad voltage is lower than or equal to the supply voltage, the I/O pad operates in the normal input mode, and, when the pad voltage is higher than the supply voltage, the I/O pad operates in the tolerance mode, and voltage of the first control signal is equal to pad voltage.

Abstract: An electrostatic discharge (ESD) circuit is used to protect an internal circuit. The ESD circuit includes: an ESD clamp, having a first terminal connected to a power and a second terminal connected to a ground voltage; and a first switch, connected between an ESD terminal of the ESD clamp and the internal circuit. A gate of the first switch is controlled by a state signal in the ESD clamp to turn off the first switch when an ESD event occurs on the first terminal of the ESD clamp and turn on the first switch when the ESD event does not occur.

Abstract: An electrostatic discharge (ESD) circuit is used to protect an internal circuit. The ESD circuit includes: an ESD clamp, having a first terminal connected to a power and a second terminal connected to a ground voltage; and a first switch, connected between an ESD terminal of the ESD clamp and the internal circuit. A gate of the first switch is controlled by a state signal in the ESD clamp to turn off the first switch when an ESD event occurs on the first terminal of the ESD clamp and turn on the first switch when the ESD event does not occur.

Abstract: The present invention provides an electrostatic discharge (ESD) protection circuit including an ESD detection circuit and a plurality of power clamp circuits. The ESD detection circuit is electrically connected to a first high power line, a second high power line and at least one low power line, and is used to detect an ESD event occurring in the first high power line and another ESD event occurring in the second high power line. The ESD detection circuit includes a first trigger unit and a second trigger unit, electrically connected to the first high power line and the second high power line respectively. Each power clamp circuit has a trigger node, and the trigger nodes are electrically connected to the first trigger unit and the second trigger unit.

Abstract: A lateral silicon controlled rectifier structure includes a P-type substrate; an N-well region in the P-type substrate; a first P+ doped region in the N-well region and being connected to an anode; a P-well region in the P-type substrate and bordering upon the N-well region; a first N+ doped region formed in the P-well region and separated from the first P+ doped region by a spacing distance, the first N+ doped region being connected to a cathode; and a gate structure overlying a portion of the P-type substrate between the first P+ doped region and the first N+ doped region.

Abstract: The present invention provides an electrostatic discharge (ESD) protection circuit including an ESD detection circuit and a plurality of power clamp circuits. The ESD detection circuit is electrically connected to a first high power line, a second high power line and at least one low power line, and is used to detect an ESD event occurring in the first high power line and another ESD event occurring in the second high power line. The ESD detection circuit includes a first trigger unit and a second trigger unit, electrically connected to the first high power line and the second high power line respectively. Each power clamp circuit has a trigger node, and the trigger nodes are electrically connected to the first trigger unit and the second trigger unit.

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 lateral silicon controlled rectifier structure includes a P-type substrate; an N-well region in the P-type substrate; a first P+ doped region in the N-well region and being connected to an anode; a P-well region in the P-type substrate and bordering upon the N-well region; a first N+ doped region formed in the P-well region and separated from the first P+ doped region by a spacing distance, the first N+ doped region being connected to a cathode; and a gate structure overlying a portion of the P-type substrate between the first P+ doped region and the first N+ doped region.

Abstract: An ESD protection device includes a p-well with first protrudent portions, an N-well with second protrudent portions, a P-well/N-well boundary, a PMOS transistor disposed in the N-well, an NMOS transistor disposed in the P-well, first P+ diffusion regions in the first protrudent portions, first N+ diffusion regions in the second protrudent portions, second P+ diffusion regions disposed between the PMOS transistor and the second protrudent portions, second N+ diffusion regions disposed between the NMOS transistor and the first protrudent portions, third P+ diffusion regions disposed between the NMOS transistor, the boundary, and two adjacent second P+ diffusion regions, and third N+ diffusion regions disposed between the PMOS transistor, the boundary, and two adjacent second N+ diffusion regions, wherein the first and second protrudent portions are interlacedly arranged at the boundary.

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: The invention discloses a method for electrostatic discharge (ESD) protection design. The method includes: placing a first input/output cell (I/O cell) and a second input/output cell at a side of a chip, wherein a routing area exists at the side of the chip and is positioned between the first input/output cell and the second input/output cell; providing an electrostatic discharge protection circuit unit; and placing the electrostatic discharge protection circuit unit in the routing area.