Abstract: The present invention provides a PMSCR (bridging modified lateral modified silicon controlled rectifier having first conductivity type) with a guard ring controlled circuit. The present invention utilizes controlled circuit such as switch to control functionally of guard ring of PMSCR. In normal operation, the switch is of low impedance such that the guard ring is short to anode and collects electrons to enhance the power-zapping immunity. Furthermore, during the ESD (electrostatic discharge) event, the switch is of high impedance such that the guard ring is non-functional. Thus, the PMSCR with guard ring control circuit can enhance both the ESD performance and the power-zapping immunity in the application of the HV (high voltage) pad.

Abstract: A substrate pump circuit and method for I/O ESD protection including NMOS fingers connected to the interconnection between an I/O pad and an internal circuit comprises a MOS device connected to the interconnection between the I/O pad and the internal circuit and the substrate under the control of a switch to turn it on to conduct a pumping current through the substrate resistor when the I/O pad is under ESD stress, so as to pull up the potential of the substrate adjacent to the NMOS fingers, resulting in the reduction of the triggering voltage of the NMOS fingers.

Abstract: An electrostatic discharge (ESD) protection circuit is disclosed. This invention relates an electrostatic discharge protection circuit for multi-power and mixed-voltage integrated circuit. In the electrostatic discharge protection circuit of the invention, an ESD protection cell formed with voltage selector, control circuit and transistor is used to connect with a independent power and ESD bus is used to connect with each ESD protection cell so that each power is isolated from each other during normal operation. Therefore, each power can be operated independently and circuit will be prevented from ESD during ESD discharging.

Abstract: An electrostatic discharge (ESD) protection structure is disclosed. The ESD protection structure of the present invention uses a resistance capacitance (RC) circuit to distinguish an overshoot phenomenon caused by the instantaneous power-on from an ESD event, so as to prevent the ESD protection device, such as a P-type modified lateral silicon controlled rectifier (MLSCR), from being triggered unexpectedly by an overshoot phenomenon which results from the power-on under normal operation, and thereby the efficiency of the ESD protection device is promoted.

Abstract: An electrostatic discharge (ESD) protection structure is disclosed. The ESD protection structure of the present invention uses a resistance capacitance (RC) circuit to distinguish an overshoot phenomenon caused by the instantaneous power-on from an ESD event, so as to prevent the ESD protection device, such as P-type modified lateral silicon controlled rectifier (MLSCR), from being triggered unexpectedly by an overshoot phenomenon resulted from the power-on under normal operation, and thereby the efficiency of the ESD protection device is promoted.

Abstract: The invention discloses an ESD (Electro Static Discharge) protection circuit, including a resistor device, a capacitor device and a PMOS device. The resistor device is connected in series between a power supply and the capacitor device. The capacitor device is connected in series between the resistor device and the ground. A gate electrode of the PMOS device is connected between the resistor device and the capacitor device. A bulk electrode of the PMOS device is interconnected to a first electrode of the PMOS device, and the first electrode is connected to the power supply. Alternatively, another ESD protection circuit for multiple power supplies includes at least two aforementioned ESD protection circuits, and a common ESD bus. The ESD protection circuits are connected to separate power supplies, and both connected to the common ESD bus. By using the ESD protection circuit, there is no noise between the separate power supplies, and an ESD current could be discharged easily and safely.

Abstract: The present invention provides an IC ESD cell, which is applicable to multiple-power-input and mixed-voltage ICs and capable of maintaining power sequence independence of each power source. The ESD cell of the present invention comprises a voltage selector circuit, which connects two separate power sources to select the one having a higher potential as the output voltage. An NMOS is used to connect the two separate power sources. An RC circuit is connected to an output of the voltage selector circuit to distinguish ESD event from normal power source. Therefore, the channel of the NMOS will be conducted to let the ESD current be led out via a designed path, hence preventing internal circuits of an IC from damage and accomplishing the object of whole chip protection.

Abstract: An electrostatic discharge (ESD) protection circuit is disclosed. This invention relates an electrostatic discharge protection circuit for multi-power and mixed-voltage integrated circuit. In the electrostatic discharge protection circuit of the invention, an ESD protection cell formed with voltage selector, control circuit and transistor is used to connect with a independent power and ESD bus is used to connect with each ESD protection cell so that each power is isolated from each other during normal operation. Therefore, each power can be operated independently and circuit will be prevented from ESD during ESD discharging.

Abstract: An I/O pad ESD protection circuit is composed of a SCR circuit, a first diode, a second diode, and an anti-latch-up circuit. The SCR circuit has a first connection terminal and a second connection terminal, respectively coupled to the I/O pad and the ground voltage, so as to discharge the electrostatic charges. The anti-latch-up circuit has two terminals, which are respectively coupled to the voltage source and the ground voltage, and another connection terminal, used to send an anti-latch-up signal to the SCR for changing the activating rate. The latch-up phenomenon is avoided.

Abstract: The present invention relates an electrostatic discharge (ESD) protection device that is applied to a mixed voltage circuit assembly. The device comprises a RC controlled circuit subassembly and a field transistor, which the RC controlled circuit is coupled with the mixed voltage circuit assembly to substantially control the ESD protection device to be ON or OFF. The field transistor is coupled between a first power supply and a second power supply of said mixed voltage circuit assembly, which is off on the condition of a normal operating condition and is conducting as an ESD event occurred.

Abstract: An electrostatic discharge protection which is electrically coupled with an interface terminal and a devices area, at least include a first bipolar junction transistor, a second bipolar junction transistor, a first MOS transistor, and a second MOS transistor. Both bipolar junction transistors forms the well-known silicon controlled rectifier, first MOS transistor locates between interface terminal and second bipolar junction transistor and second MOS transistor locates between emitter of second bipolar junction transistor and ground point, and gates of both MOS transistor electrically coupled with voltage base point whose voltage is equal to work voltage of devices area. While devices area is turned off, silicon controlled rectifier would be latch-up and provides function of electrostatic discharge protection. While devices area is turned on, second MOS transistor also is turned on so that part of current flows into ground point but not flows into second bipolar junction transistor.