Abstract: A structure is designed with an external terminal (100) and a reference terminal (102). A first transistor (106) is formed on a substrate. The first transistor has a current path coupled between the external terminal and the reference terminal. A second transistor (118) has a current path coupled between the external terminal and the substrate. A third transistor (120) has a current path coupled between the substrate and the reference terminal.

Abstract: A structure is designed with an external terminal (100) and a reference terminal (102). A first transistor (106) is formed on a substrate. The first transistor has a current path coupled between the external terminal and the reference terminal. A second transistor (118) has a current path coupled between the external terminal and the substrate. A third transistor (120) has a current path coupled between the substrate and the reference terminal.

Abstract: A structure is designed with an external terminal (100) and a reference terminal (102). A first transistor (106) is formed on a substrate. The first transistor has a current path coupled between the external terminal and the reference terminal. A second transistor (118) has a current path coupled between the external terminal and the substrate. A third transistor (120) has a current path coupled between the substrate and the reference terminal.

Abstract: A structure is designed with an external terminal (100) and a reference terminal (102). A first transistor (106) is formed on a substrate. The first transistor has a current path coupled between the external terminal and the reference terminal. A second transistor (118) has a current path coupled between the external terminal and the substrate. A third transistor (120) has a current path coupled between the substrate and the reference terminal.

Abstract: The invention comprises a system and method for providing electrostatic discharge protection. In one embodiment of the invention, an integrated circuit (10) comprising at least one input element (20) is protected by a protective circuit (40). The protective circuit (40) is operable to protect the integrated circuit (10) from damage due to electrostatic discharge and may be coupled to the input element (20). The protective circuit (40) comprises a lateral NPN transistor (T1) coupled to the input element (20) and operable to activate when the input element voltage exceeds threshold, the threshold greater than or equal to the ordinary operating voltage of circuitry coupled to the input element (20). The protective circuit (40) also may comprise a lateral PNP transistor (T2) coupled to the input element (20) and to the lateral NPN transistor (T1). The lateral PNP transistor (T2) is operable to aid in raising a potential of the base of the lateral NPN transistor (T1).

Abstract: A CDM clamp circuit integrated into the interface circuit it is protecting on an integrated circuit. Generally, the integrated CDM clamp circuit and interface circuit are adjacent to each other and share a common device element or component, thus eliminating the need for a metal interconnect. Because there is no interconnect, the parasitic resistance and inductance are also minimized or eliminated from the circuit, thus reducing or eliminating excessive voltage drop. Preferably, the CDM clamp circuit is integrated into the circuit that it is protecting by having the two circuits share the same silicon source region. In a preferred embodiment input circuit, the same diffusion region is the source of both the input transistor and its associated CDM clamp transistor.

Abstract: The invention comprises a system and method for providing electrostatic discharge protection. In one embodiment of the invention, an integrated circuit (10) comprising at least one input element (20) is protected by a protective circuit (40). The protective circuit (40) is operable to protect the integrated circuit (10) from damage due to electrostatic discharge and may be coupled to the input element (20). The protective circuit (40) comprises a lateral NPN transistor (T1) coupled to the input element (20) and operable to activate when the input element voltage exceeds threshold, the threshold greater than or equal to the ordinary operating voltage of circuitry coupled to the input element (20). The protective circuit (40) also may comprise a lateral PNP transistor (T2) coupled to the input element (20) and to the lateral NPN transistor (T1). The lateral PNP transistor (T2) is operable to aid in raising a potential of the base of the lateral NPN transistor (T1).

Abstract: The invention comprises a system and method for providing electrostatic discharge protection. In one embodiment of the invention, an integrated circuit (10) comprising at least one input element (20) is protected by a protective circuit (40). The protective circuit (40) is operable to protect the integrated circuit (10) from damage due to electrostatic discharge and may be coupled to the input element (20). The protective circuit (40) comprises a lateral NPN transistor (T1) coupled to the input element (20) and operable to activate when the input element voltage exceeds threshold, the threshold greater than or equal to the ordinary operating voltage of circuitry coupled to the input element (20). The protective circuit (40) also may comprise a lateral PNP transistor (T2) coupled to the input element (20) and to the lateral NPN transistor (T1). The lateral PNP transistor (T2) is operable to aid in raising a potential of the base of the lateral NPN transistor (T1).

Abstract: The electrostatic discharge protection circuit includes: at least two bipolar transistors Q1-Qn coupled in series; a top one Qn of the at least two bipolar transistors coupled to a protected node 10; a bottom one Q1 of the at least two bipolar transistors coupled to a common node 12; at least two resistors R1-Rn coupled in series; each of the at least two resistors is coupled to a corresponding base of one of the at least two bipolar transistors; and a bottom one R1 of the at least two resistors coupled between a base of the bottom one Q1 of the at least two bipolar transistors and the common node 12.

Abstract: A protection circuit is designed with an external terminal (300), a reference terminal (126) and a substrate (342). A semiconductor body (338) is formed by an isolation region (332, 340) formed between the substrate and the semiconductor body, thereby enclosing the semiconductor body. A plurality of transistors is formed in the semiconductor body. Each transistor has a respective control terminal (354) connected to a common control terminal (321) and a respective current path connected between the external terminal and the reference terminal. A capacitor (314) is connected between the semiconductor body and the external terminal. A resistor (318) is connected between the semiconductor body and the reference terminal.

Abstract: The electrostatic discharge protection circuit includes: at least two bipolar transistors Q1-Qn coupled in series; a top one Qn of the at least two bipolar transistors coupled to a protected node 10; a bottom one Q1 of the at least two bipolar transistors coupled to a common node 12; at least two resistors R1-Rn coupled in series; each of the at least two resistors is coupled to a corresponding base of one of the at least two bipolar transistors; and a bottom one R1 of the at least two resistors coupled between a base of the bottom one Q1 of the at least two bipolar transistors and the common node 12.

Abstract: An SCR provides for increased holding voltage by decoupling the pnp and npn parasitic bipolar transistors of the SCR. In one embodiment, a N+ region is placed between the n+ region and the p+ region normally associated with conventional SCR devices, to formulate a new resistance. The new resistance is manifested to allow more current to flow through the new resistance rather than through the SCR parasitic pnp bipolar transistor. Since the parasitic pnp bipolar transistor no longer turns on as strongly as it would otherwise without the low resistance path through the new resistor, the holding voltage of the SCR is raised.

Abstract: An SCR (68) for protecting an integrated circuit (62) against ESD events is provided having a trigger voltage which is automatically adjusted to different trigger voltage levels in response to power being applied to the integrated circuit (62). An enhancement-type P-channel transistor (78) is provided for determining the trigger voltage. When operating power is not being applied to the integrated circuit (62), the P-channel transistor (78) threshold voltage determines the voltage at which the SCR (68) is triggered. When operating power is being applied to the integrated circuit (62), the operating voltage is applied to the gate of the P-channel transistor (78), and then the operating voltage and the threshold voltage for the P-channel transistor (78) determine the trigger voltage of the SCR (68). Then, a PNP and NPN transistor pair (76, 80) that form the SCR (68) are latched to shunt the protected signal path (69) to ground.

Abstract: A novel PNP driven NMOS (PDNMOS) protection scheme is provided for advanced nonsilicide/silicide submicron CMOS processes. The emitter of a PNP transistor and the drain of protection NMOS device are connected to an I/O pad for which ESD protection is provided by the PDNMOS. The collector of the PNP transistor and the gate of the protection NMOS transistor are connected to ground through a resistor. The source of the protection NMOS transistor is grounded. The base of the PNP transistor is connected to either a capacitor or the parasitic capacitor of the integrated circuit.

Abstract: The present invention provides a high efficiency ESD circuit that requires less space through uniform activation of multiple emitter fingers of a transistor structure containing an integral Zener diode. The Zener diode is able to lower the protection circuit trigger threshold from around 18 volts to around 7 volts. This method minimizes series impedance of the signal path, thereby rendering an NPN structure that is particularly well suited for protecting bipolar and CMOS input and output buffers. The ESD circuit of the present invention provides a relatively low shunt capacitance (typically <0.5 pF) and series resistance (typically <0.5 ohm) that are desirable for input and output circuits of present and future contemplated generations of sub-micron bipolar/BiCMOS circuit processes.

Abstract: The invention provides a Bipolar structure such as a silicon controlled rectifier (SCR) that exhibits advantageously low triggering and holding voltages for use in high speed (e.g., 900 MHz->2 GHz) submicron ESD protection circuits for Bipolar/BiCMOS circuits. The Bipolar structure features a low shunt capacitance and a low series resistance on the input and output pins, allowing for the construction of ESD protection circuits having small silicon area and little to no impedance added in the signal path. In a preferred aspect of the invention, the SCR is assembled in the N-well of the Bipolar/BiCMOS device, as opposed to the P-substrate, as is customary in the prior art. A preferred aspect of the invention utilizes a Zener diode in combination with a resistor to control BSCR operation through the NPN transistor.

Abstract: The invention provides a Bipolar structure such as a silicon controlled rectifier (SCR) that exhibits advantageously low triggering and holding voltages for use in high speed (e.g., 900 MHz->2 GHz) submicron ESD protection circuits for Bipolar/BiCMOS circuits. The Bipolar structure features a low shunt capacitance and a low series resistance on the input and output pins, allowing for the construction of ESD protection circuits having small silicon area and little to no impedance added in the signal path. In a preferred aspect of the invention, the SCR is assembled in the N-well of the Bipolar/BiCMOS device, as opposed to the P-substrate, as is customary in the prior art. A preferred aspect of the invention utilizes a Zener diode in combination with a resistor to control BSCR operation through the PNP transistor.