Abstract: An active-FET ESD cell (300) for protecting an I/O pad (301) includes a first MOS transistor (310) with a gate oxide (315) of a first thickness and a second MOS transistor (320) with a gate oxide (325) of a second thickness greater than the first thickness at least by the amount required to handle the source-follower threshold voltage, the first transistor having its drain (313) tied to the I/O pad, its source (311) tied to ground, and its gate (312) tied to the source (321) of the second transistor and resistively connected to ground (340), and the second transistor having its drain (323) tied to the I/O pad and its gate tied to a capacitor (330) connected to the I/O pad and to a resistor (331) connected to ground.

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: An active-FET ESD cell (300) for protecting an I/O pad (301) includes a first MOS transistor (310) with a gate oxide (315) of a first thickness and a second MOS transistor (320) with a gate oxide (325) of a second thickness greater than the first thickness at least by the amount required to handle the source-follower threshold voltage, the first transistor having its drain (313) tied to the I/O pad, its source (311) tied to ground, and its gate (312) tied to the source (321) of the second transistor and resistively connected to ground (340), and the second transistor having its drain (323) tied to the I/O pad and its gate tied to a capacitor (330) connected to the I/O pad and to a resistor (331) connected to ground.

Abstract: An apparatus for reducing current leakage between an input locus and at least one power rail for a system includes, for each respective power rail: (a) A first diode unit coupled between the input locus and a coupling locus. The first diode unit is configured to effect substantially zero potential drop during normal operation of the apparatus. (b) A second diode unit coupled between the coupling locus and the respective power rail. The second diode unit is configured to present no forward bias during normal operation of the apparatus. The first and second diode units cooperate to effect current flow between the input locus and the respective power rail during a predetermined operational condition of the apparatus.

Abstract: A semiconductor device includes one or more LDMOS transistors and one of more SCR-LDMOS transistors. Each LDMOS transistor includes a LDMOS well of a first conductivity type, a LDMOS source region of a second conductivity type formed in the LDMOS well, and a LDMOS drain region of a second conductivity type separated from the LDMOS well by a LDMOS drift region of the second conductivity type. Each SCR-LDMOS transistor comprising a SCR-LDMOS well of the first conductivity type, a SCR-LDMOS source region of the second conductivity type formed in the SCR-LDMOS well, a SCR-LDMOS drain region of a second conductivity type, and a anode region of the first conductivity type between the SCR-LDMOS drain region and the SCR-LDMOS drift region. The anode region is separated from the SCR-LDMOS well by a SCR-LDMOS drift region of the second conductivity type.

Abstract: An electrostatic discharge (ESD) device for protecting an input/output terminal of a circuit, the device comprising a first transistor with an integrated silicon-controlled rectifier (SCR) coupled between the input/output (I/O) terminal of the circuit and a node and a second transistor with an integrated silicon-controlled rectifier coupled between the node and a negative terminal of a supply voltage, wherein the silicon-controlled rectifier of the first transistor triggers in response to a negative ESD voltage and the silicon-controlled rectifier of the second transistor triggers in response to a positive ESD voltage.

Abstract: The present invention includes a MOS device (100) that has a P-type substrate (102) and an N-type drain region (104) formed within the substrate (102). An annular N-type source region (106) generally surrounds the drain region (104). The source region (106) serves as both the source for the MOS device (100) and a sacrificial collector guard ring for an electrostatic discharge protection circuit. An annular gate region (110) generally surrounds the drain region (104) and is electrically insulated from the drain region (104) and electrically connected to the source region (106). An annular P-type bulk region (108) generally surrounds the source region (106) and is electrically connected to the source region (106).

Abstract: An electrostatic discharge (ESD) protection structure for protecting against ESD events between signal terminals is disclosed. ESD protection is provided in a first polarity, by a bipolar transistor (4C) formed in an n-well (64; 164), having a collector contact (72; 172) to one signal terminal (PIN1) and its emitter region (68; 168) and base (66; 166) connected to a second signal terminal (PIN2). For reverse polarity ESD protection, a diode (25) is formed in the same n-well (64; 164) by a p+ region (78; 178) connected to the second signal terminal (PIN2), serving as the anode. The cathode can correspond to the n-well (64; 164) itself, as contacted by the collector contact (72; 172). By using the same n-well (64; 164) for both devices, the integrated circuit chip area required to implement this pin-to-pin protection is much reduced.

Abstract: An ESD protection device includes two bipolar npn transistors that are coupled in series for use in clamping applications. The emitter of the first bipolar transistor can be coupled to a protected node and the emitter of the second bipolar transistor can be coupled to a grounded node. The first bipolar transistor and the second bipolar transistor can share a common collector.

Abstract: The present invention includes a MOS device (100) that has a P-type substrate (102) and an N-type drain region (104) formed within the substrate (102). An annular N-type source region (106) generally surrounds the drain region (104). The source region (106) serves as both the source for the MOS device (100) and a sacrificial collector guard ring for an electrostatic discharge protection circuit. An annular gate region (110) generally surrounds the drain region (104) and is electrically insulated from the drain region (104) and electrically connected to the source region (106). An annular P-type bulk region (108) generally surrounds the source region (106) and is electrically connected to the source region (106).

Abstract: An electrostatic discharge (ESD) protection structure for protecting against ESD events between signal terminals is disclosed. ESD protection is provided in a first polarity, by a bipolar transistor (4C) formed in an n-well (64; 164), having a collector contact (72; 172) to one signal terminal (PIN1) and its emitter region (68; 168) and base (66; 166) connected to a second signal terminal (PIN2). For reverse polarity ESD protection, a diode (25) is formed in the same n-well (64; 164) by a p+ region (78; 178) connected to the second signal terminal (PIN2), serving as the anode. The cathode can correspond to the n-well (64; 164) itself, as contacted by the collector contact (72; 172). By using the same n-well (64; 164) for both devices, the integrated circuit chip area required to implement this pin-to-pin protection is much reduced.

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 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: 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.