Abstract: Systems and methods for shutting down a functional circuit in response to a predetermined total ionizing dose of radiation employ at least two redundant sensing circuits operated in integrate and measure phases by one or more sequencer-type hardware or software controllers. NMOS TID sensors having leakage currents increasing monotonically with dose may be biased during integrate phases, with bias voltages or duty cycles adjusted to achieve a calibrated responsivity. TID measurements are compared to a corresponding reference, latched to generate overexpose signals, and tested for agreement. Disagreement triggers remeasurement to prevent erroneous shutdown until a minimum number of overexpose signals agree that TID exceeds the predetermined threshold. A disable circuit accepts the redundant overexpose signals and generates a signal to disable a functional circuit.

Abstract: Devices with increased susceptibility to ionizing radiation feature multiple parasitic transistors having leakage currents that increase with total ionizing dose (TID) due to negative threshold shifts from radiation-induced charge buildup in the field oxide. Leakage currents of parasitic edge transistors associated with active region sidewalls under a gate are enhanced using branching gate patterns that increase the number of these sidewalls. Other variations combine parasitic edge transistors with parasitic field transistors formed under the field oxide between active regions, or between n-wells and active regions. Arrays of such devices connected in parallel further multiply leakage currents, while novel compact designs increase the density and hence the sensitivity to TID for a given circuit area.

Abstract: Devices with increased susceptibility to ionizing radiation feature multiple parasitic transistors having leakage currents that increase with total ionizing dose (TID) due to negative threshold shifts from radiation-induced charge buildup in the field oxide. Leakage currents of parasitic edge transistors associated with active region sidewalls under a gate are enhanced using branching gate patterns that increase the number of these sidewalls. Other variations combine parasitic edge transistors with parasitic field transistors formed under the field oxide between active regions, or between n-wells and active regions. Arrays of such devices connected in parallel further multiply leakage currents, while novel compact designs increase the density and hence the sensitivity to TID for a given circuit area.

Abstract: An output discharge circuit for a load switch may include a capacitor coupled between a power rail of the output discharge circuit and a ground lead, and a diode coupled between a power input of the output discharge circuit and the power rail. The output discharge circuit may charge the capacitor via a current path formed by the diode while power is being supplied to the load switch. When the power supply to the output discharge circuit is turned off, the diode may prevent the capacitor from discharging through the current path, and the stored charge on the capacitor may be used to power the output discharge switch for a period of time after the power supply has been turned off. In this way, the output discharge circuit may continue to discharge the output of the load switch even when power is no longer being supplied to the load switch.

Abstract: An apparatus includes a FET device having a drain terminal, source terminal and a gate terminal; a first supply voltage coupled to the drain terminal of the FET; an output terminal coupled to the source terminal of the FET; a bias current supply coupled to the gate terminal of the FET; a second supply voltage coupled to the gate terminal of the FET; a current sensing circuit coupled to output a sense current proportional to the current flowing through the FET; a current limit comparator coupled to the sense current and comparing the sense current to a predetermined limit current; a pull down current circuit coupled to remove current from the gate terminal of the FET; a current time derivative circuit coupled to the sense current and outputting a sense rate current; and a circuit coupled to receive the sense rate current and coupled to the bias current supply.

Abstract: An apparatus includes a FET device having a drain terminal, source terminal and a gate terminal; a first supply voltage coupled to the drain terminal of the FET; an output terminal coupled to the source terminal of the FET; a bias current supply coupled to the gate terminal of the FET; a second supply voltage coupled to the gate terminal of the FET; a current sensing circuit coupled to output a sense current proportional to the current flowing through the FET; a current limit comparator coupled to the sense current and comparing the sense current to a predetermined limit current; a pull down current circuit coupled to remove current from the gate terminal of the FET; a current time derivative circuit coupled to the sense current and outputting a sense rate current; and a circuit coupled to receive the sense rate current and coupled to the bias current supply.

Abstract: An output discharge circuit for a load switch may include a capacitor coupled between a power rail of the output discharge circuit and a ground lead, and a diode coupled between a power input of the output discharge circuit and the power rail. The output discharge circuit may charge the capacitor via a current path formed by the diode while power is being supplied to the load switch. When the power supply to the output discharge circuit is turned off, the diode may prevent the capacitor from discharging through the current path, and the stored charge on the capacitor may be used to power the output discharge switch for a period of time after the power supply has been turned off. In this way, the output discharge circuit may continue to discharge the output of the load switch even when power is no longer being supplied to the load switch.

Abstract: An output discharge circuit for a load switch may include a capacitor coupled between a power rail of the output discharge circuit and a ground lead, and a diode coupled between a power input of the output discharge circuit and the power rail. The output discharge circuit may charge the capacitor via a current path formed by the diode while power is being supplied to the load switch. When the power supply to the output discharge circuit is turned off, the diode may prevent the capacitor from discharging through the current path, and the stored charge on the capacitor may be used to power the output discharge switch for a period of time after the power supply has been turned off. In this way, the output discharge circuit may continue to discharge the output of the load switch even when power is no longer being supplied to the load switch.

Abstract: An output discharge circuit for a load switch may include a capacitor coupled between a power rail of the output discharge circuit and a ground lead, and a diode coupled between a power input of the output discharge circuit and the power rail. The output discharge circuit may charge the capacitor via a current path formed by the diode while power is being supplied to the load switch. When the power supply to the output discharge circuit is turned off, the diode may prevent the capacitor from discharging through the current path, and the stored charge on the capacitor may be used to power the output discharge switch for a period of time after the power supply has been turned off. In this way, the output discharge circuit may continue to discharge the output of the load switch even when power is no longer being supplied to the load switch.

Abstract: An ESD protection circuit with a diode string coupled to a diode-isolated, gate-grounded NMOS ESD device. A method of forming an ESD protection circuit with a diode string coupled to a diode-isolated, gate-grounded NMOS ESD device.

Abstract: An ESD protection circuit with a diode string coupled to a diode-isolated, gate-grounded NMOS ESD device. A method of forming an ESD protection circuit with a diode string coupled to a diode-isolated, gate-grounded NMOS ESD device.

Abstract: An ESD protection circuit with a diode string coupled to a diode-isolated, gate-grounded NMOS ESD device. A method of forming an ESD protection circuit with a diode string coupled to a diode-isolated, gate-grounded NMOS ESD device.

Abstract: An ESD protection circuit with a diode string coupled to a diode-isolated, gate-grounded NMOS ESD device. A method of forming an ESD protection circuit with a diode string coupled to a diode-isolated, gate-grounded NMOS ESD device.

Abstract: A voltage level shifting circuit (10) transitions an input signal at a first voltage to a second voltage higher than the first voltage. A cross-coupled latch provides the second voltage. Cascode configured transistors (16, 26) are connected in series with input transistors (18, 28) that receive the first voltage in complementary form. Capacitive devices (34, 40) are connected between the first voltage and gates of the cascode configured transistors for allowing independent small signal variations to occur on the gates of the cascode configured transistors for better control of duty cycle and rise and fall time matching of the level shifting circuit. Isolation devices (32, 38) permit independent modification of small signal voltages to occur on the gates of the cascode configured transistors.