Abstract: An apparatus is provided which comprises: a dual stack voltage driver, wherein the dual stack voltage driver comprises a first stack of transistors, and a second stack of transistors; and one or more feedback transistors each coupled to a transistor of the second stack of transistors.

Abstract: An apparatus is provided which comprises: a dual stack voltage driver, wherein the dual stack voltage driver comprises a first stack of transistors, and a second stack of transistors; and one or more feedback transistors each coupled to a transistor of the second stack of transistors.

Abstract: An apparatus is provided which comprises: a stack of transistors of a same conductivity type, the stack including a first transistor and a second transistor coupled in series and having a common node; and a feedback transistor of the same conductivity type coupled to the common node and a gate terminal of the first transistor of the stack.

Abstract: An apparatus comprising a first stage and a second stage. The first stage may be configured to generate an intermediate signal having a first voltage in response to an input signal having a second voltage received from a pad. The second stage may be configured to generate a core voltage in response to the first voltage. The voltage received from the pad may operate at a voltage compliant with one or more published interface specifications.

Abstract: A reference circuit includes an NMOS transistor, a PMOS transistor and a bias circuit. The NMOS transistor includes a source connected with a first voltage supply and a gate adapted to receive a first bias signal. The PMOS transistor includes a source connected with a second voltage supply, a gate adapted to receive a second bias signal, and a drain connected with a drain of the NMOS transistor at an output of the reference circuit. The bias circuit generates the first and second bias signals. Magnitudes the first and second bias signals are configured to control a reference signal generated by the reference circuit such that when the reference signal is near a quiescent value of the reference signal, a current in the reference circuit is below a first level, and when the reference signal is outside of the prescribed limits, the current in the reference circuit increases nonlinearly.

Abstract: A reference circuit includes an NMOS transistor, a PMOS transistor and a bias circuit. The NMOS transistor includes a source connected with a first voltage supply and a gate adapted to receive a first bias signal. The PMOS transistor includes a source connected with a second voltage supply, a gate adapted to receive a second bias signal, and a drain connected with a drain of the NMOS transistor at an output of the reference circuit. The bias circuit generates the first and second bias signals. Magnitudes the first and second bias signals are configured to control a reference signal generated by the reference circuit such that when the reference signal is near a quiescent value of the reference signal, a current in the reference circuit is below a first level, and when the reference signal is outside of the prescribed limits, the current in the reference circuit increases nonlinearly.

Abstract: A reference circuit includes an NMOS transistor, a PMOS transistor and a bias circuit. The NMOS transistor includes a source connected with a first voltage supply and a gate adapted to receive a first bias signal. The PMOS transistor includes a source connected with a second voltage supply, a gate adapted to receive a second bias signal, and a drain connected with a drain of the NMOS transistor at an output of the reference circuit. The bias circuit generates the first and second bias signals. Magnitudes the first and second bias signals are configured to control a reference signal generated by the reference circuit such that when the reference signal is near a quiescent value of the reference signal, a current in the reference circuit is below a first level, and when the reference signal is outside of the prescribed limits, the current in the reference circuit increases nonlinearly.

Abstract: An apparatus comprising a first stage and a second stage. The first stage may be configured to generate an intermediate signal having a first voltage in response to an input signal having a second voltage received from a pad. The second stage may be configured to generate a core voltage in response to the first voltage. The voltage received from the pad may operate at a voltage compliant with one or more published interface specifications.

Abstract: An apparatus comprising a first circuit, a second circuit, and a third circuit. The first circuit may be configured to generate a first control voltage and a second control voltage. The second circuit may be configured to generate a bias signal in response to the first control voltage and the second control voltage. The third circuit may be configured to generate a filtered signal in response to the bias signal. The filtered signal may be added to the first control voltage and the second control voltage to provide AC noise suppression when generating the bias signal.

Abstract: A high voltage input receiver with hysteresis using low voltage transistors is disclosed. In one embodiment, an input receiver circuit includes a hysteresis comparator circuit, based on a plurality of low voltage transistors, for generating a first output voltage by comparing an external voltage and a reference voltage and a stress protection circuit for preventing the plurality of low voltage transistors of the hysteresis comparator circuit from exceeding their reliability limits. In addition, the reference voltage is used to set a positive trip point and a negative trip point. Moreover, the input receiver circuit includes a source follower circuit for transferring the first output voltage to an output node of the source follower circuit from a voltage level of a VDDIO to a voltage level of a VDD.

Abstract: A method includes controllably generating a first bias voltage from a supply voltage to be within an upper tolerable limit of an operating voltage of an IO receiver, and controllably generating a second bias voltage from an external voltage supplied through an IO pad to be within the upper tolerable limit of the operating voltage of the IO receiver. The method also includes deriving an output voltage from the first bias voltage during a normal condition and a tolerant condition, and deriving the output voltage from the second bias voltage during a failsafe condition. The tolerant condition is a mode of operation where the external voltage supplied through the IO pad varies from zero to a value higher than the supply voltage, and the failsafe condition is a mode of operation where the supply voltage is zero.

Abstract: A method includes controllably generating a first bias voltage from a supply voltage to be within an upper tolerable limit of an operating voltage of one or more constituent active circuit element(s) of an Input/Output (IO) core device of an integrated circuit (IC) to be interfaced with an IO pad, and controllably generating a second bias voltage from an external voltage supplied through the IO pad to be within the upper tolerable limit of the operating voltage of the one or more constituent active circuit element(s) of the IO core device to be interfaced with the IO pad. The method also includes controllably utilizing a control signal generated by the IO core to derive an output bias voltage from the first bias voltage during a driver mode of operation or the second bias voltage during a failsafe mode of operation and a tolerant mode of operation.

Abstract: A method includes controllably generating a first bias voltage from a supply voltage to be within an upper tolerable limit of an operating voltage of an IO receiver, and controllably generating a second bias voltage from an external voltage supplied through an IO pad to be within the upper tolerable limit of the operating voltage of the IO receiver. The method also includes deriving an output voltage from the first bias voltage during a normal condition and a tolerant condition, and deriving the output voltage from the second bias voltage during a failsafe condition. The tolerant condition is a mode of operation where the external voltage supplied through the IO pad varies from zero to a value higher than the supply voltage, and the failsafe condition is a mode of operation where the supply voltage is zero.

Abstract: A method includes controllably generating a first bias voltage from a supply voltage to be within an upper tolerable limit of an operating voltage of one or more constituent active circuit element(s) of an Input/Output (IO) core device of an integrated circuit (IC) to be interfaced with an IO pad, and controllably generating a second bias voltage from an external voltage supplied through the IO pad to be within the upper tolerable limit of the operating voltage of the one or more constituent active circuit element(s) of the IO core device to be interfaced with the IO pad. The method also includes controllably utilizing a control signal generated by the IO core to derive an output bias voltage from the first bias voltage during a driver mode of operation or the second bias voltage during a failsafe mode of operation and a tolerant mode of operation.

Abstract: A method includes controllably generating a first bias voltage from a supply voltage to be within an upper tolerable limit of an operating voltage of one or more constituent active circuit element(s) of an Input/Output (IO) core device of an integrated circuit (IC) to be interfaced with an IO pad, and controllably generating a second bias voltage from an external voltage supplied through the IO pad to be within the upper tolerable limit of the operating voltage of the one or more constituent active circuit element(s) of the IO core device to be interfaced with the IO pad. The method also includes controllably utilizing a control signal generated by the IO core to derive an output bias voltage from the first bias voltage during a driver mode of operation or the second bias voltage during a failsafe mode of operation and a tolerant mode of operation.

Abstract: A circuit includes a first comparator block configured to output a voltage equal to a higher of a supply voltage and a bias voltage, a second comparator block configured to output a voltage equal to a higher of the bias voltage and an external voltage supplied through an Input/Output (IO) pad, and a third comparator block configured to output a voltage equal to a higher of the output of the first comparator block and the output of the second comparator block. A voltage across one or more constituent active element(s) of each of the first comparator block, the second comparator block, and the third comparator block is within an upper tolerable limit thereof during each of a normal operation, a failsafe operation, and a tolerant operation.

Abstract: A method includes controllably utilizing a control signal generated by an Input/Output (IO) core to isolate a current path from an external voltage supplied through an IO pad to a supply voltage by transmitting a same voltage at an input terminal of a transistor, configured to be part of a number of cascaded transistors of an IO driver of an interface circuit, to an output terminal thereof during a failsafe mode of operation and a tolerant mode of operation. The method also includes feeding back an appropriate voltage to a floating node created by the isolation of the current path, and controlling a voltage across each transistor of the number of cascaded transistors to be within an upper tolerable limit thereof through an application of a gate voltage to each transistor derived from the supply voltage or the external voltage supplied through the IO pad.

Abstract: A power detect system and circuit for detecting a voltage level of an input/output supply voltage (VDDIO) in a circuit of low voltage devices is disclosed. In one embodiment, the power detect system and circuit includes a voltage divider coupled between the VDDIO and a negative supply voltage (VSS) for generating a bias voltage, a first inverter coupled between a core voltage (VDD) and the VSS for generating a first node voltage based on the bias voltage, a native device coupled between the VDDIO and the VSS for generating a second node voltage based on the bias voltage, and a switch coupled between the first inverter and the native device for controlling the second node voltage based on the first node voltage. The power detect system further includes a second inverter coupled between the VDD and the VSS for generating an output voltage based on the second node voltage.

Abstract: A power detect system and circuit for detecting a voltage level of an input/output supply voltage (VDDIO) in a circuit of low voltage devices is disclosed. In one embodiment, the power detect system and circuit includes a voltage divider coupled between the VDDIO and a negative supply voltage (VSS) for generating a bias voltage, a first inverter coupled between a core voltage (VDD) and the VSS for generating a first node voltage based on the bias voltage, a native device coupled between the VDDIO and the VSS for generating a second node voltage based on the bias voltage, and a switch coupled between the first inverter and the native device for controlling the second node voltage based on the first node voltage. The power detect system further includes a second inverter coupled between the VDD and the VSS for generating an output voltage based on the second node voltage.

Abstract: A high voltage input receiver with hysteresis using low voltage transistors is disclosed. In one embodiment, an input receiver circuit includes a hysteresis comparator circuit, based on a plurality of low voltage transistors, for generating a first output voltage by comparing an external voltage and a reference voltage and a stress protection circuit for preventing the plurality of low voltage transistors of the hysteresis comparator circuit from exceeding their reliability limits. In addition, the reference voltage is used to set a positive trip point and a negative trip point. Moreover, the input receiver circuit includes a source follower circuit for transferring the first output voltage to an output node of the source follower circuit from a voltage level of a VDDIO to a voltage level of a VDD.