Abstract: A NAND EEPROM is disclosed which is capable of variously setting, for each chip, the voltage to be applied to the control gates of memory cells. The semiconductor chip includes a NAND memory cell array and a high-voltage generating circuit for generating data writing internal voltage VPP required when data is written on the memory cell array. Moreover, the semiconductor chip includes a set voltage selection circuit for arbitrarily setting the level of the voltage VPP generated by the high-voltage generating circuit for each chip and a multiplexer for extracting, to the outside of the chip, setting signal LTF which is a signal for enabling the level of the voltage VPP set arbitrarily.

Abstract: An input buffer within an integrated circuit capable of receiving an input signal that complies with the electrical characteristic voltage levels of TTL, LVTTL, SSTL, or GTL, buffering the input signal, and converting the input signal to an output signal having voltage levels acceptable to internal circuitry of the integrated circuits is described. The input buffer will have an adjustable threshold trip point at which the input signal will cause the output signal to change between a first logic state and a second logic state. The adjustable threshold trip point will be determined by an adjustment voltage circuit that is immune to variation in semiconductor processing parameters, power supply voltage and operating temperature.

Abstract: A pulse signal output circuit charges and discharges a capacitor in response to a clock signal and outputs a pulse signal having a pulse width determined by a time for charging and discharging the capacitor. A control signal generation circuit outputs a control signal in response to the pulse signal, where the control signal has a first voltage level determined by the pulse width. An output circuit has a first output transistor and a first regulating transistor connected in series between the first power supply node and the output terminal. The first output transistor is operated in response to a signal transferred from inside or outside a semiconductor device, and the first regulating transistor is operated in response to the control signal.

Abstract: An output buffer circuit for differentially driving a symmetrical transmission line. The circuit enable power efficient operation at very high bit rates and keeps the common mode voltage on the transmission line within predetermined narrow limits. Circuitry is used to match the impedances of transmission lines and to control the bias of voltage sources at predetermined levels.

Abstract: A programmable logic device architecture with a highly routable programmable interconnect structure. The arrangement of the logic array blocks (LABs), programmable interconnect structure, and other logical elements forms a Clos network. After specific constraints have been met, the architecture is guaranteed to route. The architecture is provably routable when there is no fan-out in the middle stage. A LAB (A-200) comprises an input multiplexer region (A-504), logic elements (A-300), input-output pins (A-516), and output multiplexer region (A-508). Furthermore, a logic device and a method of operating a logic device. The device includes logic elements (B-240) that perform desired logic functions and routing functions. The logic elements (B-240) are arranged in larger logic blocks known as logic array blocks (B-230) that have local interconnection systems. The logic array blocks (B-230) are configured to provide global interconnections.

Abstract: The present invention relates to an output buffer circuit for transmitting digital signals over a transmission line with pre-emphase. It comprises an output stage and a control circuit. The output stage includes a first impedance circuit connected between an upper power supply potential and an output node. It furthermore includes a second impedance circuit connected between the output node and a power supply node at a lower supply potential. Both impedance circuits receive impedance control signals from the control circuit such that an impedance ratio between the first impedance and the second impedance takes one of at least three different predetermined values in accordance with the present state and the history of a digital data input signal, and such that the sum of the conductance provided by the first impedance circuit and the conductance provided by the second impedance circuit is independent from the generated impedance ratios.

Abstract: An interface circuit effectively prevents ringing of signal waveform. In a buffer integrated circuit, a level of an input signal to an input buffer and a reference level are compared by a comparator. A transistor is operated to be turned ON and OFF depending upon the comparison result to control level of the input signal. Even when the ringing of the waveform from the output buffer is large, ringing may not be recognized as “H” level signal so as not to cause malfunction.

Abstract: An input buffer having a stable trip point over at least process skew and supply voltage variations includes a first inverter stage; a second inverter stage; and an arrangement for compensating for process skew and supply voltage variations. The compensating arrangement is disposed both in the pull-up and pull-down paths, and increases the conductivity of the pull-up path and decreases the conductivity of the pull-down path when the DC trip point of the input buffer falls below nominal. The compensating arrangement also decreases the conductivity of the pull-up path and increases the conductivity of the pull-down path when the DC trip point rises above nominal. The compensating arrangement may include at least one device disposed in each of the pull-up and pull-down paths. The conductivity of these devices may then be controlled by a reference signal that swings about the DC trip point responsive to at least process skew corners and variations in supply voltage.

Abstract: This invention is to reduce the power dissipation of a semiconductor integrated circuit chip when it is operated at an operating voltage of 2.5 V or below. To achieve the object, a switching element is provided in each circuit block within the semiconductor integrated circuit chip. The constants of the switching element are set so that the leak current in the switching element of each circuit block in their off-state is smaller than the subthreshold current of the MOS transistors within the corresponding circuit block. The active current is supplied to the active circuit blocks, while the switching elements of the non-active circuit blocks are turned off. Thus, the dissipation currents of the non-active circuit blocks are limited to the leak current value of the corresponding switching elements. As a result, the sum of the dissipation currents of the non-active circuit blocks is made smaller than the active current in the active circuit blocks.

Abstract: A voltage adjusting circuit includes a reference voltage generator generating a reference voltage, a differential amplifier comparing the reference voltage with a distribution voltage, and compensating for a variation of the reference voltage, and a voltage divider dividing a power supply voltage and generating a constant output voltage according to an output from the differential amplifier.

Abstract: Circuits with SOI devices are coupled to a body bias voltage via a switch for selectively connecting the body bias voltage signals to the SOI device body. NMOS or PMOS SOI devices are used for the switched body SOI device and a FET is used for the switch and the gate terminal of the SOI device is connected to the FET device. The gate of the SOI device controls the FET switch connection of the body bias voltage signals to the SOI device to adjust the threshold value of the SOI device. Logic circuits incorporating the SOI devices are also disclosed, and the fabrication process for the SOI devices as well.

Abstract: An apparatus and method of communicating signals between a 2.5 volt internal circuit and both 3.3 and 5 volt external circuits using a P-well. The apparatus includes a circuit having a P-well control circuit and a number of NMOS transistors. The P-well control circuit is configured to receive a P-well control signal and an external signal, and in accordance therewith selectively generate a P-well voltage. The NMOS transistors are coupled to the P-well control circuit. At least one of the NMOS transistors has a bulk region configured to receive the P-well voltage. The NMOS transistors are further configured to receive a 5 volt signal and in accordance therewith selectively generate a 2.5 volt signal. The NMOS transistors are still further configured to receive a 3.3 volt signal and in accordance therewith selectively generate a 2.5 volt signal.

Abstract: A semiconductor circuit or a MOS-DRAM wherein converting means is provided that converts substrate potential or body bias potential between two values for MOS-FETs in a logic circuit, memory cells, and operating circuit of the MOS-DRAM, thereby raising the threshold voltage of the MOS-FETs when in the standby state and lowering it when in active state. The converting means includes a level shift circuit and a switch circuit. The substrate potential or body bias potential is controlled only of the MOS-FETs which are nonconducting in the standby state; this configuration achieves a reduction in power consumption associated with the potential switching. Furthermore, in a structure where MOS-FETs of the same conductivity type are formed adjacent to each other, MOS-FETs of SOI structure are preferable for better results.

Abstract: An input buffer circuit for a semiconductor device includes a first input buffer unit having first and second transistors, a second input buffer unit coupled to the first input buffer unit, the second input buffer unit having third and fourth transistors, a control unit for activating one of the first and second input buffer units, and a switching unit having fifth, sixth, and seventh transistors and coupled to the control unit.

Abstract: A field programmable gate array (FPGA) has an interface circuit that allows signals to be transmitted directly between the FPGA and a processor. The processor interface (PI) of the FPGA enables the processor to access data at any time from either programmable logic of the FPGA or system registers of the PI. The present invention eliminates the need for external intermediate logic previously required to interface an FPGA and a processor.

Abstract: A technique for reducing standby leakage current in a circuit block using input vector activation. A complex circuit includes a plurality of inputs and one or more transistor stacks. At least some of the transistor stacks are coupled to at least one of the inputs. The circuit also includes logic to apply a selected input vector to the plurality of inputs during a standby mode. The input vector is selected based on a configuration of the one or more transistor stacks in the circuit block to turn off a first number of transistors in the transistor stacks. The first number is within a selected percent of a maximum number of transistors in the transistor stacks that can be turned off by any vector applied at the plurality of inputs.

Abstract: A semiconductor circuit includes a logic circuit section and a latch circuit section. The logic circuit section includes higher and lower potential side actual power supply lines, higher and lower potential side quasi power supply lines, a CMOS logic circuit and a power connection section. The latch circuit section includes a first CMOS inverter, a latch circuit and a transfer gate. The first CMOS inverter is connected between the higher and lower potential side quasi power supply lines. The latch circuit is operatively and selectively connected to the first CMOS inverter in series and is composed of second and third CMOS inverters connected in series. The transfer gate has the second threshold voltage and is disposed between the first CMOS inverter and the latch circuit.

Abstract: This invention describes an improved design of CMOS. digital input circuits. This improvement reduces the switching level uncertainty range and thus increases the noise margin, compensating for manufacturing process variations. This improvement is achieved by providing resistive compensation devices in series with the P-type and the N-type CMOS transistors in the first stage of a multistage digital input circuit. These resistive devices can be implemented by means of resistors or by means of MOSFET devices which provide the required resistive function. These compensation devices modify the input-output voltage transfer characteristics of the first stage so as to reduce the switching level variation at the input to the circuit. The resulting digital input circuit has a greater tolerance to input noise levels. The improvement provided by this invention is particularly important as integrated circuits design trend is to operate with lower supply voltages.

Abstract: A Silicon-On-Insulator (SOI) CMOS circuit comprises a plurality of PMOS transistors connected in series to each other, each of the plurality of PMOS transistors having its body and gate connected to each other, and at least an NMOS transistor connected to one of the plurality of PMOS transistors, the NMOS transistor having its body connected to a low reference potential having a value of ground. The SOI CMOS circuit can further comprise a plurality of potential limiting circuits each connected between the body and gate of each of the plurality of PMOS transistors, for setting a lower limit of the potential of the body of each of the plurality of PMOS transistors to a voltage between a high reference potential and a potential obtained by subtracting a built-in potential from the high reference potential.

Abstract: A NAND EEPROM is disclosed which is capable of variously setting, for each chip, the voltage to be applied to the control gates of memory cells. The semiconductor chip includes a NAND memory cell array and a high-voltage generating circuit for generating data writing internal voltage VPP required when data is written on the memory cell array. Moreover, the semiconductor chip includes a set voltage selection circuit for arbitrarily setting the level of the voltage VPP generated by the high-voltage generating circuit for each chip and a multiplexer for extracting, to the outside of the chip, setting signal LTF which is a signal for enabling the level of the voltage VPP set arbitrarily.

Abstract: Reduction of standby leakage current in an internal circuit block using a transistor stack effect. For one embodiment, an apparatus includes a standby leakage reduction circuit to be coupled to the circuit block including a plurality of logic gates. The standby leakage reduction circuit causes a stack effect at each of the plurality of logic gates during a standby mode of the circuit block by turning off two or more series-coupled transistors of a same type (either n-type or p-type) at each of the plurality of logic gates.

Abstract: A semiconductor integrated circuit including an input circuit constituted as a single-input differential circuit which has a first MOSFET to whose gate a reception signal with a small amplitude with respect to a power supply voltage is supplied and a second MOSFET to whose gate a reference voltage corresponding to an intermediate value of the reception signal is supplied. A dummy circuit is provided and transmits substantially the same power supply noise as the power supply noise transmitted to the gate of the first MOSFET through a electrostatic protection circuit provided to an external terminal which receives the reception signal.

Abstract: Integrated circuits include an impedance control circuit having at least one output terminal coupled to an on-chip reference termination device in order to control output impedance of the reference termination device such that it matches that of an external resistance. The impedance control circuit outputs are also coupled to the on-chip impedance-controlled termination devices which are coupled to each of the external transmission lines to be terminated. In this way, a single reference resistance allows many transmission lines to be properly terminated. The impedance-controlled termination devices are may be implemented as pairs of binary weighted p-channel and n-channel field effect transistors.

Abstract: An output circuit for an integrated circuit, includes a first transistor and a second transistor connected in series between a first external voltage and a second external voltage external to the integrated circuit, respectively through first and second electrical connecting paths. The first transistor is for carrying an output line of the integrated circuit to the first external voltage, while the second transistor is for carrying the external line of the integrated circuit to the second external voltage. The second transistor is formed inside a first well of a first conductivity type contained inside a second well of a second conductivity type formed in a substrate of the first conductivity type. The second well of the second conductivity type is connected to the first external voltage through a third electrical connecting path distinct from the first electrical connecting path.

Abstract: An output buffer includes a p-channel transistor, and first and second n-channel transistors. The p-channel transistor has one of a source and drain which is connected to power supply and the other which is connected to an output node connected to an output terminal. The first n-channel transistor has one of a source and drain which is grounded and the other which is connected to the output node. The second n-channel transistor is series-connected to the p-channel transistor between a power supply and the output node and receives at a gate a power supply potential level which rises at substantially the same time as the power supply upon ON operation.

Abstract: A programmable logic device, such as a field programmable gate array (FPGA) which includes an array of configurable logic elements (CLEs) and a corresponding array of multiplier tiles. The CLEs can be operated as conventional configurable logic elements, completely disconnected from the array of multiplier tiles. However, selected CLEs can also be coupled to selected multiplier tiles, thereby creating a relatively high density multiplier circuit. Each of the multiplier tiles includes a multiplier array having a predetermined size (e.g., a 2.times.4 bit multiplier array). The multiplier tiles can be selectively coupled to one another, such that the multiplier arrays are connected to form a relatively large multiplier circuit. The desired multiplier and multiplicand bits are routed into the multiplier tiles from associated CLEs. Similarly, the resulting product bits are routed from the multiplier tiles to associated CLEs.

Abstract: An apparatus and method for controlling the power consumption of a logic device are implemented. The power dissipation, and consequently, the speed of a complementary metal oxide semiconductor (CMOS) logic device is substantially proportional to the speed of the device. The temperature of the logic device is controlled by controlling the device speed by adjusting the threshold voltage of the metal oxide semiconductor (MOS) devices forming the logic device under control. The threshold voltage of the devices is controlled by applying a back bias voltage between the bulk material in which each device under control is fabricated, and the most positive electrode of the device. The back bias voltage value is regulated in response to the logic device temperature, thereby closing a feedback loop.

Abstract: An analog process/voltage/temperature (PVT) compensated buffer includes a differential amplifier providing a first output signal indicative of a difference between an input signal and a reference signal. The input signal is compatible with a first type of logic. An active gain stage is coupled to translate the first output signal to a second output signal. The second output signal is compatible with a second type of logic. The differential amplifier and the active gain stage are coupled to receive a process/voltage/temperature (PVT) compensation signal. In one embodiment, the first type of logic is Gunning Transceiver Logic (GTL) and the second type of logic is complementary metal oxide semiconductor (CMOS) logic.

Abstract: A high-speed SCSI input receiver has separate high and low level input buffers, each operating in response to a control voltage that conditions their respective high and low level switching threshold voltages to remain stable about their design values without regard to temperature and process parameter variations. Each of the input buffers includes an input invertor with n-channel and p-channel current source transistors coupled between the output and the respective supply rails. A master circuit includes circuitry that substantially matches the operative circuitry of the input buffer, except that the input and output of the master circuit's invertor element are coupled together so as to define the elements actual switching threshold voltage. This threshold voltage is compared to a design threshold voltage defined by a resistor divider in a comparator.

Abstract: The present invention is directed to an input buffer circuit comprising a first inverter for receiving an input signal, a second inverter for receiving an output signal from the first inverter, and a transition time detecting circuit for detecting a transition time of an output signal of a sense amplifier which amplifies and reads a logic value stored in a memory cell. The transition time detecting circuit generates a control signal for a delay depending on a detected level of the transition time. A logic threshold control circuit is provided for feeding the control signal from the transition time detecting means back to an input terminal of said second inverter to control a hysteresis interval of a logic threshold level of an output signal produced in response to the input signal. An output signal from the second inverter is delayed by a delay circuit which provides the delayed output signal to the logic threshold control circuit.

Abstract: A programmable variable impedance output driver circuit uses analog biases to match driver output impedance to load input impedance. A current mirror is used to obtain a measurement of an external resistance value for matching the impedance of a driven load. The mirrored current generates the voltage "NBIAS" when passed through the resistively connected NFET. Similarly, the current is again mirrored and passed through a resistively connected PFET resulting in the voltage "PBIAS". The analog bias voltages, NBIAS and PBIAS are used to vary the impedance of complementary FETs in an impedance matched driver for a high degree of dI/dt control. The driver provides a high degree of flexibility because its turn-on and turn-off characteristics do not depend on a combination of digital control signals connected directly to the driving FETs as in the prior art.

Abstract: A ring oscillator using CMOS technology having three logic gates, including a threshold amplifier, where the transistors that set the voltage rise threshold and the voltage drop threshold in the amplifier are controlled by a bias control circuit so that the ratio of voltage rise threshold to the voltage supply diminishes and the ratio of the voltage drop threshold to the voltage supply increases, when the supply voltage falls.

Abstract: A CMOS buffer circuit having a trip point which is insensitive to variations in temperature, supply voltages and manufacturing processes. The circuit output stage has three series-connected MOS transistors including an N channel pull-down transistor connected between the buffer output and the circuit common, a first P channel pull-up transistor connected to a positive supply voltage and a second P channel pull-up transistor connected between the first P channel transistor and the buffer output. The gates of the first P channel transistor and the N channel transistor are connected together to form the buffer input. An N channel reference transistor is used to generate a reference current which is mirrored into the output stage by a third P channel transistor which is connected to the second P channel transistor of the output stage so as to form a current mirror.

Abstract: An input buffer includes a first CMOS inverter (400) made up of a PMOS transistor (602) connecting Vdd to the buffer output and an NMOS transistor (604) connecting the buffer output to Vss. NMOS transistors (404) and (414) have with series connected source to drain paths to connect the buffer output to Vss in conjunction with transistor (604) of inverter (400). PMOS transistors (402) and (412) have series connected source to drain paths connecting Vdd to the buffer output in conjunction with transistor (602). To control transistors (402, 404, 412 and 414) an inverter (420) is connected from the buffer output to the gates of transistors (402 and 404), and inverters (431, 432, 433, and 440) are connected between the buffer input and the gates of transistors (412 and 414).

Abstract: A differential input circuit includes a first differential circuit of a current mirror type for generating a first differential voltage by using an input voltage and a reference voltage, a second differential circuit of a current mirror type for generating a second differential voltage having a phase opposite to that of the first differential voltage by using the input voltage and the reference voltage, and a third differential circuit for generating an output voltage corresponding to a difference voltage of the first and second differential voltages by using the first and second differential voltages. A first clamping circuit for clamping the first differential voltage is provided between the first and third differential circuits. A second clamping circuit for clamping the second differential voltage is provided between the second and third differential circuits.

Abstract: A logic circuit having a first logic gate and the remaining logic gate or gates. The first logic gate is interposed in a signal path determining an operating speed, and includes at least one first MOS transistor which has a threshold voltage lower than a predetermined voltage and operates at a high speed. The remaining logic gate or gates include at least one of a second MOS transistor and a third MOS transistor as a transistor having a margin for operating speed. The second MOS transistor has a middle threshold voltage equal to or greater than the predetermined voltage, and the third MOS transistor has a high threshold voltage equal to or greater than the predetermined voltage. The power consumption of the entire logic circuit at the time of operation is reduced, while maintaining the maximum operating speed.

Abstract: A diode device with a low or negligible threshold voltage includes at least one field effect transistor, the gate of the field effect transistor being connected to the drain of the field effect transistor. The threshold voltage of the diode device is approximately of the same magnitude as the potential of the gate of the field effect transistor forming part of the diode device.

Abstract: A CMOS logic circuit comprises a logic gate having an input node (e.g., a storage node) coupled to a positive supply potential through a p-type field-effect transistor (PFET), with one or more n-type field-effect transistors (NFETs) being coupled between the storage node and a negative supply potential. Since the response of the circuit to a high-energy particle strike is dominated by the N+ diffusion associated with the NFETs when the state of the storage node is high, i.e., a logical "1", the gate has a switching point that is set closer to the negative supply potential than to the positive supply potential.

Abstract: A compensated CMOS receiver includes an inverter, at least one compensation transistor coupled between a first voltage and the output of the inverter, a comparison circuit coupled to the output of the inverter, and a control circuit coupled to the comparison circuit and the compensation transistor. When the receiver is driven to a calibration state, the comparison circuit generates an output signal that reflects the difference between the inverter's output voltage and a switch-point reference. The control circuit adjusts the one or more compensation transistors according to the difference signal generated by the comparison circuit.

Abstract: An output circuit which suppresses the occurrence of leakage current from the power supply of an external element to the power supply of an internal device, even if the power supply voltage of the external element is higher than the power supply voltage of the internal device. Even if a voltage (5V) from an external circuit etc. which is higher than a power supply terminal 6 voltage (3V) is input to the output terminal 8, due to the fact that a floating state N-well B1 at the substrate of PMOS transistors P12, P13 and P14 rises to around 5V, PMOS transistor P12 and PMOS transistor P13 are put into an OFF state. If PMOS transistor P12 and PMOS transistor P13 are in the OFF state, the (5V) voltage is applied to PMOS transistor P1 and there is no flow of leakage current to the power supply terminal 6 through the substrate of PMOS transistor P1.

Abstract: An input circuit (20) and a method for protecting the input circuit (20) from positive and negative overvoltages. The input circuit (20) includes an N-channel Metal Oxide Semiconductor Field Effect Transistor (MOSFET) (12), a P-channel MOSFET (13), a Zener diode (21), and a diode-connected transistor (22). The P-channel MOSFET (13) protects the N-channel MOSFET (12) from negative overvoltages. The Zener diode (21) and the diode-connected transistor (22) protect the N-channel MOSFET (12) from positive overvoltages. In addition, the Zener diode (21) protects the P-channel MOSFET (13) from positive overvoltages.

Abstract: A voltage compensating CMOS input buffer converts input TTL signals to CMOS logic levels, and compensates for changing supply voltage by using a n-channel transistor to vary the effective size ratio of pairs p-channel to n-channel transistors making up an input inverter. The compensating transistor becomes operable with increasing supply voltage to help the n-channel input inverter transistors offset the p-channel input inverter transistors whose trip points would otherwise have been increased by increasing power supply voltage. As the power supply voltage decreases, the compensating transistor turns off, returning the input inverter to its original size ratio. The gate of the compensating transistor is coupled to the supply voltage through two diodes to control the amount of current flowing through the compensating transistor. Further trip point transistors in series with the compensating transistor have their gates coupled to the input signals to help stabilize the trip points.

Abstract: A low voltage CMOS input buffer protection circuit that is used to protect an input buffer from any high voltage signal (e.g., 5 V) that may appear along a signal bus. The protection circuit is also "hot-pluggable", meaning that the protection circuit will not draw any current when not powered (i.e., when VDD is not present). The circuit includes a CMOS transmission gate and utilizes on-chip generated reference voltages to provide the necessary protection.

Abstract: A circuit configured with MOSFETs having a first range of subthreshold conduction, is provided with at least one switchable pathway between the circuit and a power or ground node, such that the switchable pathway is operable to substantially reduce leakage current through the circuit. In a further aspect of the present invention, the switchable pathway is a FET having substantially the same subthreshold conduction characteristics as the FETs in the circuit to which the switchable pathway is coupled, the FET being configured to be driven into both inversion and accumulation.

Abstract: A method and apparatus for applying a blocking potential for gating inputs of pull-up and pull-down devices of an output driver is described. The blocking potential is applied to either or both of a pull-up or pull-down transistor for reducing leakage current. In particular, a circuit having a voltage generator for producing the blocking polarity potential is connected to a voltage translator. A control signal is provided to the voltage translator for accessing the output driver. During accessing of the output driver, the blocking polarity potential is isolated from gating inputs of the pull-up and pull-down devices of the output driver. In a memory device employing the output driver, the blocking polarity potential is applied when the memory is in a state which does not activate the output driver. The blocking polarity is provided by a voltage divider using a substrate bias potential. A feedback path is employed to follow voltage applied to an output pad through substrate bias voltage.

Abstract: A small amplitude signal output circuit comprises an output section for receiving a logic signal to output a small amplitude signal, a level sense circuit for sensing the rise or fall of an output voltage at an output terminal, and a level control circuit for responding to the output of the level sense circuit to suppress the rise or fall of the output voltage. The output circuit suppresses voltage variations caused by variations in fabrication process of transistors, ambient temperature and source voltage noise.

Abstract: Various methods and circuitry for implementing output buffers with low voltage CMOS transistors capable of handling signal overshoot and undershoot conditions at an external terminal are disclosed. The present invention detects the level of the signal at the external terminal and adjusts the voltage at the gate terminals of the output transistors connecting to the external terminal in response thereto, such that oxide stress conditions are alleviated. In one embodiment, dynamic biasing techniques are developed by the present invention to ensure that the circuitry protecting the output devices is itself protected against voltage stress caused by overshoot and undershoot at the external terminal.

Abstract: A driver circuit has first and second output drivers, monitor circuitry for deriving control signals related to driven signal levels, and supply circuitry responsive to the control signals for controlling the supply voltage to the output drivers. The monitor circuitry can be connected to monitor the voltage at the supply inputs of the output drivers for deriving the control signals. Alternatively, the monitor circuitry can be connected directly to monitor driven output levels from the drivers. In the latter case, the output levels to be monitored are rectified. The monitor circuitry can comprise first and second operational amplifiers for comparing a monitored voltage from first and second output drivers, respectively, to a first and second reference voltages, respectively. The supply circuitry can comprise first and second constant current sources, for example field effect transistors.

Abstract: An input buffer within an integrated circuit capable of receiving an input signal that complies with the electrical characteristic voltage levels of TTL, LVTTL, SSTL, or GTL, buffering the input signal, and converting the input signal to an output signal having voltage levels acceptable to internal circuitry of the integrated circuits is described. The input buffer will have an adjustable threshold trip point at which the input signal will cause the output signal to change between a first logic state and a second logic state. The adjustable threshold trip point will be determined by an adjustment voltage circuit that is immune to variation in semiconductor processing parameters, power supply voltage and operating temperature.

Abstract: A loading device for use in a tester for testing a semiconductor integrated circuit device (DUT) includes a programmable voltage source for providing a selected voltage at an output terminal thereof and multiple resistive elements each having at least a first state, in which the resistive element is conductive, and a second state, in which the resistive element is substantially non-conductive. The resistive elements are connected as a two-terminal network between the output terminal of the programmable voltage source and a tester pin for connection to a pin of the DUT. A selection device selects the state of each resistive element, whereby the resistance between the output terminal of the programmable voltage source and the tester pin can be selectively varied.