An output driver circuit has a circuitry portion (70) which is used to generate a Drive-Hi control signal in response to an Output Enable, an optional Precondition signal, and a Data Input signal. A circuit portion (75) ensures that the Drive-Hi control signal is maintained at a voltage which is substantially equal to Vdd when the Output Enable is deactivated. Circuit portion (80) selectively controls the Data Output by driving Vdd onto the Data Output in response to the Drive-Hi control signal being activated. A circuit portion (100) functions to selectively drive the Data Output to a logic zero (ground potential) when a Drive-Lo signal is asserted. Circuit portions (90 and 95) generate the Drive-Lo signal in response to the Output Enable, the optional Precondition signal, and the Data Input signal. In general, the output driver circuit allows an integrated circuit powered at a first voltage to interface to another integrated circuit which is powered at a higher second voltage without loss of performance, without excessive leakage currents, without crossover current, and without increasing gate oxide stresses.

Output circuit for interfacing integrated circuits having different power supply potentials

The present invention relates to a semicustom ASIC, in which a plurality of standard cell rows are arranged. The standard cell and basic cells used in a gate array are mixedly mounted on the same chip. Respective cell rows are composed of a plurality of standard cells with an empty space. The basic cells used in the gate array are arranged as dummy cells. They are disposed in wiring channel regions between the plurality of standard cells or empty spaces between the standard cells in a same standard cell row. Only the latter may be used if the channelless type standard cells are employed. A changing request can be satisfied by forming metal wiring layers on the gate array basic cells when there is a necessity of changing circuit design or pattern. Since the circuit can be modified without change of gate polysilicon regions and source/drain regions underlying the metal wiring layers, design and manufacture can be effected in a short period of time.

Semiconductor integrated circuit with mixed gate array and standard cell

A programmable input/output device for use with a programmable logic device (PLD) is presented comprising an input buffer, an output buffer and programmable elements. The programmable elements may be programmed to select a logic standard for the input/output device to operate at. For instance, a given set of Select Bits applied to the programmable elements may select TTL logic, in which case the input and output buffers would operate according to the voltage levels appropriate for TTL logic (e.g., 0.4 volts to 2.4 volts). For a different set of Select Bits, the GTL logic standard would be applied (e.g., 0.8 volts to 1.2 volts). The invention enables a single PLD to be used in conjunction with various types of external circuitry.

System for coupling programmable logic device to external circuitry which selects a logic standard and uses buffers to modify output and input signals accordingly

An output buffer with improved tolerance to overvoltage conditions. Among other features, especially when in a high-impedance state, the output buffer prevents a leakage path from a pad (108) through a pull-up driver (101) to supply voltage VDD when any voltage above VDD is placed on the pad (108). Further, the output buffer provides improved transient response characteristics. In one embodiment, the output buffer includes a pull-up driver (101), a first tracking transistor (120), a second tracking transistor (122), a voltage bias generator (112), and a coupling capacitor (124).

Output buffer with improved tolerance to overvoltage

A CMOS bi-directional output driver normally operates at 3.3 volts but is capable of communicating with devices that operate at 5 volts.

Floating-well CMOS output driver

A method and semiconductor structure are provided for intermixing circuits of two or more different cell classes, such as standard cells and gate array cells, on a common chip or substrate with minimum gound rule separation between adjacent cells of different classes. Cell locations are defined with given boundaries and contiguously arranged on the surface of a semiconductor chip, and then either standard cell type or gate array type circuits are formed within any of the cell locations to provide a structure for balancing chip density and performance versus hardware turn-around-time.

Method of combining gate array and standard cell circuits on a common semiconductor chip

A CMOS off-chip driver circuit is provided which includes a P-channel pull up transistor and an N-channel pull down transistor serially arranged between a first voltage source having a supply voltage of a given magnitude and ground with the common point between the transistors forming an output terminal to which is connected a circuit including a second voltage source having a supply voltage of a magnitude significantly greater than that of the given magnitude. A first P-channel field effect transistor is connected between the output terminal and the gate electrode of the pull up transistor. A first input terminal is coupled to the gate electrode of the pull up transistor through a transmission gate including a first N-channel field effect transistor arranged in parallel with a second P-channel field effect transistor, with a gate electrode of the first N-channel transistor being connected to the first voltage source and the gate electrode of the second P-channel transistor being connected to the output terminal.

Cmos off chip driver circuit

An output driver circuit for a semiconductor chip has a push-pull output with a P-channel pull-up and an N-channel pull-down. Predrivers produce push-pull outputs for driving the gates of the output driver. Compensator circuits, one for the N-channel pull-down, and one for the P-channel pull-up, are used to prevent the transition from high-to-low or low-to-high from being too rapid, which could cause noise due to inductance of the package leads. A feedback circuit halts the operation of the compensator circuits after a short interval. An overvoltage circuit formed in a well of the semiconductor chip holding the driver circuit, having an input coupled to receive the data output of the predriver circuit going to the P-channel pull-up, also functions to prevent damage to the output driver circuit due to overvoltage on the output node. A stack of diodes connected in a forward direction between the N-well of the P-channel pull-up transistor and the positive terminal of the voltage supply serves to clamp the output node if it tends to go above a selected overvoltge level.

Low-power, tristate, off-chip driver circuit

A CMOS off-chip driver circuit is provided which includes a P-channel pull up transistor (12) and an N-channel pull down transistor (14) serially arranged between a first voltage source (Vdd) having a supply voltage of a given magnitude and ground with the common point between the transistors forming a output terminal (Vout) to which is connected a circuit (28) including a second voltage source having a supply voltage of a magnitude significantly greater than that of the given magnitude. A first P-channel field effect transistor (16) is connected between the output terminal (Vout) and the gate electrode of the pull up transistor (12). A first input terminal is coupled to the gate electrode of the pull up transistor (12) through a transmission gate including a first N-channel field effect transistor (24) arranged in parallel with a second P-channel field effect transistor (26), with a gate electrode of the first N-channel transistor (24) being connected to the first voltage source (Vdd) and the gate electrode of the second P-channel transistor (26) being connected to the output terminal (Vout).

Off-chip drivers

A semiconductor device structure is embedded within a semiconductor chip that calibrates a photon-emission luminosity scale by running multiple known currents through the device. The method comprises embedding at least one photon emission device in an integrated circuit having at least one functional device. A control current is applied to the at least one photon emission device. The photon emission intensity produced by the at least one photon emission device is captured. The current density of the at least one photon emission device is calculated. A test current is applied to the at least one functional device. The photon emission intensity produced by the at least one functional device is captured. The current density of the at least one functional device is estimated based on a comparison with the calculated current density of the at least one photon emission device.

Ronald A. Piro

Papers

Method of combining gate array and standard cell circuits on a common semiconductor chip

Cmos off chip driver circuit

Low-power, tristate, off-chip driver circuit

Off-chip drivers

Embedded photon emission calibration (EPEC)