Abstract: A method and system for a configurable Vcc reference and Vss reference differential current mode transmitter is described. The system includes a Vss reference differential current mode driver, a Vcc reference differential current mode driver coupled to the Vss reference current mode driver, and a controller circuit coupled to the Vss reference differential current mode driver and the Vcc reference differential current mode driver to select between the Vss reference differential current mode driver and the Vcc reference differential current mode driver based on a type of transmission interface.

Abstract: Disclosed is a line driving circuit which includes two NMOS transistors in series between a supply voltage and a ground voltage. The output of the line driving circuit is applied to an interior circuit through a transmission line, and a repeater is used when the transmission line is long.

Abstract: Various embodiments provide a high speed serial transmitter that utilizes a current-mode driver comprising a main driver and a de-emphasis driver. The de-emphasis driver includes a first driver circuit and a complementary second driver circuit that is operably coupled with the first driver circuit. Collectively, the first driver circuit and its complementary second driver circuit work in concert to compensate to correct the lower output common-mode level in de-emphasized bits.

Abstract: Techniques are provided for calibrating parallel on-chip termination (OCT) impedance circuits. An on-chip termination (OCT) calibration circuit generates first calibration codes and second calibration codes. The first calibration codes control the conductive states of first transistors that are coupled in parallel between a supply voltage and a first terminal. The second calibration codes control the conductive states of second transistors that are coupled in parallel between the first terminal and ground. The OCT calibration circuit selects a first calibration code and a second calibration code and transmits the selected calibration codes to third and fourth transistors to control a parallel on-chip termination impedance at a pin.

Abstract: In some embodiments, a transmitter includes a first circuit coupled to an input port of the transmitter, and a second circuit coupled to the first circuit and to an output port of the transmitter, wherein the first circuit is sized with respect to the second circuit such that for a pulse signal applied to the input port, the transmitter generates an output signal having a rise-time and a fall-time that are substantially equal at the output port.

Abstract: Transmitter driver circuitry includes multiple output driver stages, each of which receives a respective differently-phased version of an output signal for application to an output node of the circuitry. Each stage includes a primary current source. The circuitry also includes at least one secondary current source. The secondary current source can be used to supply supplementary current to the output node to eliminate or at least substantially reduce offset at the output node.

Abstract: A circuit device for variously controlling a current drive capacity of a semiconductor IC device as required by the user. A circuit device, capable of preventing a semiconductor IC device from failing to drive an external device, preventing an operational speed of the semiconductor IC device from being reduced, and preventing noise from being transferred to the external device.

Abstract: A high-speed signaling system with adaptive transmit pre-emphasis. A transmit circuit has a plurality of output drivers to output a first signal onto a signal path. A receive circuit is coupled to receive the first signal via the signal path and configured to generate an indication of whether the first signal exceeds a threshold level. A first threshold control circuit is coupled to receive the indication from the receive circuit and configured to adjust the threshold level according to whether the first signal exceeds the threshold level. A drive strength control circuit is coupled to receive the indication from the receive circuit and configured to adjust a drive strength of at least one output driver of the plurality of output drivers according to whether the first signal exceeds the threshold level.

Abstract: An input buffer circuit with hysteresis includes a first stage and a second stage. The first stage includes a resistive device to provide a resistance between two nodes of the first stage. The two nodes are responsive to a signal input. The second stage includes four series-coupled transistors. A first node is coupled to the control electrodes of two of the four transistors and the second node is coupled to the control electrodes of the other two transistors. The second stage includes a signal output. In some examples, a resistance provided by the resistive device is variable and provides the buffer circuit with hysteresis.

Abstract: An output buffer circuit, which minimizes or prevents output delay of output signal and degradation of slew rate while suppressing overshoot and undershoot, is provided. In a first time period when an input signal to a gate of an N-channel output transistor changes from ‘L’ level to ‘H’ level, the gate is connected to an output terminal through a capacitor element so that the overshoot is suppressed. In addition, the output buffer circuit stores negligible electrical charge in the capacitor element prior to the first time period, which results in minimal delay in outputting a buffered signal and degradation of slew rate while suppressing undershoot when the input signal changes from ‘H’ level to ‘L’ level in the first time period.

Abstract: A multi-standard transmitter includes a differential stage that includes a current generator transistor; first and second transistors connected between a first node and the generator transistor and having respective control terminals connected to a first input terminal, the first and second transistors being interconnected at a first output terminal; third and fourth transistors connected between the first node and the generator transistor and having respective control terminals connected to a second input terminal, the third and fourth transistors being interconnected at a second output terminal; and first and second resistances connected between the first and second output terminals and interconnected at a second node. The transmitter includes a selective enabling circuit connected to the first and second nodes, and to a third node corresponding to a control terminal of the generator transistor.

Abstract: Techniques are provided for individually adjusting the on-chip termination impedance that is generated by input and output (IO) buffers in an input/output (IO) bank on an integrated circuit. The IO buffers in an IO bank can generate different on-chip termination impedances. And as a result, an IO bank can support more than one class of memory interfaces. An OCT calibration block generates a digital on-chip termination (OCT) calibration code. In some embodiments, circuitry in the IO banks can be configured to shift the OCT calibration code by one or more bits to adjust the series and/or parallel on-chip termination impedance in one or more IO buffers.

Abstract: A bootstrap inverter circuit, consisting of transistors of the same type, comprises a first transistor, a second transistor, a voltage clamp circuit and an output end. The voltage clamp circuit, having a first node and a second node, controls the voltage of a gate of the second transistor. A gate and a first end of the first transistor are connected to a power source. A gate of the second transistor is connected to the second node of the voltage clamp circuit. A first end of the second transistor is connected to the power source. A second end of the second transistor is connected to the output end. The first node of the voltage clamp circuit is connected to the power source. The second node of the voltage clamp circuit is connected to a second end of the first transistor.

Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a transmitter die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains the termination resistances for the signal transmission lines. The ODT control system derives a number of calibration currents from precision voltage and resistance references and distributes the reference currents to a number of transmitters. Each transmitter then derives an ODT calibration signal using the respective reference current and another precision resistor, and then employs the calibration signal to calibrate local termination elements. Distributing calibrated currents provides excellent noise immunity, while limiting the requisite number of external voltage references reduces cost.

Abstract: A driving circuit is for an output buffer stage, with high speed and reduced noise induced on the power supply. The driving circuit may include first and second circuit portions, each intended for the generation of a respective driving signal for a corresponding transistor of the buffer stage. Each portion may include a final stage with a complementary pair of MOS transistors inserted between two supply voltage references, and a third MOS transistor having its conduction terminals connected between one of the voltage references and an interconnection node of the complementary pair and receiving, on its control terminal, an activation pulse signal coming from a logic network incorporating at least one delay chain.

Abstract: A method according to one embodiment may include switching, by an integrated circuit, a plurality of switches to generate at least one output signal having a first amplitude and a second amplitude. The method according to this embodiment may also include controlling, by the integrated circuit, a conduction state of the plurality of switches to include a first conduction state and a second conduction state. The method according to this embodiment may also include minimizing, by the integrated circuit, the number of switch transitions between the first conduction state and the second conduction state of at least one switch when the output signal goes from the first amplitude to the second amplitude.

Abstract: A differential current-mode driver that meets the IEEE 1394 standard employs a wide output range in common-mode voltage, minimizes timing skew over this wide range, and has well-controlled rise/fall times in the edge rates of the digital signals transmitted, within the window specified by the IEEE 1394 standard, without having to resort to full-swing (VDD to VSS) gate drive signals. In a preferred embodiment PMOS and NPOS transistors are used to provide current for a current driver, in the form of a current steering switch switching a pair of current mirrors. The current mirrors output is input to a predriver waveform circuit which divides current between a data source A and data source B, forming the differential signal pair. Certain key transistors in the current driver are kept in saturation to improve performance.

Abstract: An electrically programmable multiple selectable function integrated circuit module has a plurality of optionally selectable function circuits, which receive and manipulate a plurality of input data signals. The outputs of the plurality of optionally selectable function circuits are either interconnected to each other or connected to a plurality of output connectors to transmit manipulated output data signals to external circuitry. The electrically programmable multiple selectable function integrated circuit module has at least one configuration connector, which may be multiplexed with input control and timing signals, connected to a function configuration circuit to receive electrical configuration signals indicating the activation of a program mode and which of the optionally selectable function circuits are to be elected to manipulate the input data signals.

Abstract: A time required for an output voltage of a source follower to rise from Low to a predetermined voltage depends on a bias voltage. Therefore, by setting a converged voltage of an output voltage to be high by increasing the bias voltage, the time required to rise up to the predetermined voltage can be reduced. Therefore, a first source follower which is biased so that the converged value of the output voltage becomes a predetermined Hi voltage when an input data signal goes from Low to Hi, and a second source follower which is biased so as to become the Hi voltage after a period of one clock when an input data signal goes from Low to Hi, are used. The two source followers are operated with appropriate timing.

Abstract: A high-speed differential receiver is used between a high voltage domain and a low voltage domain. The high-speed differential receiver includes a common mode differential amplifier coupled to a differential level shifter. The common mode differential amplifier and differential level shifter operates at the high voltage domain. The differential level shifter receives amplified differential signals from the common mode differential amplifier and provides voltage level shifted differential signals applied to a biased differential amplifier operating at the low voltage domain.

Abstract: An input buffer circuit includes a voltage limiting circuit and a protection circuit coupled between a pull-up component and a pull-down component of a level detecting circuit. The voltage limiting circuit receives an input signal at a first voltage range and limits the input signal to a safe voltage range, the first voltage range being between an electrical ground and a first supply voltage level, and the safe voltage range being between the electrical ground and a second supply voltage level. The level detecting circuit has a pull-up component receiving the input signal directly from the input terminal and a pull-down component receiving the safe voltage range from the voltage limiting circuit. The level detecting circuit transitions the input signal from the first voltage range to the input signal at the second voltage range. The protection circuit is coupled in series between the pull-up component and the pull-down component so as to protect the level detecting circuit from gate oxide overstress.

Abstract: This document discusses, among other things, output slew rate control. Methods and structures are described to provide slew rate control of an output driver circuit such as a DRAM output driver on a die. A selectable combination of series coupled transistors are configured as a parallel array of complementary inverter pairs to provide a divided voltage to a calibrator. The calibrator is configured to respond to a differential voltage to adjust the divided voltage such that the differential voltage is forced to zero. The calibrator outputs a plurality of discrete signals from an up/down counter to switch on and off the individual transistors of the parallel array to increase and decrease a collective current. In some embodiments, transistor channel currents are modulated to step-adjust a voltage based on a ratio associated with a static resistance. In various embodiments, the divided voltage is an analog voltage based on a resistance associated with trim circuitry.

Abstract: The programmable slew rate driver uses separate and programmably selectable resistors for time constants for on and off transitions on the NMOS and PMOS output transistors. By proper setting of gate voltage time constants and overlap of NMOS and PMOS “on” times, a desired output slew rate is accomplished, having a smooth output transition, without generation of shoot-through current. The programmable slew rate driver includes a first driver transistor coupled between the first supply voltage and output, a second driver transistor coupled between the second supply voltage and output, a plurality of upper transition blocks coupled in parallel and a plurality of lower transition blocks coupled in parallel between the first and second supply voltage. The rates of change and overlap of the gate voltages are in turn substantially determined by the resistance of the lower transition control blocks and the capacitance of the gate of the second driver transistor.

Abstract: The distance between a drain contact and gate electrode in a terminating transistor, which couples a termination resistor connected to an output terminal to a power source node, is set shorter than in an output transistor, which drives an output node in accordance with an internal signal. The area of the terminating circuit is reduced while the reliability against the surge is maintained. Thus, an output circuit containing the terminating circuit that occupies a small area and is capable of transmitting a signal/data at high speed is provided.

Abstract: An output buffer circuit includes a first output buffer section and a second output buffer section. The first output buffer section includes complementary semiconductors. The second output buffer section includes complementary semiconductors and is connected in parallel with the first output buffer section. The second output buffer section starts to output an second output signal after an output voltage of the output buffer circuit reaches a reference voltage indicative of one of an on-state and an off-state by a first output signal of the first output buffer section.

Abstract: A driver circuit for driving a device or circuit disposed after it comprises a plurality of driving transistors connected in parallel, a selection unit for selecting one or more groups from a plurality of groups to each of which driving transistors having a power base of two with the same polarity belong and in which the number of driving transistors belonging to each group is different and a driving unit for driving driving transistors belonging to the group selected by the selection unit.

Abstract: Method and apparatus for analog compensation of driver output signal slew rate against device impedance variation. The method includes a signal termination device coupled to a driver output pad. In one embodiment, driver includes a pull-up circuit having at least one pull-up device and a pull-down circuit including at least one pull-down device. In one embodiment, the pull-up circuit and the pull-down circuit including corresponding pull-up and pull-down compensation resistive elements. Accordingly, the pull-up and pull-down compensation resistive elements provide analog compensation of a driver output signal slew rate against device impedance variation. In one embodiment, a slew rate of the driver output signal is within a predetermined slew rate range to avoid uncontrolled fast switching as well as unnecessarily slow switching in the driver output signal. Other embodiments are described and claimed.

Abstract: A differential transmission line driver with supplemental current sources that overcome switching anomalies and EMU issues when the logic state of the driver is switching. During a logic transition, a current source, that is directed to the output of the driver, may be prevented from delivering its current. The present invention provides a supplemental current that is active during this transition period to supply the missing current. The present disclosure also details a common mode circuit that maintains a stable common mode output level to help control EMI issues when the power supply for the driver changes.

Abstract: A system including a single ended switching topology for high-speed bidirectional signaling includes a device coupled to a plurality of bidirectional signal paths. The device includes a plurality of voltage mode driver circuits, each coupled to a respective signal path. Each of the driver circuits may source a voltage when transmitting data and terminate a respective signal path to a ground reference when receiving data. The device also includes a shunt regulator circuit coupled to a voltage supply of the device. The shunt regulator may provide a current shunt from the voltage source to the ground reference in response to detecting a transition on the voltage supply in which the voltage increases above an average DC voltage.

Abstract: A LVDS (Low Voltage Differential Signal) driver with a high PSRR (Power Supply Rejection Ration) includes a first current source for providing a working current, a switch unit for receiving the working current and determining the current directions of an output current at first and second signal nodes according to first and second input signals, a second current source connected between the switch unit and a low working power voltage, a common mode feedback unit for generating a common mode control signal according to voltages on the first and second signal nodes of the switch unit, a common mode resistance unit connected in parallel with the second current source and having a resistance value controlled by the common mode control signal, and a compensation unit connected in parallel with the second current source for compensating the current variation of the first current source caused by power noise.

Abstract: The distance between a drain contact and gate electrode in a terminating transistor, which couples a termination resistor connected to an output terminal to a power source node, is set shorter than in an output transistor, which drives an output node in accordance with an internal signal. The area of the terminating circuit is reduced while the reliability against the surge is maintained. Thus, an output circuit containing the terminating circuit that occupies a small area and is capable of transmitting a signal/data at high speed is provided.

Abstract: In an output driver circuit and method, a control circuit generates a control signal in response to a current internal data signal. An output driver generates an output data signal in response to the control signal. A pre-emphasis circuit adjusts a current flowing through a node having the control signal generated thereon in response to a previous internal data signal. The pre-emphasis circuit may also adjust the output signal in response to the previous internal data signal.

Abstract: A high-speed interface between a first network component and a second network component includes a positive voltage input (VINP) and a negative voltage input (VINN) for receiving an input data signal from the first network component; the positive voltage input (VINP) coupled to a negative output circuit (OUTN) and the negative voltage input (VINN) by a positive input bus and a negative input bus, the negative voltage input (VINN) also coupled to a positive output circuit (OUTP). Implementing the high-speed interface calls for applying a bias to the a positive input bus and a negative input bus to periodically multiplex a data signal, thus providing a common receiving path for functional data and wrap data of the data signal.

Abstract: Techniques are provided for trimming drive current in output drivers to compensate for process variations, model inaccuracies, and/or an off-target process. The actual output drive current is measured on the integrated circuit (IC) at wafer sort or during a final test. Based on the measured output drive current, the total transistor width that is required in the output driver to meet an I/O standard is calculated. A control block controls trimming transistors that are coupled in parallel with main output drive transistors. The control block adjusts the total width of the output drive transistors to bring the total width as close as possible to the desired width. Each I/O driver on a die can be adjusted individually based on its own drive current characteristics. All I/O drivers on a die can be adjusted by the same transistor width based on a single I/O measurement or on multiple I/O measurements.

Abstract: A level shifter is disclosed. The level shifter includes a level shifter core circuit and a pull-up control logic circuit. In response to an input signal and an output signal of the level shifter core circuit, the pull-up control logic circuit selectively turns on a transistor within the level shifter core circuit to prevent the occurrence of a strong P-N fight state within the level shifter.

Abstract: A signaling circuit having reduced parasitic capacitance. The signaling circuit includes a plurality of driver circuits each having an output coupled to a first output node, and a plurality of select circuits each having an output coupled to a control input of a corresponding one of the driver circuits. Each of the select circuits includes a control input to receive a respective select signal and a plurality of data inputs to receive a plurality of data signals. Each of the select circuits is adapted to select, according to the respective select signal, one of the plurality of data signals to be output to the control input of the corresponding one of the driver circuits.

Abstract: A slew-rate adjusting apparatus for use in a semiconductor memory device includes: a slew-rate modulation signal generator for generating a slew-rate modulation signal according to the number of control codes having a first logic level among a plurality of control codes, which are programmable at an exterior; and a pre-driver for adjusting a slew rate of a data signal by changing the number of switching elements turned on in response to the slew-rate modulation signal.

Abstract: An LVDS receiver of the present invention rapidly restores an LVDS inputted at a high speed into a full swing signal of CMOS or TTL level. A common mode shifter amplifies an LVDS contained in a common mode signal and then shifts a level of the common mode signal. Further, an intermediate amplifying unit amplifies a signal outputted from the common mode shifter to have a margin above and below a threshold voltage in a predetermined logic lever. In addition, an output buffer unit amplifies a signal outputted from the intermediate amplifying unit to produce a full swing signal.

Abstract: Stacked inverter delay chains. In accordance with a first embodiment of the present invention, a series stack of two p-type devices is coupled to a series stack of three n-type devices, forming a stacked inverter comprising desirable delay, die area and power characteristics. Two stacked inverters are coupled together to form a stacked inverter delay chain that is more efficient in terms of die area, active and passive power consumption than conventional delay chains comprising conventional inverters.

Abstract: A prestage for generating a control signal for an output driver of an integrated circuit, wherein the integrated circuit can be provided with a reference potential and a supply potential fixed in relation to the reference potential, comprises an input for receiving an input signal from the integrated circuit, a circuitry for generating an output signal based on the received input signal, an output for outputting the generated output signals as control signal for an output driver as well as a current source, which is effectively connected to the circuitry. Thereby, the circuitry for generating an output signal and the current source are connected in series and connected to a first potential and a second potential such that a prestage potential difference across the series circuit is higher than a supply potential difference between the supply potential and the reference potential.

Abstract: Systems and methods are disclosed herein to provide improved I/O techniques. For example, in accordance with an embodiment of the present invention, an integrated circuit includes a driver that receives data signals and provides an output signal based on the data signals, with the driver having a plurality of transistors with a first set of the plurality of transistors adapted to provide a first logical value as the output signal and a second set of the plurality of transistors adapted to provide a second logical value as the output signal based on the data signals. A sequencing circuit provides the data signals to the driver such that the first set of the plurality of transistors is switched on before the second set of the plurality of transistors is switched off, and the second set of the plurality of transistors is switched on before the first set of the plurality of transistors is switched off.

Abstract: A cascaded pass-gate test circuit including interposed split-output drive devices provides accurate measurement of critical timing parameters of pass gates. The rise time and fall time of signals passed through the pass gate can be separately measured in a ring oscillator or one-shot delay line configuration. Inverters or other buffer circuits are provided as drive devices to couple the pass gates in cascade. The final complementary tree in each drive device is split so that the only one of the output pull-down transistor or pull-up transistor is connected to the next pass gate input, while the other transistor is connected to the output of the pass gate. The result is that the state transition associated with the device connected to the pass gate input is dominant in the delay, while the other state transition is propagated directly to the output of the pass gate, bypassing the pass gate.

Abstract: The invention relates to a driver circuit for binary signals, said circuit having two branch circuits which are connected in parallel with one another between an input node and an output node, the first of which branch circuits contains an output stage which, in response to the first binary value of a binary signal that is applied to the input node, connects the output node to a first logic potential via a first nonreactive resistor, and the second of which branch circuits contains an output stage which, in response to the second binary value of the binary signal that is applied to the input node, connects the output node to a second logic potential via a second nonreactive resistor. According to the invention, the driver circuit contains a duty ratio control device for setting the signal propagation time from the input node to the output stage of one branch circuit relative to the signal propagation time from the input node to the output stage of the other branch circuit.

Abstract: An on die termination (ODT) test device includes: a control unit for selectively activating a plurality of pull-up signals and a plurality of pull-down signals by performing a logic operation to an ODT control signal for controlling a resistor of a termination terminal, an off chip driver (OCD) control signal for adjusting an impedance of an output terminal, a plurality of ODT test signals for measuring a termination resistance of the termination terminal and a plurality of ODT signals having a different resistance; and a pull-up/pull-down unit for selectively driving a plurality of pull-up drivers and a plurality of pull-down drivers according to the pull-up signals and the pull-down signals in order to output a corresponding resistance of the output terminal at a read operation mode.

Abstract: A voltage translator circuit capable of operating at high speed, saving the power consumption, and forming to have a smaller circuit area. When the output level of a decoder 110 is changed from the potential GND to the potential VDD, a pMOS transistor 125 is turned off, and the gate of nMOS transistor 124 comes to have a high impedance. Because of this, the self-boost effect acts on the gate of the nMOS transistor 124 to push up the source potential of the nMOS transistor 124. Consequently, the gate potential of the pMOS transistor 122 is abruptly raised, and this pMOS transistor 122 is turned off at high speed. The pMOS transistor 122 being turned off at high speed, the penetration current flowing through the transistors 121 and 122 is reduced and the electric potential of the word line WL falls at high speed.

Abstract: A pre-driver for large I/O pull-up and pull-down transistors is provided so that the I/O pull-up and pull-down transistors do not experience crowbar current, and the pre-driver circuit likewise does not experience crowbar current or require large driver transistors. One pre-driver circuit includes two NAND gates and two NOR gates with delay circuitry provided by two series inverters from a data input to a first node, and two additional series inverters from the first node to a second node. A further pre-driver circuit includes feedback from the pre-driver outputs to ensure its NMOS and PMOS transistors do not turn on together to create crowbar, while allowing faster switching. With the pre-driver circuit embodiments, a conventional level shifter can be used. Further with the pre-driver circuitry, slew rate control can be provided in the pull-up and pull-down driver circuitry, rather than in the pre-driver circuitry.

Abstract: The present invention provides an input buffer for use in a semiconductor device reducing a current consumption and maintaining a reliable operation speed by detecting a level of the reference voltage. The input buffer includes a comparator, having a first biasing device controlled by a buffer enable signal, for sensing a logic level of an input data by comparing voltage levels of a reference voltage and the input data, a reference voltage detector for detecting the level of the reference voltage, and a second biasing device controlled by an output signal from the reference voltage detector and parallel connected to the first biasing device.

Abstract: Differential signal output nodes of a novel CML buffer are DC-coupled by contiguous conductors to the differential signal input nodes of a load (for example, a CML logic element). The CML buffer includes a pulldown load latch that increases buffer transconductance and that provides a DC bias voltage across the conductors and onto the input nodes of the load, thereby obviating the need for the load to have DC biasing circuitry. Capacitors of a conventional AC coupling between buffer and load are not needed, thereby reducing the amount of die area needed to realize the circuit and thereby reducing the capacitance of the buffer-to-load connections. Switching power consumption is low due to the low capacitance buffer-to-load connections. Differential signals can be communicated from buffer to load over a wide frequency range of from less than five kilohertz to more than one gigahertz with less than fifty percent signal attenuation.

Abstract: An equalized driver includes a voltage mode driver to drive data on a conductor and a current mode driver to provide equalization.

Abstract: An output driver of a semiconductor device, removing the inter-symbol interference noise in data transmission in order to achieve a signal integrity, includes a main driver for driving an output terminal and a supporting driver for controlling the inter-symbol interference noise. The supporting driver is provided with a pull up supporting driver for pulling up the output terminal by detecting a transmission pattern of an output data and a pull down supporting driver for pulling down the output terminal by detecting the transmission pattern of the output data.