International Business Machines Corporation

Albert Alexander DeBrita

William L Bucossi

David Jia Chen

Michael J Lencioni

A design structure and more particularly to a design structure to minimize driver output slew rate variation. The design structure is embodied in a machine readable medium for designing, manufacturing, or testing an integrated circuit. The design structure includes a driver circuit having an input signal and an output signal, where the driver circuit is structured and arranged to control the slew rate of the output signal. A delay circuit is coupled to an output of the driver circuit, where the delay circuit has a delay proportional to a desired target slew rate of the driver output signal. A first comparator for detecting when the driver output signal rises through a specified level, and a second comparator for detecting when the driver output falls through a second specified level are included. A phase detector is coupled to outputs of the first and second comparators and an output of the delay circuit for aligning the phases (voltage-time relationships) of the comparator outputs and the delayed comparator outputs by adjusting the driver output slew rate.

Structure for time based driver output transition (slew) rate compensation

Apparatus controlling the driver output slew rate that includes a driver circuit having an input signal and an output signal, where the driver circuit is structured and arranged to facilitate control of the slew rate of the output signal. A delay circuit having a time delay proportional to a desired transition time of the driver output signal is coupled to the output of the driver circuit. A first comparator detects when the driver output signal rises through a specified level, and a second comparator detects when the driver output falls through a second specified level. A phase detector is coupled to outputs of the first and second comparators and an output of the delay circuit for aligning the phases of the comparator outputs and the delayed comparator outputs by adjusting the driver output slew rate.

Time based driver output transition (slew) rate compensation

An IO driver utilizes a slew rate boost circuit coupled to an IO driver circuit to improve the slew rate of the driver during transitions on the output of the driver. One or more additional output stages are coupled in parallel with a primary output stage of the driver, and are temporarily activated responsive to a transition in an input signal to the driver to effectively decrease the output impedance and boost the pull-up and pull-down time response characteristics of the driver during the transition of the output. The additional output stages are active only for a small part of a cycle, so the slew rate is thereby increased while the effective output impedance during most of the cycle is essentially unaffected.

IO driver with slew rate boost circuit

Apparatus and method for controlling the driver output slew rate. The apparatus includes a driver circuit having an input signal and an output signal, where the driver circuit is structured and arranged to facilitate control of the slew rate of the output signal. A delay circuit having a time delay proportional to a desired transition time of the driver output signal is coupled to the output of the driver circuit. A first comparator detects when the driver output signal rises through a specified level, and a second comparator detects when the driver output falls through a second specified level. A phase detector is coupled to outputs of the first and second comparators and an output of the delay circuit for aligning the phases of the comparator outputs and the delayed comparator outputs by adjusting the driver output slew rate.

An output of a common mode differential amplifier is initialized to a known state, which includes inputting a voltage to a network conductor of an electronic assembly, where the network conductor is coupled to a first input node of a first differential input of the amplifier. The amplifier is on an integrated circuit chip of the assembly and has a self-bias node. Circuitry of the amplifier normally adjusts to obtain an equilibrium voltage on the self-bias node in response to the inputted voltages. To initialize the amplifier output, however, preset circuitry on the integrated circuit chip overrides the normal equilibrium voltage on the self-bias node, forcing the self-bias node to a predetermined voltage regardless of the amplifier input voltages. In response, the amplifier produces an desired initial output state on a first output node of the amplifier.

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Jericho, VT, United States of America

Albert Alexander DeBrita