Agilent Technologies, Inc.

Jason Gonzalez

Guy Harlan Humphrey

M Jason Welch

C Stephen Dondale

Richard A Krzyzlowski

A novel method and apparatus is presented for controlling the slew rate of a transitioning signal on an integrated circuit transmission line. The signal driver which drives the signal onto the transmission line is connected to the transmission line via redistribution metal characterized by a characteristic capacitance appropriate to adjust the RC time constant of the transmission line to shape the signal edges to a slope resulting in the desired slew rate.

Redistribution metal for output driver slew rate control

An electrostatic discharge (ESD) structure for use in an integrated circuit (IC). The ESD structure comprises a metallic resistor and a metallic capacitor that are electrically coupled in series to form a resistor-capacitor (RC) component having an appropriate RC time constant. The RC component maintains a level of charge between ground and a shunt node to ensure that, during an ESD event, electrostatic charge on a power supply, VDD, associated with the ESD structure is shunted via a shunt path from said power supply VDD to said ground. By using metal to create the metal resistor and capacitor, charge leakage problems that result from parasitic capacitance associated with using an RC component comprised of either a poly, active, or nwell resistor in combination a diode are eliminated. By eliminating such charge leakage problems, a more reliable RC component, and thus a more reliable RC time constant, are obtained.

Method and apparatus for creating a reliable long RC time constant

A method for matching output impedance of a driver to a load impedance. In representative embodiments an external impedance is attached between an external contact and a first source potential, wherein the load impedance includes the external impedance plus impedance of interconnections between an output terminal of the driver and the external impedance. An adjustable impedance, which can be field effect transistors which can be turned on separately and in combination to change the value of the adjustable impedance and which can be located on an integrated circuit, are connected between a second source potential and the output terminal of the driver. A reference potential, wherein the reference potential has a value half-way between the first source potential and the second source potential is obtained. And a load matching impedance is obtained by changing the adjustable impedance until the absolute value of the difference between the voltage of the output terminal of the driver and the reference potential is less than a preselected value.

Conductive path compensation for matching output driver impedance

A novel method and apparatus is presented for reducing the slew rate signals on transmission lines of integrated circuits by stepwise ramping up or down the voltage level on the transmission line. Switched capacitors or current sources are connected to either directly to the transmission line itself, or to the control input of a driver device characterized by a linear region during which the output voltage on the transmission line is proportional to the voltage seen at the control input.

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Ft. Collins, CO, United States of America

Jason Gonzalez