Sun Microsystems, Inc.

Merle Tetreault

Istvan Novak

Michael C Freda

Valerie St Cyr

Daniel C Irish

Valerie StCyr

A method for achieving a desired value of electrical impedance between conductors of an electrical power distribution structure by electrically coupling multiple bypass capacitors and corresponding electrical resistance elements in series between the conductors. The resistance elements may be annular resistors, and may provide the designer a greater degree of control of the system ESR. The annular resistors may comprise a first terminal, an annular resistor, and a second terminal. The second terminal may be located within the confines of the annular resistor. The annular resistors may be printed onto a conductive plane (e.g. a power plane or a ground plane), or may be a discrete component.

Adding electrical resistance in series with bypass capacitors using annular resistors

Apparatus and methods for achieving a desired value of electrical impedance between parallel planar conductors of an electrical power distribution structure by electrically coupling multiple bypass capacitors and corresponding electrical resistance elements in series between the planar conductors. The methods include bypass capacitor selection criteria and electrical resistance determination criteria based upon simulation results. An exemplary electrical power distribution structure produced by one of the methods includes a pair of parallel planar conductors separated by a dielectric layer, n discrete electrical capacitors, and n electrical resistance elements, where n&gE;2. Each of the n discrete electrical resistance elements is coupled in series with a corresponding one of the n discrete electrical capacitors between the planar conductors. The n capacitors have substantially the same capacitance C, mounted resistance R , mounted inductance L , and mounted resonant frequency f . The mounted resistance R of each of the n capacitors includes an electrical resistance of the corresponding electrical resistance element. The electrical power distribution structure achieves an electrical impedance Z at the resonant frequency f of the capacitors. The mounted resistance R of each of the n capacitors is substantially equal to (n&middot;Z). The mounted inductance L of each of the n capacitors is less than or equal to (0.2&middot;n&middot;&mgr; &middot;h), where &mgr; is the permeability of free space, and h is a distance between the planar conductors.

Adding electrical resistance in series with bypass capacitors to achieve a desired value of electrical impedance between conducts of an electrical power distribution structure

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Tyngsboro, MA, United States of America

Merle Tetreault