Advanced Micro Devices Corporation

Benjamin Beker

Tom J Hirsch

Capacitive decoupling circuits and methods of making the same are disclosed. In one aspect, a method of manufacturing is provided that includes providing a semiconductor chip with a first power rail for a first no-load bias level and a ground rail. A first voltage divider is electrically coupled between the first power rail and the ground rail and has a midpoint node. A first pair of capacitors is electrically coupled between the first power rail, the midpoint node and the ground rail to provide capacitive decoupling for power delivered to the first power rail. A second power rail has a second no-load bias less than the first no-load bias. A second pair of capacitors is electrically coupled between the ground rail and the second power rail to provide capacitive decoupling for power delivered to the second power rail.

Capacitance for decoupling intermediate level power rails

A computer power supply system for reducing the AC impedance of a DC power supply () at inputs pins of a computing device () such as a processor. A quarter wavelength transmission line stub () is connected to a computing device DC power supply input pin. The stub is open circuited at its end opposite the pin. The wavelength is selected to match a frequency at which power supply impedance is known to be high. The stub appears as a low impedance at the selected frequency. Multiple stubs at different frequencies may be used to provide reduced impedance over a broader frequency band. Stubs may be formed from printed circuit board traces on a motherboard of from metalization patterns on a computing device package.

Growing community of inventors

Spicewood, TX, United States of America

Benjamin Beker