Power distribution system for integrated circuits
A power distribution system for integrated circuits includes methods to damp resonance between a bypass capacitor network and a power/ground cavity of the printed circuit board that (a) does not require excessive quantities of bypass/damping components or (b) does not require high plane cavity capacitance or in the alternative can insure a Q of less than 1.4 at the transition from the bypass network to the plane cavity impedance cross-over.
1. An interposer comprising:
a substrate having first and second surfaces; and
a shunt network; wherein
at least a portion of the shunt network is located at or near the periphery of the substrate;
the first surface is arranged to be attachable to a circuit board;
the second surface is arranged to be connectable to an integrated circuit package; and
the shunt network has a series resonant frequency at or near a parallel resonant frequency of a first component and a second component of a power wiring network to which the interposer will be connected, the first component having an inductance L first and the second component having a capacitance C second .
2. An interposer according to claim 1 , wherein the shunt network comprises at least one capacitor arranged at or near the periphery of the substrate.
3. An interposer according to claim 1 , wherein the substrate includes at least one wing.
4. An interposer according to claim 1 , wherein the shunt network has a Q factor of about 2 or less.
5. An interposer according to claim 1 , wherein the shunt network has a Q factor of about 1.4 or less.
6. An interposer according to claim 1 , wherein the shunt network includes reactive elements that have a characteristic impedance of about 2.0×√(L first /C second ) or less.
7. An interposer according to claim 1 , wherein the shunt network is arranged to suppress or eliminate resonant behavior of the power wiring network by altering a net phase characteristic of the power wiring network when the shunt network is connected to the power wiring network.
8. An interposer according to claim 1 , wherein the shunt network includes a plurality of branches; and
each of the plurality of branches has a zero different from that of the other branches such that a composite self-impedance of the shunt network remains within 135° electrical of a power wiring network self-impedance phase at any point in the power wiring network when the shunt network is connected to the power wiring network.
9. An interposer according to claim 1 , wherein when the shunt network is connected to the power wiring network, the shunt network is in series between the first component and the second component.
10. An interposer according to claim 1 , wherein the shunt network, when loaded by the first component, has a parallel resonant frequency at or near a parallel resonant frequency of the first component and second component.
11. An interposer according to claim 1 , wherein the shunt network is composed of a group of networks; and
at least one of the group of networks is composed of a plurality of capacitors.
12. An interposer according to claim 11 , wherein capacitances of the plurality of capacitors span a narrow range using multiple successive E12 series values.
13. An interposer according to claim 1 , further comprising:
an array of interconnects arranged in a portion of the substrate for connecting to the circuit board and for connecting to the integrated circuit package; and
at least one wing arranged outside the periphery of the portion of the substrate having the array of interconnects; wherein
at least a portion of the shunt network is located on or in said at least one wing.
14. An interposer according to claim 1 , wherein the first component includes a first capacitor of a first type and the shunt network includes a second capacitor of a second type different from the first type.
15. An interposer according to claim 14 , wherein the series resonant frequency corresponds to a self-resonant frequency of the second capacitor, the inductance L first of the first component corresponds to an inductance associated with the first capacitor, and the capacitance C second of the second component corresponds to a capacitance of the power wiring network.