Browse Prior Art Database

Drive System to Shield Termination Network for Ferrite Memories

IP.com Disclosure Number: IPCOM000090110D
Original Publication Date: 1969-Feb-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Moriarty, BM: AUTHOR

Abstract

Adjacent X drive wires of this ferrite core memory are driven from opposite sides of the array. For example, drive wire 2 threads cores 4 and has its right-hand end connected to terminating resistor 5. Its left-hand end is connected to secondary winding 7 of a transformer. Primary winding 10 is connected to driver 9 that supplies current to wire 2 for read and write operations on cores 4. Adjacent wire 3 is similarly connected at its left-hand end to terminating resistor 6 and at its right-hand end to the secondary winding 8 of a transformer. The primary winding and driver associated with wire 3 are not shown. The memory also includes a set of Y dimension wires and a sense winding that are not shown.

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Drive System to Shield Termination Network for Ferrite Memories

Adjacent X drive wires of this ferrite core memory are driven from opposite sides of the array. For example, drive wire 2 threads cores 4 and has its right- hand end connected to terminating resistor 5. Its left-hand end is connected to secondary winding 7 of a transformer. Primary winding 10 is connected to driver 9 that supplies current to wire 2 for read and write operations on cores 4. Adjacent wire 3 is similarly connected at its left-hand end to terminating resistor 6 and at its right-hand end to the secondary winding 8 of a transformer. The primary winding and driver associated with wire 3 are not shown. The memory also includes a set of Y dimension wires and a sense winding that are not shown.

Because of the capacitive and inductive coupling between the selected wire and the other wires of the array, noise currents flow throughout the array when a selected wire is energized. In the set of wires associated with the selected wire, these noise voltages propagate toward the the secondary windings of the associated set of wires are connected to the transformer winding 8 and the associated windings through a pi-network made up of resistors 11, 12 and 13. These resistors have a value to terminate the two sets of windings so as to reduce noise. The resistor end of the two sets of windings are similarly interconnected by means of a pi resistor network. An equivalent T-network may be used.

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