Browse Prior Art Database

Sense Element

IP.com Disclosure Number: IPCOM000042504D
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-03
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Jaeckel, H: AUTHOR [+2]

Abstract

Asymmetric powering with a l:m:l current injection device (CID) improves margins by allowing an increase in sense bus current without increasing the positive pulse in the transformer secondary. Fig. 1 shows a sense element in the sense bus loop. The asymmetric powering (achieved via inductive split L1:L2) is essential for operation with good margins because it allows a big increase (>N50%) of sense bus current ig in the loop without having to raise the positive pulse id+ in the secondary of the transformer. In this way, the discrimination between the positive (id+) and negative (id-) pulse can be improved even without relying on circuit dynamics (i.e., overshoot). The following numerical example illustrates the approach: The spread in normalized threshold curves (Fig.

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Sense Element

Asymmetric powering with a l:m:l current injection device (CID) improves margins by allowing an increase in sense bus current without increasing the positive pulse in the transformer secondary. Fig. 1 shows a sense element in the sense bus loop. The asymmetric powering (achieved via inductive split L1:L2) is essential for operation with good margins because it allows a big increase (>N50%) of sense bus current ig in the loop without having to raise the positive pulse id+ in the secondary of the transformer. In this way, the discrimination between the positive (id+) and negative (id-) pulse can be improved even without relying on circuit dynamics (i.e., overshoot). The following numerical example illustrates the approach: The spread in normalized threshold curves (Fig. 2) has been calculated for a BSCIL-type 1:3:1 three-junction current injection device assuming WIo = +16% and WL = +3% The noise curve corresponds to a unit current Io =50 mA and, consequently, the noise band will be narrower for any Io> 50 mA. Let us assume that the pulse in the transformer secondary will remain approximately at + NN 100 mA. Biasing the injection device at the points shown (i1 = 0.5, i2 = 3.0), we choose Io NN 100 mA as unit current in order to switch the device by id+ . Then the sense bus current ig NNdown 2 will be transferred into the isolation junction's critical current. This value is far above the magnitude of the negative pulse (NN100 mA, junction not to be swi...