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Bias Tailoring of Resistors

IP.com Disclosure Number: IPCOM000079167D
Original Publication Date: 1973-May-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 24K

Publishing Venue

IBM

Related People

Atwood, BC: AUTHOR

Abstract

A pinch resistor of tightened tolerance is realized by the addition of a bias circuit, which controls the epitaxial bed in which the pinch resistor is formed. The bias circuit senses resistance changes due to process variations and applies a bias to the epitaxy in such a manner, as to lessen variations in resistor value.

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Bias Tailoring of Resistors

A pinch resistor of tightened tolerance is realized by the addition of a bias circuit, which controls the epitaxial bed in which the pinch resistor is formed. The bias circuit senses resistance changes due to process variations and applies a bias to the epitaxy in such a manner, as to lessen variations in resistor value.

The well-known pinch resistor created within semiconductor bodies is created within an epitaxial bed. Biasing of this bed in which the resistor rests acts as a gating mechanism for changing its resistance. Thus, in the figure, changes in the pinch resistor 16 due to process variations, cause a tailoring of a second pinch resistor 10 by virtue of biasing its epitaxial bed shown as gate 12. Tailoring is in a direction as to negate much of the process variation in resistor 10.

The circuit consists of a pinch resistor 16, and a transistor 14 having its base connection 24 coupled to one side of the resistor 16 and its emitter lead 26 coupled to the opposite side of resistor 16. The gate or bed 18 in which resistor 16 is formed is connected to a five volt power supply, together with a resistor 20 coupled to the base of transistor 14 and a resistor 22 coupled to the collector of transistor 14. The collector lead 28 of the transistor 14 is also coupled to the epitaxial bed 12 in which the second resistor 10 is formed. The resistance of resistor 10 is tailored by changes in the value of the pinch resistor 16, which is subject t...