Browse Prior Art Database

VARIABLE SLOPE D/A FOR GAIN CONTROL

IP.com Disclosure Number: IPCOM000024700D
Original Publication Date: 1981-Oct-31
Included in the Prior Art Database: 2004-Apr-02
Document File: 2 page(s) / 48K

Publishing Venue

Xerox Disclosure Journal

Abstract

Many systems require that a microporcessor change voltage using a Digital-to- Analog Converter (D/A) to provide a correction or initiate some action. These systems often also require these changes to be in proportional steps, say 1%. A linear D/A configured to go from .5 VDC to 1.5 VDC and to be adjustable in at least 1% steps for example, would have to have a step size of (3 VDC) (.01)=5 mv. This would require 200 steps (8 bits) to go from .5 to 1.5 VDC and at 1.5 VDC the step would only be 0.3%.

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XEROX DISCLOSURE JOURNAL

VARIABLE SLOPE D/A FOR GAIN CONTROL Douglas G. Wiggins
Richard H. Tuhro 1nt.CI. GOlr

Proposed Classification
U.S.Class No. 324/347M

Many systems require that a microporcessor change voltage using a Digital-to- Analog Converter (D/A) to provide a correction or initiate some action. These systems often also require these changes to be in proportional steps, say 1%. A linear D/A configured to go from .5 VDC to 1.5 VDC and to be adjustable in at least 1% steps for example, would have to have a step size of (3 VDC) (.01)=5 mv. This would require 200 steps (8 bits) to go from .5 to 1.5 VDC and at 1.5 VDC the step would only be 0.3%.

If the same D/A were configured to have increasingly larger steps, each step would be 1% and 100 steps could cover the 3-1.5 VDC range adequately. This would also require only 7 bits of data which could save substantial amounts of memory and its associated cost.

Volume 6 Number 5 September/October 1981 24 1

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    XEROX DISCLOSURE JOURNAL Volume 6 Number 5 September/October 1981

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