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Title: Data converter for CT data acquisition system

Patent ·
OSTI ID:6088006

This patent describes data converter circuitry for a radiation imaging data acquisition system, comprising: a programmable gain amplifier circuit having a resistor attenuator stage and a fixed gain amplifier stage, the resistor attenuator stage providing a plurality of paths connecting the input of the programmable gain amplifier circuit with the input of the fixed gain amplifier stage, and switch means responsive to a signal received at the input of the data converter circuitry to select one of the paths for communication of the signal to the fixed gain amplifier stage, thereby selecting the gain to be provided by the programmable gain amplifier to the signal; and means for periodically setting the input of the fixed gain amplifier stage to ground, as auto-zeroing circuit for determining the differential input voltage that must be applied across the fixed gain amplifier stage to make its output voltage zero when the output of the fixed gain amplifier stage is set to ground, and means for applying the determined differential input voltage to the fixed gain amplifier stage as correction to the input offset voltage when the input of the fixed gain amplifier stage is not set to ground.

Assignee:
General Electric Co., Milwaukee, WI
Patent Number(s):
US 4815118
OSTI ID:
6088006
Resource Relation:
Patent File Date: Filed date 29 Jun 1987
Country of Publication:
United States
Language:
English