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Entry  Sun Aug 27 16:15:07 2017, awade, Craig, Notes, TempCtrl, Using AD590s for vacuum can sensing 
    Reply  Wed Aug 30 16:50:36 2017, rana, Notes, TempCtrl, Using AD590s for vacuum can sensing 
Message ID: 1887     Entry time: Wed Aug 30 16:50:36 2017     In reply to: 1882
Author: rana 
Type: Notes 
Category: TempCtrl 
Subject: Using AD590s for vacuum can sensing 

that's not how ADC noise works. #RMFT

Quote:

The acromag cards are configured to have ±10 V over 2^15 bits. The least significant bit (LSB) is therefore 20V/2^15 bit = 0.61 mV/bit.  For an AD590 hooked up to a tranimpedance amplifier one would select a 30.96 kΩ transresistance gain to achieve 10 V @ 50 C.  This make the total gain from temperature to volgate G_{temp to V} = 1µA/K * 30.96 kV/A = 30.96 mV/K.  The minimum possible resolution is therefore LSB/G_{temp to V} = 19.7 mK/bit.  Not great if we are going for 1mK temperature stabilization. 

 

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