Texas Instruments PGA112, Руководство пользователя

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4.4.1 Scaled Inputs Tab
PGA112 Software Overview
www.ti.com
Figure 13 illustrates the Scaled Inputs tab.
Figure 13. Scaled Inputs to PGA112/113
This tab has the following controls:
•
Diff Amp Input allows user to program a very small voltage input to the PGA112/113 device, so that
higher gains can be more easily evaluated
•
The Resistor Divider Input allows the user to create a unique input from an external source and the
internal 2.5V reference with a 0V to 5V output.
•
The External Input allows the user to input a sine wave or a precision external input.
•
The Reference Input field allows the user to read the actual value of the onboard 2.5V reference. The
default jumper connection for this onboard reference is to the internal V
REF_INT
; however, the reference
DAC that controls the output shift on the OPA333 operational amplifier may also be selected as the
reference. When the internal 2.5V reference is selected, the reference input appears as shown in
Figure 14 . If the user wants to change the reference jumper setting (JP_Ref) to V
REF_DAC
, choose
External on the reference input setting.
Figure 14. Selection of Internal Reference or DAC Reference
PGA112 Evaluation Module 18 SBOU073 – February 2009
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