Other Parts Discussed in Thread: TVS1400
Hello TI,
In one of our project we have used Instrumentation Amplifier i.e INA826 and we are facing some issues with it. So we need your support to solve the issue.
Issue Details:
Our Requirement is to have minimum 100Mohms impedance at the analog input. To meet this we used INA826 as the datasheet of INA826 says that it could provide input impedance of ~20Gohms. But in reality we are getting only 2Mohms on board.
Here is the Schematic of analog input. To make the debugging simpler we unmounted all the component from the board except series resistor (R4 an R7) and INA826. But still we are getting 2Mohms input impedance.
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The method which we are using to measure to Impedance:
Issue Details:
Our Requirement is to have minimum 100Mohms impedance at the analog input. To meet this we used INA826 as the datasheet of INA826 says that it could provide input impedance of ~20Gohms. But in reality we are getting only 2Mohms on board.
Here is the Schematic of analog input. To make the debugging simpler we unmounted all the component from the board except series resistor (R4 an R7) and INA826. But still we are getting 2Mohms input impedance.
The method which we are using to measure to Impedance:
We provided 5VDC input at AIN+ via Ammeter. So the flow is like: Function Generator (+ve) -->Ammeter (+ve) --> Ammeter (-ve) --> Board (AIN+) and Board(AIN-) --> Function Generator(-ve). The current we measured in Ammeter is 4.3uAmps.
We request you to look into this and share us your views as early as possible.
Regards,
Purvi
