Tool/software:
Hi expert,
We found in AMC1306 EVM, there's an 0ohm R3 shorted to AGND from AINN, what's the function? Why need this?
Many thanks!
Joyce
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Tool/software:
Hi expert,
We found in AMC1306 EVM, there's an 0ohm R3 shorted to AGND from AINN, what's the function? Why need this?
Many thanks!
Joyce
Hi Joyce,
This is to establish the common-mode input voltage. One of the inputs must be tied to ground to do this.
Best regards,
Eva
Hi Eva,
Why don't directly connect to GND but add a 0R resistor like this?
Joyce
Hi Joyce,
This gives users the option to not connect to ground if there's an application where that is necessary.
Who is your customer and what is their application?
Best regards,
Eva
Eva,
Customer is INFO CONVERGENCE with servo drives end use. They met similar issue with this e2e post((+) AMC1306M25: The Current sampling is not accurate of AMC1306M25. - Data converters forum - Data converters - TI E2E support forums). It's similar that if they use 0R resistor, noise will be huge, but if change to 1R resistor, noise will be gone. Customer wonders why should add the 0R resistor shorted to GND and why 0R resistor leads to noise.
Joyce
Hi Joyce,
The 0 Ohm resistor should not be a source of noise. It's probably a layout concern. I can take a look if that would be helpful. The resistor is not a requirement, so if removing it from their system or using a different resistor leads to better results, that is suggestable too.
Best regards,
Eva