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PaxInstruments / t400-electronics

Electronics for the Pax Instruments T400 temperature datalogger
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Properly ground isothermal plane #59

Closed charlespax closed 9 years ago

charlespax commented 10 years ago

Review the grounding on the isothermal plane. The thermocouple filtration links to it.

charlespax commented 10 years ago

Connecting the filtration to the isothermal plane and connecting the isothermal plane to GND via a 1k resistor should be fine.

charlespax commented 9 years ago

Should we connect GND and the isothermal place via an inductor like the T100? Right now we're using a 1k resistor.

samchoy88 commented 9 years ago

The PCB design should have better planning and avoid noise affecting ADC. It may require to place the regulator in better position. image

Reference: http://www.silabs.com/Support%20Documents/TechnicalDocs/an203.pdf

charlespax commented 9 years ago

In addition to regulator placement should be be isolating GND and ISOTHERMAL with a resistor, inductor, both, something else, or nothing at all?

samchoy88 commented 9 years ago

It seem the Analog ground and Digital ground connected by 0 Ohm resistor. But the resistor should place nearby Power supply and close to device with mixed signal.

charlespax commented 9 years ago

These two issues are not pretty much the same https://github.com/PaxInstruments/t400-electronics/issues/123.

charlespax commented 9 years ago

Done. Closing issue.