Part Number: ADS7830
Hello,
One question on the ADS7830, used for housekeeping voltage and current telemetry with the internal 2.5 V reference, i.e. 9.77 mV per code.
What does the device return if a conversion is requested while the internal reference is still off — zero, full scale, or a plausible but wrong number? Page 17 states that the internal reference defaults to off, and the command-byte table on page 13 gives PD1/PD0 as the control, with PD1 PD0 = 1 0 selecting internal reference on and A/D converter off. What is not in the datasheet is that case, and it is the one that concerns us: a plausible but wrong number would quietly corrupt telemetry at first power-up, which is exactly when we would be most inclined to trust it.
Two related points:
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Does the PD1/PD0 setting persist between conversions, or must it be re-sent in every command byte?
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What is the settling time from enabling the internal reference to the first accurate conversion, and what decoupling do you recommend at the reference pin?
Where you can, knowing whether an answer is datasheet-specified (with the section) or an application recommendation helps us as much as the answer itself.
This device sits on the critical path of a product we expect to build for the next several years, and we would rather settle the point with your input than design around our own assumptions. Any help you can give is appreciated, and we are happy to take it on a call if that is easier.
With thanks,
Pablo Bolívar López
Lead Hardware Engineer — Quside Technologies
