ADS7952: ADS7952 REFP and ANALOG INPUT Rise Time Sequence

Hiroyuki Itoh

Part Number: ADS7952

Please allow me to confirm the startup sequence for the ADS7952.
We are supplying 5V to +VA and 3.3V to +VBD. REFP is supplied with 2.5V.
We have confirmed on the E2E FORUM that there is no sequence for +VA and +VBD.

What we want to confirm is the rise sequence of the voltage applied to REFP and the ANALOG Input.
Are there any constraints on the voltage rise sequence for REFP and the analog input voltage?

The part number of the device we are using is ADS7952 B TI 01K CXZP.

Of course, at the point when xCS transitions from H to L and inputs the configuration information from SDI to the ADS7952, REFP has definitely risen to 2.5V.

6 months ago

0 Joel Meraz 6 months ago

TI__Mastermind 21460 points

Hello,

Yes, you are correct in that +VA and +VBD can be provided independently.

On the topic of the sequencing of the analog inputs and reference, the +VA supply should be applied before voltage is present on the REFP and analog input pins. There are ESD diodes which risk becoming damaged if the voltage on the analog input or reference pins exceed +VA.

Regards,
Joel

0 Hiroyuki Itoh 6 months ago in reply to Joel Meraz

Prodigy 10 points

Hello,
Thank you for your comment. We are adhering to the information you provided.
We wanted to confirm the relationship between the REFP and the analog input pins, but we will provide our startup waveform later. Sorry it's taking a little time.

0 Joel Meraz 6 months ago in reply to Hiroyuki Itoh

TI__Mastermind 21460 points

Hi Itoh-san,

No problem. Please update the thread when the data is available.

Regards,
Joel

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ADS7952: ADS7952 REFP and ANALOG INPUT Rise Time Sequence