ADS131A02: Chaining Configuration + Isolation

Martin Seeger

Part Number: ADS131A02
Other Parts Discussed in Thread: ADS127L01

Dear Team,

our customer would like to use 4x A02s but has requirements of isolating every channel .

The A02 chain seems to be different to the daisy-chaining of the E08 devices.

Do I understand correctly tha the A02 chain is only uses the /DONE and /CS pin, so there are no real constraints of using an isolator in between?

(With the E08, I understood that the daisy-chain seems to be a shifting register, so an extra isolation between each device could be more tricky).

Thanks and best regards
Martin

over 8 years ago

0 Tom Hendrick over 8 years ago

TI__Guru**** 183041 points

Hi Martin,

Yes, there are differences between the two daisy chain modes for the A0x and the E0x devices. DONE acts as /CS to the next device, but they all share the same SCLK, DIN, DOUT and DRDY. When you say they need isolation on each channel, is that each analog input channel or each ADS131A02 channel pair?

0 Martin Seeger over 8 years ago in reply to Tom Hendrick

TI__Expert 5411 points

Hi Tom,
thanks for the answer.
Okay, I thought the differences was in the lower channel version vs. the higher channel version.
But if I understood you correctly, the differences are between A0x and E0x? I will dig deeper into that!

Actually the customer needs 4 isolated V-channels, but unfortunately there's no ADS131E01 :) (or even E02?)

Best Regards
Martin

0 Ryan Andrews over 8 years ago in reply to Martin Seeger

TI__Guru 69166 points

Hi Martin,

The ADS127L01 may also be a nice fit for this application if you require channel-to-channel isolation. I'll contact you offline to gather more specific details.

0 Martin Seeger over 8 years ago in reply to Tom Hendrick

TI__Expert 5411 points

Hi Tom,
thanks for the answer and apologies for the late reply.

The customer needs each channel to be isolated (voltage measurement). The intention is to use only one input of the A02, but I am checking some options like isolated amplifiers - however I am afraid that this is more expensive in the overall system cost.

If you have any ideas, please let me know.

Best Regards
Martin

0 Tom Hendrick over 8 years ago in reply to Martin Seeger

TI__Guru**** 183041 points

We'll send along some info on a couple new parts.

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ADS131A02: Chaining Configuration + Isolation