ADS124S08: Multiple analog type for every channel

mansur hidayat

Part Number: ADS124S08
Other Parts Discussed in Thread: , TMUX1119, TMUX1108, TMUX1109, TMUX1111

Dear Texas Instrument,

i want to design the analog input base on ADS124S08. we want to configure every channel can be select for RTD (2,3,4 wire), TC (all type), mA (0-20 or 4-20), and voltage (0-10V or 1-5V) analog input.

can you advice me to design this system?

Regards

Mansur. H

over 5 years ago

0 Bob Benjamin over 5 years ago

TI__Guru** 112765 points

Hi Mansur,

I would suggest taking a look at 3 documents.

A Basic Guide to RTD Measurements

A Basic Guide to Thermocouple Measurements

ADS124S08EVM User's Guide

The EVM user's guide gives some various input examples and what it might look like. Making any input channel configurable to any sensor or input type is the trick. Usually this will require jumpers or switches and muxes.

Best regards,

Bob B

0 mansur hidayat over 5 years ago in reply to Bob Benjamin

Prodigy 170 points

Hi Bob,

thanks for reply,

i'm Already read all above documents, i see at ADS124S08EVM User's Guide every sensor type (analog type) is different channel.

I mean, we can configure or change the type of analog input using a digital switch ( some time for ch1 we need for RTD or TC or mA).

0 mansur hidayat over 5 years ago in reply to mansur hidayat

Prodigy 170 points

Bob,
Can yo give me sampe for siwtch or Mux xhip (TI product) that match with ads124s08.

Thanks

0 Bob Benjamin over 5 years ago in reply to mansur hidayat

TI__Guru** 112765 points

Hi Mansur,

Some considerations are leakage current, crosstalk, on-resistance and charge injection. There are many good MUXes and switches for crosstalk and low on-resistance, but finding one that is low leakage is very important to keep error to a minimum.

I have not tried these devices yet as they are relatively new to TI, but one example is the TMUX1108 which is an 8:1 MUX. This device can be used with either unipolar or bipolar supply. There is also the TMUX1109 which is a 2-channel 4:1 MUX. There is also the TMUX1119 2:1 MUX that operates unipolar supply only.

For switches there is the TMUX1111 family of devices. These are not fully released to production yet, but samples are available.

Best regards,
Bob B

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ADS124S08: Multiple analog type for every channel