ADS124S08: How many RTD can be handled by 1 ADC

Hiromu Susami

Part Number: ADS124S08

Tool/software:

Hi exparts,

In this application note, maximam 4 RTD are connected to ADC. How many RTD can be handled by 1 ADC without MUX like previous E2E thread?

Can a single ADC handle 24 RTDs with MUX? If so, what are the disadvantages of using MUX?

Regards,

Hiromu

7 months ago

0 Bryan Lizon86 7 months ago

TI__Guru 52936 points

Hi Hiromu Susami,

Can you please respond to my question in the Notes section of the Thread Tracking Toolkit?

-Bryan

0 Hiromu Susami 7 months ago in reply to Bryan Lizon86

TI__Prodigy 670 points

Hi Bryan,

I answered it.

Regards,

Hiromu

+1 Bryan Lizon86 7 months ago in reply to Hiromu Susami

TI__Guru 52936 points

Hi Hiromu Susami,

That depends on the type of RTDs you want to measure: 2-wire, 3-wire, or 4-wire. In general you can measure 4x 4-wire RTDs, 3x 3-wire RTDs (using 2x IDACs per RTD), and 6x 2-wire RTDs using a single ADS124S08

Using a mux you can measure as many RTDs as you want, including 24x. The tradeoff is sampling speed, because now you need to measure 24x sensors using a multiplexed ADC

-Bryan

0 Hiromu Susami 7 months ago in reply to Bryan Lizon86

TI__Prodigy 670 points

Hi Bryan,

Are there something we have to care when we connect multiple RTDs to 1 ADS124S08 (without mux)? Is there some documents to understand that?

Hiromu

+1 Bryan Lizon86 7 months ago in reply to Hiromu Susami

TI__Guru 52936 points

Hi Hiromu Susami,

Please see this video for more information: https://www.ti.com/video/series/precision-labs/ti-precision-labs-analog-to-digital-converters-adcs.html?videoId=6330515556112

There are also 10x other videos in that RTD measurement series if you need more information about RTD measurements

-Bryan

Data converters

Data converters forum

ADS124S08: How many RTD can be handled by 1 ADC