ADS1293 Single channel configuration issue

lakshmikanth satyavolu

Other Parts Discussed in Thread: ADS1293, ADS1298

Hi,

I am using ADS1293 for my heartrate application. I configured ADS1293 for 3-channels, it is working perfectly.

I want to test single channel application with no RL drive. But I don't see any signal on channel except some 50Hz Noise.

I modified my hardware as mentioned in ADS1298 datasheet as shown below.

I am using 0.1uF for Cblock, and 4.7MOhm for Rpull-up, which results in 0.34Hz cutoff frequency.

My ADS1293 register settings are like this.

IN1 - RA

IN2 - LA

SELRD = 00

PACE2RLD = RLDREF

Can some guide me where I am going wrong?

Regards

Lakshmikanth.

over 8 years ago

0 lakshmikanth satyavolu over 8 years ago

Expert 1670 points

Hello,

Can someone please look into it?

Regards

Lakshmikanth

0 Vishy Viswanathan over 8 years ago in reply to lakshmikanth satyavolu

TI__Mastermind 21685 points

Lakshmikanth,
Is this with ADS1298 or ADS1293? You refer to ADS1298 data sheet so the confusion
Thanks,
Vishy

0 lakshmikanth satyavolu over 8 years ago in reply to Vishy Viswanathan

Expert 1670 points

Hello Vishy,

We are using ADS1293, as the ads1293 datasheet doesn't mention any application circuit for single channel, we follow the schematic provided in ADS1298.
Please guide us how to configure ADS1293 hardware for single channel.

Regards
Lakshmikanth.

0 Vishy Viswanathan over 8 years ago in reply to lakshmikanth satyavolu

TI__Mastermind 21685 points

Lakshmikanth,

I am trying to get you help on this. Please refer to this post

e2e.ti.com/.../1448545

Thanks,
Vishy

0 lakshmikanth satyavolu over 8 years ago in reply to Vishy Viswanathan

Expert 1670 points

Hello Vishy,

Thanks for referring the post. I tried what was said in the post you suggested, by connecting RLD output to one of my input channels. I am seeing flat line in graph. No ECG/NOISE is being shown. I am using simulator for my connections.

Regards
Lakshmikanth.

0 Vishy Viswanathan over 8 years ago in reply to lakshmikanth satyavolu

TI__Mastermind 21685 points

Lakshmikanth,

Here's a presentation that provides more information on this topic.

Thanks,

Vishy

ADS1293 usage.pptx

0 lakshmikanth satyavolu over 8 years ago in reply to Vishy Viswanathan

Expert 1670 points

Hello Vishy,

Thanks for referring the presentation. It was very useful. After going through the presentation, We decided to use the solution recommended in the PPT which is to use External MUX with input protection resistors.

Below is our current configuration which is being used for 3 channel with internal MUX.

For single channel configuration, we want to use either LA or RA to be connected to the RLDOUT. Is it possible to not use the external MUX and connect RLDOUT directly to LA or RA??

Regards

Lakshmikanth.

0 lakshmikanth satyavolu over 8 years ago in reply to lakshmikanth satyavolu

Expert 1670 points

Hello Vishy,

Can you please look into this?

Regards
Lakshmi

0 Vishy Viswanathan over 8 years ago in reply to lakshmikanth satyavolu

TI__Mastermind 21685 points

Lakshmikanth,
I talked to our expert. It is ok to connect but the performance would be better with an external mux.
thanks,
Vishy

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ADS1293 Single channel configuration issue