WEBENCH® Tools/ADS1293: ADS1293 - convert raw data to voltage

vix3c

Part Number: ADS1293
Other Parts Discussed in Thread: CC2541, TIDA-00096

Tool/software: WEBENCH® Design Tools

I have developed a device based on TIDA-00096, so it's using ADS1293 and CC2541 with originally provided firmware. I'm capturing ECG values and this is what I get (example for 10 samples)

CH1

3934522
3932928
3931926
3932085
3932691
3933327
3933657
3933747
3933807

CH2

3944210
3941278
3936446
3935386
3936599
3937970
3938551
3938669
3938723

CH3

4629821
4630426
4631200
4631951
4631403
4629877
4629098
4628936
4628859

However, I really have to idea how to convert those values to real voltage level? I have searched through forums and datasheet, but haven't found out what those values actually mean.

over 8 years ago

0 Brian Pisani over 8 years ago

TI__Mastermind 38745 points

Hello vix3c,

The conversion formula is Equation 13 on page 36 in the ADS1293 datasheet. The voltages depend on your settings. Please let me know if you have further questions about this.

Regards,

Brian Pisani

0 vix3c over 8 years ago in reply to Brian Pisani

Intellectual 430 points

Hello,

thanks, I have checked out equation in 8.4.3, but I am still struggling with some values. While ADCmax is well defined in the tables and Vref in TIDA-00096 is supposedly 2,4 V, I have no idea what do Vinp and Vinm stand for? What are their values?

0 Brian Pisani over 8 years ago in reply to vix3c

TI__Mastermind 38745 points

Hello Vix3c,

Vinp and Vinm stand for the positive and negative analog input voltages, respectively. To convert the output code to an input voltage, you can solve the formula for (Vinp - Vinm). The result is the voltage at the input for that sample. To observe the ECG signals, plot the voltages with respect to time.

Brian

Data converters

Data converters forum

WEBENCH® Tools/ADS1293: ADS1293 - convert raw data to voltage