Data pattern from AFE4400

Nazrul Khan

Other Parts Discussed in Thread: AFE4400

Hello,

I am collecting data samples from the AFE4400 to construct PPG signal. I am using PRF of 500HZ. That is, I am receiving samples at 2ms interval. When, I go through the collected samples, I can see there is a pattern, which is my concern. The first few samples(say around 15) shows a increasing trend and after that the adc count values shows a constant decreasing trend, it doesn't matter how many samples, I collect. Is it normal? My expectation was, after going down, the count values should go up again to show the next cycle of the PPG signal. Also, I want to know, what are the nominal number of samples for one cycle of the PPG signal. Any thoughts, please. Regards.

Nazrul

over 9 years ago

0 Praveen Aroul over 9 years ago

TI__Mastermind 49986 points

Hi Nazrul,

We have received your inquiry about the AFE4400 device and hope to have some answers back to you shortly.

0 Nazrul Khan over 9 years ago

Prodigy 230 points

Hello Praveen,
I am still waiting for the answer. Regards.

Nazrul

0 Praveen Aroul over 9 years ago

TI__Mastermind 49986 points

Hi Nazrul,

The issue could with data setup or data collection or with the transmission.
To debug the issue, it would help if you can post the register settings and the waveforms.

The nominal number of samples for 1 cycle of PPG would depend on the heart rate of the user.
For example, at 72 BPM, the typical number of samples per PPG cycle at 500Hz PRF would be 417.

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Data pattern from AFE4400