ADS1299: Piezoelectric sensor aquisition

Mateus Martelini Souza

Part Number: ADS1299
Other Parts Discussed in Thread: ADS1263, TLV2771, TLV6742, OPA337, OPA2625

Hello!

I am working on an application using a piezoelectric sensor (disk). I have tried to use ADS1299 and ADS1263 to acquire the signal from the sensor and it has worked quite well. But the piezoelectric sensor is a high impedance sensor and has some problems in reading low frequency signals, which is my main goal (0.1 to 100 Hz). So, I would like to know if it is possible to use ADS1299 and ADS1263 for this task and which one is better. Is there a better part on the market for this application (amplifier + ADC)? Is there a specific analog front-end designed for this application (piezoelectric sensors)?

Best Regards,

Mateus

over 2 years ago

0 ChienChun Yang over 2 years ago

TI__Mastermind 19815 points

Hi,

Highly appreciate for using TI's products.

This ticket has been received/viewed, and I will get back to you between 3~5 days.

May I ask some more questions to collect more detail info?

Would you provide more info/detail, if possible schematics, pictures or drawings of the test?

Do you have an eval kit/board?

From your description. I am thinking you could put a voltage buffer/follower to bridge the impedance between the piezoelectric sensor and analog front end.

In this way, you could have high input impedance to receive signal from piezoelectric sensor, and then low output impedance to relay/send the same signal from buffer/follower to analog front end. Depends on your application, don't know whether you will need to add an active high or low pass filter.

Appreciate.

0 Mateus Martelini Souza over 2 years ago in reply to ChienChun Yang

Prodigy 60 points

Hi,

The schematic of the test is as simples as shown in the figure below:

I am using a custom board based on the ADS1299 evaluation board. Like I said, the signal that I acquire is quite good, but I would like to know from the experienced engineers of Texas Instruments whether ADS1299 and ADS1263 are suitable chips for this type of application or whether there is a better option.

Also, I am testing a Charge Mode Amplifier as an AFE, since the piezoelectric sensor generates charge. The figure below shows the topology used for the charge amplifier. Is there a product similar to ADS1299 that has a charge mode amplifier integrated?

Thank you!

0 ChienChun Yang over 2 years ago in reply to Mateus Martelini Souza

TI__Mastermind 19815 points

Hi,

I have not used a charge amplifier. Is it same as Transimpedance Amplifier ?

Would you mind describing/explaining a bit more about your circuit and application? When you say piezoelectric generates charges, does it have current flow?

Let me understand more correctly, are you looking for ADC with built-in Charge Amplifier?

While searching online, I found the following info and resources; wondering if it could help -

https://www.ti.com/lit/an/sloa033a/sloa033a.pdf

https://www.ti.com/lit/an/sboa287/sboa287.pdf?ts=1649360981477&ref_url=https%253A%252F%252Fwww.google.com%252F

https://www.ti.com/lit/an/slyt369/slyt369.pdf

https://www.ti.com/lit/ds/symlink/opa2625.pdf?HQS=dis-dk-null-digikeymode-dsf-pf-null-wwe&ts=1649361488074&ref_url=https%253A%252F%252Fwww.ti.com%252Fgeneral%252Fdocs%252Fsuppproductinfo.tsp%253FdistId%253D10%2526gotoUrl%253Dhttps%253A%252F%252Fwww.ti.com%252Flit%252Fgpn%252Fopa2625

TLV2771

TLV6742

OPA337

OPA2625

One alternative method you could try is to add a Single-End to Differential End amplifier, so you will have differential outputs to feed into the differential input ADC.

Or, May you know if your applications belong to any of the following fields? This way may help you easier to find the ADC you need -

www.ti.com/.../products.html

Biosensing AFEs

CCD/CIS imaging AFEs

Computer tomography (CT) AFEs

Digital X-ray AFEs

Integrated precision ADCs & DACs

Touch screen controllers

Ultrasound AFEs

Data converters

Data converters forum

ADS1299: Piezoelectric sensor aquisition