ADC Data Acquisition rate on OMAPL138

RAJU CM

Other Parts Discussed in Thread: OMAPL138

Hi Sir/Madam,

1) In our project we are using Few environmental sensors like Gas , Temperature and Humidity Sensors to acquire analog data which operates below 20khz range, But the ADC chip available on the Logic PD EVMOMAPL138 board has ADS901E which operates in the range of 73.2421875KHz to 1.171875MHz.

So kindly suggest the steps need to be followed to acquire the data below 20Khz range.

2) In ADS901E Chip the capacitor (0.1uf) is connected in series to pin no 27 as an Analog input but the problem is the capacitor which is connected in series will block the voltage and doesn't allow the Signal to pass through.

So Kindly suggest the ADC compatible with OMAPL138 that is capable of handling data below 20Khz.

over 11 years ago

0 Sivaraj Kuppuraj over 11 years ago

TI__Mastermind 35645 points

Hi Raju,

Thanks for your post.

I think, you shall check for TI’s precision SAR and delta-sigma ADCs operate at sampling rates < 10MSPS with 12-bit to 24-bit resolution. Here is the sorted list of products as below:

http://www.ti.com/lsds/ti/data-converters/precision-adc-less-10msps-products.page#p1089=3;40000

You shall also check for the application notes below inorder to select analog to digital converter & its performance specifications:

http://www.ti.com/lit/an/slaa407/slaa407.pdf

http://www.ti.com/lit/an/sbaa147b/sbaa147b.pdf

http://www.ti.com/lit/an/slaa416a/slaa416a.pdf

If you still need help on this, i shall move this post to data converter forum based on your need to get better response.

Thanks & regards,

Sivaraj K

-------------------------------------------------------------------------------------------------------

Please click the Verify Answer button on this post if it answers your question.
--------------------------------------------------------------------------------------------------------

0 RAJU CM over 11 years ago in reply to Sivaraj Kuppuraj

Prodigy 40 points

Hi Sir / Madam,

Is there any other method to receive the Analog data from various sensors to EVM OMAP L138 board..?

We have currently tried giving a 1khz sine wave with 2.3Vp-p , but the acquired data denoted a clipping circuit output, and the circuit provided with LOGIC PD EVMOMAPL138 had used ADS901E, it recognized the given input as a noise and sampled it.

So kindly suggest the method to get ADC output for <400kHz through uPP or some other means.

Regards,

Raju CM

We hachecked the above links

0 Sivaraj Kuppuraj over 11 years ago in reply to RAJU CM

TI__Mastermind 35645 points

Hi Raju,

I am moving your post to Data converters forum for appropriate response.

Thanks & regards,

Sivaraj K

Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

Data converters

Data converters forum

ADC Data Acquisition rate on OMAPL138