• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 46 subscribers
  • Views 593 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

TLA2021: Front End for TLA2021

TLA2021: May TLA2021 can support 0~20V analog input, 12 bit resolution A/D?

Chen Bogey8
Mastermind 9990 points
Part Number: TLA2021

Hi Sir 

May TLA2021 can support 0~20V analog input, 12 bit resolution A/D?(i check web, there seems Vp-p all under 5V)

or we have this kind application?

                                               Bogey

  • 0
    TI__Guru* 97825 points
    Chen,


    You are correct that most of our ADCs are limited in the input voltage. If you look at the TLA2021 Absolute Maximum Ratings table on page 4 of the datasheet, the analog input voltage is limited to VDD+0.3V. This means that at 5V supply, the maximum input voltage is 5.3V.

    To measure a 20V input signal, most will use a resistor voltage divider. Using a 10:1 ratio, 20V becomes 2V, and this matches the ±2.048V full scale range. Note that many of our precision ADCs are bipolar inputs, measuring AINP-AINN, so that 00 to 2V becomes 11-bits of measurement from 000h to 7FFh.


    Joseph Wu