ADS1262: Application issue.

Hi Reed,

There are a lot of questions here, but many of the answers depend on your system. Therefore I can give some general guidelines:

Reed said:

. Is external crystal oscillator or internal crystal oscillator recommended by ADC?

The ADS1262 supports both options. The internal oscillator is sufficient for most systems, but if you want tighter control of the ADC data rates, or you want to change the ADC data rates, then an external clock would be necessary. I would recommend the internal oscillator in general

Reed said:

Is an external or internal reference source recommended for ADC?

This depends on the application. You can review this video #6.11 for more info on different reference sources: https://training.ti.com/ti-precision-labs-adcs 

Reed said:

Is isolation recommended for ADC and single-board communication?

Again, this depends on your application. I think you will need to determine if isolation is required in your system, that is not something we can just tell you is or is not required

Reed said:

PT1000, PT100 and thermocouple, how to determine the excitation current?

We have documents related to RTDs and thermocouples that you should read before designing these systems

RTD: https://www.ti.com/lit/pdf/sbaa275

Thermocouple: https://www.ti.com/lit/pdf/sbaa274

Reed said:

How to reduce noise on hardware?

There are many ways to reduce noise. You can review this videos on "ADC noise" for more information: https://training.ti.com/ti-precision-labs-adcs 

Reed said:

Whether and how to calibrate ADC?

You should perform an error analysis of your system to determine the theoretical total error. If the total error is greater than your system error budget, you either need to get higher accuracy devices, or you need to calibrate 

Calibration is discussed in section 9.4.9 of the datasheet

Reed said:

How to select filtering mode?

See section 9.3.10 in the datasheet for the different filter modes. Also see the MODE1 and MODE2 registers for selecting the filter mode and data rate

Reed said:

What does IDAC remote mode do?

I don't know what an "IDAC remote" is. The IDACs are described in section 9.3.11 of the ADS1262 datasheet

Reed said:

What is the impact of different programmable conversion delay configurations?

Programmable delay time is described in section 9.4.3 in the datasheet. You can also read our application note on conversion latency that discussed programmable delay time in more detail (section 5.3): https://www.ti.com/lit/pdf/sbaa535

Reed said:

There are two modes of ADC1 acquisition. What are the differences between them? (ADS1262)

The control modes are described in section 9.4.1 in the datasheet

Reed said:

How long can ADC start to collect data after power-on? What is the recommended value of this time?

The power-on reset behavior of the ADC is described in section 9.4.10.1. Both of your questions are answered in this section

-Bryan