MSP430I2040: External source resistance value of SD24 of MSP430i2040

Hi Da,

Thanks for your detailed post.

da said:

In the case of MSP430F47187, settling time tsettling is specified by parameters such as
external input resistor RS, sampling capacitor CS, etc. as shown on page 320 of
MSP430x4xx Family User's Guide (slau056l). (Only when the built-in buffer is turned OFF)

In case of MSP430I2040, MSP430i2xx Family User's Guide (slau335) does not have the above 
description and the upper limit value of the external input resistance Rs can not be obtained.

Can you teach "the upper limit of Rs" or "technical materials that can calculate it"?
※ MSP430I2040 has no built-in buffer, so we need to calculate.

The MSP430F47187 uses a switched-capacitor input stage which indicates that this module is a discrete-time sigma-delta ADC. However, the MSP430i2041 is a continuous-time sigma-delta ADC (as discussed here) which doesn’t present a switching load to the input driver. This relaxes the bandwidth specifications on the driver and also is why the description for F47187 isn't included or necessary for the i2041. You can learn more about these types of ADCs by reading the following articles.

What’s The Difference Between Continuous-Time And Discrete-Time Delta-Sigma ADCs?

Continuous-Time Sigma-Delta ADCs

Regards,

James