MSP430F2003: 16-bits sigma-delta ADC for PT100 measurements

Sadashiva Kamath

Expert 1135 points

Part Number: MSP430F2003

Hi,

I'm exploring to use MCU's internal ADC (16-bits sigma-delta) for PT100 temperature measurements.

Looking for temperature accuracy of around 0.2degC.

Questions:

1) Can you share any reference design for PT100 measurements using MCU's internal ADC?

2) Is MSP430 variant available with digital filters for sigma delta modulator (DFSDM)? DFSDM can be used for MCU's internal16-bits sigma-delta ADC?

3) Temperature accuracy of around 0.2degC can be achieved with MCU's internal16-bits sigma-delta ADC (with DFSDM)?

over 2 years ago

0 Jace H over 2 years ago

TI__Guru 56685 points

Hello,

Please see the following application note to help you in designing with MSP430's integrated sigma-delta portfolio.

Answers to Common Sigma-Delta ADC Questions on MSP MCUs

This should help you get an overview on our devices containing sigma-delta ADCs as well as design guidelines.

As for reference designs involving PT00, I'm not aware of any from the MSP430 perspective; however, I did find the following application note that could be relevant to your situation: A Basic Guide to RT Measurements

Hope this helps!

0 Sadashiva Kamath over 2 years ago in reply to Jace H

Expert 1135 points

Thanks for response,

Do you have details for 2nd question?

2) Is MSP430 variant available with digital filters for sigma delta modulator (DFSDM)? DFSDM can be used for MCU's internal16-bits sigma-delta ADC?

+1 Jace H over 2 years ago in reply to Sadashiva Kamath

TI__Guru 56685 points

Hello Sadashiva,

I'm unfamiliar with DFSDM, but if you are asking if we have additional digital filtering hardware modules in our sigma-delta capable MSP430 devices, then no we do not. Our sigma deltas do have integrated SINC/CIC filters associated with the ADC, as they are needed for those peripherals to work. Additional digital filtering would need to be done with SW.

0 David Schultz over 2 years ago in reply to Sadashiva Kamath

Guru 18815 points

Every delta sigma ADC has a digital low pass filter. If you need something other than the SINC^2 response, you will have to design a digital filter for the ADC output.

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MSP430F2003: 16-bits sigma-delta ADC for PT100 measurements