SLAA694A February   2016  – April 2016 MSP430BT5190 , MSP430BT5190 , MSP430F1122 , MSP430F1122 , MSP430F1132 , MSP430F1132 , MSP430F1222 , MSP430F1222 , MSP430F1232 , MSP430F1232 , MSP430F133 , MSP430F133 , MSP430F135 , MSP430F135 , MSP430F147 , MSP430F147 , MSP430F148 , MSP430F148 , MSP430F149 , MSP430F149 , MSP430F155 , MSP430F155 , MSP430F156 , MSP430F156 , MSP430F157 , MSP430F157 , MSP430F1610 , MSP430F1610 , MSP430F1611 , MSP430F1611 , MSP430F1612 , MSP430F1612 , MSP430F167 , MSP430F167 , MSP430F168 , MSP430F168 , MSP430F169 , MSP430F169 , MSP430F2002 , MSP430F2002 , MSP430F2012 , MSP430F2012 , MSP430F2112 , MSP430F2112 , MSP430F2122 , MSP430F2122 , MSP430F2132 , MSP430F2132 , MSP430F2232 , MSP430F2232 , MSP430F2234 , MSP430F2234 , MSP430F2252 , MSP430F2252 , MSP430F2254 , MSP430F2254 , MSP430F2272 , MSP430F2272 , MSP430F2274 , MSP430F2274 , MSP430F2274-EP , MSP430F2274-EP , MSP430F233 , MSP430F233 , MSP430F235 , MSP430F235 , MSP430F2410 , MSP430F2410 , MSP430F2416 , MSP430F2416 , MSP430F2417 , MSP430F2417 , MSP430F2418 , MSP430F2418 , MSP430F2419 , MSP430F2419 , MSP430F247 , MSP430F247 , MSP430F248 , MSP430F248 , MSP430F249 , MSP430F249 , MSP430F249-EP , MSP430F249-EP , MSP430F2616 , MSP430F2616 , MSP430F2617 , MSP430F2617 , MSP430F2618 , MSP430F2618 , MSP430F2619 , MSP430F2619 , MSP430F2619S-HT , MSP430F2619S-HT , MSP430F4132 , MSP430F4132 , MSP430F4152 , MSP430F4152 , MSP430F435 , MSP430F435 , MSP430F436 , MSP430F436 , MSP430F437 , MSP430F437 , MSP430F438 , MSP430F438 , MSP430F439 , MSP430F439 , MSP430F447 , MSP430F447 , MSP430F448 , MSP430F448 , MSP430F449 , MSP430F449 , MSP430F4616 , MSP430F4616 , MSP430F4617 , MSP430F4617 , MSP430F4618 , MSP430F4618 , MSP430F4619 , MSP430F4619 , MSP430F5132 , MSP430F5132 , MSP430F5152 , MSP430F5152 , MSP430F5172 , MSP430F5172 , MSP430F5222 , MSP430F5222 , MSP430F5224 , MSP430F5224 , MSP430F5229 , MSP430F5229 , MSP430F5242 , MSP430F5242 , MSP430F5244 , MSP430F5244 , MSP430F5247 , MSP430F5247 , MSP430F5249 , MSP430F5249 , MSP430F5253 , MSP430F5253 , MSP430F5255 , MSP430F5255 , MSP430F5257 , MSP430F5257 , MSP430F5259 , MSP430F5259 , MSP430F5304 , MSP430F5304 , MSP430F5308 , MSP430F5308 , MSP430F5309 , MSP430F5309 , MSP430F5310 , MSP430F5310 , MSP430F5324 , MSP430F5324 , MSP430F5325 , MSP430F5325 , MSP430F5326 , MSP430F5326 , MSP430F5327 , MSP430F5327 , MSP430F5328 , MSP430F5328 , MSP430F5328-EP , MSP430F5328-EP , MSP430F5329 , MSP430F5329 , MSP430F5333 , MSP430F5333 , MSP430F5335 , MSP430F5335 , MSP430F5336 , MSP430F5336 , MSP430F5338 , MSP430F5338 , MSP430F5340 , MSP430F5340 , MSP430F5341 , MSP430F5341 , MSP430F5342 , MSP430F5342 , MSP430F5358 , MSP430F5358 , MSP430F5359 , MSP430F5359 , MSP430F5418A , MSP430F5418A , MSP430F5419A , MSP430F5419A , MSP430F5435A , MSP430F5435A , MSP430F5436A , MSP430F5436A , MSP430F5437A , MSP430F5437A , MSP430F5438A , MSP430F5438A , MSP430F5438A-EP , MSP430F5438A-EP , MSP430F5504 , MSP430F5504 , MSP430F5505 , MSP430F5505 , MSP430F5506 , MSP430F5506 , MSP430F5507 , MSP430F5507 , MSP430F5508 , MSP430F5508 , MSP430F5509 , MSP430F5509 , MSP430F5510 , MSP430F5510 , MSP430F5521 , MSP430F5521 , MSP430F5522 , MSP430F5522 , MSP430F5524 , MSP430F5524 , MSP430F5525 , MSP430F5525 , MSP430F5526 , MSP430F5526 , MSP430F5527 , MSP430F5527 , MSP430F5528 , MSP430F5528 , MSP430F5529 , MSP430F5529 , MSP430F5633 , MSP430F5633 , MSP430F5634 , MSP430F5634 , MSP430F5635 , MSP430F5635 , MSP430F5636 , MSP430F5636 , MSP430F5637 , MSP430F5637 , MSP430F5638 , MSP430F5638 , MSP430F5658 , MSP430F5658 , MSP430F5659 , MSP430F5659 , MSP430F6433 , MSP430F6433 , MSP430F6435 , MSP430F6435 , MSP430F6436 , MSP430F6436 , MSP430F6438 , MSP430F6438 , MSP430F6458 , MSP430F6458 , MSP430F6459 , MSP430F6459 , MSP430F6633 , MSP430F6633 , MSP430F6634 , MSP430F6634 , MSP430F6635 , MSP430F6635 , MSP430F6636 , MSP430F6636 , MSP430F6637 , MSP430F6637 , MSP430F6638 , MSP430F6638 , MSP430F6658 , MSP430F6658 , MSP430F6659 , MSP430F6659 , MSP430F67621 , MSP430F67621 , MSP430F67621A , MSP430F67621A , MSP430F67641 , MSP430F67641 , MSP430F6766A , MSP430F6766A , MSP430F6776 , MSP430F6776 , MSP430F6777 , MSP430F6777 , MSP430F6778 , MSP430F6778 , MSP430F6779 , MSP430F6779 , MSP430FG437 , MSP430FG437 , MSP430FG438 , MSP430FG438 , MSP430FG439 , MSP430FG439 , MSP430FG4616 , MSP430FG4616 , MSP430FG4617 , MSP430FG4617 , MSP430FG4618 , MSP430FG4618 , MSP430FG4619 , MSP430FG4619 , MSP430FR2032 , MSP430FR2032 , MSP430FR2033 , MSP430FR2033 , MSP430FR2311 , MSP430FR2311 , MSP430FR2433 , MSP430FR2433 , MSP430FR2532 , MSP430FR2532 , MSP430FR2533 , MSP430FR2533 , MSP430FR2632 , MSP430FR2632 , MSP430FR2633 , MSP430FR2633 , MSP430FR4131 , MSP430FR4131 , MSP430FR4132 , MSP430FR4132 , MSP430FR4133 , MSP430FR4133 , MSP430FR5720 , MSP430FR5720 , MSP430FR5721 , MSP430FR5721 , MSP430FR5724 , MSP430FR5724 , MSP430FR5725 , MSP430FR5725 , MSP430FR5728 , MSP430FR5728 , MSP430FR5729 , MSP430FR5729 , MSP430FR5730 , MSP430FR5730 , MSP430FR5731 , MSP430FR5731 , MSP430FR5734 , MSP430FR5734 , MSP430FR5735 , MSP430FR5735 , MSP430FR5738 , MSP430FR5738 , MSP430FR5739 , MSP430FR5739 , MSP430FR5739-EP , MSP430FR5739-EP , MSP430FR5847 , MSP430FR5847 , MSP430FR58471 , MSP430FR58471 , MSP430FR5848 , MSP430FR5848 , MSP430FR5849 , MSP430FR5849 , MSP430FR5857 , MSP430FR5857 , MSP430FR5858 , MSP430FR5858 , MSP430FR5859 , MSP430FR5859 , MSP430FR5867 , MSP430FR5867 , MSP430FR58671 , MSP430FR58671 , MSP430FR5868 , MSP430FR5868 , MSP430FR5869 , MSP430FR5869 , MSP430FR5870 , MSP430FR5870 , MSP430FR5872 , MSP430FR5872 , MSP430FR58721 , MSP430FR58721 , MSP430FR5887 , MSP430FR5887 , MSP430FR5888 , MSP430FR5888 , MSP430FR5889 , MSP430FR5889 , MSP430FR58891 , MSP430FR58891 , MSP430FR5922 , MSP430FR5922 , MSP430FR59221 , MSP430FR59221 , MSP430FR5947 , MSP430FR5947 , MSP430FR59471 , MSP430FR59471 , MSP430FR5948 , MSP430FR5948 , MSP430FR5949 , MSP430FR5949 , MSP430FR5957 , MSP430FR5957 , MSP430FR5958 , MSP430FR5958 , MSP430FR5959 , MSP430FR5959 , MSP430FR5967 , MSP430FR5967 , MSP430FR5968 , MSP430FR5968 , MSP430FR5969 , MSP430FR5969 , MSP430FR5969-SP , MSP430FR5969-SP , MSP430FR59691 , MSP430FR59691 , MSP430FR5970 , MSP430FR5970 , MSP430FR5972 , MSP430FR5972 , MSP430FR59721 , MSP430FR59721 , MSP430FR5986 , MSP430FR5986 , MSP430FR5987 , MSP430FR5987 , MSP430FR5988 , MSP430FR5988 , MSP430FR5989 , MSP430FR5989 , MSP430FR5989-EP , MSP430FR5989-EP , MSP430FR59891 , MSP430FR59891 , MSP430FR5994 , MSP430FR5994 , MSP430FR6820 , MSP430FR6820 , MSP430FR6822 , MSP430FR6822 , MSP430FR68221 , MSP430FR68221 , MSP430FR6870 , MSP430FR6870 , MSP430FR6872 , MSP430FR6872 , MSP430FR68721 , MSP430FR68721 , MSP430FR6877 , MSP430FR6877 , MSP430FR6879 , MSP430FR6879 , MSP430FR68791 , MSP430FR68791 , MSP430FR6887 , MSP430FR6887 , MSP430FR6888 , MSP430FR6888 , MSP430FR6889 , MSP430FR6889 , MSP430FR6920 , MSP430FR6920 , MSP430FR6922 , MSP430FR6922 , MSP430FR69221 , MSP430FR69221 , MSP430FR6927 , MSP430FR6927 , MSP430FR6928 , MSP430FR6928 , MSP430FR6970 , MSP430FR6970 , MSP430FR6972 , MSP430FR6972 , MSP430FR69721 , MSP430FR69721 , MSP430FR6977 , MSP430FR6977 , MSP430FR6979 , MSP430FR6979 , MSP430FR69791 , MSP430FR69791 , MSP430FR6987 , MSP430FR6987 , MSP430FR6988 , MSP430FR6988 , MSP430FR6989 , MSP430FR6989 , MSP430FR69891 , MSP430FR69891 , MSP430G2131 , MSP430G2131 , MSP430G2132 , MSP430G2132 , MSP430G2152 , MSP430G2152 , MSP430G2153 , MSP430G2153 , MSP430G2230 , MSP430G2230 , MSP430G2230-EP , MSP430G2230-EP , MSP430G2231 , MSP430G2231 , MSP430G2231-EP , MSP430G2231-EP , MSP430G2232 , MSP430G2232 , MSP430G2233 , MSP430G2233 , MSP430G2252 , MSP430G2252 , MSP430G2253 , MSP430G2253 , MSP430G2332 , MSP430G2332 , MSP430G2332-EP , MSP430G2332-EP , MSP430G2333 , MSP430G2333 , MSP430G2352 , MSP430G2352 , MSP430G2353 , MSP430G2353 , MSP430G2432 , MSP430G2432 , MSP430G2433 , MSP430G2433 , MSP430G2444 , MSP430G2444 , MSP430G2452 , MSP430G2452 , MSP430G2453 , MSP430G2453 , MSP430G2513 , MSP430G2513 , MSP430G2533 , MSP430G2533 , MSP430G2544 , MSP430G2544 , MSP430G2553 , MSP430G2553 , MSP430G2744 , MSP430G2744 , MSP430G2755 , MSP430G2755 , MSP430G2855 , MSP430G2855 , MSP430G2955 , MSP430G2955 , MSP430TCH5E , MSP430TCH5E

 

  1.   General Oversampling of MSP ADCs for Higher Resolution
    1.     Trademarks
    2. 1 Introduction
    3. 2 Oversampling Process
      1. 2.1 ADC Operation
      2. 2.2 Improving ADC Resolution
    4. 3 Hardware Description
      1. 3.1 DAC8560EVM
      2. 3.2 MSP-EXP430FR4133 and MSP-EXP432P401R Connections
    5. 4 Firmware Overview
      1. 4.1 Setting Constants
      2. 4.2 Running the Demonstration
      3. 4.3 Oversampling Method Extraction
    6. 5 Results
      1. 5.1 MSP-EXP430FR4133 and DAC8560 Oversampling
      2. 5.2 Silicon Results of Oversampling and Decimation on MSP432P401R
    7. 6 Conclusion
    8. 7 References
  2.   Revision History

2.1 ADC Operation

N-bit ADCs have 2N number of steps that can be used across a large input range to measure small changes in a parameter. The input range itself depends on the minimum and maximum references selected, VR- and VR+, which are determined by the MSP ADC registers. The expected resolution, ADCRES, can therefore be calculated as shown in Equation 1:

Equation 1. eq1_adcres_vr.gif

For analog waveforms that are being reconstructed from the digital samples taken using such a conversion, the SNR is the ratio in dB of the full-scale analog input root mean squared (RMS) value to the RMS quantization error. Increasing the resolution increases the SNR and vice versa, where the theoretical limit of the ADC SNR comes from quantization error inherent to the conversion process. The SNR for an ideal ADC driven with a sine wave whose dynamic range eclipses the full range of VR- to VR+ is found using Equation 2:

Equation 2. eq2_snrdb_6p02.gif

In this equation, SNRDB increases by 20 × log10(2) = 6.02 with every step increase in N, and 1.76 is a constant caused by the characteristics of a sine wave. Due to the presence of quantization, thermal, or reference noise and clock jitter, an N-bit ADC can be expected to have an ENOB less than N. The ENOB can be characterized by sampling a pure sinusoidal input and performing an FFT on the collected data. This can then be applied to Equation 2 by replacing N to calculate the effective SINAD in place of the SNR.