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
Multiple MSP ultra-low-power microcontrollers offer analog-to-digital converters (ADCs) to convert physical quantities into digital numbers, a function that is widely used across numerous applications. There are times, however, when a customer design demands a higher resolution than the ADC of the selected MSP can offer. This application report, which is based on the previously-published Oversampling the ADC12 for Higher Resolution (SLAA323), therefore describes how an oversampling method can be incorporated to increase ADC resolution past the currently available number of bits. Code example projects (available for download from http://www.ti.com/lit/zip/slaa694) and detailed instructions are provided for the MSP430FR4133 and MSP432P401R microcontrollers but can be modified so that oversampling is supported for a myriad of MSP MCU derivatives, sampling frequencies, and extra bits of resolution.
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Most often an MSP microcontroller from the device portfolio can be selected that meets all of the application requirements, including footprint size, memory capacity, peripherals included, and cost. But then it can sometimes be disclosed that the analog-to-digital converter (ADC) resolution is lower than desired, a requirement which may be critical enough to make the user consider other options that do not fit their design needs as adequately. An alternative to this outcome would be incorporating a software-based oversampling method to obtain extra bits of ADC resolution. The following sections of this application report examine the theory behind oversampling and discuss in detail how software algorithms are employed to achieve the extra resolution desired. An example project that has been designed for operation across various ultra low-power MSP MCU modules, sample frequencies, and desired extra bits of resolution is also provided to instruct and advise the user regarding how their current application can be modified to integrate the ADC oversampling solution with ease.
This section describes the fundamentals of ADC operation and discusses the equation involved in calculating the signal-to-noise ratio (SNR) given the number of bits (N) available from the ADC. This section also describes the relationship between this data and the signal-to-noise and distortion ratio (SINAD) as well as the effective number of bits (ENOB). Implementation of the oversampling method to improve ADC resolution is then detailed. All information provided is sourced from Oversampling the ADC12 for Higher Resolution (SLAA323).