Part Number: ADS131A04
We are utilizing the ADC as a single 3.3V device with an external REFEXT of 3.0V supplied by a REF1930. The analog signals are offset to 1.5V also from the REF1930. We are using multiple device chaining with the first device configured as asynchronous interrupt mode and the remaining devices configured as synchronous slave mode. All devices are configured for 32 bit SPI word transfers and Hamming code is turned off. According to the datasheet 184.108.40.206 Data Words in Table 10. 24-Bit Ideal Output Code versus Input Signal the output codes are output in 2's complement format. What is the proper method to compensate for the 2's complement? Can this be turned off?
Hi Aaron, Sorry, but the output data format cannot be changed in our devices. To convert the output data word, test the MSB to see if it's 1 or 0. If it's set to 0, simply multiply the decimal equivalent by the LSB size. If it's set to 1, you first need to subtract 2^24 from the decimal equivalent, then multiply by the LSB size. *edited 6/8*
The LSB size is equal to 2*VREF/Gain/2^24.
Though it's a different device, there is an Excel tool for the ADS127L01 that includes an ADC Code Conversions tab if you're interested:
Precision Analog ΔΣ ADCs
In reply to Ryan Andrews:
In reply to Doug Kehn:
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.