SPRUHX5I August 2014 – May 2024 TMS320F28374S , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376S , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378S , TMS320F28379S
The ADC supports two signal modes: single-ended and differential.
In single-ended mode, the input voltage to the converter is sampled through a single pin (ADCINx), referenced to VREFLO.
In differential signaling mode, the input voltage to the converter is sampled through a pair of input pins, one of which is the positive input (ADCINxP) and the other is the negative input (ADCINxN). The actual input voltage is the difference between the two (ADCINxP – ADCINxN).
The data sheet for a particular device places some requirements on how close this voltage needs to be to: (VREFHI + VREFLO)/2
Note: The above condition is not met by connecting the negative input to VSSA or VREFLO.
The signal mode must be configured by using either the ADC_setMode() or AdcSetMode() functions, depending on the header files used, provided in C2000warein F2837xS_Adc.c. These functions make sure that the correct trim is loaded into the ADC trim registers. These functions must be called at least once after a device reset. The signal mode must not be configured by writing to the ADCCTL2 register directly.