SPRUJ53B April 2024 – September 2024 TMS320F28P550SJ , TMS320F28P559SJ-Q1
On some packages, the voltage reference pins for multiple ADCs can be combined. In this case, configure the ganged references identically when selecting external versus internal reference mode and for selecting an internal reference voltage range of 3.3V or 2.5V.
For example, if ADC A and ADC B reference pins are combined and the desired reference mode is 2.5V internal reference mode, the following reference configuration code can be run:
//ADCA VREFHI and ADCB VREFHI share a pin
//ADCA VREFLO and ADCB VREFLO share a pin
//Both references must be explicitly configured
//Both references must be configured identically
SetVREF(ADC_ADCA, ADC_INTERNAL, ADC_VREF2P5);
SetVREF(ADC_ADCB, ADC_INTERNAL, ADC_VREF2P5);
Internal device hardware makes sure multiple references do not drive conflicting voltages onto the same pin. Because of this, references can be configured in any order or over any amount of time.