10.4. Voltage Sensor
Intel® Arria® 10 supports an on-chip voltage sensor. The voltage sensor provides a 6-bit digital representation of the analog signal being observed. The voltage sensor monitors two external differential inputs and six internal power supplies as shown in the following figure. To get the ADC input, the VCCPT voltage value is divided by two. To get the actual VCCPT voltage value, multiply the ADC output by two.
The conversion speed of the ADC is 500 ksps cumulative. When multiple channels are used, the speed per channel is reduced accordingly.
For better ADC performance, tie VREFP_ADC and VREFN_ADC pins to an external 1.25 V accurate reference source (±0.2%). An on-chip reference source (±10%) is activated by connecting the VREFP_ADC pin to GND. Treat VREFN_ADC together with VREFP_ADC as an analog 1.25 V differential signal.
Connect both VREFP_ADC and VREFN_ADC pins to GND if no external reference is supplied.