Intel® Arria® 10 Core Fabric and General Purpose I/Os Handbook

ID 683461
Date 1/21/2022
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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.

Figure 182. Voltage Sensor

The conversion speed of the ADC is 500 ksps cumulative. When multiple channels are used, the speed per channel is reduced accordingly.

Note: VREFP_ADC pins consume very little current, most of the current drawn is attributed to the leakage current, which is less than 10 µA. For VREFN_ADC pins, the current is less than 0.1 mA.

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.