5.4.4 Voltage References (VREF)
The PIC16F, PIC18F and PIC32CM MCUs provide programmable fixed voltage references (VREF/FVR) that supply stable reference voltages to analog peripherals, such as ADCs, DACs and ACs. The PIC16F, PIC18F and PIC32CM VREFs are designed to enhance measurement precision, support low-power operation, and allow easy configuration of the reference source for different application needs. Table 5-17 provides a comparison of features between PIC16F, PIC18F and PIC32CM.
| Feature | PIC16F FVR/VREF | PIC18F FVR/VREF | PIC32CM VREF |
|---|---|---|---|
| Integration | Stand-alone FVR/VREF peripheral | Stand-alone FVR/VREF peripheral | Integrated into the Supply Controller (SUPC) peripheral |
| Reference Voltage Options | Multiple internal voltages | Multiple internal voltages | Multiple internal voltages External VREF pin |
| Target Peripherals |
ADC DAC Analog Comparator |
ADC DAC Analog Comparator HLVD CTMU OPA |
ADC DAC Analog Comparator |
| Programmable Levels | 1.024V, 2.048V and 4.096V | 1.024V, 2.048V and 4.096V | Varies per device
family: 1–4.096V |
| Low-Power Operation | Supported | Supported | Supported |
| Configuration | Software registers | Software registers | Software registers |
| Additional Features | Stabilization ready flags (RDY/FVRRDY) | Stabilization ready flags (RDY/FVRRDY) | May include advanced supply management features |
| Output to Pin | Supported | Supported | Supported |