51.3 External Analog Reference Connections

The following schematic checklist is only necessary if the application is using one or more of the external analog references. If the internal references are used instead, the following circuits in Figure 51-4 and Figure 51-5 are not necessary.

Figure 51-4. External Analog Reference Schematic With Two References
Figure 51-5. External Analog Reference Schematic With One Reference
Table 51-2. External Analog Reference Connections
Signal NameRecommended Pin ConnectionDescription
VREFx1.0V to (VDDANA - 0.6V) for ADC 
1.0V to (VDDANA - 0.6V) for DAC
Decoupling/filtering capacitors
100nF(1)(2) and 4.7µF(1)External reference VREFx for the analog port
GNDGround

1. These values are only given as a typical example.

2. Decoupling capacitor should be placed close to the device for each supply pin pair in the signal group.