47.3 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 two circuits are not necessary.

Figure 47-4. External Analog Reference Schematic With Two References
Figure 47-5. External Analog Reference Schematic With One Reference
Table 47-2. External Analog Reference Connections
Signal NameRecommended Pin ConnectionDescription
VREFA/VREFB1.0V to (VDDANA - 0.6V) for ADC 


Decoupling capacitors 
100nF(1)(2) and 4.7µF(1)

External reference VREFA/VREFBfor 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.