36.3 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 are not necessary.

Figure 36-2. External Analog Reference Schematic With Two References
Figure 36-3. External Analog Reference Schematic With One Reference
Table 36-2. External Analog Reference Connections
Signal NameRecommended Pin ConnectionDescription
VREFx

1.0V 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 from VREFx pin on 
the analog port
GNDGround
  1. These values are given as a typical example.
  2. Decoupling capacitor should be placed close to the device for each supply pin pair in the signal group.