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 circuits in the following two figures are not necessary.

Figure 1. External Analog Reference Schematic With Two References
Figure 2. External Analog Reference Schematic With One Reference
Table 1. External Analog Reference Connections
Signal Name Recommended Pin Connection Description
VREFx 1.0V to (VDDANA - 0.6V) for ADC 
1.0V to (VDDANA - 0.15V) for DAC
Decoupling/filtering capacitors
100nF(1)(2) and 4.7µF(1) External reference VREFx for the analog port
GND   Ground

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.