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 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
VREFA	2.0V to V_DDANA - 0.6V for ADC 1.0V to V_DDANA - 0.6V for DAC Decoupling/filtering capacitors: 100nF⁽¹⁾⁽²⁾ and 4.7µF⁽¹⁾	External reference from VREFA pin on the analog port.
VREFB	1.0V to 5.5V for SDADC Decoupling/filtering capacitors: 100nF⁽¹⁾⁽²⁾ and 4.7µF⁽¹⁾	External reference from VREFB pin on the analog port.
GND		Ground

Note:

These values are given as a typical example.
Decoupling capacitor should be placed close to the device for each supply pin pair in the signal group.