Data Sheet

1010
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181G–SAM-D21_Datasheet–09/2015
Figure 38-3. External Analog Reference Schematic With One Reference
Notes: 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.
Table 38-2. External Analog Reference Connections
Signal Name Recommended Pin Connection Description
VREFx
1.0V 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 VREFx pin on
the analog port
GND Ground
GND
VREFA
EXTERNAL
REFERENCE
4.7μF 100nF
GND
VREFB
100nF
Close to device
(for every pin)