Datasheet

Table 42-1. Power Supply Connections, V
DDCORE
From Internal Regulator
Signal Name Recommended Pin Connection Description
V
DDIO
1.62V - 3.63V
Decoupling/filtering capacitors 100nF
(1)(2)
and 10μF
(1)
Decoupling/filtering inductor 10μH
(1)(3)
Digital supply voltage
V
DDANA
1.62V - 3.63V
Decoupling/filtering capacitors 100nF
(1)(2)
and 10μF
(1)
Ferrite bead
(4)
prevents the V
DD
noise interfering the
V
DDANA
Analog supply voltage
V
DDCORE
1.6V to 1.8V
Decoupling/filtering capacitor 1μF
(1)(2)
Core supply voltage / external
decoupling pin
GND Ground
GND
ANA
Ground for the analog power
domain
Note:
1. These values are only given as typical examples.
2. Decoupling capacitor should be placed close to the device for each supply pin pair in the signal
group, low ESR caps should be used for better decoupling.
3. An inductor should be added between the external power and the V
DD
for power filtering.
4. Ferrite bead has better filtering performance than the common inductor at high frequencies. It can
be added between V
DD
and V
DDANA
for preventing digital noise from entering the analog power
domain. The bead should provide enough impedance (e.g. 50Ω at 20MHz and 220Ω at 100MHz)
for separating the digital power from the analog power domain. Make sure to select a ferrite bead
designed for filtering applications with a low DC resistance to avoid a large voltage drop across the
ferrite bead.
42.3 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.
SAM D21 Family
Schematic Checklist
© 2018 Microchip Technology Inc.
Datasheet Complete
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