Datasheet

Figure 59-7. External Reset Circuit Schematic
GND
RESET
100nF
10kΩ
V
DD
330Ω
A pull-up resistor makes sure that the Reset does not go low and unintentionally causing a device Reset.
An additional resistor has been added in series with the switch to safely discharge the filtering capacitor,
i.e. preventing a current surge when shorting the filtering capacitor which again can cause a noise spike
that can have a negative effect on the system.
Table 59-2. Reset Circuit Connections
Signal Name Recommended Pin Connection Description
RESET Reset low level threshold voltage
V
DDIO
= 1.71V - 2.0V: Below 0.33 * V
DDIO
V
DDIO
= 2.7V - 3.6V: Below 0.36 * V
DDIO
Decoupling/filter capacitor 100nF
(1)
Pull-up resistor 10kΩ
(1,2)
Resistor in series with the switch 330Ω
(1)
Reset pin
1. These values are only given as a typical example.
2. The SAM D5x/E5x features an internal pull-up resistor on the RESET pin, hence an external pull-up is
optional.
59.5 Unused or Unconnected Pins
For unused pins the default state of the pins will give the lowest current leakage. Thus there is no need to
do any configuration of the unused pins in order to lower the power consumption.
59.6 Clocks and Crystal Oscillators
The SAM D5x/E5x can be run from internal or external clock sources, or a mix of internal and external
sources. An example of usage can be to use the internal 48MHz DFLL as source for the system clock
and an external 32.768kHz watch crystal as clock source for the Real-Time counter (RTC).
SAM D5x/E5x Family Data Sheet
Schematic Checklist
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 2102