Datasheet

Figure 58-10. 3 to 20 MHz Crystal Oscillator Schematics
XIN
XOUT
C
LEXT
C
L
C
LEXT
C
CRYSTAL
Microchip MCU
R = 1K if crystal frequency
is lower than 8 MHz
C
LEXT
= 2 × (C
CR
YSTAL
– C
L
– C
PCB
)
where, C
PCB
is the capacitance of the printed circuit board (PCB) track layout from the crystal to the pin.
58.4.7 3 to 20 MHz Crystal Characteristics
Table 58-24. 3 to 20 MHz Crystal Characteristics
Symbol Parameter Conditions Min. Typ. Max. Unit
ESR Equivalent Series Resistor Fundamental at 3 MHz – – 150 Ohm
Fundamental at 8 MHz 140
Fundamental at 12 MHz 120
Fundamental at 16 MHz 80
Fundamental at 20 MHz 50
C
M
Motional capacitance Fundamental at 3 MHz 3 – 8 fF
Fundamental at 8–20 MHz 1.6 – 8
C
SHUNT
Shunt capacitance – – – 7 pF
C
CR
YSTAL
Allowed Crystal Capacitance Load From crystal specification 12.5 – 17.5 pF
P
ON
Drive Level 3 MHz – – 15 µW
8 MHz – – 30
12 MHz, 20 MHz – – 50
58.4.8 3 MHz-20 MHz XIN Clock Input Characteristics in Bypass Mode
Table 58-25. 3 MHz-20 MHz XIN Clock Input Characteristics in Bypass Mode
Symbol Parameter Conditions Min. Typ. Max. Unit
1/(t
CPXIN
) XIN Clock Frequency (see Note 1) – – 20 MHz
t
CHXIN
XIN Clock High Half-period (see Note 1) 25 – – ns
t
CLXIN
XIN Clock Low Half-period (see Note 1) 25 – – ns
V
XIN_IL
V
XIN
Input Low-level V
oltage (see Note 1)
Min of V
IL
for CLOCK
pad
–
Max of V
IL
for CLOCK
pad
V
V
XIN_IH
V
XIN
Input High-level Voltage (see Note 1)
Min of V
IH
for CLOCK
pad
–
Max of V
IH
for CLOCK
pad
V
Note: 1.These characteristics are applicable only when the 3 MHz-20 MHz crystal oscillator is in Bypass mode.
SAM E70/S70/V70/V71 Family
Electrical Characteristics for SAM ...
© 2019 Microchip T
echnology Inc.
Datasheet
DS60001527D-page 1831