Datasheet

90
XMEGA A1U [DATASHEET]
Atmel-8385H-AVR-ATxmega64A1U-128A1U-Datasheet–AVR–04/2014
Note: 1. Numbers for negative impedance are not tested in production but guaranteed from design and characterization.
37.1.14.8 External 32.768kHz crystal oscillator and TOSC characteristics
Table 37-29. External 32.768kHz crystal oscillator and TOSC characteristics.
Note: 1. See Figure 37-4 for definition.
Figure 37-4. TOSC input capacitance.
Start-up time
XOSCPWR=0,
FRQRANGE=0
0.4MHz resonator, CL=100pF 1.0
ms
XOSCPWR=0,
FRQRANGE=1
2MHz crystal, CL=20pF 2.6
XOSCPWR=0,
FRQRANGE=2
8MHz crystal, CL=20pF 0.8
XOSCPWR=0,
FRQRANGE=3
12MHz crystal, CL=20pF 1.0
XOSCPWR=1,
FRQRANGE=3
16MHz crystal, CL=20pF 1.4
C
XTAL1
Parasitic capacitance XTAL1 pin 6
pF
C
XTAL2
Parasitic capacitance XTAL2 pin 10
C
LOAD
Parasitic capacitance load 3.8
Symbol Parameter Condition Min. Typ. Max. Units
Symbol Parameter Condition Min. Typ. Max. Units
ESR/R1
Recommended crystal
equivalent series resistance
(ESR)
Crystal load capacitance 6.5pF 60
k
Crystal load capacitance 9.0pF 35
C
TOSC1
Parasitic capacitance TOSC1 pin 4.0
pFC
TOSC2
Parasitic capacitance TOSC2 pin 4.1
C
L
Parasitic capacitance load 2.0
Recommended safety factor Capacitive load matched to crystal specification 3
C
L1
C
L2
2CS
O
T
1
CS
O
T
Device internal
External
32.768kHz crystal