Datasheet

77
XMEGA D4 [DATASHEET]
8135P–AVR–01/2014
32.1.13.8 External 32.768kHz crystal oscillator and TOSC characteristics
Table 32-26. External 32.768kHz crystal oscillator and TOSC characteristics.
Note: See Figure 32-4 for definition.
R
Q
Negative impedance
XOSCPWR=1,
FRQRANGE=1,
CL=20pF
9MHz crystal 1500

12MHz crystal 650
16MHz crystal 270
XOSCPWR=1,
FRQRANGE=2,
CL=20pF
12MHz crystal 1000
16MHz crystal 440
XOSCPWR=1,
FRQRANGE=3,
CL=20pF
12MHz crystal 1300
16MHz crystal 590
ESR SF = safety factor min(R
Q
)/SF k
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
5.9
pF
C
XTAL2
Parasitic capacitance
XTAL2 pin
8.3
C
LOAD
Parasitic capacitance load 3.5
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
Crystal load capacitance 12pF 28
C
TOSC1
Parasitic capacitance TOSC1 pin 3.5
pF
C
TOSC2
Parasitic capacitance TOSC2 pin 3.5
Recommended safety factor
capacitance load matched to
crystal specification
3