Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK 데이터 시트

1048

SAM9N12/SAM9CN11/SAM9CN12 [DATASHEET]

11063K–ATARM–05-Nov-13

Note:

1. The C

CRYSTAL

 value is specified by the crystal manufacturer. In our case, C

CRYSTAL

 must be between 12.5 pf and 17.5 

pF. All parasitic capacitance, package and board, must be calculated in order to reach 12.5 pF (minimum targeted 
load for the oscillator) by taking into account the internal load C

INT

. So, to target the minimum oscillator load of 12.5 

pF, external capacitance must be: 12.5 pF - 2.1 pF = 10.4 pF which means that 20.8 pF is the target value (20.8 pF 
from xin to gnd and 20.8 pF from xout to gnd) If 17.5 pF load is targeted, the sum of pad, package, board and external 
capacitances must be 17.5 pF - 2.1 pF = 15.4 pF which means 30.8 pF (30.8 pF from xin to gnd and 30.8 pF from 
xout to gnd).

1/(t

CPMAIN

)

Crystal Oscillator Frequency

8

16

20

MHz

C

CRYSTAL

Crystal Load Capacitance

12.5

17.5

pF

C

Internal Load Capacitance

1.85

2.1

2.35

pF

C

LEXT

External Load Capacitance

C

CRYSTAL

 = 12.5 pF

20.8

pF

C

CRYSTAL

 = 17.5 pF

30.8

pF

Duty Cycle

%

t

ST

Startup Time

@3MHz 

@8MHz 

@16MHz

@20MHz

20

4

2

2

ms

I

DDST

Standby Current Consumption

Standby mode

1

µA

P

ON

Drive Level

@3MHz 

@8MHz 

@16MHz

@20MHz

15

30

50

50

µW

I

DD ON

Current Dissipation

@3MHz 

@8MHz 

@16MHz

@20MHz

280

380

500

580

380

510

630

750

µA

1K

XIN

XOUT

GNDPLL

C

LEXT

C

LEXT

C

CRYSTAL