Atmel Evaluation Kit AT91SAM9G25-EK AT91SAM9G25-EK Data Sheet

1046

SAM9G25 [DATASHEET]

11032C–ATARM–25-Jan-13

Note:

1. The C

CRYSTAL

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

CRYSTAL

 must be between 15 pF and 20 pF. 

All parasitic capacitance, package and board, must be calculated in order to reach 15 pF (minimum targeted load for 
the oscillator) by taking into account the internal load C

INT

. So, to target the minimum oscillator load of 15 pF, external 

capacitance must be: 15 pF - 4 pF = 11 pF which means that 22 pF is the target value (22 pF from xin to gnd and 22 
pF from xout to gnd). If 20 pF load is targeted, the sum of pad, package, board and external capacitances must be 20 
pF - 4 pF = 16 pF which means 32 pF (32 pF from xin to gnd and 32 pF from xout to gnd).

1/(t

CPMAIN

)

Crystal Oscillator Frequency

12

16

MHz

C

CRYSTAL

Crystal Load Capacitance

15

20

pF

C

LEXT

External Load Capacitance

C

CRYSTAL

 = 15 pF

27

pF

C

CRYSTAL

 = 20 pF

32

pF

Duty Cycle

40

60

%

t

ST

Startup Time

2

ms

I

DDST

Standby Current Consumption

Standby mode

1

μA

P

ON

Drive Level

150

μW

I

DD ON

Current Dissipation

@ 12 MHz

0.52

0.55

mA

@ 16 MHz

0.7

1.1

mA

1K

XIN

XOUT

GNDPLL

C

LEXT

C

LEXT

C

CRY

S

TAL