ATWINC1500_14 Datasheet, PDF (10/26 Pages) ATMEL Corporation – Single Chip IEEE 802.11 b/g/n Network Controller SOC

7. Clocking
7.1 Crystal Oscillator
Table 7-1. WINC1500 Crystal Oscillator Parameters
Parameter
Min
Typical
Max
Crystal Resonant Frequency
12
32
Crystal Equivalent Series Resistance
50
150
Stability
-25
25
Units
MHz

ppm
The block diagram in Figure 7-1(a) shows how the internal Crystal Oscillator (XO) is connected to the external
crystal. The XO has 5pF internal capacitance on each terminal XO_P and XO_N. To bypass the crystal
oscillator with an external reference, an external signal capable of driving 5pF can be applied to the XO_N
terminal as shown Figure 7-1(b).
Figure 7-1.
WINC1500 XO connections to crystal when (a) the crystal oscillator is used, and (b) the crystal oscillator is bypassed
([WHUQDO&ORFN
;2B1
;2B3
;2B1
;2B3
:,1&
:,1&
D
E
Table 7-2. WINC1500 Bypass Clock Specification
Parameter
Oscillator frequency
Voltage swing
Stability
Phase Noise
Conditions
@ 1KHz
Offset
Jitter (RMS)
Min
12
0.5
-100
Max
32
1.8
+100
Units
MHz
Vpp
ppm
Comments
Must be able to drive 5pF load @ desired frequency
Must be AC coupled
-130 dBc/Hz
<1psec
Based on integrated phase noise spectrum from
1kHz to 1MHz
7.2 Low Power Oscillator
Atmel WINC1500 device provides an internally-generated 32kHz clock to provide timing information for various
sleep functions. In addition, WINC1500 allows for an external 32kHz clock to be provided through Pin 24.
Software selects whether the internal clock or external clock is used.
10 Atmel ATWILC1500A [PRELIMINARY DATASHEET]
Atmel-42353A-WINC1500-SmartConnect-Datasheet_092014