User's Manual

apmcomm confidential
apm6658/6659 WiFi 802.11 b/g/n & BT2.1+EDR Dual Radio Module
Product Information Data Sheet
Page 18 of 30
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apmcomm Proprietary and Confidential – Product information is subject to change without notice.– May 30 2011
1-7 Recommended Clock Characteristics
1-7-1 WiFi Clock
The external reference clock is applied to the apm6658/6659 WL_CLK input pin. This signal should meet the
specifications outlined in the table below. The default WiFi clock in the module is set as 26MHz. We recommended
customer to design with 26MHz OSC to prevent inconvenience.
Supported Parameter Min Typ Max
Frequency 16MHz
26MHz
52MHz
Frequency tolerance - - +20ppm
Duty cycle 40:60 50:50 60:40
Edge jitter - - 15ps rms
Signal level AC coupled sinusoidal 400mV pk-pk - 750mV pk-pk
1-7-2 BT Clock
The external reference clock is applied to the apm6658/6659 BT_CLK input pin. This signal should meet the
specifications outlined in the table below. The default BT clock in the module is set as 26MHz. We recommended
customer to design with 26MHz OSC to prevent inconvenience.
Supported Parameter Min Typ Max
Frequency 12MHz 26MHz 52MHz
Frequency tolerance -20ppm - +20ppm
Edge jitter - - 15ps rms
Signal level AC coupled sinusoidal 400mV pk-pk - 750mV pk-pk