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Wi-Fi&Bluetooth Module Series
FC908A_Hardware_Design 31 / 49
3.7.2. XTAL_IN/OUT
The XTAL_IN and XTAL_OUT pins are external crystal pins, and the recommended crystal frequency is
26 MHz. These pins are optional pins, and the crystal position has been reserved inside the module, and
customers can choose according to their needs.
The following table is the recommended crystal parameters. It is recommended that customers select the
crystal according to the following table:
Table 19: XO parameter definition
3.7.3. GPIOs
GPIO1/GPIO2 are function configuration pins, which can be used to enter JTAG mode. Please contact
QUECTEL if necessary.
Table 20: Pin Definition of GPIO1/GPIO2
3.8. RF Antenna Interfaces
ANT_WIFI0/BT is the RF antenna pin, and the RF port requires
50 Ω characteristic impedance.
Parameter
Min
Typ.
Max
Unit
Frequency
-
26
-
MHz
load capacitance
-
12
-
pF
ESR
-
60
-
Ω
Drive level
200
-
-
μW
Frequency tolerance Initial
+ over temperature
-20
-
20
ppm
Pin Name
Pin No.
I/O
Description
Comment
GPIO1
40
DIO
General-purpose input/output
VDDIO power domain.
GPIO2
39
DIO
General-purpose input/output