
Wi-Fi&Bluetooth Module Series
FC905A_Hardware_Design 20 / 51
The module supports external crystal or built-in crystal, so XTAL_IN and XTAL_OUT pins are optional
pins.
3.4. Power Supply
3.4.1. Power Supply Pins Introduction
The following table shows the power supply pins and ground pins of FC905A.
2
JTAG mode can be configured by configuring GPIO1/GPIO2. If you need, please contact the QUECTEL team.
WLAN_SLP_CLK
24
DI
External 32.768 kHz low
power clock input
XTAL_IN
10
DI
Crystal input
Optional.
XTAL_OUT
11
DO
Crystal output
SDIO_VSEL
29
DI
SDIO mode selection
1.8 V: pull-up by default
3.3 V: pull-down and
connect to GND through
10 k
Ω resistor
GPIO1
2
40
DIO
General-purpose
input/output
VIO power domain.
If unused, keep them open.
GPIO2
39
DIO
GPIO3
38
DIO
GPIO4
37
DIO
RESERVED
Pin Name
Pin No.
Comment
RESERVED
4, 5, 8, 30, 32, 35
Keep them open.
NOTE