Fibocom MG661-EU - Page 17

2 Pin Definition
14
Pin No.
Pin Name
I/O
Power
Domain
Description
Pins are internally pulled up to VBAT,
and no external pull up is required.
82
USB_BOOT/KEYIN0
DI
1.8V
If USB_BOOT is pulled down to
ground or up to 1.8V, the module will
enter the download mode if it is
powered on or reset. It is
recommended to pull down
USB_BOOT to enter the download
mode.
Table 8. Baseband interface
Pin No.
Pin
Name
RESET
VALUE
I/O
Power
Domain
Description
5
GPIO29
PU
DIO
1.8V
GPIO pin
6
GPIO30
PU
DIO
1.8V
GPIO pin
44
VRTC*
- -
PI
3.0V
RTC power input, not recommended,
can be suspended
102
ISINK
- -
PI
- -
Current source input pin, can be
connected to the cathode of the
backlight, by adjusting the ISINK
current to adjust the brightness of the
backlight
1, 10, 27,
34, 36-37,
40-41, 45-
48, 70-73,
88-95
GND
- -
G
- -
Ground