Specifications

Smart Machine Smart Decision
SIM5800_Hardware Design_V1.01 42 2018-10-08
Table 20: Keypad interface
Recommended keypad circuit is as the following:
KPROW1
KPROW0
KPCOL0
Module
46
90
96
Figure 35: Keypad reference circuit
4.19 Antenna Interface
SIM5800 provides three antenna interfaces including MAIN antenna, GNSS antenna, and WiFi/BT antenna. To
ensure good RF performance, users should meet the following requirements:
● Keep the RF traces at 50Ω.
● Maintain a complete and continuous reference ground plane from antenna pin to the RF connector.
● The RF traces should be away from any other noisy traces.
● Keep the RF traces as short as possible.
4.19.1 MAIN Antenna reference circuit
The recommended circuit is shown as Figure 36:
RF connector
(optional)
C1
Module
87
ANT_MAIN
GND
C2
88
R1
Matching circuit
MAIN ANT
86
GND
Pin Name
Pin
I/O
Description
USB_BOOT
46
I
KPCOL0
GPIO69
90
O
KPROW0
GPIO65
96
O
KPROW1