Smart Module Series
SC690A_Series_Hardware_Design 80 / 105
⚫
In user systems, GNSS RF signal lines and RF components should be placed far away from high-
speed circuits, switched-mode power supplies, power inductors, the clock circuit of single-chip
microcomputers, etc.
⚫
For applications with a harsh electromagnetic environment or with high requirement on ESD
protection, it is recommended to add ESD protection diodes for the antenna interface. Only diodes
with ultra-low junction capacitance such as 0.5 pF can be selected. Otherwise, it will influence the
impedance characteristic of RF circuit loop or cause attenuation of bypass RF signals.
⚫
Control the impedance of either feeder line or PCB trace to 50
Ω, and keep the trace length as short
as possible.
5.3. Wi-Fi/Bluetooth
The module provides a shared antenna interface ANT_WIFI/BT for Wi-Fi and Bluetooth functions. The
interface impedance is
50 Ω. You can connect external antennas such as PCB antenna, sucker antenna
and ceramic antenna to the module via these interfaces to achieve Wi-Fi and Bluetooth functions.
Table 38: Pin Definition of Wi-Fi/Bluetooth Application Interfaces
Table 39: Wi-Fi/Bluetooth Frequency
5.3.1. Wi-Fi Overview
The module supports 2.4 GHz/5 GHz double-band WLAN wireless communication based on IEEE
802.11a/b/g/n/ac standard protocols. The maximum data rate is up to 433 Mbps. The features are as
below:
⚫
Support Wake-on-WLAN (WoWLAN)
⚫
Support ad hoc mode
⚫
Support WAPI SMS4 hardware encryption
Pin Name
Pin No.
GPIO No.
Default Status
Comment
ANT_WIFI/BT
129
AIO
Wi-Fi/Bluetooth antenna interface
50 Ω impedance
Type
Frequency
Unit
802.11a/b/g/n/ac
2402
–2482
5180
–5825
MHz
Bluetooth 5.1
2402
–2480
MHz
