Wi-Fi&Bluetooth Module Series
AF20_Hardware_Design
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Table 12: Pin Definition of 32KHZ_IN
Pin Name Pin No.
I/O
Description
Comment
32KHZ_IN 19
DI
Used as a timer in low power modes.
External 32.768 kHz clock input is
required in sleep mode.
1.8 V power domain.
If unused, keep this pin
open.
3.9. RF Antenna Interface
3.9.1. Pin Definition of the RF Antenna Interface
Table 13: Pin Definition of the RF Antenna Interface
Pin Name
Pin No.
I/O
Description
Comment
RF_ANT
30
AIO
Wi-Fi/Bluetooth antenna interface
50 Ω impedance
3.9.2. Operating Frequency
Table 14: Operating Frequency of the Module
Feature
Frequency
Unit
2.4 GHz Wi-Fi
2.412
–
2.472
GHz
5 GHz Wi-Fi
5.180
–
5.825
GHz
Bluetooth
2.402–2.480
GHz
3.9.3. Reference Design
AF20 module provides an RF antenna interface for antenna connection. A reference circuit design for RF
antenna interface is shown below. It is recommended to reserve a π-type matching circuit for better RF
performance, and the π-type matching components (C1, C2, R1) should be placed as close to the
antenna as possible. The capacitors are not mounted by default.
