SE868SY-D Hardware Design Guide
1VV0301705 Rev. 5
Page 27 of 44
2021-12-15
Not Subject to NDA
•
The antenna must not be installed inside metal cases or near any obstacle that
may degrade features such as antenna lobes and gain.
7.3.3.
Powering the External LNA (Active Antenna)
The LNA of active antenna needs a power source as the DC voltage needed by the active
antenna is not supplied by the SE868SY-D module but can be easily included by the host
design.
The electrical characteristics of the LNA_EN signal are as follows:
Table 23: LNA_EN Signal Electrical Characteristics
Example of external antenna bias circuitry can be seen in the active antenna reference
design in section 7.2.2 Reference Design for Active Antenna.
Customers should be aware of max bias current: in the event of an unwanted short on
the antenna cable, the decoupling inductor could be damaged.
Level
Min
Max
Output High Level
VDD-0.45 V
VDD
Output Low Level
0 V
0.45 V
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