Chengdu Ebyte Electronic Technology Co., Ltd
E21-400G37 User Manual
Copyright ©2012–2019, hengdu Ebyte Electronic Technology Co., Ltd
7
Note:
1. TXEN and RXEN cannot be opened at the same time at any time, which may cause direct damage to
PA module.
2. The bottom bonding pad is connected to the internal GND, which needs to be coated with silicone
grease for heat dissipation or welded to the base plate to enhance heat dissipation.
Chapter 4 Basic Operation
4. 1 Hardware design
It is recommended to use DC regulated power supply to supply power to the module. The ripple coefficient
of the power supply should be as small as possible. The module should be reliably grounded. It is recommended
to use power supply above 20W;
Please pay attention to the correct connection of the positive and negative poles of the power supply. If
the connection is reversed, the module may be permanently damaged;
Please check the power supply to ensure that it is between the recommended power supply voltages. If it exceeds
the maximum value, the module will be permanently damaged;
Please check the stability of the power supply, and the voltage cannot fluctuate significantly and frequently;
When designing power supply circuit for modules, it is often recommended to reserve more than 30% margin,
which is conducive to long-term stable operation of the whole machine;
The module shall be as far away from power supply, transformer, high-frequency wiring and other parts with
large electromagnetic interference as possible;
High frequency digital wiring, high frequency analog wiring and power wiring must avoid the lower part of
the module. If it is really necessary to pass under the module, suppose that the module is welded on the
Top Layer, and the top layer of the module contact part is paved with copper (all are paved with copper and
well grounded), and must be close to the digital part of the module and routed on the Bottom Layer;
If the module is welded or placed in the top layer, it is also wrong to randomly route in the bottom layer
or other layers, which will affect the stray and receiving sensitivity of the module to varying degrees;
If there are components with large electromagnetic interference around the module, it will also greatly affect
the performance of the module. According to the intensity of the interference, it is recommended to keep
away from the module properly. If circumstances permit, appropriate isolation and shielding can be done;
Assuming that there are wiring (high-frequency digital, high-frequency analog, power wiring) with large
electromagnetic interference around the module will also greatly affect the performance of the module, it
is recommended to keep away from the module appropriately according to the intensity of the interference,
and appropriate isolation and shielding can be done if circumstances permit;
The antenna installation structure has a great impact on the module performance. It is necessary to ensure
that the antenna is exposed, preferably vertically upwards. When the module is installed inside the enclosure,
high-quality antenna extension cable can be used to extend the antenna outside the enclosure;
The antenna must not be installed inside the metal shell, which will greatly weaken the transmission distance.
Pay attention to the good grounding, large area of grounding, small power ripple, increase the filter capacitor
and try to be close to the VCC and GND pins of the module;
