Espressif Systems ESP8266EX, Руководство пользователя по оборудованию, Страница: 20 / 48

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Espressif Systems
ESP8266EX
Hardware User Guide
A π matching circuit near the RF Pin should be reserved in RF lines. RF lines connecting the chip and
antenna should not cover drills, which means cross layer lines are not allowed.
The width of RF lines should not be less than 6 mil and should keep up to10 mil.
RF lines should not be set at a vertical, or a 45-degree angle. Circular lines are allowed if necessary.
No signal lines of high frequency should be set near RF lines.
RF antenna should be set away from high frequency transmitting devices, such as crystal oscillators,
DDR, and certain high frequency clocks (SDIO_CLK, etc).
Figure 12 ESP8266EX RF PCB Layout
2.3.2. ESP8266EX as Slave Device
When ESP8266EX is matched with CPU as a slave unit, information integrity in layout design is more
important than that in analogue design.
Due to the system accountability, the increasing high frequency signals would result in interference
in ESP8266EX. Attentions should be paid to those interferences.
Main boards in PAD or TV BOX will be discussed.
Espressif Systems / Jun 1, 2015 20 48