Schematics - Espressif ESP8266 Series System Description

Pin
29
30
31
32
Note:
GPIO2, GPIO0 and MTDO can be configured to a 3-bit strapping register that determines the
booting mode and the SDIO timing mode.

1.4. Schematics

The highly integrated design of ESP8266EX tremendously reduce the number of components
required. Beside ESP8266EX, less than 10 resistors and capacitors, 1 crystal oscillator and 1 SPI
flash are needed to make a complete module with wireless communication capability. The
following is a detailed description on ESP8266EX schematics and layout design to ensure
optimum functionality.
The complete circuit diagram of ESP8266EX is illustrated in Figure 1-3.
ESP8266EX schematics design includes six aspects:
•
Power supply
•
Power-on sequence and reset
Espressif
Name Type
VDDD P
VDDA P
RES12K I
EXT_RSTB I
Figure 1-3: ESP8266EX Schematics
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Functions
Analog power 3.0 V ~ 6 V
Analog power 3.0 V ~ 3.6 V
Serial connection with a 12 kΩ resistor to the ground
External reset signal (Low voltage level: Active)
ESP8266EX
2016.06