Espressif ESP8266 Series User Manual

ESP8266EX
Figure 1-8: ESP8266EX RF
1.4.6.
External Resistor 12K
An external ground resistor should be connected o ERS12K pin (Pin31). The ground resistor
requires high accuracy when controlling the bias current. An accuracy of 12K ± 1% is
recommended.
Figure 1-9: ESP8266EX External Resistor
1.5.
Layout Design
Two layout designs are introduced in this section:
•
Standalone ESP8266EX module
•
ESP8266EX module as salve device
1.5.1.
Standalone ESP8266EX Module
Layout Design
The printed circuit board has four layers:
•
The first layer is the TOP layer for signal lines and components.
•
The second layer is the GND layer, no signal lines are laid to ensure an entire plain GND
plane.
•
The third layer is the POWER layer where only power lines can be placed. It is acceptable to
place some signal lines under unavoidable circumstances.
Espressif
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Espressif ESP8266 Series Specifications

General

RAM	50 KB
Wi-Fi	802.11 b/g/n
GPIO Pins	17
ADC	1
ADC Resolution	10-bit
I2S	Yes
Operating Temperature	-40°C to +125°C
Clock Speed	80 MHz (can be overclocked to 160 MHz)
Flash Memory	External, up to 16 MB
Operating Voltage	3.0V to 3.6V
I2C	Yes (software implementation)
UART	2
Deep Sleep Power Consumption	10 µA
Dimensions	Varies depending on module
Processor	Tensilica L106 32-bit