Data Sheet
Table Of Contents
- 1.General Overview
- 1.1.Introduction
- 1.2.Features
- 1.3.Parameters
- 1.4.Ultra Low Power Technology
- 1.5.Major Applications
- 2.Hardware Overview
- 3.Pins and Definitions
- 3.1.GPIO
- 3.2.Secure Digital Input/Output Interface (SDIO)
- 3.3.Serial Peripheral Interface (SPI/HSPI)
- 3.4.Inter-integrated Circuit Interface (I2C)
- 3.5.I2S
- 3.6.Universal Asynchronous Receiver Transmitter (UART)
- 3.7.Pulse-Width Modulation (PWM)
- 3.8.IR Remote Control
- 3.9.ADC (Analog-to-digital Converter)
- 3.10.LED Light and Button
- 4.Firmware & Software Development Kit
- 5.Power Management
- 6.Clock Management
- 8.FCC Warming Statement
- This device complies with part 15 of the FCC Rules
- (1)This device may not cause harmful interference,
- (2)and this device must accept any interference re
- FCC Radiation Exposure Statement:
- This equipment complies with FCC radiation exposur
- Information to the user.
- Note: This equipment has been tested and found to
- -Reorient or relocate the receiving antenna.
- -Increase the separation between the equipment and
- -Connect the equipment into an outlet on a circuit
- -Consult the dealer or an experienced radio/TV tec
- 9.Appendix: QFN32 Package Size
ESP8266 Datasheet
Espressif Systems
Espressif Systems
June1,2015
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Figure 3 Illustration of Power Management
6.
Clock Management
6.1.
High Frequency Clock
The high frequency clock on ESP8266EX is used to drive both transmit and receive mixers. This clock
is generated from the internal crystal oscillator and an external crystal. The crystal frequency can
range from 26MHz to52MHz.
While internal calibration of the crystal oscillator ensures that a wide range of crystals can be used, in
general, the quality of the crystal is still a factor to consider, to have reasonable phase noise that is
required for good performance. When the crystal selected is sub-optimal due to large frequency
drifts or poor Q-factor, the maximum throughput and sensitivity of the WiFi system is degraded.
Please refer to the application notes on how the frequency offset can be measured.