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3. Functional Description

3.2.2. External Clock Requirements

An externally generated clock is available with the frequency ranging from 24 MHz to 52

MHz. The following characteristics are expected to achieve good performance of radio.

3.3. Radio

ESP8266EX radio consists of the following blocks.

•

2.4 GHz receiver

•

2.4 GHz transmitter

•

High speed clock generators and crystal oscillator

•

Bias and regulators

•

Power management

3.3.1. Channel Frequencies

The RF transceiver supports the following channels according to IEEE802.11b/g/n

standards.

Table 3-2. External Clock Reference

Parameter

Symbol

Min

Max

Unit

Clock amplitude

VXO

0.8

1.5

Vpp

External clock accuracy

ΔFXO,EXT

–15

15

ppm

Phase noise @1-kHz offset, 40-MHz clock

-

-

–120

dBc/Hz

Phase noise @10-kHz offset, 40-MHz clock

-

-

–130

dBc/Hz

Phase noise @100-kHz offset, 40-MHz clock

-

-

–138

dBc/Hz

Table 3-3. Frequency Channel

Channel No.

Frequency (MHz)

Channel No.

Frequency (MHz)

1

2412

8

2447

2

2417

9

2452

3

2422

10

2457

4

2427

11

2462

5

2432

12

2467

6

2437

13

2472

7

2442

14

2484

Espressif

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2018.11