Espressif Systems ESP8266EX - Page 10

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Espressif Systems
ESP8266EX
Hardware User Guide
Pin
Name
Type
Function
1
VDDA
P
Analog Power 3.0 ~3.6V
2
LNA
I/O
RF Antenna Interface,
Chip Output Impedance=50Ω
No matching required but we recommend that the π-type
matching network is retained.
3
VDD3P3
P
Amplifier Power 3.0~3.6V
4
VDD3P3
P
Amplifier Power 3.0~3.6V
5
VDD_RTC
P
NC(1.1V)
6
TOUT
I
ADC Pin
7
CHIP_EN
I
Chip Enable. High: On, chip works properly; Low: Off, small
current
8
XPD_DCDC
I/O
Deep-Sleep Wakeup；GPIO16
9
MTMS
I/O
GPIO14; HSPI_CLK
10
MTDI
I/O
GPIO12; HSPI_MISO
11
VDDPST
P
Digital/IO Power Supply (1.8V~3.3V)
12
MTCK
I/O
GPIO13; HSPI_MOSI; UART0_CTS
13
MTDO
I/O
GPIO15; HSPI_CS; UART0_RTS
14
GPIO2
I/O
UART Tx during flash programming; GPIO2
15
GPIO0
I/O
GPIO0; SPI_CS2
16
GPIO4
I/O
GPIO4
17
VDDPST
P
Digital/IO Power Supply (1.8V~3.3V)
18
SDIO_DATA_2
I/O
Connect to SD_D2 (Series R: 200Ω); SPIHD; HSPIHD; GPIO9
19
SDIO_DATA_3
I/O
Connect to SD_D3 (Series R: 200Ω); SPIWP; HSPIWP; GPIO10
20
SDIO_CMD
I/O
Connect to SD_CMD (Series R: 200Ω); SPI_CS0; GPIO11
21
SDIO_CLK
I/O
Connect to SD_CLK (Series R: 200Ω); SPI_CLK; GPIO6
22
SDIO_DATA_0
I/O
Connect to SD_D0 (Series R: 200Ω); SPI_MSIO; GPIO7
23
SDIO_DATA_1
I/O
Connect to SD_D1 (Series R: 200Ω); SPI_MOSI; GPIO8
Espressif Systems  / Jun 1, 2015 10 48