• MediaTek X20 Development Board Hardware User Manual
  • Table of Contents
  • Introduction
  • What’s in the Box
  • Board Overview
  • System Block Diagram
  • Getting Started
    • Prerequisites
    • Starting the board for the first time
  • Component Details
    • Processor
    • PMIC
    • Memory (DRAM)
    • Storage
    • Micro SDHC
    • Boot ROM
    • Networking
      • Wifi
      • Bluetooth
      • GPS
    • HDMI
    • MIPI-DSI
    • Camera Interface
    • USB Ports
    • USB Host ports
    • USB Device ports
    • Audio
    • DC Power
    • Power Measurement
    • External fan Connection
    • UART
    • Buttons
      • Power Button
      • Reset Button
      • Volume up
      • Volume down
      • Dip-switch
    • LED Indicators
      • Two activity LEDs
      • four User LEDs
    • Additional functionality
  • Expansion Connectors
    • Low Speed Expansion Connector
    • UART {0/1}
    • I2C {0/1}
    • GPIO {A-L}
    • SPI 0
    • PCM/I2S
    • Power and Reset
    • Power Supplies
  • High Speed Expansion Connector
    • MIPI DSI 0
    • MIPI CSI {0/1}
    • I2C {2/3}
    • SD/SPI
    • Clocks
    • USB
    • HSIC
    • Reserved
  • Analog Expansion Connector
    • Speaker
    • Mic
    • Earphone
    • Headset
    • fM Antenna
  • Power Management Overview
    • Block Diagram
    • DC Power Input
    • Power Source Selection and Sequencing
    • Voltage Rails
  • Mechanical Specification
    • 2D Reference Drawing

MediaTek X20 Development Board Hardware User Manual

Table of Contents

• Table of Contents
• Introduction
• What’s in the Box
• Board Overview
• Key Components
• System Block Diagram
• Getting Started
  • Prerequisites
  • Starting the board for the first time
• Component Details
  • Processor
  • PMIC
  • Memory (DRAM)
  • Storage
  • Micro SDHC
  • Boot ROM
  • Networking
  • Wifi
  • Bluetooth
  • GPS
  • HDMI
  • MIPI-DSI
  • Camera Interface
  • USB Ports
  • USB Host ports
  • USB Device ports
  • Audio
  • DC Power
  • Power Measurement
  • External fan Connection
  • UART
  • Buttons
  • LED Indicators
  • Additional functionality
• Expansion Connectors
  • Low Speed Expansion Connector
  • High Speed Expansion Connector
  • Analog Expansion Connector
• Power Management Overview
  • Block Diagram
  • DC Power Input
  • Power Source Selection and Sequencing
  • Voltage Rails
• Mechanical Specification

Introduction

The MediaTek X20 Development Board is a 96Boards compliant community board based on MediaTek X20 platform.The following table lists its key features:

• Processor:
  • MediaTek X20 MT6797
  • Dual-core ARM@Cortex-A72 MPCoreTM operating at up to 2.3GHz
  • Quad-core ARM@Cortex-A53 MPCoreTM operating at up to 1.85GHz
  • Quad-core ARM@Cortex-A53 MPCoreTM operating at up to 1.4GHz
  • Quad-core Mali-T880, operating at up to 700MHz
  • Two ARM@Cortex-R4 processors operating at up to 800MHz for MD MCU
  • Embedded connectivity system including WLAN/BT/fM/GPS
• Memory / Storage:
  • 2GB LPDDR3 2CH, 933MHz
  • 8GB eMMC 5.1
  • SD 3.0 (Micro SD card slot)
• Video:
  • HEVC decoder 2160p@30fps
  • VP9 decoder 2160p@30fps
  • H.264 decoder 2160p@30fps
  • Sorenson H.263/ H.263 decoder: 1080p@60fps/40Mbps
  • MPEG-4 SP/ASP decoder: 1080p@60fps/40Mbps
  • DIVX4/ DIVX5/ DIVX6/ DIVX HD/XVID decoder: 1080p@60fps/40Mbps
  • MPEG-4 encoder: Simple profile D1@30fps
  • H.263 encoder: Simple profile D1@30fps
  • H.264 encoder: High profile 2160p@30fps
  • HEVC encoder: Main profile 2160p@30fps
• Camera Support:
  • Main camera IO supports 25M camera module
  • Sub camera IO supports 8M camera module
• Audio:
  • Audio encoding: AMR-NB, AMR-WB,AAC,OGG,ADPCM
  • Audio decoding:WAV,MP3,MP2,AAC,AMR-NB,AMR-WB,MIDI,Vorbis,APE,AAC-plus v1/2,fLAC,WMA,ADPCM
• Connectivity:
  • WLAN 802.11a/b/g/n 2.4GHz and 5GHz(On-board BT and WLAN antenna )
  • Bluetooth® wireless technology 4.1 +HS compliant
  • GPS (with antenna connector)
  • One USB 2.0 micro B (device mode only)
  • Two USB 2.0 (host mode only)
• I/O Interfaces:
  • One 40-pin Low Speed (LS) expansion connector
    • UART, SPI, I2S, I2C x2, GPIO x12, DC power
  • One 60-pin High Speed (HS) expansion connector
    • 4L-MIPI DSI, USB, I2C x2, 2L+4L-MIPI CSI
  • One 16-pin analog expansion connector
    • Stereo headset/line-out, speaker and analog line-in
• EXternal Storage:
  • Micro SD card slot (SD 3.0)
• User Interface:
  • 4 Buttons :Power/Reset/Volume Up/down
  • 6 LED indicators
    • 4 -user controllable
    • 2 -for radios (BT and WLAN activity)
• OS Support:
  • Android 6.0
• Mechanical:
  • Dimensions: 54mm by 85mm meeting 96Boards™ Consumer Edition standard dimensions specifications.
• Environmental:
  • Operating Temp: -20°C to +45°C
  • RoHS and Reach compliant

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What’s in the Box

The box contains one MediaTek X20 Development Board and a quick start guide.

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Board Overview

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System Block Diagram

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Getting Started

Prerequisites

Before you power up your MediaTek X20 Development Board for the first time you will need the following:

• MediaTek X20 Development Board.
• A 96Boards compliant power supply (sold separately ).
• A HDMI or DVI LCD Monitor that supports a resolution of 1080P/60Hz.
• HDMI-HDMI cable or HDMI-DVI cable to connect the board to the Monitor.
• A computer keyboard with USB interface.
• A computer mouse with USB interface.

Starting the board for the first time

To start the board, follow these simple steps:

1. Connect the HDMI cable to the MediaTek X20 Development Board connector (marked CON6501) and to the LCD Monitor.
2. Set the the third pin (USB HOST SET) of switch SW3205 to the position ON and connect the keyboard to USB connector marked CON6402 and the mouse to the USB connector marked CON6401. (It doesn’t matter which order you connect them in. )
3. Plug the power supply into the power outlet.
4. Press down the button (marked SW3201), and keep more than 3 seconds, the Android system will start.

Note: If set the first pin (AUTO_BOOT_SET) of switch SW3205 to the position ON, the Android system will start automatically when the power supply is plugged into the power outlet.

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Component Details

Processor

MT6797 is a highly integrated application processor which uses an industry-leading Tri-Cluster Deca-Core CPU Architecture. The chip integrates Dual-core ARM@Cortex-A72 MPCoreTM operating at up to 2.3GHz, Quad-core ARM@Cortex-A53 MPCoreTM operating at up to 1.85GHz, Quad-core ARM@Cortex-A53 MPCoreTM operating at up to 1.4GHz, Quad-core Mali-T880 operating at up to 700MHz and an ARM@Cortex-R4 MCU . In addition, an extensive set of interfaces and connectivity peripherals are included to interface to cameras, touch-screen displays and MMC/SD cards.MT6797 also embodies wireless communication device, including WLAN, Bluetooth® wireless technology and GPS.

PMIC

There are a PMIC and two dedicated DC - DC converters for MT6797 platform.

• MT6351 is a power management system chip, containing 8 buck converters and 31 LDOs.
• DA9214 is a 4-phase high efficiency buck converter. It is applied to offer the kernel power of APU.
• fAN53555 is high efficiency step-down switching regulator. It is applied to offer the DVDD power of GPU.

Memory (DRAM)

The MediaTek X20 Development Board provides 2GB LPDDR3-SDRAM which is a 2-channel and 32bit width bus implementation interfacing directly to the MT6797 build-in LPDDR controller. The maximum DDR clock is 933MHz. It is mounted over the MT6797 using pop technology.

Storage

The MediaTek X20 Development Board provides an 8GB EMMC which is compliant with EMMC 5.1.

Micro SDHC

The MediaTek X20 Development Board SD slot signals are routed directly to the MT6797 MSDC1 interface. It meets the SD3.0 standard.

Boot ROM

The MediaTek X20 Development Board boots up from the EMMC.

Networking

Wifi

• Dual-band (2.4/5GHz) single stream 802.11 a/b/g/n/ac Rf, 20/40/80MHz bandwidth.
• Integrated 2.4GHz PA with max. 20dBm CCK output power, 5GHz PA OfDM 54Mbps output power 17dBm and VHT80 MCS9 output power 15dBm.
• Typical Rx sensitivity :-76.5dBm at both 11g 54Mbps mode and 11a 54Mbps mode,-62dBm at 11ac VHT80 MCS9 mode
• Integrated power detector to support per packet Tx power control

The MediaTek X20 Development Board also has a Rf connector to connect the external antenna or other Rf device. If you want to use this function, you should put the R5072 on with 0ohm resistor and remove the R5071 from the board.

Bluetooth

• Bluetooth specification V2.1+EDR, 3.0+HS and 4.1+HS compliant
• Integrated PA with 8dBm (class 1) transmit power
• Typical Rx sensitivity: GfSK -94dBm, DQPSK -93dBm, 8-DPSK -87.5dBm.

GPS

The GPS implementation is based on MTK connectivity chip MT6631 (U5003) supporting GPS, Galileo, Glonass and Beidou. It can receive GPS, Galileo, Beidou / Glonass simultaneously for more accurate positioning. But there is no GPS antenna on the board. You need to connect an external antenna to the Rf connector CON5006.

HDMI

• The 96Boards specification calls for an HDMI port to be present on the board. The MT6797 doesn’t include a built-in HDMI interface.
• The MediaTek X20 Development Board deploys the built-in DPI interface as the source for the HDMI output. A peripheral Bridge IC (U6502, MT8193) performs this task and it supports a resolution from 480i to 1080p at 30Hz.

MIPI-DSI

• The 96Boards specification calls for a MIPI-DSI implementation via the High Speed Expansion Connector.
• The MediaTek X20 Development Board implements a 4-lane MIPI_DSI interface meeting this requirement. It can support up to fHD(1080p@60fps). The MediaTek X20 Development Board routes the MIPI_DSI interface signals to the DSI-0 interface of the MT6797.

Camera Interface

• The 96Boards specification calls for two camera interfaces.
• The MediaTek X20 Development Board supports two camera interfaces, one with a 4-lane MIPI_CSI interface and one with 2-lane MIPI_CSI interface, meeting this requirement. The 4-lane MIPI_CSI interface can support 25M camera and the 2-lane MIPI_CSI interface can support 8M camera.

USB Ports

The MediaTek X20 Development Board supports a USB device port and three USB host ports via a USB MUX(U6503). The input channel( D+/D-) of USB MUX is connected to the P0 port of the SOC MT6797, and the two output channels(1D+/1D-,2D+/2D-) are connected to micro USB port and USB hub respectively. The three USB host ports are connected to the downstream ports of the USB hub.The control of U6503 is done via a software controlled GPIO (USB_SW_SEL, EINT9 from the SOC MT6797). When this signal is logic low, ‘0’, the USB data lines are routed to the Micro USB connector and the MT6797 P0 port is set to device mode. When ‘USB_SW_SEL’ is logic level high, ‘1’, the USB data lines are routed to U6401 (a 3-port USB HUB) and the MT6797 P0 port is set to host mode. The user can overwrite the software control by sliding switch 3 of dip-switch SW3205 to the ‘ON’ position. That action forces the USB–MUX (U6503) to route the USB data lines to the USB HUB. The overwrite option exists for the host mode only, you cannot hardware overwrite the MUX to force device mode.

USB Host ports

The MediaTek X20 Development Board supports three USB host port via a USB2.0 hub (U6401 USB2513-AEZG). Its upstream signal is connected to USB_P0 interface of MT6797.

• Port 1 of the USB HUB is routed to CON6401, a Type ‘A’ USB Host connector. A current limited controller (U6402) sets the Power Current limit to 1.18A.
• Port 2 of the USB HUB is routed to CON6402, a Type ‘A’ USB Host connector. A current limited controller (U6403) sets the Power Current limit to 1.18A.
• Port 3 of the USB HUB is routed to the High Speed Expansion connector. No current limited controller is implemented on the board for this channel.

USB Device ports

The MediaTek X20 Development Board implements a device port. The port is located at CON6403, a Micro USB type B. It is routed to USB_P0 interface of MT6797.

Note: the board can work in one mode at a time, Host mode or Device mode, not both.

Audio

The MediaTek X20 Development Board has four audio ports: BT, HDMI, PCM and analog port. The analog port which connected to MT6351 includes a stereo handset IO and two analog audio outputs.

DC Power

The MediaTek X20 Development Board can be powered by two ways:

• 8V to 18V supply from a dedicated DC jack(J901)
• 8V to 18V supply from the DC_IN pins on the Low Speed Expansion Connector(CON7001)

Power Measurement

The MediaTek X20 Development Board has three current sense resistors R916\ R923\ R924.

External fan Connection

The 96Boards specification calls for support for an external fan. That can be achieved by using the 5V or the SYS_DCIN (12V), both present on the Low Speed Expansion connector.

UART

The MediaTek X20 Development Board has two UART ports (UART1 / UART0), both present on the Low Speed Expansion connector. They are routed to the UART1 (UART1_TxD, UART1_RxD) and UART0 (UART0_TxD, UART0_RxD, UART0_CTS, UART0_RTS) interface of MT6797 separately. The UART1 is used for the serial console output.

Buttons

The MediaTek X20 Development Board presents four buttons. They are Power key,VOL up key,VOL down key and Reset key. The power ON/Off and RESET signals are also routed to the Low Speed Expansion connector.

Power Button

The push-button SW3201 serves as the power-on/sleep button. Upon applying power to the board, press the power button for more than 3 seconds, the board will boot up. Once the board is running you can turn power-off by pressing the power button for more than 3 seconds. If the board is in a sleep mode, pressing the power bottom will wake up the board. Oppositely, if the board is in an active mode, pressing the power bottom will change the board into sleep mode.

Reset Button

The push-button SW3204 serves as the hardware reset button. press the button for more than 1 seconds,the system will be rebooted.

Volume up

The Volume UP button is used to control the output speaker volume of the MediaTek X20 Development Board.

Volume down

The Volume Down button is used to control the output speaker volume of the MediaTek X20 Development Board.

Dip-switch

There is a four-channel dip-switch(SW3205) on the board.

• Channel 1:”AUTO BOOT”,used to boot the board automatically. If set the switch on , the system will start automatically when the power supply is plugged into the power outlet.
• Channel 2:NC.
• Channel 3:”USB HOST SET”,The user can overwrite the software control by sliding the switch to the ‘ON’ position.The overwrite option exists for the host mode only, you cannot hardware overwrite the MUX to force device mode.
• Channel 4: NC

LED Indicators

The MediaTek X20 Development Board has six LEDs.

Two activity LEDs

• Wifi activity LED –The MediaTek X20 Development Board drives this Yellow LED via BPI_BUS12, an IO from MT6797.
• BT activity LED –The MediaTek X20 Development Board drives this Blue LED via BPI_BUS13, an IO from MT6797.

four User LEDs

The four user LEDs are surface mount Green in 0603 size located next to the micro USB connector. The MediaTek X20 Development Board drives the four LEDs from the MT6797 GPIO: BPI_BUS8, BPI_BUS9，BPI_BUS10 and BPI_BUS11.

Additional functionality

The MediaTek X20 Development Board also has a additional interface (CON9001)for user debugging. It includes JTAG , UART0 and UART1 interface. The position is reserved, but the component is not mounted in the mass production. The component of CON9001 is AXT640124 produced by Panasonic. This interface should be used with the MTK debug board.

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Expansion Connectors

Low Speed Expansion Connector

UART {0/1}

The 96Boards specifications calls for a 4-wire UART implementation, UART0 and an optimal second 2-wire UART, UART1 on the Low Speed Expansion Connector.

• The MediaTek X20 Development Board implements UART0 as a 4-wire UART that connects directly to the MT6797 SoC. These signals are driven at 1.8V.
• The MediaTek X20 Development Board implements UART1 as a 2-wire UART that connects directly to the MT6797 SoC. These signals are driven at 1.8V.

I2C {0/1}

The 96Boards specification calls for two I2C interfaces to be implemented on the Low Speed Expansion Connector. The MediaTek X20 Development Board implements both interfaces named I2C4 and I2C5. They connect directly to the MT6797 SoC. Each of the I2C lines is pulled up to VIO18_PMU via 4.7K resistor.

GPIO {A-L}

The 96Boards specification calls for 12 GPIO lines to be implemented on the Low Speed Expansion Connector. Some of these GPIOs may support alternate functions for DSI/CSI control

The MediaTek X20 board implements this requirement. All GPIOs are routed to the MT6797 SoC.

• GPIO A -Connects to EINT16 of MT6797 SoC, can serves as external interrupt supporting the 96Boards requirements to create a wake-up event for the SoC. It is a 1.8V signal.
• GPIO B -Connects to EINT5 of MT6797 SoC, can serves as external interrupt supporting the 96Boards requirements to create a wake-up event for the SoC. It is a 1.8V signal.
• GPIO C -Connects to EINT4 of MT6797 SoC, can serves as external interrupt supporting the 96Boards requirements to create a wake-up event for the SoC. It is a 1.8V signal.
• GPIO D -Connects to EINT3 of MT6797 SoC, can serves as external interrupt supporting the 96Boards requirements to create a wake-up event for the SoC. It is a 1.8V signal.
• GPIO E -Connects to EINT2 of MT6797 SoC, can serves as external interrupt supporting the 96Boards requirements to create a wake-up event for the SoC. It is a 1.8V signal.
• GPIO f -Connects to EINT1 of MT6797 SoC, can serves as external interrupt supporting the 96Boards requirements to create a wake-up event for the SoC. It is a 1.8V signal.
• GPIO G -Connects to DSI_TE of MT6797 SoC, can serves as DSI_TE or GPIO179. It is a 1.8V signal.
• GPIO H -Connects to LCM_RST of MT6797 SoC, can serves as LCM_RST or GPIO180. It is a 1.8V signal.
• GPIO I -Connects to CAM_RST0 of MT6797 SoC, can serves as CAM_RST0 or GPIO32. It is a 1.8V signal.
• GPIO J -Connects to CAM_PDN0 of MT6797 SoC, can serves as CAM_PDN0 or GPIO28. It is a 1.8V signal.
• GPIO K -Connects to CAM_RST1 of MT6797 SoC, can serves as CAM_RST1 or GPIO33. It is a 1.8V signal.
• GPIO L -Connects to CAM_PDN1 of MT6797 SoC, can serves as CAM_PDN1 or GPIO29. It is a 1.8V signal.

SPI 0

The 96Boards specification calls for one SPI bus master to be provided on the Low Speed Expansion Connector. The MediaTek X20 Development Board implements a full SPI master with 4 wires, CLK, CS, MOSI and MISO. The signals are connected directly to the MT6797 SoC and driven at 1.8V.

PCM/I2S

The 96Boards specification calls for one PCM/I2S bus to be provided on the Low Speed Expansion Connector. The CLK, fS and DO signals are required while the DI is optional. The MediaTek X20 Development Board implements a PCM/I2S interface with 4 wires, CLK, fS, DO and DI. The signals are connected directly to the MT6797 SoC and driven at 1.8V.

Power and Reset

The 96Boards specification calls for a signal on the Low Speed Expansion Connector that can power on/off the board and a signal that serves as a board reset signal. The MediaTek X20 Development Board routes the PWR_BTN_N (named PWRKEY on schematic) signal to the PWRKEY pin of the PMIC MT6351. This signal is driven by SW3201 as well, the on-board power on push-button switch. A mezzanine implementation of this signals should not drive it with any voltage, the only allowed operation is to force it to GND to start the board from a sleep mode. The MediaTek X20 Development Board routes the RST_BTN_N (named SYSRSTB on schematic) signal to the SYSRSTB pin of the PMIC MT6351.

Power Supplies

The 96Boards specification calls for three power rails to be present on the Low Speed Expansion Connector:

• +1.8V Max of 100mA
• +5V Provide a minimum of 5W of power (1A).

SYS_DCIN 8-18V input with enough current to support all the board functions or the output DCIN from on-board DC Connector able to provide a minimum of 7W of power.

The MediaTek X20 Development Board supports these requirements as follows:

• +1.8V Driven by PMIC MT6351 up to 1000mA. It is the system IO power (VIO18_PMU), and it can supply power up to 200mA to the Low Speed Expansion Connector.

• +5V Driven by a 6A DC-DC buck converter (U901). It also provides the VBUS power to the two USB host connectors (CON6401, CON6402) and the HDMI 5V power to the HDMI connector (CON6501).The remaining capacity provides a max current of 2A to the Low Speed Expansion Connector, for a total of 10W which meets the 96Boards requirements.

• SYS_DCIN Can serves as the board’s main power source or can receive power from the board.

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High Speed Expansion Connector

MIPI DSI 0

The 96Boards specification calls for a MIPI-DSI to be present on the High Speed Expansion Connector. A minimum of one lane is required and up to four lanes can be accommodated on the connector. The MediaTek X20 Development Board implementation supports a full four lane (1.2Gbps/lane) MIPI-DSI interface that is routed to the High Speed Expansion Connector. The MIPI-DSI signals are directly connected to DSI-0 of MT6797.

MIPI CSI {0/1}

The 96Boards specification calls for two MIPI-CSI interfaces to be present on the High Speed Expansion Connector. Both interfaces are optional. CSI0 interface can be up to four lanes while CSI1 is up to two lanes. The MediaTek X20 Development Board implementation supports a full four lane MIPI-CSI interface on CSI0 and two lanes of MIPI-CSI on CSI1. All MIPI-CSI signals are routed directly to/from the MT6797SoC. CSI0 can support up to 25M@30fps and CSI1 can support up to 8M@30fps. The max data rate of each lane is 2.5Gbps.

I2C {2/3}

The 96Boards specification calls for two I2C interfaces to be present on the High Speed Expansion Connector. Both interfaces are optional unless a MIPI-CSI interface has been implemented. Then an I2C interface shall be implemented. The MediaTek X20 Development Board implementation supports two MIPI-CSI interfaces and therefore must support two I2C interfaces. for MIPI-CSI0 the companion I2C2 is routed directly from the MT6797SoC. for MIPI-CSI1, the companion I2C is I2C3. Each of the I2C lines is pulled up to VIO18_PMU via 4.7K resistor.

SD/SPI

The 96Boards specification calls for an SD interface or a SPI port to be part of the High Speed Expansion Connector. The MediaTek X20 Development Board implements a full SPI master with 4 wires (96Boards SPI Configuration), CLK, CS, MOSI and MISO. All the signals are connected directly to the MT6797 SoC. These signals are driven at 1.8V.

Clocks

The 96Boards specification calls for one or two programmable clock interfaces to be provided on the High Speed Expansion Connector. These clocks may have a secondary function of being CSI0_MCLK and CSI1_MCLK. If these clocks can’t be supported by the SoC than an alternative GPIO or No-Connect is allowed by the specifications. The MediaTek X20 Development Board implements two CSI clocks which are connected directly to the MT6797 SoC. These signals are driven at 1.8V.

USB

The 96Boards specification calls for a USB Data line interface to be present on the High Speed Expansion Connector. The MediaTek X20 Development Board implements this requirement by routing USB channel 3 from the USB HUB to the High Speed Expansion Connector.

HSIC

The 96Boards specification calls for an optional MIPI-HSIC interface to be present on the High Speed Expansion Connector. The MediaTek X20 Development Board implementation doesn’t support this optional requirement.

Reserved

The pin 60 of the High Speed Expansion Connector is pulled up to VIO18_PMU via 100K resistor.

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Analog Expansion Connector

Speaker

The speaker signals are routed from the MT6351 built-in Audio CODEC. It should be connected to an external speaker amplifier. Do not connect it to speaker directly. The two signals are:

• AU_LOLP
• AU_LOLN

The main parameters are list in table below.

Mic

The microphone signals are routed to the MT6351 built-in Audio CODEC. It is an uplink input channel and it can be connected to a MIC or a codec line out. The signals are:

• AU_VIN0_P
• AU_VIN0_N
• MICBIAS0(The bias voltage output step size is 0.1V, the range is 1.7~2.1V/2.5~2.7V)

Earphone

The earphone signals are routed from the MT6351 built-in Audio CODEC. It can support stereo earphone directly (Single-ended Output, RLOAD=16/32Ω). The singles are:

• AU_HPL
• AU_HPR
• ACCDET1
• AU_VIN0_P
• AU_VIN0_N
• MICBIAS0

There are two ways (ACC mode and DCC mode ) to detect the accessory. In DCC mode, the ACCDET1 is not use. And the system can detect the earphone inserting via a EINT (External interrupt GPIO of MT6797 ). In ACC mode, the ACCDET1 should be connected to the positive of MIC input signals (between the bypass capacitor and the earphone jack). It is used to detect the Up key, Down Key and Hook key. for the earphone inserting detection, you also need to use an EINT GPIO. The main parameters are list in table below.

| Parameter | Min. | Typ. | Max. | Unit | |:——————————————–|:—–:|:—–:|:—–:|:—–:| |4-pole Microphone Detection |2K| |14K| Ω| |Microphone impedance detection after 4-pole Microphone plugged-in| |MICD_LVL[0]: Up key |400| | 620| Ω| |MICD_LVL[1]: Down key |150| |320| Ω| |MICD_LVL[2]:Hook key |0 | |100| Ω| *Load impedance detection range (ACCDET1) by 1&1.5kΩ (1%) MICBIAS resistors.

Headset

The headset signals are routed from the MT6351 built-in Audio CODEC. It can support 16/32Ω receiver directly. The singles are:

• AU_HSP
• AU_HSN

fM Antenna

The fM antenna signals are routed to the MT6631 (U5003), an integrated connectivity device. The two signals below should be kept in differential trace to audio jack.

• fM_ANT
• fM_RX_N_6631

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Power Management Overview

Block Diagram

DC Power Input

• An 8V to 18V power from a dedicated DC jack J901.
• An 8V to 18V power from the SYS_DCIN pins on the Low Speed Expansion Connector CON7001.

Note: Please refer to the mechanical size of the DC plug below.The inside diameter of the plug is 1.7mm，the outer diameter of the plug is 4.75mm.The positive electrode of the DC plug is in the inside, and the negative pole is outside.

Power Source Selection and Sequencing

The user of the MediaTek X20 Development Board should never apply power to the board from J901 and the Low Speed Expansion connector at the same time. There is no active or passive mechanism on the MediaTek X20 Development Board to prioritize one source over the other.

Voltage Rails

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Mechanical Specification

2D Reference Drawing

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