MY-IMX6 motnherboard layout instruction
This document is for users to have a quick design of base board,with guidance for how to solve the questions clients may meet commonly,in order for clients to design a product which can be used in all kinds of environments。
power supply
schematic
MY-I.MX6 series of core board only needs 5V power source（constant current is not small than 2A，peak value 2.5A-3A）as an input。details as below。
if it is a direct 5V input，5V power source need a over voltage protection，the protection circuit can be designed with following reference。
if it is high voltage input to be converted to 5V through DCDC principle,the core board will output 3P3V power source with a maximum current 500mA of which can be used as power supply for base board if current with 3.3V on the base board is too small，in this case,please put in serial a fuse for this 3P3V power source 。
since current with 3.3V on the base board is usually over 500mA，normally users will generate a another 3.3V through DCDC or LDO。
note：enable control must be done for 3.3V on base board by 3P3V on core board instead of being conducted by other power sources on the base board.if there are other power sources on base board,their enable controls must be conducted by 3P3V as well,this is up to the nature of I.MX6 chip。
reference circuit as below：
PCB
capacitor with big capacity should be placed near 5V input on core board, to ensure contiguous power supply even when sudden extra load is added for CPU。if there is via hole,need to make sure via hole can go through 3A peak current,more via holes can be built to increase current。
serial port design
principle
for serial port design,common questions arising are inversion between RXD and TXD。network standard in the schematic as below
TXD——CPU output
RXD——CPU input
PCB
note：we can provide schematic and PCB diagram for design of base board,our serial port is female head as connector.please assure your design to be consistent with our offer,if change serial port to be male head connector,then RS232 signal connector head need to be changed accordingly.For the details of male and female head connector,please get on internet for consuls.
SD card design
principle
for users'design of SD card,please follow strictly schematic to arrange IO dropdown，excessive dropdown will enable SD card not to work normally。reference diagram as below
note：if users don't need SD card,but need TF card,since TF card doesn't have function of write-protect.Write-protect signal（SD3_RST/SD3_WP）need to pull down,which can't be hanged directly in the air.If TF card booth is designed with hot swap，must make clear which pin of TF card is for dectection. normally when insert the card,detection pin will be grounded，the inserted detection pin KEY_COL/SD3_CD_B）need to pull up.If TF card booth is designed with flip type,write-protect need to pull up,at the same time the inserted detection signal need to be grounded（just as a card is kept in the booth）
if need additional ESD protect,please ensure a small capacity value on SD_CLK signal。
PCB
SD0，SD1，SD2，SD3，CMD，CLK signal need an equal treatment。ESD originals need to be very close to SD card booth。
SATA design
principle
SATA principle is simple by contrast, only need to ensure a correct direction. since current on SATA is normally a little big, 5V current inputted is better not to be as low as 3A。
PCB
the four capacitors which are seriated to SATA signal should be close to SATA booth。
100 ohm difference resistance matching up
length tolerance for each group of differences pairs is controlled within ±5mil
require a full reference to ground level
HDMI
principle
HDMI stand can't be linked with wrong definition
PCB
100 ohm difference resistance matching up。
length tolerance for each group of differences pairs is controlled within±5mil
require a full reference to ground level
protect component CM2020 can't be ignored。
LVDS
principle
if transmitting distance for LVDS signal is long，and screen linked with is big，magnetic coupling can be put in serial on LVDS signal for a better transmiting quality。
PCB
100 ohm difference resistance matching up。
length tolerance for each group of differences pairs is controlled within±5mil
if two way LVDS signal is used for 1080p display,。LVDS0 and LVDS1 signal need an equal treatment。
require a full reference to ground level
RGB port LCD
principle
LCD as RGB port need to be matched up with interface model with 24bit，18bit
CPU signal（note1） | 24bit（note2） | 18bit（note3） | 18bit(note4) |
D0 | B0 |
| B0 |
D1 | B1 |
| B1 |
D2 | B2 | B0 | B2 |
D3 | B3 | B1 | B3 |
D4 | B4 | B2 | B4 |
D5 | B5 | B3 | B5 |
D6 | B6 | B4 | G0 |
D7 | B7 | B5 | G1 |
D8 | G0 |
| G2 |
D9 | G1 |
| G3 |
D10 | G2 | G0 | G4 |
D11 | G3 | G1 | G5 |
D12 | G4 | G2 | R0 |
D13 | G5 | G3 | R1 |
D14 | G6 | G4 | R2 |
D15 | G7 | G5 | R3 |
D16 | R0 |
| R4 |
D17 | R1 |
| R5 |
D18 | R2 | R0 |
|
D19 | R3 | R1 |
|
D20 | R4 | R2 |
|
D21 | R5 | R3 |
|
D22 | R6 | R4 |
|
D23 | R7 | R5 |
|
note1.
D0 indicate a minimal level for CPU liquid crystal port，
D23 indicate a maximal level for CPU liquid crystal port
note2
B0-24 bit blue bit of liquid crystal at minimal level，
B7-24 bit blue bit of liquid crystal at maximal level,
G0-24 bit green bit of liquid crystal at minimal level，
G7-24 bit green bit of liquid crystal at maximal level
R0-24 bit red bit of liquid crystal at minimal level，
R7-24 bit red bit of liquid crystal at maximal level
note3.
in use of this kind of link，LCD software still choose 24bit model
B0-18 bit blue bit of liquid crystal at minimal level，
B5-18 bit blue bit of liquid crystal at maximal level
G0-18 bit green bit of liquid crystal at minimal level，
G5-18 bit green bit of liquid crystal at maximal level
R0-18 bit red bit of liquid crystal at minimal level，
R5-18 bit red bit of liquid crystal at maximal level
note 4.
if in use of this link method，LCD software need to choose 18bit model
B0-18 bit blue bit of liquid crystal at minimal level，
B5-18 bit blue bit of liquid crystal at maximal level
G0-18 bit green bit of liquid crystal at minimal level，
G5-18 bit green bit of liquid crystal at maximal level
R0-18 bit red bit of liquid crystal at minimal level，
R5-18 bit red bit of liquid crystal at maximal level
if there is a strict request with static，need ESD protect for LCD signal。
PCB
for all data lines，need an equal treatment for CLK signal
request a full reference to ground level
CMOS
principle
PCB
since frequency of MCLK and PIXCLK signal is very high，need isolation treatment when Layout
data，need an equal treatment for clk signal。
request a full reference to ground level
USB
principle
USBHOST expanded with 4 and USBHOST via LAN9514，and expanded with one way 10M/100M ethernet interface。
a coupling inductance is put in serial on USB line。
Core board USB_H1_VBUS signal of core board need to be connected with 5V power supply through magnetic bead。
if power supply Host out of the board,please include over-current protect component for USD。
so far only device port can be done in layout of hardware for MINIUSB port，if need function of HOST，please refer to OTG layout from FSL official。
PCB
90 ohm difference resistance matching up
request a full reference to ground level
current to supply outside need to be big enough。
CAN
principle
since CAN的TX,RX signal is 3.3V electrical level，attention to conversion of electrical level。
PCB
CANH,CANL check signal。
PCIE
principle
TX,RX signal need to connect in serial with 0.1uF capacitor（if an external module is already with a capacitor in serial,then no need to connect a capacitor again）
CLK signal connect in serial with 0.1uF capacitor,at the same time put a 49.8 resistor to ground in parallel with another end of the capacitor 。
PCB
85 ohm difference resistance matching up
request a full reference to ground level
If you would like to know more about our products, please visit www.myzr-tech.com or email to enquiry@myzr.com.cn.
