Forlinx third generation iMX6ULL core board hardware design guide and power consumption table

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Forlinx third generation iMX6ULL core board hardware design guide and power consumption table [Copy link]

NXP i.MX6ULL expands the i.MX6 series, which is a high-performance, ultra-efficient, low-cost processor sub-series, using the advanced ARM Cortex-A7 core, running at up to 800MHz. The i.MX6ULL application processor includes an integrated power management module, which reduces the complexity of the external power supply and simplifies the power-on timing. The target applications are: automotive telematics, IoT gateways, human-machine interfaces, home energy management systems, smart energy information concentrators, smart industrial control systems, electronic POS devices, portable medical devices, printers and 2D scanners, etc.

i.MX6ULL Application Processor Block Diagram

The FETMX6ULL-C core board is developed and designed based on the NXP i.MX6ULL processor, using the low-power ARM Cortex-A7 architecture and running at up to 800MHz. It natively supports 8-way UART, 2-way Ethernet, 2-way CAN bus, 2-way USB, LCD and other common interfaces. It also adopts an ultra-small size design, with the core board size of only 40*29mm, which is suitable for more volume-limited application scenarios.

FETMX6ULL-C core board Linux system power consumption measurement table

serial number	Test items	Supply voltage (V)	Working current
			Instantaneous peak value (mA)	Steady value(mA)
1	No display + no operation	5±5%	-	250
2	With 4.3-inch screen + no operation	5±5%	-	315
3	With 7-inch screen + no operation	5±5%	-	587
4	Loading 4.3-inch screen + video playback + 100% CPU usage	5±5%	360	340
5	Loading 7-inch screen + video playback + 100% CPU usage	5±5%	715	700

Note:

Peak current: the maximum current value during the startup process;

Steady value current: The current value when it stays at the power-on interface after startup.

Core board hardware design description

The FETMX6ULL-C core board has integrated the power supply, reset monitoring circuit, and storage circuit into a small module. The required external circuit is very simple. A minimum system only needs a 5V power supply, a reset button, and a startup configuration to run, as shown in the following figure:

Design of minimum system schematic based on FETMX6ULL-C core board

Note:

When users design the baseboard themselves, they must reserve some circuits for the serial port to facilitate debugging;

When users design the baseboard by themselves, they must reserve some circuits for the DIP switches to facilitate program burning;

When users design the baseboard themselves, they should pay attention to the power-on sequence to prevent the latch effect from damaging the CPU (refer to 3.5.1 Baseboard Power Supply for specific design).

Generally, except for the minimum system, it is recommended to connect some external devices, such as the debug serial port, otherwise the user cannot determine whether the system is started. After doing this, add the functions required by the user based on the default interface definition of the core board provided by Feiling. The pin definition of the iMX6ULL series core board can be obtained by contacting Feiling Embedded Customer Service.

Hardware Design Guidelines

1. Boot configuration method

i.MX6ULL has multiple burning and booting modes. After the system is powered on or reset, different burning and booting modes can be selected by reading the status of the system startup configuration pins.

When users design the baseboard, they must add this circuit. For specific configuration methods, please refer to the development board baseboard schematic diagram and the Boot configuration section of this manual. At the same time, users are reminded that if they need to use both SD card burning and eMMC boot modes at the same time, they must add control of the LCD_DATA11 pin. Otherwise, they can fix the level of LCD_DATA11 as needed.

2. PMIC_ON_REQ driving capability issue

GEN_5V and GEN_3.3V on the baseboard are obtained through the control of the PMIC_ON_REQ pin. The current driving capability of the PMIC_ON_REQ pin is too weak, and a voltage-controlled switching element is required. The development board uses the N-channel field effect transistor AO3416. Please refer to the baseboard power supply circuit design.

3. Add pull-up resistor to IIC bus

When users design the baseboard themselves, they need to pay attention to the IIC bus must be added with a pull-up resistor, otherwise the IIC bus device may not be used. Currently, the two IIC buses led out of the baseboard are pulled up to 3.3V through a 1.5K resistor.

4. USB1-1 error occurs during debugging

When using the USB interface, the user needs to connect USB_OTG1_VBUS and USB_OTG2_VBUS to 5V, otherwise an error will be reported. Currently on the baseboard, the USB_OTG2_VBUS pin is connected to GEN_5V through a 0Ω resistor.

5. CAN circuit RX pin output level

The default CAN transceiver chip used by the development board is TJA1040T. The output level of the RX terminal of the chip is 5V, while the level of the CPU pin is 3.3V. In order not to affect the 3.3V power supply inside the CPU, it is necessary to connect a resistor to the ground in series at the RX terminal of the chip to divide the voltage before connecting to the CPU. Please refer to the CAN circuit.

6. Please leave pins not used by the user floating.