Forlinx FET3506J-C is an ultra-small (40 x 29mm) Rockchip RK3506J SoM with board-to-board connectors

Forlinx Embedded FET3506J-C is an ultra-small system-on-module (SoM) based on Rockchip RK3506J triple-core Cortex-A7 SoC measuring just 40 x 29mm, and equipped with up to 512MB DDR3, and 256MB NAND flash, or 8GB eMMC flash.

I first thought I had already written about it, but the Forlinx FET3506J-S module introduced last March has a different design. It measures 44 x 35mm and exposes all I/Os through castellated holes, while the FET3506J-C features two 80-pin board-to-board (B2B) connectors instead. The company also provides the OK3506J-C single board computer for evaluation, but considering the module is inserted into the carrier board, as opposed to soldered, the carrier board could potentially be used with future modules using the same B2B connectors design.

Forlinx FET3506J-C system-on-module

Tiny Rockchip RK3506J SoM — Note: the silkscreen implies either RK3506J (industrial-grade) or RK3506B could be used..

Specifications:

SoC – Rockchip RK3506J/B
- CPU
  - 3x Arm Cortex-A7 core up to 1.5 GHz (RK3506J) or 1.6 GHz (RK3506B)
  - Arm Cortex-M0 real-time core @ 200 MHz
- GPU – 2D GPU only
- No VPU, no NPU
System Memory – 256MB or 512MB DDR3
Storage
- 256MB NAND Flash or
- 8GB eMMC flash
2x 80-pin board-to-board connectors (0.5mm pitch)
- Storage
  - 4-bit SDIO (only available if eMMC flash is not soldered)
  - FSPI (only available if NAND flash is not soldered)
- Display
  - 2-lane MIPI DSI
  - 24-bit RGB LCD interface with resolution up to 1280×1280 @ 60Hz; note multiplexed with FLEXBUS and DSMC interfaces
- FLEXBUS parallel interface for high-speed I/Os
- DSMC data bus for PSRAM and FPGA communication. (8-bit/16-bit master mode, 8-bit slave mode)
- Audio
  - 4x SAI (2x 1-lane Tx/1-lane Rx, 1x 4-lane TX/1-lane Tx, 1x 1-Lane Tx/4-lane Rx)
  - 4ch PDM
  - S/PDIF TX/RX
  - Audio ADC
  - 2x Audio DSM
- Networking – 2x 10/100Mbps Ethernet (RMII)
- USB – 2x USB 2.0, including one supporting OTG
- Other I/Os
  - 2x CAN 2.0 / CAN-FD interfaces
  - 3x SPI, up to 6x UART (UART0 serves as debug port), 3x I2C up to 1 Mbps
  - Up to 11x PWM
  - Analog – Up to 4x 10-bit SARADC up to 1MS/s; input voltage range: 0 to 1.8V
  - Up to 8x touch key interfaces
  - Up to 76x GPIOs (70x GPI, 76x GPO)
- Debugging – JTAG
Supply Voltage – 5V DC
Dimensions – 40 x 29mm
Temperature Range – -40°C to +85°C

The interfaces listed on the 80-pin B2B connectors are the same as on the 146 castellated edge for the “S” module, despite the larger number of pins, as it must be what the process supports.

Forlinx Embedded provides a Linux 6.1 BSP with support for LVGL 9.2, and Linux RT, as well as the OK3506J-C carrier board described below. The module is designed for industrial automation, new energy solutions, consumer electronics products, and smart medical devices.

OK3506J-C single board computer

Specifications:

SoM – Forlinx FET3506J-C described above
Storage – MicroSD card slot (only working with the NAND flash version of the module)
Display Interface
- 2-lane MIPI DSI connector
- 24-bit RGB LCD connector supporting up to 1280×1280 @ 60Hz.
- Only one display is supported
Audio
- 3.5mm audio jack with stereo audio and microphone
- Onboard microphone
Networking
- 2x 10/100Mbps Fast Ethernet RJ45 ports
- Wi-Fi 4 & Bluetooth 4.0 module via Realtek RTL8723DU (USB 2.0) module and SMA antenna connector
- Optional 4G LTE module via mini PCIe (USB 2.0) socket, Nano SIM card socket, and SMA antenna connector
USB
- USB Type-C port
- 2x USB 2.0 Type-A ports
Serial via terminal block
- 2x CAN Bus and CAN-FD with isolation and protection.
- RS485 with isolation and protection
Expansion – DSMC header
Debugging
- USB to serial converter via USB Type-C port
- JTAG via header
Misc
- Power on/off switch
- 6x buttons for Reset , Maskrom, VOL+, VOL-, MENU, and ESC
- Onboard RTC chip and coin-cell battery holder.
Power Supply – 12V DC jack
Dimensions – TBD

The OK3506J-C SBC is essentially the same as the OK3506-S SBC, except it’s designed for the Forlinx FET3506J-C module with board-to-board connectors.

As usual, Forlinx did not provide price and availability information for their new system-on-module and development board, and the company asks people to request a quote instead. More details may be found on the product page and a blog post. [Update: price is available on Digikey. See the comments section:

256MB RAM + 256MB Flash for $15
512MB RAM + 8GB Flash for $20
]

Jean-Luc Aufranc (CNXSoft)

Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.