Unex SOM-352 Series - User Manual

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Overview

Function Description
Important Technical Specifications
Usage Features
Maintenance Features

The Unex SOM-352 family of products are V2X mPCIe System-On-Modules designed for various applications, including C-V2X and ITS-G5 stacks for Europe and C-V2X and WAVE stacks for the USA. This quick start guide provides essential information for setup, installation, operation, and maintenance of these modules.

Function Description:

The SOM-352 modules serve as a core component for V2X (Vehicle-to-Everything) communication, enabling vehicles to communicate with each other (V2V), with infrastructure (V2I), and with other entities. They integrate a V2X mPCIe System-On-Module, with specific variants supporting different communication standards and regions. The modules are designed to be integrated into a host system via a mini PCIe slot, offering flexibility in deployment. Key functionalities include V2X communication, GNSS (Global Navigation Satellite System) for positioning, and various I/O interfaces for control and data transfer. The modules support firmware upgrades and incorporate tamper detection for security.

Important Technical Specifications:

Product Variants:
- SOM-352: V2X mPCIe System-On-Module, 0A1
- SOM-352EC: V2X mPCIe System-On-Module, V2Xcast® - C-V2X stack, Europe, 0A1
- SOM-352ED: V2X mPCIe System-On-Module, V2Xcast® - ITS-G5 stack, Europe, 0A1
- SOM-352UC: V2X mPCIe System-On-Module, V2Xcast® - C-V2X stack, USA, 0A1
- SOM-352UD: V2X mPCIe System-On-Module, V2Xcast® - WAVE stack, USA, 0A1
Dimensions and Weight:
- Length: 51.0 mm
- Width: 38.5 mm
- Height: 11.5 mm
- Weight: 21.2 g
- Note: The module is 8.5mm wider than the standard 30mm mini PCIe width, requiring at least 3mm clearance on both sides. A total height limitation of 13mm is recommended.
Electrical Characteristics (Absolute Maximum Ratings):
- Storage Temperature: -40 to 105 °C
- Supply Voltage (mPCIe 5V): -0.3 to 6.0 V
- Supply Voltage (mPCIe 3.3 Vaux): -0.3 to 3.9 V
- V2X Maximum Input Level: 10 dBm
- GNSS Maximum Input Level: -10 dBm
Electrical Characteristics (Recommended Operating Conditions):
- Ambient Operating Temperature: -40 to 85 °C
- Supply Voltage (mPCIe 5V): 4.8 to 5.2 V (Typical 5.0V)
- Supply Voltage (mPCIe 3.3 Vaux): 3.0 to 3.6 V (Typical 3.3V)
- mPCIe 1PPS (P49) Tolerance: Accuracy/Bias -100 to 100 ns, Precision/Jitter -30 to 30 ns, Pulse width 15 ns
- V2X Sensitivity (PER ≤ 10%): -92 dBm (at 25°C), -82 dBm (at -40 to +85°C)
- V2X Maximum Output Level: 20 dBm
- V2X Adjacent Channel Rejection: 13 dB
- V2X Non-Adjacent Channel Rejection: 29 dB
- GNSS Sensitivity (C/No) Acquisition: 22 to 45 dB-Hz (Typical 30 dB-Hz)
- GNSS Antenna Bias: 3.0 to 3.3 V (for IANT ≤ 20mA)
- GNSS Antenna Detection Current: 12 to 58 mA
- GNSS Maximum Total External Gain: 24 dB
Power Consumption (Typical at 25°C, CPU idle and V2X stack loaded):
- Dual Voltage (5V/3.3V): 5V (0.40A), 3.3 Vaux (0.105A)
- External Cable (5V/3.3V): 5V (0.40A), 3.3 Vaux (0.105A)
- Single Voltage (3.3V): 3.3 Vaux (0.70A)
Antenna Connectors: Three 50 Ω RF connectors (I-PEX MHF I 20279-001E-03) for two V2X antennas and one GNSS antenna.
I/O Interfaces: Mini PCIe Card Pinout (5V, 3.3V Vaux, UART, PERST#, 1PPS, TAMPER#, USB data lines, BOOTSTRP), I/O Cable Pinout (5V, RXD, TXD, EX_RSTn, 1PPS, TAMPER#, GND).
DIP Switch Functions: Controls 5V power source, UART RXD/TXD source, CRATON2 reset source, 1PPS source, TAMPER# source/trigger mode, and boot mode (NAND/USB0 DFU).
USB: USB 2.0 high-speed (480 Mbits/s) transceiver for control, data transfers, diagnostic monitoring, and firmware upgrade.
Serial Port: 3.3V TTL logic level UART interface.

Usage Features:

Flexible Powering Options: The SOM-352 can be powered in three ways: dual voltage (5V/3.3V) via the mini PCIe slot, external cable (5V/3.3V) via the Molex 7-pin connector, or single voltage (3.3V) via the mini PCIe slot.
Antenna Detection: Built-in V2X antenna detection for Unex EX-55 or EX-53 antennas, and GNSS antenna detection based on current consumption (OPEN, NORMAL, SHORT status reported via NMEA message).
Boot Mode Selection: The BOOTSTRP pin (P46) and DIP switch SW1.8 allow selection between normal boot from NAND and firmware upgrade (DFU mode) via USB0.
Host System Integration: Designed for integration with Windows 10/11 and Linux host systems, using RNDIS over USB for network connectivity and SSH for terminal access.
I/O Cable for Existing Systems: An optional I/O cable (Molex Pico-Lock system 504051-0701) allows installation on existing mini PCIe system boards without hardware modification, directing power and I/O signals.
GNSS 1PPS Input: Supports external 1PPS signal input for precise timing, with options to switch between internal and external GNSS sources via software settings.
Reset Functionality: The PERST# pin (P22) provides a low-active reset, rebooting Linux on a rising edge. Pulling this pin low can put the SOM-352 into standby mode to save power.

Maintenance Features:

Firmware Upgrade: Supports firmware upgrades via USB0 in DFU mode, controlled by the BOOTSTRP pin or DIP switch SW1.8.
Troubleshooting Guide: Provides steps for diagnosing common issues such as repetitive resetting (suggests supplying 5V power from J1.1) and no response after applying power (checks power supply, DIP switch settings, UART console, RNDIS driver, and IP address conflicts).
Thermal Management: Recommendations for heat dissipation include adding thermal vias, exposing bare copper on the system board, and using a soft silicone thermally conductive pad between the module and the system board.
Safety Guidelines: Emphasizes keeping the working area clean and dry, considering environmental control in extreme temperatures, and ensuring all accessories (antenna cables, mPCIe socket latch/screws) are fastened.
Antenna Cable Extraction: Provides specific instructions and tool recommendations (I-PEX 90192-001 or 90224-001) for safe extraction of antenna cables to prevent damage to connectors.
Tamper Detection (Optional): Supports FIPS 140-2 Level 3 security requirements. The tamper detection mechanism is hardware-based, with software APIs to enable production mode (normal or standby) or test mode. In production mode, a tamper event erases critical security parameters.
Design-in Guidelines: Offers recommendations for power line traces (width, routing), power sequence (5V before 3.3V Vaux), grounding (good GND connection, multiple vias), and USB data line routing (impedance, differential pair routing, trace length, avoiding interference from oscillators).
Host GPIO Control: Allows the host system's GPIO to control the boot mode when mPCIe Pin 46 (BOOTSTRP) is connected to it and BOOTSW (SW1.8) is ON.