A System on Module (SoM) is a compact, pre-integrated computing unit that contains the core components of an embedded system, typically a processor (CPU or SoC), memory, power management, and essential peripherals, on a single board. Instead of designing these complex subsystems from scratch, engineers can integrate a SoM into a custom carrier board tailored to their specific application.

Conclusive Engineergin RCHD-PF SoMConclusive Engineering RCHD-PF SoM

In modern embedded product development, SoMs significantly reduce time-to-market, engineering complexity, and risk. They are widely used in industries like IoT, industrial automation, automotive, and medical devices, where rapid prototyping and scalability are critical. By abstracting the most challenging parts of hardware design, SoMs allow teams to focus on differentiation (software, connectivity, and application-specific features) rather than reinventing foundational computing hardware.

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Technical Explanation: How a System on Module Works

At its core, a SoM functions as the “brain” of an embedded system. It integrates multiple subsystems that would otherwise require extensive hardware design effort.

Key Components of a SoM

A typical SoM includes:

  • Processor / SoC (System on Chip). ARM-based processors are most common (e.g., NXP i.MX, STM32MP1, Qualcomm), though x86-based SoMs are also used for higher-performance applications.
  • Memory
    • RAM (DDR3/DDR4/LPDDR)
    • Non-volatile storage (eMMC, NAND, NOR flash)
  • Power Management IC (PMIC). Handles voltage regulation and sequencing for stable operation.
  • Connectivity Interfaces
    • Ethernet, USB, PCIe
    • CAN, UART, SPI, I2C
    • Wireless modules (Wi-Fi, Bluetooth, LTE, 5G)
  • Optional Accelerators
    • GPU / NPU (for AI/ML workloads)
    • DSP (for signal processing)

Architecture Overview

Think of a SoM as a modular compute block:

[ System on Module ]
   ├── CPU / SoC
   ├── RAM
   ├── Flash Storage
   ├── Power Management
   └── High-speed Interfaces
           ↓
[ Carrier Board ]
   ├── Connectors (USB, HDMI, etc.)
   ├── Sensors / Actuators
   ├── Custom I/O
   └── Power Input

The carrier board is application-specific, while the SoM remains reusable across multiple products.

How System on Modules are Integrated

The SoM connects to the carrier board via:

  • Board-to-board connectors (e.g., edge connectors, mezzanine connectors)
  • High-speed interfaces routed through standardized pinouts

This separation allows:

  • Hardware reuse across projects
  • Easier upgrades (swap SoM without redesigning the full system)
  • Faster certification cycles (especially for RF modules)

Common Challenges

Despite their advantages, SoMs introduce certain engineering considerations:

  • Thermal management: High-performance SoMs require careful heat dissipation.
  • Signal integrity: High-speed interfaces (PCIe, DDR) still need proper layout on the carrier board.
  • Vendor lock-in: Switching SoM vendors may require redesign due to pinout differences.
  • Long-term availability: Critical in industrial and automotive sectors.

Applications & Industry Relevance

SoMs are widely adopted across industries where embedded systems must balance performance, reliability, and development speed.

1. Industrial Automation

  • Human-Machine Interfaces (HMIs)
  • PLC controllers
  • Edge gateways

Why SoMs?

Industrial systems require long lifecycle support and robust performance. SoMs reduce design risk while enabling scalable deployments.

2. Internet of Things (IoT)

  • Smart home hubs
  • Industrial IoT gateways
  • Edge AI devices

Example:

An IoT gateway using an ARM-based SoM can handle sensor aggregation, edge processing, and cloud communication without requiring a full custom board design.

Read also: 5G Automotive Gateway with Advanced Connectivity Options - Conclusive Engineering Case Study

3. Automotive Systems

  • Telematics units
  • Infotainment systems
  • ADAS edge processors

Why SoMs?

They simplify compliance with automotive standards and enable rapid iteration in evolving architectures like software-defined vehicles.

4. Medical Devices

  • Diagnostic equipment
  • Patient monitoring systems
  • Imaging devices

Key advantage:

Pre-certified SoMs reduce regulatory burden and accelerate time-to-market in highly controlled environments.

Read also: Medical Devices Development Services

5. Consumer Electronics

  • Smart displays
  • Robotics
  • Home automation systems

SoMs allow rapid prototyping and scaling from proof-of-concept to production.

Develop system on modules and other electronic hardware with Conclusive Engineering.

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System on Module vs System on Chip vs Single Board Computer

Understanding how SoMs compare to related concepts is essential for selecting the right architecture.

SoM vs SoC (System on Chip)

Feature SoM SoC
Definition Complete module with memory & peripherals Integrated chip with CPU, GPU, etc.
Design effort Low (plug-and-play) High (requires full hardware design)
Flexibility High Limited
Use case Product development Component-level design

A SoC is a component; a SoM is a ready-to-use subsystem built around that component.

SoM vs Single Board Computer (SBC)

Feature SoM SBC
Customization High (via carrier board) Limited
Production use Ideal Often not optimized
Cost at scale Lower Higher
Examples RCHD-PF WHLE-LS1

SBCs are great for prototyping; SoMs are designed for production-grade systems.

Read also: What Is a Single Board Computer?

Best Practices: How to Use a System on Module Effectively

To maximize the benefits of a SoM, engineering teams should follow these practices:

1. Choose the Right SoM Early

Consider:

  • CPU performance requirements
  • Memory capacity
  • Industrial vs consumer-grade components
  • Long-term availability (10-15 years for industrial)

2. Design a Robust Carrier Board

Even with a SoM, carrier board design is critical:

  • Proper power design and filtering
  • High-speed signal routing (PCIe, USB 3.0)
  • EMC/EMI compliance

This is where hardware design expertise becomes essential.

3. Optimize Firmware and BSP Integration

  • Use vendor-provided Board Support Packages (BSPs)
  • Customize Linux (Yocto/Buildroot) or RTOS environments
  • Ensure security updates and OTA capability

This ties directly into firmware development workflows.

4. Plan for Thermal and Mechanical Constraints

  • Use heat sinks or thermal pads
  • Ensure airflow in enclosure design
  • Validate under worst-case conditions

5. Avoid Vendor Lock-In

  • Prefer standardized form factors (e.g., SMARC, Qseven)
  • Evaluate second-source availability

Common Mistakes and Pitfalls

Treating SoM as “Plug-and-Play”

While easier than full hardware design, integration still requires:

  • Signal integrity validation
  • Power sequencing considerations
  • Software customization

Ignoring Lifecycle Constraints

Consumer-grade SoMs may be discontinued quickly. Always verify:

  • Product lifecycle guarantees
  • Industrial-grade availability

Underestimating Software Complexity

Even with a SoM:

  • Linux bring-up
  • Driver integration
  • Security hardening

…can still be significant engineering efforts.

Poor Carrier Board Design

Most system failures originate here, not in the SoM itself.

FAQs: System on Modules

What is the difference between SoM and SOM module?

They refer to the same concept: “System on Module.” The duplication is just naming variation.

Is a SoM better than a custom board?

It depends:

  • SoM → faster development, lower risk
  • Custom board → optimized cost at very high volumes

Can you upgrade a SoM?

Yes. One major advantage is the ability to:

  • Swap to a newer SoM with minimal redesign
  • Improve performance without changing the full system

Are SoMs suitable for mass production?

Absolutely. They are widely used in:

  • Industrial systems
  • Medical devices
  • Automotive electronics

Do SoMs support real-time systems?

Yes. Many SoMs support:

  • RTOS (FreeRTOS, Zephyr)
  • Real-time Linux (PREEMPT_RT)

The Takeaway

A System on Module (SoM) is a powerful abstraction that simplifies embedded system design by packaging complex computing subsystems into a reusable, production-ready module. It allows engineering teams to accelerate development, reduce risk, and focus on product differentiation rather than low-level hardware integration.

For organizations building IoT devices, industrial systems, or advanced embedded products, SoMs provide a practical balance between flexibility and efficiency. However, success depends on proper carrier board design, firmware integration, and lifecycle planning.

At Conclusive Engineering, we help teams leverage SoMs effectively, from hardware design and PCB development to firmware engineering and system optimization, ensuring robust, scalable embedded solutions tailored to real-world applications.