Although the term “single board computer” implies that everything required for a full-fledged computer is available on a single PCB board, in practice, there are two types of SBCs – one of which requires a backplane to function, while the other requires only an external power source and a chassis on which to mount the board. SBCs can be classified by their form factor or the type of system bus interface used.
IndustriesSingle board computers have traditionally been used in a range of industries including industrial automation and process control, telecommunications, environment monitoring, power plants, oil refineries, chemical processing, steelmaking and military applications, all of which rely heavily on SBCs designed for embedded systems.
But the target markets for embedded systems are not limited to these heavy industries; SBCs are now finding their way into a virtually unlimited range of markets, from home automation to intelligent transportation systems to in-flight entertainment, digital signage, ATMs and other self-service machines, electronic kiosks and ticketing machines, casino game systems, and virtually any other industry in which compact affordable computer platforms can speed up, automate or enhance an existing process.
SBC RequirementsTime-to-market challenges, combined with complex, long-life software and hardware requirements, have a considerable impact on the embedded computing marketplace. The pressure to keep up with the latest technology leads to demands for upgraded platforms at an unprecedented pace, while maintaining compatibility with legacy interfaces. These market forces have led to a proliferation of new designs developed around non-proprietary computing standards and operating systems.
A number of factors influence demand for embedded systems. SBCs designed for OEM applications must consider operating system and software availability, time-to-market demands, the availability of experienced engineers, availability of peripherals and the demand for open systems. Demands on industrial PC technology are far greater than for standard consumer motherboards because consumer motherboards are optimized for production cost, but not for longevity. Consumer motherboards also lack solutions for intelligent cabling, EMI shielding or optimized cooling.
Industrial PCs traditionally focus on improved mechanics to overcome the limitations posed by the standard consumer PC set-up. Price still plays a very important role but today, the ultimate deciding factors are size, power consumption, availability of compatible software and peripheral hardware, and the low mean time between failures (MTBF).
SBCs are designed for high density integrated systems, with improved reliability features such as EMI shielding, optimized cooling, dust-free enclosures, shock resistance and extended temperature testing to ensure continued operation in extreme environments.
Lanner SBC AdvantagesLanner maintains strategic partnerships with leading manufacturers such as Intel, AMD, VIA, Microsoft, Winbond, Realtek and Broadcom, enabling Lanner to offer a comprehensive line of embedded computing products ranging from software to integrated hardware designs and engineering services.
Lanner SBCs are highly integrated with all key system interfaces and functions designed onto the board. This means that only application-specific I/O needs to be integrated to build a complete solution. This is made easy with standard accessories and contributes to the ultimate in fast system set-up – no specialized R&D knowledge or additional development time is required.
Lanner designs and manufactures a range of motherboards and slot cards that function as embedded SBCs in OEM and industrial applications. Lanner’s SBC product lines include PICMG CPU slot cards, ISA CPU slot cards, 3.5” SBCs, 4.5” SBCs and backplanes. Coupled with our integration services, Lanner delivers full system industrial computing platforms and components for applications requiring high durability, long life and low power consumption.
Lanner's small form factor SBCs provide extensive modern I/O interfaces including multiple LAN ports, VGA, DVI, S-Video and HDMI video ports, numerous COM ports and audio in/out jacks. Modern storage interfaces include CompactFlash sockets and SATA II drive connectors. USB 2.0 has become a standard component and is available on nearly all Lanner SBCs. Some models offer even more flexibility by providing PCI, mini-PCI or PCI Express expansion slots, PS2 keyboard/mouse connectors, digital I/O ports and other expansion interfaces.
SBCs are often categorized by the type of bus offered. Typical SBC buses include both standard consumer PC interfaces such as ISA, PCI and PCI Express, as well as more industrial-focused interface standards such as VMEbus, Compact-PCI and STD Bus.
More commonly, SBCs are classified by their form factor. The following is a brief description of the various form factors used in embedded computing.
PC/104, PC/104-Plus and PCI/104
These small form factor single board computers have been delivering low-cost, highly-integrated, trusted solutions for a long time, and they are designed to continue providing the same basic functionality from generation to generation. This includes connectors in the same locations from board to board and core integrated features such as graphics and I/O support always on board.
PC/104 is approximately the size of a 3.5" floppy drive. PC/104 components are small, reliable, easy-to-use, cost-effective, scalable, and powerful embedded computing building blocks used for a variety of industrial applications. At its most basic, PC/104 is simply the ISA bus repackaged for industrial use. PC/104 SBCs offer the advantage of not requiring a backplane; rather, they provide a standard stackable interface that allows them to be stacked on top of one another to add functionality. The PC/104 specification defines standards for self-stacking SBCs as well as the PC/104 interface. The original PC/104 specification was later expanded to take advantage of the PCI bus and renamed the PC/104-plus standard. PC/104-plus was eventually replaced by the PCI/104 standard which uses only PCI and does away with the legacy ISA bus.
EPICEarly small form factor stackable SBC’s were either PC/104 or EBX form factor, until at some point, the market demanded a form factor in between the two typical sizes. Several options have since become available, including mini-ITX, ETX and EPIC. The EPIC standard was developed as an internationally standardized small form factor midway between the industry standard PC/104 stackable format and EBX board size. However, an SBC designed to meet the EPIC specifications requires licensing from the several manufacturers who developed the standard, and therefore other PCB makers have employed non-standard SBC board sizes. The EPIC specification defines a 4.5 x 6.5 inch board, and allows I/O connections to be implemented as either pin-headers or PC-style ("real world") connectors.
3.5" SBC3.5-inch single board computers are so named because the board size is the same width and depth as a traditional 3.5” floppy disk drive (actual dimensions are 146 x 102mm). 3.5” SBCs deliver computing performance suited to fit a wide range of embedded applications from diagnostics tools to box PC control systems. The 3.5” SBC typically contains all of the functions of a full PC system and does not require a baseboard for use in a system. These highly integrated SBCs make designing simple with consistent features including expandable memory sockets, onboard connectors for multiple USB 2.0 devices, single and dual Gigabit Ethernet offerings, integrated graphics and audio capabilities, multiple serial ports and even PCI-Express or PCI/104 expansion if required.
ESM (Embedded System Module)The Embedded System Module form factor is a compact (149 x 71 mm) Computer on Module (COM) standard that can be inserted into a carrier board or used as a standalone embedded board. ESM modules are pin compatible with the PCI-104 standard, enabling stacking with other compatible modules.
Other Single Board Computer Form Factors
ISA: "slot boards" (full-length, 13.8 x 4.8 in.; half-length, 7.1 x 4.8 in.)
PC/104: modules (3.6 x 3.8 in.) & PC/104-Plus
ETX: highly integrated and compact (3.7 x 4.4 in.) COMs (computer-on-modules) that can be used in a design application much like an integrated circuit component.
EBX: PC/104 and PC/104 Plus expandable SBC the size of a CD/DVD drive (or an old 5 ¼” inch floppy drive). EBX stands for “Embedded Board, eXpandable.” EBX boards are large enough to host modern operating systems, yet small enough (5.75” x 8.0”) to fit in the tight spaces of embedded applications. EBX combines a standard footprint with open interfaces, and is small enough for deeply embedded applications yet large enough to contain the functions of a full embedded computer system: CPU, memory, storage, display, serial ports, parallel ports and others.
Pico-ITX: Pico-ITX SBCs are very small (100 x 72 mm), powerful and cost effective SBCs designed by VIA as the “world’s smallest x86 mainboard.” The Pico-ITX form factor is designed to host ultra-low power processors and provide nearly all of the features considered to constitute a full-featured x86 mainboard.
Mini-ITX: 170 mm x 170 mm (6.7” x 6.7”) slightly smaller than micro-ATX
Micro-ATX: 243.84 mm x 243.84 mm (9.6” x 9.6”)
4.5” SBC: 170 mm x 140 mm. Lanner’s enhanced 4.5” SBCs are small enough to fit in an extensive range of embedded solutions, but large enough to include almost all “real world” PC connections on the market today. Additionally, their low power requirements allow for fanless system design, which drastically reduces the number of moving parts.
QSeven: 70 x 70 mm Computer on Module
CoreExpress: 58 x 65 mm proprietary
COM Express: 95 x 95mm
nanoETXexpress: 55 x 84mm
XTX: a new open standard for embedded SBCs based on the ETX form factor, but with newer interfaces such as SATA and PCI Express in exchange for the increasingly obsolete ISA bus.