Small Outline Dual Inline Memory Module
SO-DIMMs ( Small Outline Dual Inline Memory Modules ) are memory modules that are mainly used in notebook systems. Due to their design and high energy efficiency, they are particularly suitable for this purpose.
The modules (like the larger DIMM modules) have separate connections on each side of the board and are 67.6 mm wide and 30 mm high in the DDR versions. In order to avoid the installation of incompatible modules, the different versions have notches at different points in the connection strip.
Installation
Unlike DIMMs, which are inserted perpendicular to the board, SO-DIMMs are often inserted at an angle and then pressed down so that they are parallel to the board, where they snap into two springy retaining tabs on the side. In this way, very flat hardware designs are possible.
Specifications
The standards for memory modules are adopted by the JEDEC Solid State Technology Association . The different variants differ externally in the number of contacts and the notches in the contact strip. The most important variants:
- SO-DIMMs, FPM , EDO or SDRAM chips with 5 V or 3.3 V (since 1997) 72 pins, with
- SO-DIMMs, 144 pins, with EDO or SDRAM chips with 3.3 V (since 1999)
- SO-DIMMs, 200 pins, with DDR or DDR2 SDRAM chips (since 2003)
- SO-DIMMs, 204 pins, with DDR3-SDRAM chips (since 2010)
- SO-DIMMs, 260 pins, with DDR4-SDRAM chips (since September 2014)
The RAM module specifications are defined by various JEDEC working groups and are collected in their standard document JESD21-C . Chapter 4, "Multi-Chip Memory Modules and Cards", contains the official specifications for multi-chip modules, including a. also for SO-DIMM modules:
page | Number of pins | designation | Last rev. |
---|---|---|---|
4.04.04 | 72 | DRAM SO-DIMM | 06/1997 |
4.04.05 | 88 | DRAM SO-DIMM | 06/1997 |
4.05.05 | 144 | DRAM SO-DIMM | 03/1999 |
4.05.06 | 144 | SDRAM SO-DIMM | 03/1999 |
4.05.08 | 144 | SGRAM / SDRAM SO-DIMM Family | 10/2000 |
4.05.09 | 144 | DDR SGRAM SO-DIMM | 03/1999 |
4.20.03 | 144 | PC133 SDRAM Unbuffered SO-DIMM | 10/2003 |
4.20.06 | 200 | PC-2700 / PC-2100 / PC-1600 Unbuffered SO-DIMM SDRAM | 10/2003 |
4.20.11 | 200 | DDR2 SDRAM Unbuffered SO-DIMM | 06/2008 |
4.20.16 | 144 | EP2-2100 DDR2 SDRAM 32b SO-DIMM | 02/2007 |
4.20.18 | 204 | DDR3 SDRAM Unbuffered SO-DIMM Design Specification, Rev 2.0. | 12/2010 |
4.20.21 | 204 | EP3-6400 / EP3-8500 / EP3-10600 / EP3-12800 DDR3 SDRAM 72b-SO-DIMM | 01/2010 |
The table of contents and other parts of the collection can be viewed, but registration is required to download the standard documents. Individual standard documents such as B. are made available in part by chip manufacturers.
Web links
Individual evidence
- ↑ Micron Technical Note: Summary of Common DRAM Module Form Factors
- ↑ JEDEC: Memory Configurations: JESD21-C (accessed April 8, 2011)
- ↑ JEDEC: Current SO-DIMM specifications (accessed on April 8, 2011)
- ↑ a b micron.com - JESD21-C 4.20.6: 200 pin, PC2700 DDR SDRAM Unbuffered SO – DIMM REFERENCE DESIGN SPECIFICATION ( Memento from September 23, 2010 in the Internet Archive ) (PDF; 152 kB)