What is form factor

Form factor

  • With fiber optic connectors, the form factor is a ratio of the connector dimensions. This factor is important for the connection density in optical distribution systems such as patch panels. There is a special group of small fiber optic connectors called SFF, Small Form Factor connectors.

  • In the case of chip packages, the form factor indicates the area ratio between the package size and the chip size. For example, the QFP package has a form factor of approx. 5.5. This means that the size of the package is 5.5 times the size of the chip in the package. With other packages such as the CSP package, the package area is only about 20% larger than the chip. The form factor is approx 1.2.

  • In the case of computers, the form factor stands for the size, which is largely determined by the motherboard. Even if laptops typically have a clamshell case, there are notebooks, subnotebooks, ultrabooks, UMPCs, hybrid PCs and netbooks with portable computers of different sizes.

  • With motherboards, the form factors are about the layout format of the motherboard, which is matched to the PC case. This format takes into account the position of the individual components, the sockets, slots and connections, and defines which housing and which power supply unit may be used with which form factor. Drill holes and the power connection are also defined in the form factor. It takes into account transit times between the components as well as heat radiation.

    There are form factors for the Advanced Technology (AT), the BAT form factor, the ATX form factor for the extended AT version and the Micro ATX version, LPX, NLX, the ITX form factor with the smaller variants Mini-ITX, Nano-ITX and Pico-ITX, the DTX form factor and the BTX form factor. The ATX and BTX form factors are standardized by the Formfactors organization. In addition to the form factors for personal computers, there is one for workstations, the WTX form factor.
  • In the case of power supplies, the form factor indicates the power supply specifications, their dimensions and development guidelines.

  • In the case of hard disks, the form factor describes the diameter of the hard disk in connection with the overall height. Well-known formats are the hard disks and miniature hard disks of 5.25 ", 3.5", 2.5 ", 1.8" and 1.3 ", whereby these inches correspond to the form factor. The height of the hard disk drives is also For example, there are housings that are designed in half height, known as slimline, with an overall height of 41 mm and in low profile with 25.4 mm.

  • The term form factor is also used for bandpass filters and indicates the selectivity of the filters. This is decisive for how strongly a frequency can be separated from an adjacent frequency. The selectivity is expressed in the steepness of the filter slope. The form factor of filters is defined as the ratio of the bandwidths with attenuation of -6 decibels (dB) to -60 dB.

  • Plastic cards are also marked with a format. The ID1 card has the form factor (FF) 1, which is why it is referred to as 1FF. The mini SIM card has the designation 2FF, the micro SIM card is 3FF and the nano SIM card is 4FF.