Adapters

An adapter is a device that enables compatibility between two otherwise incompatible interfaces, systems, or standards. In electronics and computing, adapters may modify physical connectors, electrical signals, or communication protocols. They can be passive, simply reconfiguring pins or signal lines, or active, containing circuitry that converts one format into another.

Power and travel adapters illustrate common uses. A plug adapter lets a device with one outlet shape connect to another outlet without changing voltage. Voltage converters or power adapters can change mains voltage to the level required by a device. Many travel adapters do not alter voltage and require a separate converter if the device is not rated for the local supply.

In computing and networking, adapters cover a wide range of functions. Network adapters (NICs) connect devices to a network and may be built-in or add-on cards. Display adapters convert video signals between formats, such as HDMI to VGA or DisplayPort to HDMI. USB adapters enable connections between USB and other interfaces (USB-C to USB-A, USB to Ethernet, etc.). There are also Bluetooth adapters, and internal expansion adapters like PCIe-to-SATA adapters.

Design considerations include impedance and signal integrity, bandwidth and latency, and compatibility with standards and operating systems. Adapters may be passive, relying on compatible interfaces, or active, providing signal conversion, translation, or amplification. They must also meet safety and electromagnetic compatibility requirements to avoid damaging devices or creating interference.

Overall, adapters extend interoperability, allowing devices and systems to work together across evolving technologies.