Current mode logic or source-coupled logic (SCL), is a differential

Differential signaling

Differential signaling is a method of transmitting information electrically by means of two complementary signals sent on two separate wires. The technique can be used for both analog signaling, as in some audio systems, and digital signaling, as in RS-422, RS-485, Ethernet , PCI Express and USB...

 digital

Digital

A digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...

 logic family

Logic family

In computer engineering, a logic family may refer to one of two related concepts. A logic family of monolithic digital integrated circuit devices is a group of electronic logic gates constructed using one of several different designs, usually with compatible logic levels and power supply...

 intended to transmit data at speeds between 312.5 Mbit/s and 3.125 Gbit/s over a standard printed circuit board

Printed circuit board

A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...

.

The transmission is point-to-point, unidirectional and is usually terminated

Electrical termination

Electrical termination of a signal involves providing a terminator at the end of a wire or cable to prevent an RF signal from being reflected back from the end, causing interference...

 at the destination with 50 Ω

Ohm

The ohm is the SI unit of electrical resistance, named after German physicist Georg Simon Ohm.- Definition :The ohm is defined as a resistance between two points of a conductor when a constant potential difference of 1 volt, applied to these points, produces in the conductor a current of 1 ampere,...

 resistor

Resistor

A linear resistor is a linear, passive two-terminal electrical component that implements electrical resistance as a circuit element.The current through a resistor is in direct proportion to the voltage across the resistor's terminals. Thus, the ratio of the voltage applied across a resistor's...

s to V_cc

VCC

VCC may refer to:as a three-letter acronym:* Common-collector voltage , plus collector supply line voltage in a common NPN circuit.* Vale of Catmose College, an arts college in England.* Valencia Community College, in Orlando, Florida...

 on both differential lines. CML is the physical layer used in DVI

Digital Visual Interface

The Digital Visual Interface is a video interface standard covering the transmission of video between a source device and a display device. The DVI standard has achieved widespread acceptance in the PC industry, both in desktop PCs and monitors...

 and HDMI

HDMI

HDMI is a compact audio/video interface for transmitting uncompressed digital data. It is a digital alternative to consumer analog standards, such as radio frequency coaxial cable, composite video, S-Video, SCART, component video, D-Terminal, or VGA...

 video links, and is frequently used in interfaces to fiber optic components.

This technology has been also used in design of high speed integrated circuits such as in telecommunication applications (serial data transceivers, frequency synthesizers, etc.). This fast operation of CML circuits is mainly due to their lower output voltage swing compared to the static CMOS

CMOS

Complementary metal–oxide–semiconductor is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits...

circuits and also the very fast current switching taking place at the input differential pair circuit.