Current Mode Logic(CML) is a current-driven logic circuit, also known as Source-Coupled Logic (SCL). It operates in the non-saturated region with differential inputs and outputs.
With CML logic, a quiescent current is switched into one of two working resistors. The CML logic is low impedance, it responds extremely quickly and requires only a small voltage change of 800 mV for switching. CML logics are therefore used in high-speed circuits in the range of several 100 MHz up to several gigahertz.
CML logics belong to the differential digital logics and are characterized by low noise. CML logics are used in DVI and HDMI interfaces and in the DisplayPort.