Emitter-coupled logic operates by steering current through a differential amplifier configuration rather than switching transistors completely on or off. Because the transistors never enter deep saturation, they avoid the base charge storage time that slows down standard bipolar circuits. This allows for extremely fast switching speeds, though it comes at the cost of constant current draw and high power dissipation.
We had to add extra fans to the chassis because the emitter-coupled logic runs incredibly hot even when the bus is idle.
Because it uses a negative power supply and small voltage swings, interfacing ECL with standard TTL or CMOS requires dedicated level-shifting chips.
Also heard as
- ECL
Related terms
ECL
Emitter-coupled logic is a high-speed bipolar logic family.
TTL
Transistor-transistor logic is a classic digital circuit design family built from bipolar junction transistors.
CMOS
Complementary metal-oxide-semiconductor is the dominant fabrication technology for integrated circuits.
Logic level
A specific voltage range that represents a distinct binary state in a digital circuit.