Direct-coupled transistor logic
Encyclopedia
A special type of resistor–transistor logic (RTL) , a direct-coupled transistor logic or DCTL gate is one wherein the bases of the transistor
s are connected directly to inputs without any base resistor
s. Without the base resistors, DCTL gate
s are more economical and simpler to fabricate onto integrated circuit
s than RTL gates with base resistors. Unfortunately, DCTL has a high susceptibility to ground noise and requires consistent transistor characteristics.
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
s are connected directly to inputs without any base 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. Without the base resistors, DCTL gate
Gate
A gate is a point of entry to a space enclosed by walls, or a moderately sized opening in a fence. Gates may prevent or control entry or exit, or they may be merely decorative. Other terms for gate include yett and port...
s are more economical and simpler to fabricate onto integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
s than RTL gates with base resistors. Unfortunately, DCTL has a high susceptibility to ground noise and requires consistent transistor characteristics.