A multiple-emitter transistor is a specialized

bipolar transistor A bipolar junction transistor (BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor (FET), uses only one kind of charge carrier. A ...

mostly used at the inputs of

integrated circuit An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...

TTL NAND

logic gate A logic gate is a device that performs a Boolean function, a logical operation performed on one or more binary inputs that produces a single binary output. Depending on the context, the term may refer to an ideal logic gate, one that has, for ...

s. Input signals are applied to the emitters. The voltage presented to the following stage is pulled low if any one or more of the base–emitter junctions is forward biased, allowing logical operations to be performed using a single

transistor A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch electrical signals and electric power, power. It is one of the basic building blocks of modern electronics. It is composed of semicondu ...

. Multiple-emitter transistors replace the

diode A diode is a two-Terminal (electronics), terminal electronic component that conducts electric current primarily in One-way traffic, one direction (asymmetric electrical conductance, conductance). It has low (ideally zero) Electrical resistance ...

s of

diode–transistor logic Diode–transistor logic (DTL) is a class of digital circuits that is the direct ancestor of transistor–transistor logic. It is called so because the logic gating functions AND and OR are performed by diode logic, while logical inversi ...

(DTL) to make

transistor–transistor logic Transistor–transistor logic (TTL) is a logic family built from bipolar junction transistors (BJTs). Its name signifies that transistors perform both the logic function (the first "transistor") and the amplifying function (the second "transistor" ...

(TTL), and thereby allow reduction of switching time and

power dissipation In thermodynamics, dissipation is the result of an irreversible process that affects a thermodynamic system. In a dissipative process, energy ( internal, bulk flow kinetic, or system potential) transforms from an initial form to a final form, ...

Logic gate use of multiple-emitter transistors was patented in 1961 in the UK and in the US in 1962.B. A. Boulter, ''The Multiple Emitter Transistor In Low Power Logic Circuits'' in Edward Keonjian (ed) ''Micropower Electronics'', Elsevier, 2013, , p. 105 ff

References

External links

Tutorial on bipolar-transistor logic
Digital electronics {{Physics-stub