A current conveyor is a three-terminal analogue electronic device abstraction. It is a type of electronic amplifier with a gain of one. The idealized device is available in three generations: CCI, CCII, and CCIII. When combined with other circuit elements, real current conveyors can perform a wide range of analogue signal processing functions, much like op-amps and the ideal concept of the op-amp.
A current conveyor is a component of an electronic circuit that can be used to transfer and amplify electrical current signals. It is commonly used in the design of analog circuits and signal-processing applications. The current conveyor has two input (X and Y) and two output (Z and W) terminals. It is a versatile current amplifier that can transfer, amplify, and control current signals between circuit components.
History
When Sedra and Smith first introduced the current conveyor concept in 1968, it was unclear what the benefits would be. Since the 1940s, the concept of the op-amp had been widely known, and integrated circuit manufacturers were better able to capitalize on this widespread knowledge within the electronics industry. There were no monolithic current conveyor implementations, and the op-amp became widely used. Since the early 2000s, implementations of the current conveyor concept have proven beneficial, particularly in larger VLSI projects such as mobile phones.
Current conveyors are classified into two types: current conveyor type I (CCI) and current conveyor type II (CCII). The current at the X terminal is transferred to the Z terminal in a CCI, whereas the current at the X terminal is transferred to both the Z and W terminals in a CCII. CCII is more adaptable than CCI and can be used in a wide range of circuit configurations.
Advantages
Under both small and large signal conditions, current conveyors can provide better gain-bandwidth products than comparable op-amps. The gain of instrumentation amplifiers is determined solely by the absolute value of a single circuit element, rather than by matching pairs of external components.
Current conveyors are used in a variety of applications, including analog signal processing, analog computing, current-mode circuits, and translinear circuits. They can be used to implement a variety of analog functions, including amplifiers, filters, oscillators, mixers, and modulators. Because the current conveyor can directly handle current signals, it is well suited for low-power and high-frequency applications.
