A low voltage very high impedance current mirror circuit and its application

摘要

Current mirror circuit has served as the basic building block in analog circuit design since the introduction of integrated circuits. In this paper, “A Very high impedance current mirror, operating in reduced power supply which does not use any additional biasing circuit and its application” is proposed. The design uses a high swing super Wilson current mirror which has negative feedback. A feedback action is used to force the input and output currents to be equal. The output current is expected to be mirrored with a transfer error less than 1% when the input current is increased from 5µA to 40µA. As an application, the current mirror circuit has been used in the design of a high gain, improved output swing differential amplifier. A telescopic differential amplifier is chosen for designing since it is used in low power application. A comparative study of different current mirror circuits and amplifier is also made. The output swing of the circuit is improved than what is expected.