일정 트랜스컨덕컨스 $g_m$를 갖는 저전압 Rail-to-Rail 연산증폭기의 입력단 회로의 설계

A Constant $g_m$ Input Stage for Low Voltage Rail-to-Rail Operational Amplifier

This paper presents a constant gm input stagefor low-voltage rail-to-rail operational amplifier. A proposed scheme uses two current paths to keep sum of the biasing currents of the complimentary input pairs. The op amp was designed in a $0.8\mu\textrm{m},$ n-well CMOS, double-polysilicon and double-metal technology. This achieved in weak inversion. The circuit can operate in power supply voltage from 1.5V up to 3V. An open-loop gain, AV, was simulated as 84dB for 15pF load. An unit-gain frequency, fT was 10MHz.