ROMJIST Volume 24, No. 2, 2021, pp. 182-200
Adrian Constantin VESELU, Cornel STĂNESCU, Gheorghe BREZEANU New Constant-gm circuit for precision chopper offset-stabilized operational amplifiers
ABSTRACT: The paper presents a low-voltage chopper offset-stabilized operational amplifier with a new constant-gm technique, having a 1.8-5.5 V supply range, designed and simulated in a 0.25 µm CMOS process. The amplifier has an offset voltage of ±5 µV, minimum CMRR of 106 dB, minimum PSRR of 121 dB, 51 nV/√Hz voltage noise density and 550 kHz unity-gain bandwidth. The quiescent current is only 36 µA and was obtained due to the new low current constant-gm technique, which provides a variation of only 4% of the input transconductance and almost constant unity-gain bandwidth within the common-mode voltage range.KEYWORDS: Microelectronics and electronic packaging, chopper offset-stabilized operational amplifier, constant-gm, low current, offset voltage, noiseRead full text (pdf)