A 36 V Chopper Offset-Stabilized Operational Amplifier With Fast Settling and Reduced Input Transient Currents

The paper presents a dual mux-friendly high voltage chopper offset-stabilized operational amplifier with a symmetrical $RC$ notch filter, having a 4–36 $V$ supply range, and being fabricated in a 0.25 $\mu m$ CMOS process. The chopper stage operates at $300 kHz$ New mux-friendly and settling-enhancing techniques are used, together with a modified input stage for delivering high Slew-Rate. The circuit has a typical offset voltage of 1. 5 $\mu V$ a settling time of $0.75\mu s$, a minimum Power Supply Rejection Ratio (PSRR) and Common Mode Rejection Ratio (CMRR) of 145 $dB$, a noise Power Spectral Density $(PSD)$ of 7.5 $nV/\surd {}Hz, 15 MH\mathrm{z}$ unity gain bandwidth, and 20 $V/\mu s$ Slew-Rate, while consuming 1. 75 $mA$ per channel.