A 0.4-V Miniature CMOS Current Mode Instrumentation Amplifier

Abstract

This brief presents a new low-power miniature instrumentation amplifier based on the operational floating current conveyor (OFCC). The OFCC is a general-purpose current mode device capable of realizing all functions as an operational amplifier. The proposed OFCC is designed and implemented in both TSMC low-power 90-nm and UMC high-speed 130-nm CMOS technology for use in low-voltage applications. A single supply of 0.4 V is used to reduce the power consumption. The design utilizes the energy-efficient subthreshold region. A self-cascode technique is used to enhance the tracking capability of the OFCC. Post-layout simulation and Monte Carlo analysis show promising results. The current mode instrumentation amplifier in 90 nm occupies 0.023 mm2 while consuming $11~ {\mu }\text{W}$ with 14 kHz gain-independent bandwidth and common mode rejection ratio (CMRR) of 76 dB. The 130-nm design exhibits input referred noise of $1.1~ {\mu }\text{V}_{\text{RMS}}$ for a bandwidth of 0.07–150 Hz while consuming $14~ {\mu }\text{W}$ and CMRR of 65 dB with 100-kHz bandwidth with chip area 0.021 mm $^{{2}}$ .