A current mode instrumentation amplifier based on the flipped voltage follower in 0.50 A mu m CMOS

作者：Zamora Mejia Gregorio^*; Martinez Castillo Jaime; Miguel Rocha Perez Jose; Diaz Sanchez Alejandro

来源：Analog Integrated Circuits and Signal Processing, 2016, 87(3): 389-398.

DOI：10.1007/s10470-016-0731-3

• Biopotential
• Current mode instrumentation amplifier CMIA
• Flipped voltage follower FVF
• Common mode rejection ratio CMRR
• Gain-bandwidth product GBW

This work presents the design of a current mode instrumentation amplifier (CMIA) based on the flipped voltage follower (FVF), used as a double current sense mechanism. Unlike current state of the art, the proposed CMIA senses the sourced and sank current of the voltage follower buffer inside the Op-Amp inputs. The FVF low-impedance input node allows to monitor the sink current provided by the low-impedance drain node of the active load in the voltage follower buffer. Proposed CMIA uses Split-Length compensated op-amps at the inputs, and Nulling-Resistor compensation technique is used at the output Op-Amp. The proposed CMIA is able to provide continuous programmable gains from 16 to 56 dB by adjusting resistor ratios from 6.3 to 630 respectively. A gain-bandwidth product of 1.23 MHz and a common mode rejection ratio (CMRR) of 96 dB is obtained. A -3 dB CMRR cutoff frequency of 115 Hz is observed in all gain cases. An overall CMIA power consumption of 315.5 A mu W is measured; 95 A mu A at +/- 1.65 V. The proposed CMIA was simulated and fabricated using 0.50 A mu m ON-Semiconductor CMOS standard technology.

• 出版日期2016-6