Low Common-Mode Gain Instrumentation Amplifier Architecture Insensitive to Resistor Mismatches

Abstract

In this paper, an instrumentation amplifier architecture for biological signal is proposed. First stage of conventional instrumentation amplifier architecture was modified by using fully balanced differential difference amplifier and evaluated by using 1P 2M 0.6µm CMOS process. From HSPICE simulation result, lower common-mode voltage can be achieved by proposed instrumentation amplifier architecture. Actual fabrication was done and six chips were evaluated. From the evaluation result, average commonmode gain of proposed instrumentation amplifier architecture is 10.84 dB lower than that of conventional one without requiring well-matched resistors. Therefore, the proposed instrumentation amplifier architecture is suitable for biological signal processing.

A New Instrumentation Amplifier Architecture Based on Differential Difference Amplifier for Biological Signal Processing

“…Therefore, gain of second stage is often set to 0 dB to avoid deterioration of the A c . In this way, the A c of the 3 op-amps based IA architecture is sensitive to the resistor mismatches [3].…”

“…In order to overcome this problem, we proposed IA architecture shown in Fig. 3a [3]. The number of resistors in the conventional IA architecture is as same as that in the Fig.…”

“…Sensing of biological signals is a very challenging research. The biological signals, such as Electroencephalogram (EEG), Electrooculogram (EOG), Electrocardiogram (ECG), Electromyogram (EMG), and Axon Action Potential (AAP) have amplitudes in the order of µV to mV and frequencies span from DC to a few kHz, as shown in Fig.1 [1]- [3].…”

“…In reference [3], an IA architecture based on Fully Balanced Differential Difference Amplifier (FBDDA) which its A c is low and insensitive to resistor mismatches was presented. In this paper, it is called as conventional IA architecture.…”

Proposal and design methodology of switching mode low dropout regulator for Bio-medical applications

“…Recently expanding demands for bio-medical devices have driven extensive research on low-power mixed-signal integrated circuit technologies [1][2][3][4][5][6]. The building blocks of the analog front-end (AFE) in the bio-medical system-on-chip (SoC) like as instrumentation amplifier (IA), programmable gain amplifier (PGA), low-pass filter (LPF) and analog-to-digital converter (ADC) require the power supply voltages suitable for each, therefore the multiple low dropout (LDO) regulators are implemented as the post-regulators following the dc-dc converters to achieve high-efficiency power management solution [5][6].…”