Design of a high bandwidth ECG signal low noise amplifier circuit for wearable devices

Abstract

Nowadays, more than one million people die due to heart problems annually. Detecting the Electrocardiogram curve is an effective way to evaluate heart condition. Compared with large devices in the hospital, wearable devices are showing their advantage in detecting peoples Electrocardiogram whenever and wherever possible. However, in traditional amplifier circuit design, there is less attention to the bandwidth. The noise is negatively correlated with the current while the power consumption is positively correlated with the current, so it is challenging to balance the noise and power. Therefore, a design of a high bandwidth Electrocardiogram signal low noise amplifier circuit for wearable devices is proposed in this paper. The improved circuit is based on a conventional instrumentation amplifier and consists of two stages. The op-amps were replaced with Operational Transconductance Amplifier. The circuit also has a Driven-Right-Leg circuit part, which can tremendously reduce the effect of common-mode noise. The simulation result shows that the circuit has a high bandwidth and stable gain. Meanwhile, the circuit consumes less power and has a low integrated input-referred noise. This study is extremely helpful in expanding the application of wearable Electrocardiogram signal-detecting devices.