An electronically programmable current balancing instrumentation amplifier for biomedical monitoring

Instrumentation amplifiers (IA) used in wearable biomedical monitoring systems have to satisfy several performance requirements, such as low-voltage supply and low-power consumption, enabling increased portability. In the same time, a very important feature is wide range parameter programmability. This paper proposes a solution to implement electronic gain programming into an IA. The proposed solution is developed around the current balancing concept. An electronically tunable transconductance amplifier is used for adjusting the IA voltage gain as a function of the transconductor bias currents. Additionally, the proposed IA outputs a differential signal, useful for latter differential analog signal processing. Simulation results validate the proposed IA.