Practical experiments with ultra-low voltage biomedical amplifiers

Low power amplifiers are crucial in many biomedical devices such as muscle signal interfaces and neurological front ends. Furthermore, their importance in analog computing platforms is gaining ground as they provide improved efficiency under increasing demands. As such, reducing amplifier's operational voltage is imperative for low power design. Two topologies were optimized and tested for useful gain at low voltage. A first topology was tested in CMOS and with OTS components, it used body input transconductance. The second, a common source design using an array of MOSFETs that minimized the voltage stack whilst maximizing gain. Both methods provided suitable gain for application in biomedical circuits, and were tested using practical interface biasing. The body amplifier provides useful gain down to 290mV and the CS amplifier provides suitable gain down to 190mV.Clinical and Translational Impact Statement-Low voltage and low power amplifiers reduce risks, as battery longevity is extended. As such, they are a crucial component of medical devices and implants such as heart monitors, pacemakers and health tracking. In addition, these amplifiers are poised to gain importance in biomimetic computing systems based on analog memory.