A 4-Channel NMES IC for Wearable Applications

This paper presents an integrated circuit solution for multi-channel neuromuscular electrical stimulation (NMES). The stimulation waveform is digitally controlled and supports monophasic pulses, and both symmetric and asymmetric biphasic pulses. In addition, the current intensity is programmable, ranging from 0 mA to 31 mA with 5-bit resolution. The integrated circuit occupies an area of 1 mm(2) and it is designed and simulated in a 180 nm high-voltage CMOS technology. The circuits are powered using standard 1.8 V and 3.3 V power supplies for the digital control and digital-to-analog converter, and a single 40 V power supply for the output drivers. The simulation results show that the design achieves a voltage compliance of up to 35 V, meeting the requirements for NMES applications while offering a very compact and scalable solution.