Design of Sigma-Delta Modulator for Medical Implantable Device Using 180nm Technology

A first order sigma-delta modulator which is the fundamental building block of sigma-delta analog-to-digital converter is designed in this paper. Sigma-Delta Modulator is widely used in biomedical applications due to their high resolution and low power consumption, especially important for portable or battery operated implantable devices. The modulator is designed to minimize power usage to extend battery life or reduce heat generation. Sigma-Delta Modulator includes Integrator, comparator, D-flip flop and 1 bit DAC as a feedback loop. A Two stage OTA is designed and implemented which is used for designing the component of Sigma Delta Modulator such as Switched-Capacitor Integrator. Sigma Delta Modulator is simulated in 180nm CMOS technology with supply voltage of 1.8 V in cadence virtuoso tool.