A high-performance low-power two-stage OPAMP realized in 90nm CMOS process for biomedical application

The functionality of modern system on chip (SOC) technology is realized by integrating both digital and analog components. To realize complex analog circuitry, designers need digital-to-analog converter (DAC), analog-to-digital converter (ADC), filters, bias voltage generator, switched-capacitor circuit etc. where optimization of power, performance, area, noise etc. are the design target. A two-stage OPAMP is the core component of many high-performance analog system. The target performance parameters of an OPAMP are power, gain, phase margin, CMRR, offset voltage, SQNR, slew rate, GBW and so on. In this paper, we discuss about our designed OPAMP for bio-medical applications, which is implemented in 90nm CMOS process and supplied by 1.5 Volt. The CADENCE spectra simulation results show that the circuit dissipates 0.21mW power with 71.3dB gain, 66.3° phase margin, 45.2dB SNR, 103dB CMRR, and 50ns delay. The circuit has the unity GBW of 3.3 GHz and the slew rate of 34.7V/µs.