Design of CMOS integrator circuit for sigma delta ADC for aerospace application

Abstract

In this research paper, a design of CMOS integrator circuit for sigma delta ADC has been carried out. The proposed integrator claims a key role in low-power CMOS sigma delta ADC. The low-power CMOS sigma delta ADC is used to design smart temperature sensor for aerospace application which would sense a temperature range of −50 to 150 °C. The analog output of temperature sensor is digitized using low power CMOS sigma delta ADC. The integrator behaves as a low-pass filter for input signal and high-pass filter for quantization noise. Here, the input and output are measured across the capacitor. This circuit is designed using Cadence Virtuoso UMC90 nm CMOS technology. For the proper operation of the circuit, power supply is used in the range of +1.3 to −1.3 V. As the input square wave is applied, during the positive half cycle, the voltage across capacitor increases from zero to the maximum (peak value of applied voltage). During the negative half cycle, the capacitor starts to discharge and comes to zero.