Fully differential gain-boosted ota design for pipeline DA-converter in 180nm CMOS technology

This paper describes a fully differential gain-boosted improved OTA for high performance pipeline DA-converter in UMC 180 nm technology for a 3.3 V power supply applications. The architecture chosen for the design is a folded cascode OTA structure for the main and gain boosting stages. The designed OTA achieved a very high DC gain greater than 95 db with a unity gain band width of 500 MHz for a 500 fF load with a power consumption of 14.5 mW and phase margin of more then 55 degrees, which meets the design specifications. The design is meant to be used for implementation of a pipeline DA-converter, using selection inversion based on Gray coded bit vector. Simulation is done using Cadence Affirm Spectre circuit simulator. Layout of the OTA structure has been finished and prepared to be taped out.