The performances of two full differential operational amplifiers (Op-Amps) telescopic and folded-cascode are evaluated to satisfy the stringent requirements on the amplifier to be used in a Multiplying Digital-to-Analog Converter (MDAC) stage of a pipelined ADC (Analog-to-Digital Converter). The paper shows the solutions found to reach high gain, wide bandwidth and short settling time without degrading too much the output swing. The Op-Amp specifications are extracted according to the ADC requirements, then the two Op-Amp topologies are designed, tested and their performances are compared. Simulation results show that the Op-Amp folded-cascode topology is more suitable architecture for pipelined ADC than the telescopic one. Moreover, the use of this type of Op-Amp generates an Integral Non-Linearity (INL) error less than that of the telescopic one. The analyses and simulation results are obtained using 0.18 µm AMS (Austria Mikro System) CMOS process parameters with a power supply voltage of 1.8V. The predicted performance is verified by analysis and simulations using Cadence EDA simulator.

Setif city covers an area of 6550 km2; it is located about 300 km southeast of Algiers and 100 km to the south of the Mediterranean sea. The aim of our study is to know the tectonic mechanisms responsible for the emergencies and to highlight their chemical characteristics of water springs in Setif. Wherein thermalism is characterized by the presence of a number of thermal springs, the latest are usually related to recent large fractures deeply affecting the sedimentary formations and sometimes even crystallin basement. These fractures are often injected by Triassic evaporates; their directions are NNW–SSE, NW–SE, and NE–SW and limiting great structural units. Four groundwater facies were identified: the high percentage of sources, staking major accidents related to limestone mountains or to the basement, shows a calcium or sodium sulfate facies; and the sources are often hot (meso or hyperthermal). A second group, related to terrigenous saliferous formations, shows a sodium bicarbonate or sodium chloride facies. The geothermic interpretation allows us to conclude that the reservoir supplies the two aquifer systems of the thermal complex, and is stored in fissured Jurassic limestone, where water storage and circulation is beyond 2600 m deep.