Design Of Pipeline ADC For Uncooled Infrared Detector

With the rapid development of uncooled infrared thermal imaging technology, the research of high performance intelligent system level chip is the main research direction of the non refrigeration infrared detector, and it is very important to study the digital analog converter with high precision Inside the integrated chip.Based on this theory, Pipelined analog digital converter(ADC) is studied in this paper.With SMIC 0.18μm 1P6M CMOS technology, the design of integrated non refrigeration infrared readout circuit chip in pipelined ADC is put forward in this paper. The development status of infrared technology and the development trend of ADC are analyzed, content of research and significance of this paper are expatiated.1.The working principle of ADC is analyzed,the features of ADC is presentated, the Key performance indicators (kpis) is summarized.2. The key circuit design of 14 bit ADC Pipelined is analyzed, mainly includes multiplication analog digital converter (MDAC) unit, high-speed comparator, sampling switch circuit, operational amplifier, a voltage reference source and the digital calibration circuit.3.The overall 14 bit pipelined ADC is designed, using 2.5 bit MDAC structure and 0.5 bit redundant code to reduce the offset of comparator. A kind of amplifier sharing techniqueis put forward to reduce power consumption,the digital background calibration circuit is used to reduce the performance requirements of the amplifier and the effect of the capacitor mismatch circuit.4.At 100MS/s, the ADC aehieves that DNL is 0.2LSB,INL is -0.32LSB-0.25 LSB,90.23 dB of SFDR,79.31dB of SNDR and 12.9bits of ENOB for an input signal of 8MHz. With power supply of 3.3V, the power consumption is 350mW, which meets the design requirements.5.Analyzes the matters needing attention, the whole layout is planned.Adopting the most reasonable way to reduce the chip area and improve the chip rate meanwhile, finally layout area is 6.5mm2.