Design of a 12-Bit 2.5 MS/s Integrated Multi-Channel Single-Ramp Analog-to-Digital Converter for Imaging Detector Systems

作者：Gao, Wu^*; Gao, Deyuan; Hu-Guo, Christine; Hu, Yann

来源：IEEE Transactions on Instrumentation and Measurement, 2011, 60(6): 1942-1951.

DOI：10.1109/TIM.2010.2047585

• Analog-to-digital converter (ADC)
• delay-locked loop (DLL)
• imaging detectors
• ramp ADC

This paper presents a novel design of a 12-bit multi-channel single-ramp analog-to-digital converter (ADC) for imaging detector systems. To overcome the problem of long conversion time in the classic Wilkinson ADC, a new architecture using a counter and delay line interpolations is proposed. Two 5-bit Gray counters are designed for the coarse conversion. The time interpolation using an array of five delay-locked loops (DLLs) and the multiphase sampling technique are proposed for the fine conversion. The 140-phase delay clocks are generated by the array and pseudo 7-bit fine resolution is achieved. A one-channel prototype chip is implemented in AMS 0.35 mu m CMOS technology. The total conversion time is about 400 ns, which corresponds to a sampling rate of 2.5 MS/s. The proposed ADC can be utilized in many fields, such as high-energy physics, biomedical imaging, and space applications.

• 出版日期2011-6
• 单位西北工业大学