ABSTRACT

Localized data conversions for sensors placed under harsh environmental conditions often require Analog to Digital Converters (ADC) capable of working under wide operating temperature range. Even though the fastest analog to digital converter, flash ADC is omitted from the high temperature regime due to the requirements of reference voltage source, reference voltage divider and a comparator array capable of providing stable operation under wide operating temperatures. A CMOS Schmitt inverter-based internal reference comparator array for flash ADC which is efficient in terms of area and power consumption, capable of working under wide temperature range is presented in this paper. The proposed idea replaces the reference voltage source, resistive reference voltage divider and differential comparator array of a conventional flash ADC by an array of suitably sized Schmitt inverters. The circuit was simulated for static and dynamic characteristics with gpdk 180 nm library using cadence virtuoso simulation suite. The voltage transfer characteristic curve (VTC) of the proposed comparator array was found invariable when a temperature sweep in the range of −40 to 170 degree Celsius was performed. Each of the comparator in the proposed array consumes a silicon area of 40.68 ${\mathrm{u}\mathrm{m}}^2$ and the average dynamic power consumption per cycle is estimated as 103.1 uW.

摘要

放置在恶劣环境条件下的传感器的本地化数据转换通常需要能够在宽工作温度范围内工作的模数转换器 (ADC)。尽管是最快的模数转换器，但由于需要参考电压源、参考分压器和能够在宽工作温度下稳定工作的比较器阵列，闪存 ADC 在高温条件下被省略。本文介绍了一种用于闪存 ADC 的基于 CMOS 施密特反相器的内部参考比较器阵列，该阵列在面积和功耗方面都很高效，能够在宽温度范围内工作。提出的想法取代了参考电压源，由适当大小的施密特反相器阵列组成的传统闪存 ADC 的电阻参考分压器和差分比较器阵列。使用 cadence virtuoso 仿真套件使用 gpdk 180 nm 库对电路的静态和动态特性进行了仿真。当执行 -40 至 170 摄氏度范围内的温度扫描时，发现所提出的比较器阵列的电压传输特性曲线 (VTC) 不变。建议阵列中的每个比较器占用 40.68 的硅面积 当执行 -40 至 170 摄氏度范围内的温度扫描时，发现所提出的比较器阵列的电压传输特性曲线 (VTC) 不变。建议阵列中的每个比较器占用 40.68 的硅面积 当执行 -40 至 170 摄氏度范围内的温度扫描时，发现所提出的比较器阵列的电压传输特性曲线 (VTC) 不变。建议阵列中的每个比较器占用 40.68 的硅面积 ${\mathrm{你}\mathrm{米}}^{\mathrm{2个}}$每个周期的平均动态功耗估计为 103.1 uW。