کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4953748 | 1443117 | 2018 | 12 صفحه PDF | دانلود رایگان |
This paper presents a 7-bit 15Â ÃÂ interleaved SAR ADC that operates up to 3Â GS/s, using 180Â nm CMOS technology. The ADC utilizes the transient information of a dynamic SAR voltage-comparator to resolve 2Â bits per clock cycle, using a time-comparator block. Thus, only 5 clock cycles are needed to resolve 7Â bits. This results in speed improvement of about 60%, compared to conventional ADC. Also, an improved Quasi C-2Â C DAC structure with reduced internal node swing and reduced switching activity are utilized, which decreases the power consumption of DAC up to 65%. We employ the above techniques in designing a 7-bit SAR ADC, in which 3Â bits are resolved with time-comparator blocks and 4Â bits are resolved with a voltage-comparator. To calibrate the proposed time-comparator block, a calibration process is proposed. ADS simulation of the ADC illustrates an ENOB (Effective Number of Bits)Â >Â 6.5-bit and SFDR (Spur Free Dynamic Range)Â =Â â52.8 dBc for a single SAR converter with sampling at 200Â MS/s. For the time-interleaved SAR ADC with 15 single SAR converters, ENOB is 6.15-bit and SFDRÂ =Â â45 dBc with sampling at 3Â GS/s up to Nyquist frequency. This ADC consumes 150Â mW at 1.8Â V supply and achieves a Figure-of-Merit (FoM) of 700 fJ/conv-step.
Journal: AEU - International Journal of Electronics and Communications - Volume 83, January 2018, Pages 138-149