ﻣﻘﺎﯾﺴﻪﮐﻨﻨﺪه ﺣﻮزه زﻣﺎن ﺑﺎﻟﮏ-دراﯾﻮ ﺑﺎ ﺑﻬﺮه وﻟﺘﺎژ ﺑﻪ زﻣﺎن ﺑﺎﻻ و ﺗﻮان ﻣﺼﺮﻓﯽ ﭘﺎﯾﯿﻦ

Low Power Bulk-Driven Time-Domain Comparator with High Voltage-to-Time Gain

در اﯾﻦ ﻣﻘﺎﻟﻪ ﯾﮏ ﻣﻘﺎﯾﺴﻪ ﮐﻨﻨﺪه ﺣﻮزه زﻣﺎن ﺑﺮاي ﮐﺎر در وﻟﺘﺎژﻫﺎي ﺗﻐﺬﯾﻪ ﺑﺴﯿﺎر ﮐﻢ، ﺑﺮاي ﮐﺎرﺑﺮد در ﻣﺪارﻫﺎﯾﯽ ﮐﻪ ﺣﺪاﮐﺜﺮ ﺗﻐﯿﯿﺮات وﻟﺘﺎژ ﻣﺸﺘﺮك ورودي ﻣﻘﺎﯾﺴﻪﮐﻨﻨﺪه، ﻧﺼﻒ وﻟﺘﺎژ ﺗﻐﺬﯾﻪ اﺳﺖ، اراﺋﻪ ﺷﺪه اﺳﺖ. در ﻣﻘﺎﯾﺴﻪﮐﻨﻨﺪه ﭘﯿﺸﻨﻬﺎدي، ﯾﮏ اﻟﻤﺎن ﺗﺎﺧﯿﺮ ﺟﺪﯾﺪ ﺑﺎ ﺑﻬﺮه ﺗﺎﺧﯿﺮ-وﻟﺘﺎژ ﺑﺴﯿﺎر ﺑﺎﻻ ﭘﯿﺸﻨﻬﺎد ﺷﺪه اﺳﺖ. ﻫﺪف از ﻃﺮاﺣﯽ اﯾﻦ ﻣﻘﺎﯾﺴﻪﮐﻨﻨﺪه دﺳﺘﯿﺎﺑﯽ ﺑﻪ ﺑﻬﺮه ﺗﺎﺧﯿﺮ-وﻟﺘﺎژ ﺑﺎﻻ در اﻟﻤﺎن ﺗﺎﺧﯿﺮ اﺳﺖ ﮐﻪ ﻣﻨﺠﺮ ﺑﻪ اﻓﺰاﯾﺶ دﻗﺖ ﻣﻘﺎﯾﺴﻪﮐﻨﻨﺪه و ﻫﻤﭽﻨﯿﻦ ﮐﺎﻫﺶ ﭼﺸﻤﮕﯿﺮ ﺗﻮان ﻣﺼﺮﻓﯽ و ﻣﺴﺎﺣﺖ اﺷﻐﺎﻟﯽ ﻧﺴﺒﺖ ﺑﻪ ﻣﻘﺎﯾﺴﻪﮐﻨﻨﺪهﻫﺎي ﺣﻮزه زﻣﺎن راﯾﺞ ﻣﯽﺷﻮد. اﯾﺪه اﺻﻠﯽ اﯾﻦ ﮐﺎر، ﺑﻪ ﮐﺎرﮔﯿﺮي ﻣﻔﻬﻮم ﻧﺎﺣﯿﻪ زﯾﺮ آﺳﺘﺎﻧﻪ ﺗﺮاﻧﺰﯾﺴﺘﻮر و ﻫﻤﭽﻨﯿﻦ اﺳﺘﻔﺎده از وﻟﺘﺎژ ﺑﺎﻟﮏ ﺗﺮاﻧﺰﯾﺴﺘﻮر ﺑﻪ ﻋﻨﻮان ورودي ﻣﻘﺎﯾﺴﻪﮐﻨﻨﺪه، ﻣﯽﺑﺎﺷﺪ. ﻣﻘﺎﯾﺴﻪﮐﻨﻨﺪه ﭘﯿﺸﻨﻬﺎدي در ﺗﮑﻨﻮﻟﻮژي 0.18µm TSMC و در وﻟﺘﺎژ ﺗﻐﺬﯾﻪ 1V ﺷﺒﯿﻪ ﺳﺎزي ﺷﺪه اﺳﺖ ﮐﻪ ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﮐﺎرﺑﺮد ﻣﻮرد ﻧﻈﺮ، وﻟﺘﺎژ ﺗﻐﺬﯾﻪ را ﻣﯽﺗﻮان ﺗﺎ ﺣﺪود 0.4V ﻧﯿﺰ ﮐﺎﻫﺶ داد. ﻧﺘﺎﯾﺞ ﺷﺒﯿﻪ ﺳﺎزيﻫﺎ ﻧﺸﺎن ﻣﯽدﻫﺪ ﮐﻪ ﻣﻘﺎﯾﺴﻪﮐﻨﻨﺪه ﭘﯿﺸﻨﻬﺎدي در وﻟﺘﺎژ 1V و ﺑﺎ ﻓﺮﮐﺎﻧﺲ 2.5MHz ﺗﻮان ﻣﺼﺮﻓﯽ ﺣﺪود 250nW دارد. ﺿﺮﯾﺐ ﺷﺎﯾﺴﺘﮕﯽ 0.1µW/MHz ﻧﺸﺎن دﻫﻨﺪه ﻋﻤﻠﮑﺮد ﻣﻨﺎﺳﺐ ﻣﻘﺎﯾﺴﻪﮐﻨﻨﺪه ﭘﯿﺸﻨﻬﺎدي ﻣﯽﺑﺎﺷﺪ. ﻫﻤﭽﻨﯿﻦ ﻣﻘﺎﯾﺴﻪ ﮔﺮ ﭘﯿﺸﻨﻬﺎدي ﻣﻘﺎوﻣﺖ ﺧﻮﺑﯽ ﻧﺴﺒﺖ ﺑﻪ ﺗﻐﯿﯿﺮات ﺗﮑﻨﻮﻟﻮژي دارد و ﺑﺮ اﺳﺎس ﺷﺒﯿﻪ ﺳﺎزي ﻣﻮﻧﺖ ﮐﺎرﻟﻮ اﻧﺠﺎم ﺷﺪه، ﻣﯿﺰان آﻓﺴﺖ اﯾﻦ ﻣﻘﺎﯾﺴﻪﮐﻨﻨﺪه 2.8mV ﻣﺤﺎﺳﺒﻪ ﺷﺪه اﺳﺖ.

This paper presents a time-domain comparator with low supply voltage and low power consumption for using in circuits that comparator’s input common-mode voltages swing is 0 to half supply voltage. To design the time-domain comparator, a delay element with a very high delay-voltage gain is proposed. The purpose of designing this comparator is to achieve high delay-voltage gain, which leads to an increase in the accuracy of the comparator, as well as a significant reduction in power consumption and occupied area compared to conventional time-domain comparators. This time-domain comparator utilizes subthreshold concept and also uses the bulk-voltage of transistor as a comparator input. The proposed comparator is simulated in 0.18μm TSMC technology at 1V supply voltage, which according to the intended application, the supply voltage can be reduced to about 0.4V. The simulation results show that with supply voltage of 1V the proposed comparator consumes 250nW at the clock frequency of 2.5MHz. The figure of merit of 0.1μW/MHz indicates the high performance of the proposed comparator. Based on the Monte Carlo simulation, the offset voltage of this comparator is obtained 2.8mV.