manissri
Full Member level 5

dear all
i am desinging the 10 msps pipelined adc
for this i am designing the sample and hold amplifier and switch capacitor.
for switch which type i choose either nmos r tran gate r boosted clock.
actually if i use nmos switch , i have to pass the 3 volt signal and the gate of nmos is at 5 volt. and my vt is 0.7volt. the C=1pf.
and my nmos switch is on for 50 ns. the Ron i calculated for this nmos switch is 2.5k ohm. and my RC = 2.5ns ( for C=1pf). so RC=2.5ns << 50ns( on time for switch).i read in books that RC<< T for switch to pass successfully. ( T=on time of switch)
so this will be ok to use nmos switch r i would go for boosted clock r tran gate.
plz give ur comment.
waiting for ur reply ..
manish
i am desinging the 10 msps pipelined adc
for this i am designing the sample and hold amplifier and switch capacitor.
for switch which type i choose either nmos r tran gate r boosted clock.
actually if i use nmos switch , i have to pass the 3 volt signal and the gate of nmos is at 5 volt. and my vt is 0.7volt. the C=1pf.
and my nmos switch is on for 50 ns. the Ron i calculated for this nmos switch is 2.5k ohm. and my RC = 2.5ns ( for C=1pf). so RC=2.5ns << 50ns( on time for switch).i read in books that RC<< T for switch to pass successfully. ( T=on time of switch)
so this will be ok to use nmos switch r i would go for boosted clock r tran gate.
plz give ur comment.
waiting for ur reply ..
manish