why PMOS is used as pullup device and NMOS is used as pull down device.
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sonal aggarwal
Apr 25, 2011, 4:43:49 AM4/25/11
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why PMOS transistors is used as pullup device while NMOS is used as pulldown device?
Narveer Yadav
Apr 25, 2011, 4:52:53 AM4/25/11
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NMOS can pull-down output to 0V but it can pull-up maximum to VDD-Vtn. So it is bad-1 and good-0. PMOS can pull-up output to VDD but it can pull-down to Vtp. So it is bad-0 but good-1
where Vtn,Vtp are threshold voltage for NMOS and PMOS respectively.
where Vtn,Vtp are threshold voltage for NMOS and PMOS respectively.
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