Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

NAND or NOR is faster

Status
Not open for further replies.
A

amara

Member level 1
Joined
Apr 6, 2006
Messages
32
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
1,542
nand pmos

In NAND and NOR gate which one is faster,why
i think both or at same speed because in charging condition one is faster & another is slower while come to discharge this is vice versa.
 

nand nor mobility resistance

Pmos is slower than NMOS becos of high electron velocity, in Nand for I/P to O/P we need to pass only one of the PMOS xsistor while in case of NMOS xsistor we have to go through both PMOS xsistor,


thats why Nand is faster than NOR...


Bye,
Prasad
 

transistor level nand

NAND is faster than NOR in CMOS techno.
 

Nand is faster in CMOS,but not in others.
 

NAND is faster than NOR in CMOS but you have to perform error correction on all data as NAND is very susceptible to data corruption.
 

Basically in the context of deep submicron tecnology the velocity of electron is not the highest due to velocity saturation.But the hole speed can be max.So we have to see we have more pmos resistance as nmos are anyway going to be saturated hence less effect of stacking one above other.And we get the answer as the NAND gate as it has two parallel PMOS as compared to that in NOR.The results can also be explained in the context of logical effort.:idea:
 

NAND is faster than NOR ...
 

it actually depends upon type
HS LS AS

for each type there is a difference in time delay.when we check time delays then NOR has a small time delay which is usually told.and it would b amzing that by theory NAND is fast but actually by time delays NOR is fast
 

NAND is faster than NOR, coz of less stacking effect in NAND than NOR. this results in reduced ON resistance of pmos in NAND. hence it is faster than NOR
 

Nand is faster because of parallel resistance.
 

nand is faster than nor becos i has a less logical effort(4/3) than nor(5/3)..therefore its rise and fall times are lesser compared to nor..
 

Nand is faster due to the architecture of ttl
 

NAND is faster than NOR,

because NMOSFET has less resistance than PMOSFET with same W/L ratio.

best regards





amara said:
In NAND and NOR gate which one is faster,why
i think both or at same speed because in charging condition one is faster & another is slower while come to discharge this is vice versa.
Click to expand...
 

Hi,

If you take a look at the NAND gate schematic NMOS is in series and in NOR gate schematic NMOS is in parallel. since NMOS is in series in NAND, NAND gate iss faster and is usually preferred.
 

Cosidering CMOS logic
0-1 transition is faster in NAND compared to inv
1-0 transition is faster in NOR compred to inv
 

Ok, they all told you than NAND is faster.. .but how much ???


My libraries (which I cannot name) have a input->output for a NOR at 12 ps and NAND at 8ps
 

nand has two nmos in series
nor has two pmos in series
and the mobility of nmos is higher than that of pmos for the same W/L
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top