What is the body effect when transistors are connected in parallel?

[mujju433]

If two nmos transistors are connected in parallell then wt is the effect of body effect?

If two nmos transistors are conected in series then we are saying that threshold is getting added bcoz of body effect... So wt we are doing is we are connecting Vsb =0 so that it gets reduced....

In the case of prallel transistor wt is the effect of body??

 

[Chethan]

Re: body effect

Hi,
When two NMOS transistors are connected in series then the NMOS tarnsistor in the top transistor experiences higher body effect because its Source terminal is not at VSS value. But when two NMOS transistors are connected in parallel then the body effect each experience is same as that of a single NMOS transistor.

 

[Sadegh.j]

Re: body effect

Basically, ANY difference between the source and the bulk voltage creates the body effect, regardless of the type of connection.

 

[dragonfury]

If two nmos transistors are connected in parallell then wt is the effect of body effect?

If two nmos transistors are conected in series then we are saying that threshold is getting added bcoz of body effect... So wt we are doing is we are connecting Vsb =0 so that it gets reduced....

In the case of prallel transistor wt is the effect of body??

In case of parallel transistor there is no body effect whatsoever because both the drains are connected to the same terminal.

 

[Braski]

In case of parallel transistor there is no body effect whatsoever because both the drains are connected to the same terminal.

it seems this is not true. the body effect is independent of the connection, as told before. It arises when VSB is different than 0 and make the Vth higher.

 

[dragonfury]

it seems this is not true. the body effect is independent of the connection, as told before. It arises when VSB is different than 0 and make the Vth higher.

sorry what i meant was source rather than drain.in parallel transistors there is no variation in source voltage because both are grounded in case of NMOS or both are connected to Vdd incase of PMOS.