Does the number of PMOS and NMOS transistors in a CMOS gate level have to be equal?

[pratap_v]

Is it always that the number of PMOS and NMOS transistors in a CMOS gate level netlist must be equal.If not please let me know, why?
Thank you

 

[tarkyss]

CMOS

there are similiar, but not equal exactly
for example, for a inverter, there are a pmos and a nmos, but if you want to increase the drive capacity of the inverter, because the speed of nmos is larger than pmos, so there are maybe two pmos and a nmos for the new inverter.
by the way,in the example above, the two pmos is connected in parallel, so you can take the two pmos as one.but in the netlist, there are two pmos.

 

[gerryhsu]

Re: CMOS

In physical layout, they can draw as many NMOS or CMOS they want to make sure the matching, But in logicwise 2 NOS or 2 PMOS parallel with same source and same drain are considered one.

 

[tarkyss]

CMOS

besides the reasons i mentioned above,
if the gate level netlist of your ram in your netlist can be seen, you can check that, the number of nmos and pmos are not equal normally. it depends on the basic structure of your ram, for example, for standard 6t sram, there are 4 nmos and 2 pmos

 

[choplin]

CMOS

In circuit unit, the number of nmos and pmos are equal normally for low power consume,and the others NMOS are switchs.

 

[trendwest2]

Re: CMOS

besides the reasons i mentioned above,
if the gate level netlist of your ram in your netlist can be seen, you can check that, the number of nmos and pmos are not equal normally. it depends on the basic structure of your ram, for example, for standard 6t sram, there are 4 nmos and 2 pmos

SRAM is not CMOS !

 

[tarkyss]

CMOS

trendwest2
what is CMOS? are you sure??????