g NMOS PMOS p x is 123 for the each MOSFET DDA A DD bias un
Solution
Solution:- The given circuit is the basic current mirror circuit using Mosfets.
Since Width of Mosfet is not given, therefore in this solution Width of Mosfet is assumed to be 0.25um for simplicity. If different width is required simply change the slight calculations.
And all Mosfets are assumed to be in Working in Saturation Region.
So,
Id2= Id1(W/L)2/(W/L)1
Since Length of each transistor is 0.25 um. Therefore
(W/L)1=(W/L)2= 1
Therefore Id2 =Id1
Drain Current across Mosfet in Saturation Regioin is given by
Id= µnCox(W/L)(Vgs-Vt)2
In this question
Id2 =Id1= Ibias= 200uA
For NMOS Transistor Q3
Source is at ground (Vgs=Vg)
Vgs= Vg
200= 100(Vgs- 1)2
Vgs(Q1) =2.41 V
For PMOS Transistor Q2
Here Vs= Vdd = 4V
Id= µpCox(W/L)(Vgs-Vt)2
Also Same current will flow across transistor Q2 and Q3
Therefore, Id(Q2) = Id(Q3)= 200 uA
200= 50(Vg-4-(-0.7)2
Therefore Vg2= 2+4.7= 6.7
So, Vgs= 4.7-4= 0.7V
For Transistor Q1
Since same Current is flowing across both PMOS and Vdd is also same
Therefore
Vgs(Q1)= Vgs(Q2)= 0.7V

