Please show all steps! Thanks Given: Find: Find the DC bias operating point, VDS

Question

Please show all steps! Thanks

Given: Find: Find the DC bias operating point, VDS and ID. What range of values of RD will result in Saturation ? What is the value of VDSSAT ? Plot the iD versus vDS characteristic curves for a few (2 or 3) values of vGS above and a few (2 or 3) values of vGS below the DC bias value, VGS, established in this circuit. Show the DC load lines for the originally given value of RD and for the value of RD that results in a DC bias point on the boundary between Saturation and Triode. Indicate the 2 different operating points on the vGS = VGS curve. With the given, fixed values of R1 and R2, and with some positive drain resistance, i.e. RD > 0 , is it possible for M to operate in cutoff in this circuit? Why or why not? Find VG first. Write a KVL around the DS loop.

Explanation / Answer

sol)

Vg= Vdd*R2/(R1+R2) ==>oltage division rule

=5*375/(875+375) = 1.5V

Vs=0V groung

Vgs= Vg-Vs= 1.5-0=1.5

(Vgs-Vt)= 1.5-1.2=0.3 which is greater than zero hence the transistor in either sat or linear

let us asume sat Vds>= Vgs-Vt

Id=1/2 * kn' * W/L (Vgs-Vt)^2

=0.5*50micro*40/5(1.5-1.2)^2 = 8 micro A

writing KVL

Vdd -Id*Rd-Vds=0

5-8 micro *13.5k -Vds=0

Vds=4.9V

b) for transistor to be in sat Vds>=Vgs-Vt

taking min conditio Vds=Vgs-Vt= 1.5-1.2 = 0.3V

now

writing KVL

Vdd-Id*Rd-Vds=0

Rd(max)=4.7/8micro = 587.5 K ohm

the range of Rd 0 -   587.5 K ohm

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.