Electronic Circuits II Course:

NMOS DC Circuits

Dr. Yehya H. Ghallab

Outline

• MOSFET Formulas

• MOSFET Circuits at DC

• NMOS Inverter with Resister Load

2

Outline

• MOSFET Formulas

• MOSFET Circuits at DC

• NMOS Inverter with Resister Load

3

MOSFET Formulas

4

Outline

• Introduction

• MOSFET Formulas

• MOSFET Circuits at DC

• NMOS Inverter with Resister Load

5

Example

6

Solution

7

Example

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Solution

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Outline

• Introduction

• MOSFET Formulas

• MOSFET Circuits at DC

• NMOS Inverter with Resister Load

10

NMOS Inverter with Resistor Load

11

• As the input voltage increases (VGS

), the drain to source

voltage (VDS

) decreases and the transistor inter into the

nonsaturation (linear) region.

• If VI <VTN , the transistor is in cutoff and iD = 0, there is no voltage drop across RD, and the output voltage is Vo=VDD=VDS

• If VI >VTN , the transistor is onand initially is biased insaturation region, sinceVDS > VGS -VTN .

NMOS Inverter with Resistor Load

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If VGS <VTN , the transistor is in cutoff and iD = 0, there is

no voltage drop across RD, and the output voltage is

Vo=VDD=VDS

NMOS Inverter with Resistor Load

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NMOS Inverter with Resistor Load

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NMOS Inverter with Resistor Load

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NMOS Inverter with Resistor Load

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Summary of NMOS inverter with

Resistor Load

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Example

For the NMOS inverter shown inFig. V

DD= 3V. Assume transistor

parameters of K’n = 60 μA/v2,W/L = 5, and V

TN= 0.5 V.

(a) Find the value of RD

such thatvo

= 0.1 V when vI= 3 V.

(b) Using the results of part (a)determine the transition pointfor the driver transistor

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Solution

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