Download presentation

Presentation is loading. Please wait.

Published byGretchen Caldwell Modified about 1 year ago

1
Transistor nMOS Q channel = CV C = C g = ox WL/t ox = C ox WL V = V gc – V t = (V gs – V ds /2) – V t v = E (mobility) E = V ds /L Time for carrier to cross channel: t = L / v C ox = ox / t ox

2
nMOS Linear I-V Now we know –How much charge Q channel is in the channel –How much time t each carrier takes to cross

3
nMOS Operation CutoffLinearSaturated V gs < V t V gs > V t V ds < V gs –V t V gs > V t V ds > V gs –V t I ds 0 I ds = ( V gs –V t –V ds /2 ) V ds I ds = ( V gs –V t ) 2

4
Esempio 180 nm process W/L= 4/2 nm nm t ox =40Å cm 2 /(V·s) V t = 0.4V = C ox W/L = 180 * (3.9*8.85 *10 -14 F/cm)/(40*10 -8 ) =155 V 1)I dsmax @ (V gs =1V) = 155 V V) 2)I ds (V gs =2V, V ds =1V) = 155 V

5
I-V Characteristics

6
CMOS Inverter n-well n-well contact (n+) p+ diffusions polysilicon n+ diffusions substrate contact (p+) polysilicon contacts diffusion contacts

7
DC Transfer Curve For a given V in : –Plot I dsn, I dsp vs. V out –V out must be where |currents| are equal in Transcribe points onto V in vs. V out plot

8
Operating Regions RegionnMOSpMOS ACutoffLinear BSaturationLinear CSaturation DLinearSaturation ELinearCutoff

9
Beta Ratio If p / n 1, switching point will move from V DD /2

10
Inverter a Carico Resistivo V out I

11
Inverter a Carico Attivo V out I

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google