{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

115A_1_EE115A_W10-Chap7

115A_1_EE115A_W10-Chap7 - Chapter 7 CMOS Amplifiers 7.1...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 7 CMOS Amplifiers head2right 7.1 General Considerations head2right 7.2 Common-Source Stage 312 head2right 7.3 Common-Gate Stage head2right 7.4 Source Follower head2right 7.5 Summary and Additional Examples
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Chapter Outline CH7 CMOS Amplifiers 313
Background image of page 2
MOS Biasing ( ) TH DD TH GS V V R R V R V V V V V 1 2 2 1 2 1 2 1 1 = - + + + - - = CH7 CMOS Amplifiers 314 head2right Voltage at X is determined by V DD , R 1 , and R 2 . head2right V GS can be found using the equation above, and I D can be found by using the NMOS current equation. S ox n R L W C μ 1
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Self-Biased MOS Stage DD D S GS D D V I R V R I = + + CH7 CMOS Amplifiers 315 head2right The circuit above is analyzed by noting M1 is in saturation and no potential drop appears across R G .
Background image of page 4
Current Sources CH7 CMOS Amplifiers 316 head2right When in saturation region, a MOSFET behaves as a current source. head2right NMOS draws current from a point to ground (sinks current), whereas PMOS draws current from V DD to a point (sources current).
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Common-Source Stage CH7 CMOS Amplifiers 317 D D ox n v D m v R I L W C A R g A μ λ 2 0 - = - = =
Background image of page 6
Operation in Saturation ( ) TH GS DD D D V V V I R - - < CH7 CMOS Amplifiers 318 head2right In order to maintain operation in saturation, V out cannot fall below V in by more than one threshold voltage. head2right The condition above ensures operation in saturation.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
CS Stage with λ =0 319 L out in L m v R R R R g A = = - =
Background image of page 8
CS Stage with λ 0 CH7 CMOS Amplifiers 320 head2right However, Early effect and channel length modulation affect CE and CS stages in a similar manner. ( ) O L out in O L m v r R R R r R g A || || = = - =
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
CS Gain Variation with Channel Length CH7 CMOS Amplifiers 321 head2right Since λ is inversely proportional to L, the voltage gain actually becomes proportional to the square root of L. D ox n D ox n v I WL C I L W C A μ λ μ 2 2 =
Background image of page 10
CS Stage with Current-Source Load CH7 CMOS Amplifiers 322 head2right To alleviate the headroom problem, an active current- source load is used.
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}