chap3part2

# chap3part2 - amplifiers(Chapter3:Section3.13.8 ECE412...

This preview shows pages 1–9. Sign up to view the full content.

Adaptive Integrated Microsystems Basic current mirrors and single stage  amplifiers (Chapter 3: Section 3.1-3.8) ECE 412 Introduction to mixed-signal circuits (Fall 2007) Class website: http://www.egr.msu.edu/classes/ece412/shantanu

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

View Full Document
Adaptive Integrated Microsystems Bias point Bias Point Linear operation Bias point for a transistor is determined by its drain current and gate-to-source voltage o I TH GS o m V V I g - = 2 o TH GS ox n DS D D DS ds I V V L W C V I I V r λ μ 1 ) ( 2 1 / 1 2 = - = = = o d I g =
Adaptive Integrated Microsystems Bias point Bias Point Linear operation Transconductance ratio only depends on gate-to-source voltage o I λ ) ( 2 th gs d m V V g g - = If we keep the gate-to-source voltage CONSTANT, then transconductance ratio will also be approximately CONSTANT.

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

View Full Document
Adaptive Integrated Microsystems Small signal calculation G D S Id D S G Id m gs ds g V I = d ds ds g V I = NMOS Transistor PMOS Transistor d m g g Current flow from drain to source. Current flow from source to drain. m gs ds g V I = - d ds ds g V I = -
Adaptive Integrated Microsystems Common source amplifier is the bias current, therefore initially Vin and Vout are fixed such that Q1 conducts . b I b I This means that based on this bias point the transconductance parameters gm and gd can be calculated. If Vin increases by , then the current through Q1 will increase by in V in m V g The extra current will decrease Vout by out V Vout will decrease such that it compensates for increase in current due to Vin

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

View Full Document
Adaptive Integrated Microsystems Common source amplifier 0 = + out d in m V g V g Small signal gain ds m v r g A - d m in out g g V V - = Change in current due to gate + Change in current due to drain = 0
Adaptive Integrated Microsystems Specification Gain Input impedance Output impedance Input voltage swing Output voltage swing Power dissipation b dd d I V P = ds m v r g A - = = in Z ds out r Z = th in th dd V V V V - eff out dd V V V

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

View Full Document
Adaptive Integrated Microsystems Common gate amplifier Gain Input impedance Output impedance
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 03/01/2010 for the course ECE 412 taught by Professor - during the Fall '08 term at Michigan State University.

### Page1 / 32

chap3part2 - amplifiers(Chapter3:Section3.13.8 ECE412...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online