chap3part2 - Basiccurrentmirrorsandsinglestage

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

View Full Document Right Arrow Icon
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
Background image of page 1

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

View Full DocumentRight Arrow Icon
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 =
Background image of page 2
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.
Background image of page 3

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

View Full DocumentRight Arrow Icon
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 = -
Background image of page 4
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
Background image of page 5

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

View Full DocumentRight Arrow Icon
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
Background image of page 6
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
Background image of page 7

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

View Full DocumentRight Arrow Icon
Adaptive Integrated Microsystems Common gate amplifier Gain Input impedance Output impedance
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 32

chap3part2 - Basiccurrentmirrorsandsinglestage

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

View Full Document Right Arrow Icon
Ask a homework question - tutors are online