Announcements Homework 6 due today No labs this week EE105 Fall 2005 Microelectronic Devices and Circuits Lab 5 next week Lecture 13 Reading Chapters 9 4 8 MOS only Midterm 1 on Thursday Two Port Models Common Source Amplifiers Revisited Review session today October 13 6 30 8pm Sibley October 11 6 30 8pm 277 Cory No office hour next Monday Please come and see me after the lecture on Tuesday 2 Lecture Material Maximize Gain of CS Amp Last lecture Av g m RD ro MOS current sources Increase gm more current Increase RD free Don t need to dissipate extra power Limit Must keep the device in saturation This lecture Generalized two port models Common source amplifier again VDS VDD I D RD VDS sat 3 Current Source Supply For a fixed current the load resistor can only be chosen so large To have good swing we d also like to avoid getting to close to saturation 25 CS Amp with Current Source Supply Solution Use a current source Current independent of voltage for ideal source 26 27 1 Load Line for DC Biasing Two Port Parameters From current source supply Rin Gm g m Both the I source and the transistor are idealized for DC bias analysis Rout ro roc 28 29 Two Port Model Parameters P Channel CS Amplifier Small signal model for PMOS and for rest of circuit DC bias VSG VDD VBIAS sets drain current IDp ISUP 30 31 2
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