On Monday we will go over the direct coupled cascode connection which is used in lab and then discuss techniques for direct coupling when merging is not possible. We move on to voltage and current supplies and their design to provide reference voltages and currents. A resistor is shown to provide a 'poor man's' basic current reference in building the voltage and current supplies. We then consider the complete design of an amplifying circuit including the bias voltages and reference currents.
Supplement Lecture by presenting the near ideal CB-CG current buffer and an example of direct coupling with out merging common drain MOS amplifier.
Experiment #10: Multistage Amplifiers. Now we now are ready. Please be sure to look at the cascode circuit in 9.3.3 in text. It is CS-CB, has infinite Rin, Gm = gm1 and Rout is very large (so it makes a good current supply). In class we did the current buffer CB-CG. Look at it also in 9.3.2 and read the analysis of it in 9.3.2.
Problem Set 12 covers the building a cascade of circuits for a specific application, the cascode circuit and a mirror current supply design.
Schedule and Assignments:
Lecture 33 - Cascode connection, use of p-type and n-type
devices to cascade stages and DC voltage supplies.
Lecture 34 - Current sources, totem-pole voltage references, and design of complete multistage amplifier including voltage references and current sources.
Reading - 9.4-9.5
Lecture 35 - Further consideration of the complete design and then the analysis of a BiCMOS 3 stage amplifier.
Reading 9.5 and 9.6
Homework #12 is due in box outside of 277 Cory on way into the classroom at start of class.