Analysis versus design Given a system, find its properties. The solution is unique. Design: Given a set of properties, come up with a system possessing them. The solution is rarely unique.

The IC Design Process, Allen’s view

Texas Instruments, or Vaibhav Kumar’s view PG: pattern generation, also called tapeout, to generate GDS RTM: release to manufacturing NPD: new product development (delivery)

Texas Instruments, or Vaibhav Kumar’s view

Product definition & specification Based on market study Future market opportunities Gaps/niches in existing products Cost effective replacements Customer needs to specifications Application environment Interfaces with other components I/O requirements Accuracy/linearity requirements …

Electrical Design the process from the specifications to a circuit solution Requires active and passive device electrical models for Creating the design Verifying the design Determining the robustness of the design

Physical Design From electrical design to a layout pattern

Test Design To verify that fabricated circuit meet specifications To characterize additional “behavior” To trouble-shoot design To fine tune certain parameters To trim certain parameters Top designers are top test engineers

Skill-set for Analog IC design Good physics background Decent math skills Skilled in measurements Good understanding of principles, concepts, and assumptions Skilled in simulation Grasp of technology and modeling Intuition for reasonable simplifications Audacity to try new things, but guided by theory and physics Not afraid of failure, but methodical learning from failures/mistakes Wide range of knowledge

Technology scaling The good: The bad: The challenging: Smaller geometries Smaller parasitics Higher transconductance Higher bandwidths The bad: Reduced voltages Smaller channel resistances (lower gain) More nonlinearity Deviation from square-law behavior The challenging: Increased substrate noise in mixed signal applications Threshold voltages are not scaling with power supply Reduced dynamic range Poor matching at minimum channel length

There are many applications with signal frequencies in the few kHz to MHz range. Examples include automotive, automation, and more.

There are other things that are getting attention, some are close to real market, some are early research. Keep track of the ITRS: International Technology Roadmaps for Semiconductors.

Signal naming conventions

Schematic Symbols

Circuit analysis skills Please review materials in appendix A Make sure you are fluent at Nodal analysis, KCL Mesh analysis (dual to nodal), KVL Cascade stages Small signal analysis, including linearization Equivalent circuits Miller simplification

Cascade V1 = Vout = Vout/vin =

Nodal analysis KCL at node A: KCL at node B: Solve for Vout/Iin =

Small signal analysis The amplifier may be nonlinear, but near an operating point, it has a small signal model of: vo = Av * vin. By definition, SSA is always linear.

Making Equivalent substitutions Simplified Cascade

Miller simplification If v2 = K*v1 i1 = (v1-Kv1)/Z =(1-K)v1/Z i2 = (v2-v1/K)/Z =(K-1)/K v2/Z

HW Browse through problems 1.1-4 to 1.1-12 If you are excellent, write a statement to indicate so. If you are rusty on these, briefly do all of these problems and check your answers against book answers.