概论

Why Analog

• The sensing interface still demands high-performance analog design (to amplify the signal).
• At lower speeds, it is more efficient to digitize the signal and perform the required function(s) in the digital domain, whereas athigher speeds, we implement the function(s) in the analog domain.
• Sensors can only use analog design.

Why CMOS

CMOS - complemetary metal-oxide-silicon

• The low cost of fabrication
• The possibility of placing both analog and digital circuits on the same chip so as to improve the overall performance and/or reduce the cost of packaging
• Device scaling continued to improve the speed of MOSFETs

Analog Design Challenges

• THranistor IMperfections
• Declining Supply Voltages
• Power Consumption
• Circuit Complexity
• PVT Variations

Levels of Abstraction