This text discusses sigma- delta- type function circuits, peak detecting function circuits, and peak sampling function circuits in a detailed manner. It further covers all the function circuits designed by using the basic principles of the six building blocks: integrator, the 555 timer integrated circuit, switch, low pass fi lter, peak detector, and sample and hold circuit. It is a useful reference text for senior undergraduate and graduate students in the fi elds of electrical engineering and electronics and communication engineering. This book is accompanied by teaching resources, including a solution manual for the instructors.* Discusses function circuits such as multipliers, dividers, and multiplier cum dividers using the 555 timer.* Explains how function circuits are developed with a simple integrator and the 555 timer.* Extends the applications of 555 timers to perform in function circuits.* Covers important topics such as monostable multivibrator, inverting amplifi er, and peak responding divider.* Presents function circuit conversion such as multiplier to square root and divider to a multiplier.This comprehensive book covers the design of function circuits with the help of 555 timer integrated circuits in a single volume. It further discusses how derived function circuits are implemented with integrator, comparator, low pass fi lter, peak detector, and sample and hold circuits.