This file type includes high resolution graphics and schematics. You can build an analog calculator using a pulse-width modulator (PWM) to perform accurate four-quadrant multiplication and division.

Fig 1. An op amp easily accomplishes addition, while a Gilbert cell handles the task of multiplication.caption of image Fig 2. Two digital words are added by combining a series of full adder cells.

Basically in digital system there are two type of circuit: combinational logic circuit and sequential logic circuit. When the authors talk about combinational circuit, this circuit is that circuit of ...