Positive and Negative logic in Digital Electronics

Basic difference between positive and negative logic

There are two types of representations used in digital systems, the positive logic and the negative logic representations.

In positive logic representation Bit 1 represents Logic high and Bit 0 represent a Logic low as shown in fig 2 a and b. High is represented by +5 Volts and low is represented by -5 Volts or 0 Volts.

Positive logic representationPin

In Negative logic representation Bit 1 represents logic low and Bit 0 represents logic high as shown in Fig 3 a and b. In terms of voltage level, bit 1 can be represented as +5V and bit 0 can be represented as 0 V or -5 Volts

Negative logic representationPin

See also
Advantages of Digital Systems