Binary → Gray Circuit (4-bit)

0B3 0B2 0B1 0B0 XOR XOR XOR G30 G20 G10 G00 BINARY GRAY
Binary 0000 = 0
Gray 0000

Truth Table (all 16 codes)

DecB3B2B1B0G3G2G1G0
0 0000 0000
1 0001 0001
2 0010 0011
3 0011 0010
4 0100 0110
5 0101 0111
6 0110 0101
7 0111 0100
8 1000 1100
9 1001 1101
10 1010 1111
11 1011 1110
12 1100 1010
13 1101 1011
14 1110 1001
15 1111 1000

How Gray Code Works

Formula

G3 = B3
G2 = B3 ⊕ B2
G1 = B2 ⊕ B1
G0 = B1 ⊕ B0

Key Property

Only one bit changes between any two consecutive Gray codes. This eliminates glitches in encoders and minimizes switching errors.

Used In

Rotary encoders, analog-to-digital converters, Karnaugh maps, and error correction codes.