MAX12555 Datasheet, PDF (21/28 Pages) Maxim Integrated Products – 14-Bit, 95Msps, 3.3V ADC

14-Bit, 95Msps, 3.3V ADC
BINARY-TO-GRAY-CODE CONVERSION
1) THE MOST SIGNIFICANT GRAY-CODE BIT IS THE SAME
AS THE MOST SIGNIFICANT BINARY BIT.
D13 D11
D7
D3 D0
01 1011 0100 1100
BIT POSITION
BINARY
0
GRAY CODE
2) SUBSEQUENT GRAY-CODE BITS ARE FOUND ACCORDING
TO THE FOLLOWING EQUATION:
GRAY_X = BINARY_X BINARY_X+1
WHERE IS THE EXCLUSIVE OR FUNCTION (SEE TRUTH
TABLE BELOW) AND X IS THE BIT POSITION.
GRAY₁₂ = BINARY₁₂
GRAY₁₂ = 1 0
GRAY₁₂ = 1
BINARY₁₃
D13
D11
D7
D3 D0 BIT POSITION
0 1 1 0 1 1 0 1 0 0 1 1 0 0 BINARY
01
GRAY CODE
GRAY-TO-BINARY-CODE CONVERSION
1) THE MOST SIGNIFICANT BINARY BIT IS THE SAME
AS THE MOST SIGNIFICANT GRAY-CODE BIT.
D13 D11
D7
D3 D0
0 1 0 1 10 1 1 1 0 1 0 1 0
BIT POSITION
GRAY CODE
0
BINARY
2) SUBSEQUENT BINARY BITS ARE FOUND ACCORDING
TO THE FOLLOWING EQUATION:
BINARY_X = BINARY_X+1 GRAY_X
WHERE IS THE EXCLUSIVE OR FUNCTION (SEE TRUTH
TABLE BELOW) AND X IS THE BIT POSITION.
BINARY₁₂ = BINARY₁₃
BINARY₁₂ = 0 1
BINARY₁₂ = 1
GRAY₁₂
D13
D11
D7
D3 D0 BIT POSITION
0 1 _{0 1 1 0 1 1 1 0 1 0 1 0 GRAY CODE}
01
BINARY
3) REPEAT STEP 2 UNTIL COMPLETE.
GRAY₁₁ = BINARY₁₁
GRAY₁₁ = 1 1
GRAY₁₁ = 0
BINARY₁₂
D13 D11
D7
01 1011 0100
01 0
D3 D0
1100
BIT POSITION
BINARY
GRAY CODE
3) REPEAT STEP 2 UNTIL COMPLETE.
BINARY₁₁ = BINARY₁₂
BINARY₁₁ = 1 0
BINARY₁₁ = 1
GRAY₁₁
D13 D11
D7
01 0110 1110
D3 D0
1010
01 1
BIT POSITION
GRAY CODE
BINARY
4) THE FINAL GRAY-CODE CONVERSION IS:
D13 D11
D7
01 1011 0100
01 0110 1110
D3 D0
1100
1010
BIT POSITION
BINARY
4) THE FINAL GRAY-CODE CONVERSION IS:
D13 D11
D7
01 0110 1110
D3 D0
1010
GRAY CODE
01 1011 0100 1100
EXCULSIVE OR TRUTH TABLE
AB
Y=A B
00
0
01
1
10
1
11
0
BIT POSITION
GRAY CODE
BINARY
Figure 9. Binary-to-Gray and Gray-to-Binary Code Conversion
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