Intel 8253 - Page 204

Conversion Code
Range of
Analog Input
Values
Digital Output
Code
4.5 • 5.5 101
3.5 • 4.5 100
2.5 • 3.5 011
1.5 • 2.5 010
0.5 • 1.5 001
0 • 0.5 000
THE IDEAL TRANSFER FUNCTION (ADC)
-1/2 LSB
+1/2 LSB
Elements of Transfer Diagram for an Ideal Linear ADC
Digital Output
Code
Ideal Straight Line
Center
Step Width (1 LSB)
Analog Input Value
0
Quantization
Error
0 1 32 4 5
3 4 521
Analog Input Value
Midstep Value of
011
Inherent Quantization Error (±1/2 LSB)
001
011
010
000
100
101
Analog and Mixed-Signal Center (ESS)