Maxim Integrated MAXQ7667 - Manual (Page 244)

_________________________________________________________________________________________________________ 14-12
MAXQ7667 User’s Guide
14.5.4 Transfer Function
The MAXQ7667 ADC output is straight binary in unipolar mode. Figure 14-4 shows the MAXQ7667 ADC unipolar transfer function.
Table 14-2 shows the unipolar relationship between the differential analog input voltage and the digital output code.
Figure 14-4. Unipolar Transfer Function
000
001
002
003
004
FFC
FFB
FFD
FFE
FFF
0 1 2 3 4 FS
FS - 1.5 LSB
FULL-SCALE
TRANSITION FS = REF
ZS = 0
1 LSB = REF/4096
O
U
T
P
U
T
C
O
D
E
(h
e
x
)
DIFFERENTIAL INPUT VOLTAGE (LSB)
Table 14-2. Unipolar Code Table
BINARY DIGITAL
OUTPUT CODE
D11–D0
HEXADECIMAL
EQUIVALENT OF
D11–D0
DECIMAL
EQUIVALENT OF
D11–D0 (CODE 12 )
DIFFERENTIAL INPUT
VOLTAGE (V)
(EXTERNAL, REF = 2.5V)
1111 1111 1111 0xFFF 4095 +2.49939 ± 0.5 LSB
1111 1111 1110 0xFFE 4094 +2.498779 ± 0.5 LSB
1000 0000 0001 0x801 2049 +1.25061 ± 0.5 LSB
1000 0000 0000 0x800 2048 +1.25 ± 0.5 LSB
0111 1111 1111 0x7FF 2047 +1.24939 ± 0.5 LSB
0000 0000 0001 0x001 1 +0.0061 ± 0.5 LSB
0000 0000 0000 0x000 0 +0.000 + 0.5 LSB