Datasheet

AD977/AD977A
–15–REV. D
Table III. Output Codes and Ideal Input Voltages
Digital Output
Two’s Complement Straight Binary
Description Analog Input (SB/BTC LOW) (SB/BTC HIGH)
Full-Scale Range ±10 V ± 5 V ±3.33 V 0 V to 10 V 0 V to 5 V 0 V to 4 V
Least Significant Bit 305 µV 153 µV 102 µV 153 µV 76 µV 61 µV
+Full Scale (FS–1 LSB) 9.999695 V 4.999847 V 3.333231 V 9.999847 V 4.999924 V 3.999939 V 0111 1111 1111 1111 1111 1111 1111 1111
Midscale 0 V 0 V 0 V 5 V 2.5 V 2 V 0000 0000 0000 0000 1000 0000 0000 0000
One LSB Below Midscale –305 µV –153 µV –102 µV 4.999847 V 2.499924 V 1.999939 V 1111 1111 1111 1111 0111 1111 1111 1111
–Full Scale –10 V –5 V –3.333333 V 0 V 0 V 0 V 1000 0000 0000 0000 0000 0000 0000 0000
Table IV. Input Ranges, Offset and Full-Scale Errors Without External Resistors
AD977 Offset Error Full-Scale Error AD977A Offset Error Full-Scale Error
Input Range A/B/C Grade A/B/C Grade Input Range A/B/C Grade A/B/C Grade
–9.890 V to 9.90 V ±25 mV/±25 mV ± 0.75%/± 0.50% –9.800 V to 9.970 V ±40 mV/±40 mV ± 0.80%/± 0.55%
–4.943 V to 4.995 V ±25 mV/±25 mV ± 0.75%/± 0.50% –4.900 V to 4.985 V ±40 mV/±40 mV ± 0.80%/± 0.55%
–3.295 V to 3.330 V ±25 mV/±25 mV ± 0.75%/± 0.50% –3.267 V to 3.323 V ±40 mV/±40 mV ± 0.80%/± 0.55%
0.008 V to 9.946 V ±10 mV/± 10 mV ± 0.75%/± 0.50% 0.007 V to 9.893 V ± 10 mV/±10 mV ± 0.75%/± 0.50%
0.004 V to 5.023 V ±10 mV/± 10 mV ± 0.75%/± 0.50% 0.004 V to 5.039 V ± 10 mV/±10 mV ± 0.75%/± 0.50%
0.003 V to 4.010 V ±10 mV/± 10 mV ± 0.75%/± 0.50% 0.003 V to 4.016 V ± 10 mV/±10 mV ± 0.75%/± 0.50%
200
V
IN
100
33.2k
2.2 F
2.2
F
R1
IN
R2
IN
R3
IN
REF
AGND2
CAP
AGND1
AD977A
AD8031
200
33.2k
2.2 F
2.2
F
R1
IN
R2
IN
R3
IN
REF
AGND2
CAP
AGND1
AD977A
V
IN
100
AD8031
200
V
IN
100
33.2k
2.2 F
2.2
F
R1
IN
R2
IN
R3
IN
REF
AGND2
CAP
AGND1
AD977A
AD8031
Figure 11. AD977A Bipolar Input Configuration Using the Internal Reference; (a) V
IN
= ± 10 V, (b) V
IN
= ± 5 V, (c) V
IN
= ± 3.33 V
a.
c.
b.