MAX1491 Datasheet, PDF (19/25 Pages) Maxim Integrated Products – 3.5- and 4.5-Digit, Single-Chip ADCs with LCD Drivers

3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
Transfer Functions
Figures 15–18 show the MAX1491/MAX1493s’ transfer
functions. The transfer function for the MAX1493/
MAX1495 with AIN+ - AIN- ≥ 0 and RANGE = GND is:
Counts = 1.024
×


V_AIN+
V_REF+
- V_AIN-
- V_REF-


×
20,000
The transfer function for the MAX1493 with AIN+ - AIN-
< 0 and RANGE = GND is:
Counts = 1.024
×


V_AIN+
V_REF+
- V_AIN-
- V_REF-
×

20, 000_
+1
The transfer function for the MAX1491 with AIN+ - AIN-
≥ 0 and RANGE = GND is:
Counts = 1.024
×


V_AIN+
V_REF+
-
-
V_AIN-
V_REF-


×
2000
The transfer function for the MAX1491 with AIN+ - AIN-
< 0 and RANGE = GND is:
Counts
= 1.024
×


V_AIN+
V_REF+
- V_AIN-
- V_REF-
×

2000_
+1
The transfer function for the MAX1493/MAX1495 with
AIN+ - AIN- ≥ 0 and RANGE = DV_DD is:
Counts = 1.024
×


V_AIN+
V_REF+
-
-
V_AIN-
V_REF-


×
20,000 × 10
The transfer function for the MAX1493 with AIN+ - AIN-
< 0 and RANGE = DV_DD is:
Counts = 1.024
×


V_AIN+
V_REF+
- V_AIN-
- V_REF-
×

20,000_
× 10 + 1
The transfer function for the MAX1491 with AIN+ - AIN-
≥ 0 and RANGE = DV_DD is:
Counts = 1.024
×


V_AIN+
V_REF+
-
-
V_AIN-
V_REF-


×
2000
× 10
The transfer function for the MAX1491 with AIN+ - AIN-
< 0 and RANGE = DV_DD is:
Counts
= 1.024
×


V_AIN+
V_REF+
- V_AIN-
- V_REF-
×

2000_
× 10 + 1
LCD
1----
19,999
2
1
0
-0
-1
-2
-19,999
-1----
-2V
-100µV 0 100µV
+2V
ANALOG INPUT VOLTAGE
Figure 15. MAX1493/MAX1495 Transfer Function ±2V Range
LCD
1----
19,999
2
1
0
-0
-1
-2
-19,999
-1----
-200mV
-10µV 0 10µV
+200mV
ANALOG INPUT VOLTAGE
Figure 16. MAX1493/MAX1495 Transfer Function ±200mV Range
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