Rainbow Electronics MAX1494 - Manual (Page 31)

MAX1492/MAX1494
3.5- and 4.5-Digit, Single-Chip ADCs
with LCD Drivers
______________________________________________________________________________________ 31
0.1 µF
R
AIN-
AIN+
4–20mA
R = 100 Ω for ±2V RANGE
10 Ω for ±200mV RANGE
0.1 µF
MAX1492
MAX1494
±1.8.8.8.8
Figure 23. 4–20mA Measurement
>4E1Fh
4E1Fh
0002h
0001h
0000h
FFFFh
FFFEh
FFFDh
B1E0h
<B1E0h
-2V 0
ANALOG INPUT VOLTAGE
+2V
ADC RESULT LCD
1 - - - -
19,999
2
1
0
- 0
- 1
- 2
-19,999
- 1 - - - -
-100 µV 100µV
Figure 24. MAX1494 Transfer Function, ±2V Range
4E1Fh
4E1Fh
0002h
00001h
0000h
FFFFh
FFFEh
FFFDh
B1E0h
<B1E0h
-200mV 0
ANALOG INPUT VOLTAGE
+200mV
ADC RESULT LCD
1 - - - -
19,999
2
1
0
- 0
- 1
- 2
-19,999
- 1 - - - -
-10 µV 10 µV
Figure 25. MAX1494 Transfer Function ±200mV Range
7CFh
7CFh
002h
001h
000h
FFFh
FFEh
FFDh
830h
<830h
-200mV 0
ANALOG INPUT VOLTAGE
+200mV
ADC RESULT LCD
1 - - -
1999
2
1
0
- 0
- 1
- 2
-1999
- 1 - - -
-100 µV 100µV
Figure 26. MAX1492 Transfer Function ±200mV Range