MAX1459 Datasheet, PDF (4/24 Pages) Maxim Integrated Products – 2-Wire, 4-20mA Smart Signal Conditioner

2-Wire, 4–20mA
Smart Signal Conditioner
ELECTRICAL CHARACTERISTICS (continued)
(V_DD = +5V, V_SS = 0, T_A = +25°C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP MAX UNITS
DIGITAL PINS
High-Level Input Voltage
V_IH
Low-Level Input Voltage
V_IL
Input Hysteresis
0.75 x V_DD
V
0.25 x V_DD V
2
V
High-Level Output Voltage
Low-Level Output Voltage
V_OH
V_OL
I_SOURCE = 1mA
I_SINK = 2mA
4
V
0.5
V
Note 1: Excludes the sensor or load current.
Note 2: All electronics temperature errors are compensated together with sensor errors.
Note 3: The sensor and the MAX1459 must always be at the same temperature during calibration and use.
Note 4: This is the maximum allowable sensor offset.
Note 5: This is the sensor’s sensitivity normalized to its drive voltage, assuming a desired full-span output of 4V and a bridge
voltage of 2.5V. Sensors smaller than +10mV/V require an auxiliary op amp.
Note 6: Bit weight is ratiometric to V_DD.
__________________________________________Typical Operating Characteristics
(V_DD = +5V, V_SS = 0, T_A = +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
2.5
V_OUT = 2.47V AT +25°C
2.0
1.5
1.0
0.5
0
-40 -20
0 20 40 60 80 100 120
TEMPERATURE (°C)
R_TEMP vs. TEMPERATURE
200
180
160
140
120
100
80
60
40
20
0
-40 -20
0 20 40 60 80 100 120
TEMPERATURE (°C)
V_OUT vs. TEMPERATURE
5.0
4.5
4.0
3.5
V_OUT = 2.5V AT +25°C
V_IN = 56.5mV
3.0
2.5
2.0
1.5
V_OUT = 2.47V AT +25°C
1.0
V_IN = 0
0.5
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
4 _______________________________________________________________________________________