Datasheet

MAX31865
RTD-to-Digital Converter
3Maxim Integrated
ELECTRICAL CHARACTERISTICS (continued)
(3.0V P V
DD
P 3.6V, T
A
= -40NC to +125NC, unless otherwise noted. Typical values are T
A
= +25NC, V
DD
= V
DVDD
= 3.3V.) (Notes 2
and 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
ADC Common-Mode Input
Range
0 V
BIAS
V
Input Leakage Current
RTDIN+, RTDIN-, 0NC to +70NC, on-state
2
nA
RTDIN+, RTDIN-, -40NC to +85NC, on-state
5
RTDIN+, RTDIN-, -40NC to 100NC, on-state
14
Bias Voltage V
BIAS
1.95 2.00 2.06 V
Bias Voltage Output Current I
OUT
0.2 5.75 mA
Bias Voltage Load Regulation
I
OUT
P 5.75mA
30 mV/mA
Bias Voltage Startup Time (Note 4) 10 ms
ADC Full-Scale Error
±1
LSB
ADC Integral Nonlinearity
Differential Input, endpoint fit, 0.3 x V
BIAS
P V
REF
P V
BIAS
±1
LSB
ADC Offset Error -3 +3 LSB
Noise (over Nyquist Bandwidth) Input referred 150
FV RMS
Common-Mode Rejection 90 dB
50/60Hz Noise Rejection Fundamental and harmonics 82 dB
Temperature Conversion Time
(Note 5)
t
CONV
Continuous conversion (60Hz notch) 16.7 17.6
ms
Single conversion (60Hz notch) 52 55
Single conversion (50Hz notch) 62.5 66
Continuous conversion (50Hz notch) 20 21
Automatic Fault Detection Cycle
Time
From CS high to cycle complete
550 600
Fs
Power-Supply Rejection 1 LSB/V
Power-Supply Current (Note 6)
I
DD
Shutdown
Bias off, ADC off 1.5 3 mA
I
DD
Bias on, active conversion 2 3.5 mA
Power-On Reset Voltage
Threshold
2 2.27 V
Power-On Reset Voltage
Hysteresis
120 mV
Input Capacitance C
IN
Logic inputs 6 pF
Input Leakage Current I
L
Logic inputs -1 +1
FA
Output High Voltage V
OH
I
OUT
= -1.6mA
V
DVDD
- 0.4
V
Output Low Voltage V
OL
I
OUT
= 1.6mA 0.4 V