MLX90323 Datasheet, PDF (1/25 Pages) Melexis Microelectronic Systems – 4 – 20 mA Loop Sensor Interface with Signal Conditioning and EEPROM

MLX90323
4 – 20 mA Loop Sensor Interface
with Signal Conditioning and EEPROM
Features and Benefits
Programmable Sensor Interface IC with 4 to
20 mA current loop output
Power supply from 6 to 35V_DC
External or internal temperature sensor for
compensating temperature errors
Application Examples
Industrial pressure transducers.
Strain gauges, accelerometers, position
sensors, etc.
Any bridge type sensor with current loop
output.
Ordering code
Product Code Temperature Code
MLX90323
K
MLX90323
K
Package Code
DF
DF
Option Code
AAA-000
AAA-000
Legend:
Temperature Code:
Package Code:
Packing Form:
K for Temperature Range -40°C to +125°C
DF for SOIC300Mil
RE for Reel, TU for Tube
Ordering example: MLX90323KDF-AAA-000-TU
Packing Form Code
TU
RE
1 Functional Diagram
2 General Description
FET VDD1
OFC
FLT
VDD
Supply Regulator
The IC converts small changes of output voltage
of full Wheatstone resistive bridge (caused by
mechanical stimulus such as pressure, force,
torque, light or magnetic field) to large changes of
the IC output current.
VBP
VBN
TMP
GND
3.5V
DAC_Offset
OPA
0V
x 35
x2
INV
Hardware Gain = 70
Coarse Offset
1.24kOhm
2-bit
CSGN
GAIN
0.97V/V
0.48V/V
Fine Gain DAC
External
Temp Sensor
Internal
Temp Sensor
3.5V
ADC
Temp Amp Gain
GNTP [1:0]
0V
Micro-
Processor
It removes parasitic DC level (Offset) from the
output bridge voltage and amplifies this signal
certain times (Gain). Offset and Gain are
temperature dependant, so the IC allows
temperature compensation of bridge parasitic DC
GAIN
CMO
CMN shift and sensitivity. Temperature can be
measured either by internal or external (resistor)
IO1
IO2
temperature sensor. The values of Offset and
COMS _{Gain and their temperature dependency are}
gotten during the calibration process and are
stored in the EEPROM..
TSTB
The IC has industry standard 4 – 20 mA current
loop output interface and takes power directly from
2-wire signal line. The MLX90323 works properly
over wide voltage range (from 6 to 35 V) at the
signal line.
3901090323
Rev 003
Page 1 of 25
Data Sheet
Feb/12