MLX90320 Datasheet, PDF (9/32 Pages) Melexis Microelectronic Systems – Automotive small sensor interface

6 Detailed Description
MLX90320
Automotive small sensor interface
Figure 1: General block diagram of the MLX90320
The MLX90320 can be used with almost any type of resistive bridge sensor without the need of any additional
signal conditioning.
The differential input signal is offset compensated and amplified to achieve the desired output voltage. With a
coarse gain calibration the MLX90320 can easily accommodate sensor output spans in the 1.8mV/V to 63mV/V
range to achieve 4 V output span. Sensor output offset in the 0.4mV/V to 97.2mV/V range (depending on the
sensor output span and on the desired output offset, see table 3 for the details) can be compensated with the
coarse offset calibration to achieve an output offset in the 0.5V to 4.5V range. Figure 2 shows two typical output
characteristics that can be obtained with the calibration of the MLX90320. The option of swapping the inputs by
setting one bit in EEPROM and the wide variation of the output offset with the coarse offset calibration allows
calibrating a decreasing output characteristic as shown in figure 2. All output characteristics between those
described in figure 2 can be achieved for a wide range of sensor output span and offset.
3901090320
Rev 004
Page 9 of 32
Data Sheet
Mar/05