MLX90320LFRLFR MELEXIS [Melexis Microelectronic Systems], MLX90320LFRLFR Datasheet - Page 13

• Manufacturer Part Number: MLX90320LFRLFR
• Description: Automotive small sensor interface
• Manufacturer: MELEXIS [Melexis Microelectronic Systems]

Explanation of the parameters used in the global equations:
The different sensor chain calibration parameters with their range will be described in the following paragraphs.
6.4.1 The Gain calibration of the sensor signal chain.
Three programmable coarse gain stages allow calibrating a wide range of sensor output spans (1.8mV/V to
63mV/V range) to the desired MLX90320 output span. Amplifier DIDO is a differential input – differential output
amplifier, while amplifier DTS and CS are dual-to-single-ended amplifiers giving a single ended output voltage
referred to the ground.
Each one of these three amplifiers is one bit programmable:
Besides the three programmable coarse gain stages, there is also a 10 bits programmable fine gain stage within
the range 44.88% to 99%. The fine gain calibration allows an accurate adjustment of the output span. The fine
gain can be calculated by the formula:
Equation 1
Explanation of parameters used in equation 1:
The fine gain calibration allows also a second order compensation of the drift with temperature of the sensor
sensitivity. The value of the fine gain is given by the formula:
Equation 2
Explanation of parameters used in equation 2:
3901090320
Rev 004
OUT
FN
FNGain
GAIN
real
. 1
INP-INM is the differential output from the sensor
IINV is the bit that swaps the MLX90320 inputs INP and INM
POS
schematic of the sensor signal chain (fig 5)
AGND is an analog ground dependent of the supply voltage V
G
FN
FN
OUT is the application mode output of the MLX90320.
The DIDO gain is 3.25 or 13 depending on the value of the corresponding bit stored on the address 7
of the EEPROM.
The DTS gain is 2 or 5 depending on the value of the corresponding bit stored on the address 7 of the
EEPROM.
The CS gain is 1.24 or 1.9375 depending on the value of the corresponding bit stored on the address 7
of the EEPROM.
FN
FNGain
. 0
DIDO
667
OFF
GAIN
GAIN
448
out
G
, G
and CS
, NEG
0
is the sensor signal chain fine gain programmable.
is the fine gain used in the signal sensor chain.
real
Gn
DTS
FNGain
G
is the value of the fine gain in the [0..1] range with 10 bits resolution.
, G
OUT
1
out
OFF
CS
, Dts
T
form the sensor signal chain coarse gain programmable.
. 1
are respectively the sensor signal chain fine and coarse offset programmable.
real
1668
out
T
1
, CS
. 0
G
out
V
99
2
, Gn
DD
T
. 0
in
448
and Gn
T
1
Page 13 of 32
2
out
are MLX90320 internal nodes represented in the
Automotive small sensor interface
DD
.
MLX90320
Data Sheet
Mar/05