MLX90320_12 Datasheet, PDF (27/33 Pages) Melexis Microelectronic Systems – Automotive sensor interface

MLX90320
Automotive sensor interface
8 to 10
11
15
12 to 14
15
16 to 18
19
23
20 to 22
23
27
23
24 to 26
28 to 30
31
31
0 to 3 G1 for Gain DAC
0 to 3
1 to 3
0 to 3
CSOF[6..0]
G0 for Gain DAC
0
0 to 3
ClampSet
T1 for Offset DAC
0 to 3 CLAMP[5..0]
2 and 3
0 to 3 O2 for Offset DAC
0
0 to 3
TMP_OFFSET[4:0]
1
TMP_SELECT
0 to 3 O1 for Offset DAC
0 to 3 O0 for Offset DAC
0
1 to 3
NOT USED
TMP_GAIN[2:0]
Contains the first order fine gain coefficient used to
compensate the sensor sensitivity drift with temperature.
The MSB is the sign bit (two’s complement): If G1[11] =
1 then G1 is negative, if G1[11] = 0 then G1 is positive.
7 bits used to operate the coarse offset calibration.
Contains the zero order fine gain coefficient
(independent from the temperature) used to adjust
accurately the output span at room temperature. 12 bits
are stored but only the 10 first are used. The two MSB
must be 0.
Bit used to enable(when ClampSet =1) or disable(when
Clampset=0) the clamping
Contains the value of T1 used to calculate the fine offset
in order to operate the second order compensation of
the offset drift with temperature.
6 bits used for calibrating the clamping levels.
CLAMP[2:0] are used for the low clamp levels (000
gives 4% at output and 111 gives 14% at output) and
CLAMP[5:3] are used for the high clamp levels (000
gives 86% at output and 111 gives 96% at output).
Contains the second order fine offset coefficient used to
compensate the offset drift with temperature.
The MSB is the sign bit (two’s complement): If O2[11] =
1 then O2 is negative, if O2[11] = 0 then O2 is positive.
These 5 bits are used to calibrate the offset of the
external temperature sensor. If TMP_OFFSET[4:0] =
11111 then the TMP pin has the lowest voltage. If
TMP_OFFSET[4:0] = 00000 then the TMP pin has the
highest voltage. Goal is to calibrate in the
neighbourhood of 2.5V. The internal temperature sensor
offset calibration is only factory set.
Bit used to choose between an internal or an external
temperature sensor. If TMP_SELECT=1 then the
internal temperature sensor is chosen else an external
temperature sensor is needed.
Contains the first order fine offset coefficient used to
compensate the offset drift with temperature.
The MSB is the sign bit (two’s complement): If O1[11] =
1 then O1 is negative, if O1[11] = 0 then O1 is positive.
Contains the zero order fine offset coefficient
(independent from the temperature) used to
compensate accurately the sensor offset at room
temperature. 12 bits are stored but only the 10 first are
used. The two MSB must be 0.
These 3 bits are used to calibrate the gain of the
external temperature sensor. If TMP_GAIN[2:0] = 111,
the gain is the highest. If TMP_GAIN[2:0] = 000, the
3901090320
Rev 007
Page 27 of 33
Data Sheet
Feb/12