MLX75031 Datasheet, PDF (39/67 Pages) Melexis Microelectronic Systems – Optical Gesture & Proximity Sensing IC

MLX75031
Optical Gesture & Proximity Sensing IC
with Integrated LED Drivers
Datasheet
After upload of a SD command, no other commands will be accepted till DR is high. This is done to avoid too
much disturbances in the analog part. Once DR is high, the next command will be accepted. An exception
however is the Chip Reset command. This will always be accepted.
The SD command is not available in Standby Mode.
The execution time tdr for the diagnostics measurements is between 605µs and 712µs.
The Output Data Frame is defined in the table below :
Data Byte Number
Data Byte Contents after SD command
Byte 3
ADCtest0 (8 MSB)
Byte 4
ADCtest0 (8 LSB)
Byte 5
ADCtest1 (8 MSB)
Byte 6
ADCtest1 (8 LSB)
Byte 7
ADCtest2 (8 MSB)
Byte 8
ADCtest2 (8 LSB)
Byte 9
ADCtest3 (8 MSB)
Byte 10
ADCtest3 (8 LSB)
Byte 11
DAC-ADC Test (8 MSB)
Byte 12
DAC-ADC Test (8 LSB)
Byte 13
00000 + CDE Ambient Diodes Detection (3 bit)
Byte 14
CRC (8 bit)
Table 22 : SD Output Data Frame
ADCtest0/1/2/3
These measurements are AD conversions of some internal reference voltages:
• ADCtest0 is typically at 1/16 of the ADC range: ADCtest0 = 0x0E00 .. 0x1200.
• ADCtest1 is typically at 1/4=4/16 of the ADC range: ADCtest1 = 0x3E00 .. 0x4200.
• ADCtest2 is typically at 15/16 of the ADC range: ADCtest2 = 0xEE00 .. 0xF200.
ADCtest3 is similar to ADCtest0/1/2: an AD conversion of an internal reference voltage is made. However,
an independent voltage reference is used as input for the ADC in case of ADCtest3. In the case of
ADCtest0/1/2, the reference voltages are generated from the references used for the ADC.
The typical output for ADCtest3 will be at half of the ADC range: ADCtest3 = 0x7888 .. 0x89D0. These values
are valid for VDD=3.3V +/-2%.
DAC-ADC test
A DAC-ADC test measurement is performed in the following way: the DAC output is connected to the ADC
input. The DAC input will be DACA<7:0> from register 'SetAH'. This DAC-input will be converted to an analog
output voltage that will be converted again by the ADC to give a digital value. This digital value is given in
the bytes DAC-ADC Test. Note that the values written to DACA<7:0> should be limited to the range
0x80..0xFF during the DAC-ADC test.
REVISION 001 – JANUARY, 2013
39010xxxxx
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