MLX75030 Datasheet, PDF (33/72 Pages) Melexis Microelectronic Systems – Universal ActiveLight Sensor Interface

MLX75030 Universal ActiveLight Sensor Interface
Datasheet
The SM command contains an option bit T. If this bit is set to 0, normal active light measurements are performed (i.e. the
external LEDs are fired and the active light channels A and/or B are measured). If this bit is set to 1, no LEDs are fired, but
internal test pulses are applied to channels A and/or B. The internal test pulses can be influenced in amplitude by the bits
DACA7 and DACA6. Limits for ADC outputs of the TIA test pulses are shown in Table 15 : Current levels for active light test
mode.
DACA7
0
0
1
1
DACA6
0
1
0
1
I_Testpulse [uA]
5
13
21
29
Table 15 : Current levels for active light test mode
In the Control2 byte an even parity bit P is foreseen. The parity bits calculation is based on the measurement selection bits
M₆..M₀. If the number of ones in the given data set [M₆..M₀] is odd, the even parity bit P shall be set to 1, making the total
number of ones in the set [M₆..M₀, P] even.
The SPI invalid flag will be set when the parity bit does not correspond to the calculated parity bit.
After upload of a SM/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.
Note that none of the SM/SD commands are available in Standby Mode.
7.2.2.7. RO – Start Read-Out
When the state of the DR pin changed into a high state, the measurement data is available for read-out. The RO command
shall be uploaded to start a read-out cycle and to start reading out the data that was stored in the internal registers.
To make sure that no memory effects can occur, all data registers are cleared at the end of each read-out cycle.
A typical timing diagram is given in Figure 12 below:
Figure 12 : Timing diagram for Read-Out
The data that appears on the MISO pin depends on the type of measurement that was done (i.e. it depends on the command
that was uploaded: SM/SD and the selected measurement bits M₆..M₀).
REVISION 005 – DECEMBER 2013
3901075030
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