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Document Feedback CMV12000 Functional Description Datasheet • PUBLIC DS000603 • v6 - 00 • 2023 -Sep- 22 84 │ 63 Figure 87 : Temperature Sensor Calibration Examples Figure 88 : Temperature Sensor Register Reg. Name Addres…
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CMV12000
Functional Description
Datasheet • PUBLIC
DS000603 • v6-00 • 2023-Sep-22
84 │ 62
Figure 86:
Test Pattern Data
7.6.5 Temperature Sensor
A 16-bit digital temperature sensor is included in the image sensor and can be controlled by the SPI-
interface. An input clock at pin CLK_IN must be applied to use the temperature sensor. The on-chip
temperature can be calculated by reading out the Temp_sensor register.
The value in the temperature sensor register is dependent on the CLK_IN frequency. The value has
an offset (so at 0 °C the value in this register is not 0) and a slope (DN/°C). Both are input clock
dependent. For example, if you read out a value of 1000DN at 40 MHz, you will read a value of 500DN
at 20 MHz at the same temperature.
The offset and slope values will vary between devices. The typical offset and slope values are:
Equation 6:
Equation 7:
As the offset value varies between devices, at least a 1-point calibration per device should be done at
a known temperature to compensate this offset. As the slope variation is and has less of an influence
on the accuracy, a 2-point calibration is only needed if higher accuracy of the temperature is needed.
Below is an example of two devices (CLK_IN = 60 MHz) register values at different temperatures. The
offset and slope vary about 300DN and 0.5DN/°C between each other. You can clearly see that not
calibrating for the offset difference (so using 1600DN) will result in a very large error while using the
typical 7DN/°C will yield only small inaccuracy.
0
20
40
60
80
100
120
140
160
0 128 256 384 512 640 768 896 1024 1152 1280 1408 1536 1664 1792 1920 2048 2176 2304 2432 2560 2688 2816 2944 3072 3200 3328 3456 3584 3712 3840 3968 4096
Output [DN]
Column number
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CMV12000
Functional Description
Datasheet • PUBLIC
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Figure 87:
Temperature Sensor Calibration Examples
Figure 88:
Temperature Sensor Register
Reg. Name
Address
Bits
Default
Description
Temp_sensor
127
[15:0]
-
Read-Only. Contains a value for calculating the sensor
temperature.
The on-chip temperature sensor is located in the middle of the left side. See Figure 89.
y = 6.82x + 1505
y = 7.38x + 1804
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
0 10 20 30 40 50 60
Register Value [DN]
Device Temperature [°C]
Reg_val_dev1
Reg_val_dev2
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CMV12000
Functional Description
Datasheet • PUBLIC
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84 │ 64
Figure 89:
Temperature Sensor Location
7.6.6 Digital Test Outputs
The sensor has two digital test output pins (TDIG1, TDIG2), which can be used to easily monitor the
sensor state without using the high-speed LVDS control channel.
Use register 123[7:0] to program the output functionality:
Figure 90:
Digital Test Pins
Reg123[3:0]
TDIG1
Reg123[7:4]
TDIG2
0
LVAL
0
DVAL
2
FOT
3
INTE_1
3
INTE_2
5
CLK_PIX (= Output clock divided by the bit mode)
15
FVAL
7.7 Additional Required Register Settings
Depending on the mode or clock speed of the sensor, some additional registers are required to be set.
7.7.1 8b Mode
These settings need to be adjusted per number of channels used per side and normal, X&Y-
subsampling or binning mode.