BH1710FVC-TR Rohm Semiconductor, BH1710FVC-TR Datasheet - Page 11

• Manufacturer Part Number: BH1710FVC-TR
• Description: IC AMBIENT LIGHT SENSOR WSOF6
• Manufacturer: Rohm Semiconductor
• Type: Ambient Light Sensor with Serial Outputr
• Series: -r

Specifications of BH1710FVC-TR

• Wavelength: 560nm
• Output Type: I²C™
• Package / Case: 6-WSOF Exposed Pad
• Product: Ambient Light Sensor
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

●Adjust measurement result for influence of optical window. (sensor sensitivity adjusting )
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BH1710FVC
www.rohm.com
Please input the opecode at PowerDown state to change Mtreg.There is a possibility of malfunctioning when the opecode to
change Mtreg is input while the illuminance measurement is going .
BH1710FVC is possible to change sensor sensitivity. And it is possible to cancel the optical window influence (difference with
/ without optical window) by using this function. Adjust is done by changing measurement time. For example, when
transmission rate of optical window is 50% (measurement result becomes 0.5 times if optical window is set), influence of
optical window is ignored by changing sensor sensitivity from default to 2 times
Sensor sensitivity is shift by changing the value of MTreg (measurement time register). MTreg value has to set 2 times if
target of sensor sensitivity is 2 times. Measurement time is also set 2 times when MTreg value is changed from default to 2
times.
ex) Procedure for changing target sensor sensitivity to 2 times.
1)Changing High bit of Mtreg
2)Changing Low bit of Mtreg
3)Input Measurement Command.
4)After about 240ms, measurement result is registered to Data Register. (High Resolution mode is typically 120ms, but
The below table is seeing the changeable range of MTreg.
It is possible to detect 0.24lx by using this function at H-resolution mode.
The below formula is to calculate illuminance per 1 count.
Illuminance per 1 count ( lx / count ) = 1 / 1.2 *( 300 / X )
The below table is seeing the detail of resolution.
ST
ST
ST
Please change Mtreg from ” 01_0010_1100” ( default ) to ” 10_0101_1000” ( default * 2 ).
measurement time is set twice.)
range of Mtreg
Changeable
00100_01100
01001_01100
11111_11110
Mtreg value
Slave Address
Slave Address
Slave Address
Binary
Decimal
(sensitivity : default*0.47)
(sensitivity : default*0.47)
00100_01100
Min.
140
R/W
R/W
R/W
1.2 : Measurement accuracy
300 : Default value of MTreg
X
0
0
0
※This example is High Resolution mode, but it accepts the other measurement.
: Mtreg value
lx / count
Ack
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11/16
1.79
0.83
0.24
01001_01100
default
default
Typ.
300
010_10010
0001_0000
011_11000
(sensitivity : default*3.41)
(sensitivity : default*3.41)
11111_11110
Technical Note
Max.
1022
2010.06 - Rev.B
Ack
Ack
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SP
SP
SP