BH1715FVC-TR Rohm Semiconductor, BH1715FVC-TR Datasheet - Page 11

• Manufacturer Part Number: BH1715FVC-TR
• Description: Industrial Optical Sensors Ambient Light Sensor Digital 16Bit Serial
• Manufacturer: Rohm Semiconductor
• Type: Ambient Light Sensor with Digital Outputr
• Series: -r

Specifications of BH1715FVC-TR

• Product: Ambient Light Sensor
• Ic Function: Light To Digital Output Sensor
• Supply Voltage Range: 2.4V To 3.6V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: SOP
• No. Of Pins: 6
• Supply Voltage Max: 3.6V
• Wavelength: 560nm
• Output Type: I²C™
• Package / Case: 6-WSOF Exposed Pad
• Interface Type: Serial, I2C
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

●Adjust measurement result for influence of optical window. ( sensor sensitivity adjusting )
© 2010 ROHM Co., Ltd. All rights reserved.
BH1715FVC
www.rohm.com
BH1715FVC 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 regisiter ). 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.
Please change Mtreg from ”0100_0101” ( default ) to ”1000_1010” ( default * 2 ).
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.
The below table is seeing the changable range of MTreg.
It is possilbe to detect 0.23lx by using this function at H-resolution mode.
The below formula is to calculate illuminance per 1 count.
The below table is seeing the detail of resolution.
ST
ST
ST
range of MTreg
(High Resolution mode is typically 120ms, but measurement time is set twice.)
Illuminance per 1 count ( lx / count ) = 1 / 1.2 *( 69 / X )
changable
MTreg value
0100_0101
0001_1111
1111_1110
Slave Address
Slave Address
Slave Address
binary
decimal
( sensitivity : default * 0.45 )
( sensitivity : default * 0.45 )
0001_1111
Min.
31
R/W
R/W
R/W
0
0
0
※This example is High Resolution mode, but it accepts the other measurement.
1.2 : Measurement accuracy
69 : Default value of MTreg ( dec )
X : MTreg value
lx / count
Ack
Ack
Ack
1.85
0.83
0.23
11/16
0100_0101
default
default
Typ.
69
01000_100
011_01010
0001_0000
( sensitivity : default * 3.68 )
( sensitivity : default * 3.68 )
1111_1110
Technical Note
2010.06 - Rev.B
Max.
254
Ack
Ack
Ack
SP
SP
SP