Rohm BH1771GLC-E2 1 chip optical proximity sensor ambient light sensor ic Datasheet

Ambient Light Sensor ICs
1 Chip Optical Proximity Sensor +
Ambient Light Sensor IC
BH1771GLC
No.11046EBT11
●Descriptions
BH1771GLC is the IC into which optical proximity sensor and digital ambient light senor are unified. Proximity sensor part
detects the human or object approach by reflection of infrared LED(IrLED) light. And this device can drive maximum 3 IrLEDs,
and touch-less motion detection function can be implemented. Ambient light part can detect the wide range illuminance from
the dark up to under direct sun light. The illuminant intensity of LCD display and keypad can be adjusted, so lower current
consumption or higher visibility are possible.
●Features
2
1) Correspond to I C bus interface ( f/s mode & Hs mode support )
2) Low Current by power down function
3) Correspond to 1.8V logic interface
4) ALS spectral responsibility is approximately human eye response ( Peak wavelength : typ. 550nm )
5) Correspond to wide range of light intensity ( 1-65535 lx range )
6) Rejecting 50Hz/60Hz light noise (ALS function)
2
7) Detection range of proximity sensor is around 10 - 100mm (configurable by I C bus)
8) Touch-less motion detection function
9) Built in ambient light cancelation (Proximity sensor function)
10) Built in configurable IrLED current driver
●Applications
Mobile phone, DSC, Portable game, Camcoder, Car navigation, PDA, LCD display etc.
●Absolute Maximum Ratings
( Ta = 25℃ )
Parameter
Symbol
Ratings
Units
Vccmax
4.5
V
VSDAmax, VSCLmax,
VGNDNCmax
4.5
V
VLEDmax, VINTmax
7
V
Operating Temperature
Topr
-40～85
℃
Storage Temperature
Tstg
-40～100
℃
SDA, INT Sink Current
Imax
7
mA
Pd
250※
mW
VCC, Supply Voltage
SDA,SCL,GNDNC Terminal Voltage
LED1,LED2,LED3 INT Terminal Voltage
Power Dissipation
※ 70mm × 70mm × 1.6mm glass epoxy board. Decreasing rate is 3.33mW/℃ for operating above Ta=25℃
●Operating Conditions
Parameter
Symbol
Ratings
Min.
Typ.
Max.
Units
VCC Voltage
Vcc
2.3
2.5
3.6
V
LED1,LED2,LED3 Terminal Voltage
Vled
0.7
2.5
5.5
V
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2011.06 - Rev.B
BH1771GLC
Technical Note
●Electrical characteristics ( VCC = 2.5V, Ta = 25℃, unless otherwise noted. )
Parameter
Supply current for ALS
Symbol
Icc1
Limits
Min.
Typ.
90
－
Max.
180
Units
Conditions
μA
Ev = 100 lx ※1
Average current when
ALS_CONTROL
register(40h) = ” 03h ”
and the other registers
are default.
Average current when
PS_CONTROL
register(41h) = ” 03h ”
and the other registers
are default.
Supply current for PS
Icc2
－
90
180
μA
Supply current for PS during driving
LED current
Icc3
－
6.5
8.5
mA
Standby mode current
Icc4
－
0.8
1.5
μA
ALS & PS standby
No Input Light
f/s mode
tMALS
－
100
125
ms
H-Resolution mode
ALS measurement accuracy
S/A
0.85
1.0
1.15
Times
Sensor out / Actual lx,
Ev = 1000 lx ※1
ALS dark ( 0 lx ) sensor out
ALS0
0
0
2
count
H-Resolution mode
PS sensor out (No proximity object)
PS0
0
0
9
count
Ambient irradiance =
2
0μW/cm
PS sensor out ( Irradiance by
proximity object = 324μW/cm2)
PS324u
120
128
136
count
Ambient irradiance =
0μW/cm2
ILED pulse duration
twILED
－
200
250
μs
Cumulative ILED pulse duration
twILED2
－
1
1.25
ms
PS measurement time
tMPS
－
10
12.5
ms
LED1 terminal sink current at LED1
terminal voltage = 1.3V
ILED1
18
20
22
mA
ILED register(42h)
[2:0] = ” 010 ”
LED2 terminal sink current at LED2
terminal voltage = 1.3V
ILED2
18
20
22
mA
ILED register(42h)
[5:3] = ” 010 ”
LED3 terminal sink current at LED3
terminal voltage = 1.3V
ILED3
18
20
22
mA
ILED3 register(43h)
[2:0] = ” 010 ”
INT output ‘L’ Voltage
VINT
0
－
0.4
V
SCL SDA input 'H' Voltage
VIH
1.26
－
－
V
SCL SDA input ‘L’ Voltage
VIL
－
－
0.54
V
SCL SDA input 'H'/’L’ Current
IIHL
-10
－
10
μA
I2C SDA output ‘L’ Voltage
VOL
0
－
0.4
V
ALS measurement time
※1
ILED register(42h)
[7:6] = ”11”
IINT = 3mA
IOL = 3mA
White LED is used as optical source
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2011.06 - Rev.B
BH1771GLC
Technical Note
●I2C bus timing characteristics ( VCC = 2.5V, Ta = 25℃, unless otherwise noted. )
Parameter
Symbol
Limits
Min.
Typ.
Max.
Units
Conditions
I2C SCL Clock Frequency
fSCL
0
－
400
kHz
f/s mode
I2C SCL Clock Frequency2
fSCLH
0
－
3.4
MHz
Hs mode Cb=100pF
I2C Hold Time ( Repeated ) START
Condition
tHD;STA
0.6
－
－
μs
f/s mode
I2C Hold Time ( Repeated ) START
Condition2
tHD;STA
160
－
－
ns
Hs mode
I2C ‘L’ Period of the SCL Clock
tLOW
1.3
－
－
μs
f/s mode
I2C ‘L’ Period of the SCL Clock2
tLOW
160
－
－
ns
Hs mode
I2C 'H' Period of the SCL Clock
tHIGH
0.6
－
－
μs
f/s mode
I2C 'H' Period of the SCL Clock2
tHIGH
60
－
－
ns
Hs mode
I2C Set up time for a Repeated START
Condition
tSU;STA
0.6
－
－
μs
f/s mode
I2C Set up time for a Repeated START
Condition2
tSU;STA
160
－
－
ns
Hs mode
I2C Data Hold Time
tHD;DAT
0
－
－
μs
f/s mode
I2C Data Hold Time2
tHD;DAT
0
－
70
ns
Hs mode Cb=100pF
I2C Data Setup Time
tSU;DAT
100
－
－
ns
f/s mode
I2C Data Setup Time2
tSU;DAT
10
－
－
ns
Hs mode
I2C Set up Time for STOP Condition
tSU;STO
0.6
－
－
μs
f/s mode
I2C Set up Time for STOP Condition2
tSU;STO
160
－
－
ns
Hs mode
I2C Bus Free Time between a STOP
and START Condition
tBUF
1.3
－
－
μs
I2C Data Valid Time
tVD;DAT
－
－
0.9
μs
f/s mode
I2C Data Valid Acknowledge Time
tVD;ACK
－
－
0.9
μs
f/s mode
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3/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●Package outlines
A
B
Production code
Lot No.
WLGA010V28
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4/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●Reference Data
56
1.0
0.6
0.4
0.2
48
Measurement Result
Measurement Result
10000
0.8
Ratio
100000
64
1.2
40
32
24
16
1000
100
10
8
1
0
0.0
400
500
600
700
800
900
1000
0
1100
8
16
24
32
40
48
56
1
64
10
100
Wavelength [ nm ]
1.2
1.2
1
1
10000
100000
Fig.3 Illuminance ALS Measurement Result 2
Fig.2 Illuminance ALS Measurement Result
Fig.1 ALS Spectral Response
1000
Illuminance [ lx ]
Illuminance [ lx ]
10
1pin
0.6
0.4
-
0.6
1pin
-
0.4
+
-
+
0.2
0.2
0
-90
-60
-30
0
Measurement Result
8
0.8
+
-
Ratio
Ratio
0.8
30
60
2
+
-90
-60
-30
0
30
60
0
90
-40
Fig.5 ALS Directional Characteristics 2
Ratio
Halogen Light
0.6
Kripton Light
0.4
Artifical Sun
Light
0.2
White LED
60
80
60
80
100
150
100
50
0
0
0
40
Fig.6 ALS Dark Response
ICC @ Measurement [ uA ]
Incandescent
Light
0.8
40
20
200
Fluorescent
Light
1
20
0
Ta [ ℃ ]
1.2
0
-20
Angle [ deg ]
Fig.4 ALS Directional Characteristics 1
-20
4
0
90
Angle [ deg ]
-40
蛍光灯白熱灯感度比
6
0.5
1
1.5
Ratio
2
2
2.5
3
VCC [ V ]
3.5
4
100
Ta [ ℃ ]
Fig.7 ALS Measurement Accuracy
Temperature Dependency
1.2
1
1.20
1.2
1.00
1
0.80
0.8
Ratio
0.6
Ratio
1pin
0.8
Ratio
Fig.9 VCC - ICC
( During ALS measurement )
Fig.8 ALS Light Source Dependency
( Fluorescent Light is set to '1' )
0.60
0.4
0.2
2.4
2.6
2.8
3
3.2
VCC [ V ]
3.4
3.6
3.8
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© 2011 ROHM Co., Ltd. All rights reserved.
+
0
0.00
400
500
600
700
800
900
1000
Wavelength [nm]
Fig.10 ALS Measurement Result
VCC Dependency
-
0.2
0.20
0
2.2
+
0.6
0.4
0.40
-
Fig.11 PS Spectral Response
5/32
1100
-90
-60
-30
0
30
60
90
Angle [ deg ]
Fig.12 PS Directional Characteristics 1
2011.06 - Rev.B
BH1771GLC
Technical Note
1.2
200
260
240
1
ICC @ Measurement [ uA ]
220
200
180
PS_DATAOUT
Ratio
0.8
-
0.6
1pin
-
0.4
160
140
120
100
80
+
60
0.2
+
150
100
50
40
20
0
-90
-60
-30
0
30
60
0
0
0.001
90
Angle [ deg ]
0.01
0.1
1
10
100
2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 3.8
VCC [ V ]
1000
Irradiance(mW/cm2]
Fig.13 PS Directional Characteristics 2
Fig.15 VCC - ICC
( During PS measurement )
Fig.14 Irradiance – PS_DATAOUT
200
20
160
16
120
ICC @ POWER DOWN [ uA ]
24
ILEDC[mA]
12
80
8
40
4
0
0
0
1
2
3
4
5
0
6
1
3
4
5
Fig.16 VLEDC – ILEDC@ ILED is set
200mA by ILED register
0.1
6
-40
200
PS_DATAOUT [count]
140
130
120
110
-20
0
20
40
60
80
100
160
ILED=200mA
LED : SIM-030ST
Center to Center : 10mm
between BH1771GLC
and SIM-030ST
120
80
40
18％ Kodak GrayCard
0
50
100
Object Distance [mm]
150
200
120
80
SIM-030ST
40
PS_DATAOUT [count]
ILED=200mA
Reflector:
18%Kodak Graycard
Center to Center : 10mm
between BH1771GLC
and Infrared LED
A=5mm
160
A=20mm
A=30mm
80
80
100
80
40
ILED=50mA
50
100
150
Object Distance [mm]
Fig.21 Object Distance – PS_DATAOUT
of different ILED
ILED=200mA
LED : SIM-030ST
Reflector :
18%Kodak Graycard
Center to Center : A
between BH1771GLC
and Infrared LED
A=10mm
120
60
LED : SIM-030ST
Reflector :
18%Kodak Graycard
Center to Center : 10mm
between BH1771GLC
and SIM-030ST
120
0
Fig.19 PS sensor out
Fig.20 Object Distance – PS_DATAOUT
Temperature Dependency
of different reflector
2
(Irradiance by Proximity object = 324μW/cm )
SIM-040ST
40
ILED=100mA
0
0
20
ILED=200mA
Human hand
160
Ta [℃]
160
0
Fig.18 VCC – ICC@0 Lx
( POWER DOWN )
90％ White paper
100
-40
-20
Ta [ ℃ ]
Fig.17 VLEDC – ILEDC@ ILED is set
20mA by ILED register
150
PS_DATAOUT [count]
1
VLEDC [V]
VLEDC [V]
PS_DATAOUT [count]
2
PS_DATAOUT [count]
ILEDC[mA]
10
240
A=50mm
A=70mm
40
0
0
0
50
100
Object Distance [mm]
150
Fig.22 Object Distance – PS_DATAOUT
of different Infrared LED
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0
50
100
150
Object Distance [mm]
Fig.23 Object Distance – PS_DATAOUT
of different distance between
BH1771GLC and SIM-030ST
6/32
2011.06 - Rev.B
BH1771GLC
Technical Note
・Fig.24-27 are PS_DATAOUT measurement results which depend on the position of the reflector. The reflector is a White
paper of reflectivity 90% and this size is 50mm×50mm. The characteristic of 90%White paper is nearly similar to human
hand(human palm).
1) The reflector moves to the parallel direction for the position of BH1771GLC and LED.
Direction of reflector movement
BH1771GLC
LED : SIM-030ST
50mm
BH1771GLC
Reflector
Reflector
-A/2
+A/2
0
1pin
A
50mm
80
A=10mm
A=30mm
A=50mm
120
100
PS_DATAOUT [count]
PS_DATAOUT [count]
140
A=70mm
80
60
40
20
0
-100
-50
0
50
Height of reflector
A=10mm
A=30mm
A=50mm
60
A=70mm
40
20
0
-100
100
Position of reflector [mm]
-50
0
50
PCB
Measurement conditions
・ILED=200mA
・LED : SIM-030ST
・Reflector : 90%White paper
50mm×50mm
・Center to Center : A
(between BH1771GLC
and SIM-030ST)
・Ambient irradiance = 0μW/cm2
100
Position of reflector [mm]
Fig.25 Position of reflector – PS_DATAOUT
Height of reflector is 100mm
Fig.24 Position of reflector – PS_DATAOUT
Height of reflector is 50mm
2) The reflector moves to the vertical direction for the position of BH1771GLC and LED.
Direction of reflector movement
LED : SIM-030ST
LED : SIM-030ST
50mm
Reflector
A
Reflector
0
-
+
1pin
50mm
Height of reflector
BH1771GLC
PCB
BH1771GLC
A=10mm
80
A=30mm
120
A=50mm
100
A=70mm
80
60
40
20
0
-100
-50
0
50
100
Position of reflector [mm]
Fig.26 Position of reflector – PS_DATAOUT
Height of reflector is 50mm
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PS_DATAOUT [count]
PS_DATAOUT [count]
140
A=10mm
A=30mm
A=50mm
60
A=70mm
40
20
0
-100
-50
0
50
Measurement conditions
・ILED=200mA
・LED : SIM-030ST
・Reflector : 90%White paper
50mm×50mm
・Center to Center : A
(between BH1771GLC
and SIM-030ST)
・Ambient irradiance = 0μW/cm2
100
Position of reflector [mm]
Fig.27 Position of reflector – PS_DATAOUT
Height of reflector is 100mm
7/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●I2C bus communication
1) Slave address "0111000"
2) Main write format
1. Case of “Indicate register address”
Slave Address
0111000
ST
W
0
ACK
Indicate register address
010XXXXX
ACK
SP
2. Case of "write to data register after indicating register address"
Slave Address
0111000
ST
Data specified at register address
field
W
0
ACK
ACK
ACK
・・・・・・
Indicate register address
010XXXXX
ACK
Data specified at register address
field + N
ACK
SP
BH1771GLC continues to write data with address increments until master issues stop condition.
Write cycle is 40h - 41h - 42h - 43h - 44h - 45h - 46h – 52h ……… 5Dh – 5Eh - 40h ………
Ex ) If register address field is 45h, then BH1771GLC writes data like seeing in below.
45h - 46h -52h ……… 5Dh – 5Eh - 40h………It is continued until master issues stop condition.
3) Main read format
1. Case of read data after indicate register address and read data ( Master issues restart condition )
ST
ST
Slave Address
0111000
Slave Address
0111000
Data specified at register address
field + 1
2.
W
0
ACK
R
1
ACK
ACK
ACK
・・・・・・
Indicate register address
010XXXXX
ACK
Data specified at register address
field
ACK
Data specified at register
address field + N
NACK
Data specified at register address
field
ACK
Data specified at register address
field + N
NACK
SP
Case of read data after selecting register address
ST
Slave Address
0111000
Data specified at register address
field + 1
R
1
ACK
・・・・・・
ACK
ACK
SP
BH1771GLC outputs data from specified address field until master issues stop condition.
Read cycle is 40h - 41h - 42h - 43h - 44h - 45h - 46h – 4Ah ……… 5Dh – 5Eh - 40h ………
Ex ) If register address field is 4Ch, then BH1771GLC outputs data like seeing in below.
4Ch - 4Dh -4Eh ……… 5Dh – 5Eh - 40h………It is continued until master issues stop condition.
from slave to master
from master to slave
※
※
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BH1771GLC operates as I2C bus slave device.
Please refer formality I2C bus specification of NXP semiconductors
8/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●Block diagram and block explanation
VDD LED
IrLED
VDD LED
IrLED
VCC
VDD LED
IrLED
LED1
LED2
LED3
Proximity Sensor
LED
Pulse
Gen.
IrLED
Drivers
DC light
rejection
Amp
Reflector
GND_LED
Ambient
Light
Linear
ADC
PS
Control
Logic
Linear /
Log
converter
PD_PS
Data
Registers
INT
interface
INT
POR
Timing Controller
OSC
16bit
ADC
ALS
Control
Logic
PD_ALS
I 2C
Interface
SDA
SCL
Ambient Light Sensor
 I2C Interface
GND
GNDNC
I2C bus interface. f/s mode and Hs mode is supported. 1.8V logic interface is supported.
 POR
Power on reset function.
 OSC
Internal oscillator.
 Timing controller
Internal management block for proximity sensor and ambient light sensor.
 INT interface
INT terminal control block. Details are on Page 14 - 16
 DATA registers
Register for strage of measurement results or commands. Details are on Page 17.
 PS control logic
This block controls proximity sensor analog block
 LED Pulse Gen
LED current generator. LED current value is configurable by ILED( 42h ) and ILED3( 43h ) register.
 IrLED Drivers.
IrLED driver block. Active LED terminal is set by ILED( 42h ) register.
 PD_ALS
Photo diode for ambient light sensor. Peak wavelength is approximately 550nm.
 16bit ADC
AD converter for ALS.
 ALS control logic
This block controls ambient light sensor analog block.
 PD_PS
Photo diode for proximity sensor. Peak wavelength is approximately 850nm.
 DC light rejection Amp
DC light is rejected in this block. And generated Infrared pulse is passed to linear ADC block.
 Linear ADC
2
2
AD converter for proximity sensor. Detection range is very wide ( 1μW/cm - 100mW/cm ).
 Linear/Log converter
Linear to logarithm converter for proximity sensor. Output data is 8bit.
PS irradiance calculation example is on Page 26.
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9/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●Example of application circuit diagram
If you do not use the INT pin, please connect to GND or opening (non connect).
1) In case of using 1IrLED
(ex. SIM-030ST(Rohm))
2.5 - 5.5V
2.3 – 3.6V
IrLED
(ex. 0.1μF)
(ex. 10μF)
1.65 – 5.5V
VCC
6
LED1
Proximity Sensor
3
LED2
LED3
2
LED
Pulse
Gen
IrLED
Drivers
1
DC light
rejection
Amp
Data
PS
Control
Logic
INT
INT
interface
5
Linear /
Log
converter
Linear
ADC
1.65 – 3.6V
PD_PS
POR
or
OSC
Timing Controller
Baseband
SCL
I 2C
Interface
ALS
Control
Logic
16bit
ADC
Micro
Controller
Processor
8
SDA
9
PD_ALS
Ambient Light Sensor
4
10
7
GND_LED
GND
GNDNC
If you do not use the LED2 or LED3, please connect to VDD_LED or opening (non connect).
2) In case of using 3 IrLEDs
(ex. SIM-030ST(Rohm))
IrLED
IrLED
2.5 - 5.5V
2.3 – 3.6V
IrLED
(ex. 0.1μF)
(ex. 10μF)
1.65 – 5.5V
VCC
6
LED1
Proximity Sensor
3
LED2
LED3
2
LED
Pulse
Gen
IrLED
Drivers
1
DC light
rejection
Amp
Data
PS
Control
Logic
INT
INT
interface
5
Linear /
Log
converter
Linear
ADC
1.65 - 3.6V
PD_PS
POR
or
OSC
Timing Controller
Baseband
SCL
I 2C
Interface
ALS
Control
Logic
16bit
ADC
Micro
Controller
8
Processor
SDA
9
PD_ALS
Ambient Light Sensor
4
GND_LED
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10
7
GND
10/32
GNDNC
2011.06 - Rev.B
BH1771GLC
Technical Note
3) In case of extending proximity sensor detection distance
BH1771GLC can drive maximum 200mA(Typ) current. By adding simple external circuit, it is possible to increase IrLED
current and to extend detection distance. In case of driving large current forIrLED, note that the current value must not be
over the absolute maximum rating for IrLED.
VDD_LED
4.5 - 5.5V
2.3 – 3.6V
1kOhm
(ex. 0.1μF)
(ex. 10μF)
1.65 – 5.5V
VCC
6
PMOS
LED1
(ex. SIM-030ST
(Rohm))
Proximity Sensor
3
（ex. RTR030P02
(Rohm)）
LED2
LED3
2
LED
Pulse
Gen
IrLED
Drivers
1
DC light
rejection
Amp
IrLED
Data
PS
Control
Logic
INT
INT
interface
5
Linear /
Log
converter
Linear
ADC
1.65 - 3.6V
PD_PS
POR
or
OSC
Timing Controller
Baseband
SCL
I 2C
Interface
ALS
Control
Logic
16bit
ADC
Micro
Controller
8
Processor
SDA
9
PD_ALS
Ambient Light Sensor
4
GND_LED
10
7
GND
GNDNC
* In the case of the following setting for above circuit, LED current is proximity 500mA.
VDD_LED=5V, R1=3.9Ohm
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11/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●Terminal description
PIN
No.
1
2
Terminal Name
Equivalent Circuit
Nch open drain LED3 terminal. LED
current and emitting interval is defined
by internal register. Register value is
possible to configure by I2C bus.
LED3
Nch open drain LED2 terminal. LED
current and emitting interval is defined
by internal register. Register value is
2
possible to configure by I C bus.
LED2
3
LED1
4
GND_LED
5
INT
6
VCC
7
GND
Function
Nch open drain LED1 terminal. LED
current and emitting interval is defined
by internal register. Register value is
possible to configure by I2C bus.
GND terminal for LED driver
Nch open drain output.
Interrupt setting is defined by internal
register. Register value is possible to
2
configure by I C bus.
Power supply terminal
GND terminal
2
I C bus Interface SCL terminal
8
SCL
2
I C bus Interface SDA terminal
9
SDA
Non connect or pull down to GND
VCC
10
GNDNC
If you do not use the INT pin, please connect to GND or opening (non connect).
If you do not use the LED2 or LED3, please connect to VDD_LED or opening (non connect).
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12/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●Proximity sensor measurement sequence
The below figure shows proximity sensor measurement sequence. First PS measurement is triggered by I2C bus master
writes measurement command to PS_CONTROL register ( 41h ). BH1771GLC has 3 LED-drivers and their combinations
are set by ILED,ILED3 register ( 42h, 43h ). In the case of only LED2 is inactive, LED3 emit immediately after LED1 emittion.
1. Forced mode
PS measurement is done only 1time and PS trigger bit ( 44h<0> ) is overwritten from 'H' to ‘L’ after PS measurement
complete. PS measurement is re-started by master writes PS trigger bit to 'H'.
2. Stand alone mode
PS measurement is continuously done until master select the other mode. Measurement interval is defined at
PS_MEAS_RATE register ( 45h ).
start
measurement
LED1 LED2 LED3
start
measurement
LED1 LED2 LED3
PS meas rate
tMPS
twILED2
twILED
twILED :
twILED2 :
tMPS :
PS meas rate:
LED current pulse duration, please refer P2 ( Electrical Characteristics ).
Cumulative LED current pulse duration, please refer P2 ( Electrical Characteristics ).
Proximity sensor measurement time, please refer P2 ( Electrical Characteristics ).
Measurement result is generated in this term.
In case of stand alone mode, It is defined at PS_MEAS_RATE register ( 45h ).
In case of forced mode, it means the term until overwriting PS trigger bit to ‘H’.
●Ambient light sensor measurement sequence
The below figure shows ambient light sensor measurement sequence. First ALS measurement is triggered by I2C bus
master writing measurement command to ALS_CONTROL register ( 40h ).
1. Forced mode
ALS measurement is done only 1time and ALS trigger bit( 44h<1> ) is overwritten from 'H' to ‘L’ after ALS measurement
is completed. ALS measurement is re-started by master writes ALS trigger bit to 'H'.
2. Stand alone mode
ALS measurement is continuously done until master select the other mode. Measurement interval is defined at
ALS_MEAS_RATE register ( 46h ). If ALS rate disable bit ( 46h<7> ) is ‘H’, there is no interval between measurement.
start
measurement
start
measurement
tMALS
tMALS :
ALS meas rate :
ALS meas rate
Ambient light sensor measurement time, please refer P2 ( Electrical Characteristics ).
Measurement result is generated in this term.
In case of stand alone mode, It is defined at ALS_MEAS_RATE register ( 46h )
In case of forced mode, it means the term until overwriting ALS trigger bit to ‘H’.
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13/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●Interrupt function
Interrupt function compares ALS or PS measurement result to preset interrupt threshold level. PS uses one threshold level or
two threshold level ( in hysteresis mode ) and ALS uses two threshold level (upper and lower ). Interrupt status is monitored
by INT pin or ALS_PS_STATUS register ( 4Eh ) and Interrupt function is able to be controlled by INTERRUPT register ( 52h ).
Interrupt threshold is defined at ALS_TH_UP and ALS_TH_LOW and PS_TH_LED and PS_TH_L_LED registers ( 53h - 59h,
5Ch - 5Eh ). PS_TH_L_LED registers are effective when PS hysteresis bit ( 52h<4> ) is ‘H’.
Interrupt persistence function is defined at PERSISTENCE register ( 5Bh ).
INT pin is Nch open drain terminal so this terminal should be pull-up to some kind of voltage source by an external resister.
Maximum sink current rating of this terminal is 7mA.
There are two output modes about interrupt function ( latched mode and unlatched mode ).
In case of using ALS and PS interrupt functions at the same time, latch mode is recommended.
INT terminal is high impedance when VCC is supplied.
INT terminal becomes inactive by setting INTERRUPT register (52h)[1:0] to “00”. ( It is not worked during power down mode.
Power down mode means ALS_CONTROL(40h)<1>=’0’ and PS_CONTROL(41h)<1> = ‘0’.)
INT terminal keeps just previous state which power down command is sent. So to set INT terminal to high impedance is
recommended. VCC current(approximately 25μA at VCC=2.5V) is consumed during INT terminal is ‘L’. There are two
method to set INT terminal to high impedance.
1) Send software reset command. (Write ‘H’ to ALS_CONTROL(40h)<2>. Software reset is also worked during power down.
All registers are initialized by software reset command.)
2) Write “000” to INTERRUPT register(52h)<2:0>.
ex1) In case of using PS ‘H’ threshold （INTERRUPT register 52h<4> : ‘0’）
In case of unlatch mode if the measurement value exceed the PS interrupt threshold ‘H’ value, the interrupt becomes
active. And if the measurement value goes below the threshold, the interrupt becomes inactive.
In case of latch mode once the interrupt becomes active, it keeps the status until end of measurement after INTERRUPT
register is read.
In case of persistence function is set to active, if the interrupt is inactive, it keeps inactive status until the measurement
value is beyond the threshold ‘H’ value continuously. If the interrupt is active, it keeps active status until the measurement
value is below threshold ‘H’ value continuously or until end of measurement after INTERRUPT register is read.
Master reads INTERRUPT register
Latch mode
Unlatch mode
Unlatch mode
persistence = 2
active
inactive
PS interrupt threshold ‘H’ level
Sequential measurement result
time
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14/32
2011.06 - Rev.B
BH1771GLC
Technical Note
ex2 ) In case of using PS ‘H/L’ threshold （( INTERRUPT register 52h<4> : ‘1’)
In case of unlatch mode if the measurement value exceed the PS interrupt threshold ‘H’ value, the interrupt becomes
active. And if the measurement value is below the threshold “L” value, the interrupt becomes inactive.
In case of latch mode once the interrupt becomes active, it keeps the status until end of measurement after INTERRUPT
register is read.
In case of persistence function is set to active, if the interrupt is inactive, it keeps inactive status until the measurement
value is beyond the threshold ‘H’ value continuously. If the interrupt is active, it keeps active status until the measurement
value is below threshold “L” value continuously or until end of measurement after INTERRUPT register is read.
Master reads INTERRUPT register
Latch mode
Unlatch mode
Unlatch mode
persistence = 2
active
inactive
PS interrupt threshold ‘H’ level
PS interrupt threshold ‘L’ level
Sequential
Sequential measurement
measurement result
result
time
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15/32
2011.06 - Rev.B
BH1771GLC
Technical Note
ex3 ) Ambient light sensor interrupt function
In case of unlatch mode if the measurement value is within the range set by ALS interrupt threshold ‘H’ and “L” value, the
interrupt becomes inactive. And if the measurement value is out of the range set by threshold ‘H’ and ”L” value, the
interrupt becomes active.
In case of latch mode once the interrupt becomes active, it keeps the status until end of measurement after INTERRUPT
register is read.
In case that persistence function is set to active, if the interrupt is inactive, it keeps inactive status until the measurement
value is continuously out of the range set by threshold ‘H’ and “L” value. If the interrupt is active, it keeps active status until
the measurement value is continuously within the range set by threshold ‘H’ and ”L” value or until end of measurement
after INTERRUPT register is read.
Master reads INTERRUPT register
Latch mode
Unlatch mode
Unlatch mode
persistence = 2
active
inactive
ALS interrupt threshold ‘H’ level
ALS interrupt threshold ‘L’ level
Sequentialmeasurement
measurementresult
result
Sequential
time
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16/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●Command set
Address
40h
41h
Type
RW
RW
Register name
ALS_CONTROL
PS_CONTROL
Register function
ALS operation mode control and SW reset
PS operation mode control
42h
RW
I_LED
43h
RW
I_LED3
Selection of active LED and LED1, LED2
current setting
LED3 current setting
44h
RW
ALS_PS_MEAS
Forced mode trigger
45h
RW
PS_MEAS_RATE
PS measurement rate
46h
RW
ALS_MEAS_RATE
ALS measurement rate
4Ah
R
-
Reserved
4Bh
4Ch
4Dh
4Eh
4Fh
50h
51h
R
R
R
R
R
R
R
MANUFACT_ID
ALS_DATA_0
ALS_DATA_1
ALS_PS_STATUS
PS_DATA_LED1
PS_DATA_LED2
PS_DATA_LED3
Manufacturer ID
ALS data (Low Byte)
ALS data (High Byte)
Measurement data and interrupt status
PS data from LED1
PS data from LED2
PS data from LED3
52h
53h
54h
55h
56h
57h
58h
59h
5Ah
5Bh
5Ch
5Dh
5Eh
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
INTERRUPT
PS_TH_LED1
PS_TH_LED2
PS_TH_LED3
ALS_TH_UP_0
ALS_TH_UP_1
ALS_TH_LOW_0
ALS_TH_LOW_1
ALS_SENSITIVITY
PERSISTENCE
PS_TH_L_LED1
PS_TH_L_LED2
PS_TH_L_LED3
Interrupt setting
PS interrupt H threshold for LED1
PS interrupt H threshold for LED2
PS interrupt H threshold for LED3
ALS upper threshold low byte
ALS upper threshold high byte
ALS lower threshold low byte
ALS lower threshold high byte
ALS sensitivity setting
INT pin INTERRUPT persistence setting
PS interrupt L threshold for LED1
PS interrupt L threshold for LED2
PS interrupt L threshold for LED3
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17/32
2011.06 - Rev.B
BH1771GLC
Technical Note
○ ALS_CONTROL ( 40h )
7
RES
6
5
4
3
2
1
0
RES
RES
RES
ALS
Resolution
SW
Reset
ALS mode
default value 00h
Field
Bit
Type
Description
RES
7:4
RW
ALS Resolution
3
RW
SW reset
2
RW
ALS mode
1:0
RW
Write 0000
0 : H-Resolution mode, 1 lx step output
1 : M-Resolution mode, 4 lx step output
0 : initial reset is not started
1 : initial reset is started
00 : Standby mode
01 : Don’t use.
10 : Forced mode
11 : Stand alone mode
○ PS_CONTROL ( 41h )
7
X
6
5
4
3
2
1
X
X
X
X
X
PS mode
default value 00h
Field
NA
Bit
7:2
Type
-
PS mode
1:0
RW
0
Description
Ignored
00 : Standby mode
01 : Don’t use.
10 : Forced mode
11 : Stand alone mode
○ I_LED ( 42h )
7
6
PS active
5
4
LED2 current
3
2
1
LED1 current
0
default value 1Bh
Field
Bit
Type
PS active
7:6
RW
LED2 current
5:3
RW
LED1 current
2:0
RW
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© 2011 ROHM Co., Ltd. All rights reserved.
Description
00 : LED1 is active, LED2,3 are inactive
01 : LED1,2 are active, LED3 is inactive
10 : LED1,3 are active, LED2 is inactive
11 : All LEDs are active
000 : 5mA
001 : 10mA
010 : 20mA
011 : 50mA
100 : 100mA
101 : 150mA
11X : 200mA
18/32
2011.06 - Rev.B
BH1771GLC
Technical Note
○ I_LED3 ( 43h )
7
6
5
4
3
2
1
X
X
X
X
X
LED3 current
0
default value 03h
Field
NA
LED3 current
○ ALS_PS_MEAS ( 44h )
7
X
Type
-
2:0
RW
Description
Ignored
000 : 5mA
001 : 10mA
010 : 20mA
011 : 50mA
100 : 100mA
101 : 150mA
11X : 200mA
6
5
4
3
2
1
X
X
X
X
X
ALS
PS
trigger
trigger
default value 00h
Field
NA
*2
Bit
7:3
Bit
7:2
Type
-
ALS trigger
1
RW
PS trigger
0
RW
0
Description
Ignored
0 : Ignored
1 : Start ALS measurement at force mode*2
0 : Ignored
1 : Start PS measurement at force mode *2
Even if trigger is set during measurement, the measurement doesn’t start. The measurement will start, in case that It is set
to forced mode by ALS_CONTROL register (40h) or PS_CONTROL register (41h) and is not during measurement.
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19/32
2011.06 - Rev.B
BH1771GLC
Technical Note
○ PS_MEAS_RATE ( 45h )
7
6
X
X
5
4
3
2
1
X
X
PS meas rate
0
default value 05h
Field
NA
Bit
7:4
Type
-
PS meas rate
3:0
RW
○ ALS_MEAS_RATE ( 46h )
7
6
ALS
rate
disable
5
4
X
Description
Ignored
0000 : 10ms
0001 : 20ms
0010 : 30ms
0011 : 50ms
0100 : 70ms
0101 : 100ms
0110 : 200ms
0111 : 500ms
1000 : 1000ms
1001 : 2000ms
101X : 2000ms
11XX : 2000ms
3
X
X
2
X
1
0
ALS meas rate
default value 02h
Field
Bit
Type
7
RW
6:3
-
ALS rate disable
NA
ALS meas rate
2:0
RW
Description
0 : ALS meas rate( 46h<2:0> ) is active
1 : ALS meas rate( 46h<2:0> ) is inactive
Ignored
000 : 100ms
001 : 200ms
010 : 500ms
011 : 1000ms
1XX : 2000ms
○ ( 4Ah )
7
6
5
4
3
2
1
X
X
X
X
X
X
X
Field
NA
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© 2011 ROHM Co., Ltd. All rights reserved.
Bit
7:0
Type
R
0
X
default value 93h
Description
Reserved
20/32
2011.06 - Rev.B
BH1771GLC
Technical Note
○ MANUFACT_ID ( 4Bh )
7
6
Manufacturer ID
5
4
3
2
1
0
default value 01h
Field
Manufacturer ID
○ ALS_DATA ( 4Ch, 4Dh )
7
6
Bit
7:0
5
Type
R
4
Description
00000001
3
2
1
0
ALS data
default value 00h
Register
ALS data LSBs
ALS data MSBs
○ ALS_PS_STATUS ( 4Eh )
7
6
ALS
ALS
data
INT
status
status
Address
4Ch
4Dh
4
LED3
data
status
3
LED2
INT
status
Bit
Type
Description
ALS INT status
7
R
ALS data status
6
R
LED3 INT status
5
R
LED3 data status
4
R
LED2 INT status
3
R
LED2 data status
2
R
LED1 INT status
1
R
LED1 data status
0
R
Field
5
LED3
INT
status
Bit
7:0
7:0
Type
R
R
2
LED2
data
status
Description
ALS data Low byte
ALS data High byte
1
0
LED1
LED1
data
INT
status
status
default value 00h
0 : ALS interrupt signal inactive
1 : ALS interrupt signal active
0 : ALS old data (data is already read)
1 : ALS new data (data is renewed after previous reading)
0 : LED3 interrupt signal inactive
1 : LED3 interrupt signal active
0 : LED3 old data (data is already read)
1 : LED3 new data (data is renewed after previous reading)
0 : LED2 interrupt signal inactive
1 : LED2 interrupt signal active
0 : LED2 old data (data is already read)
1 : LED2 new data (data is renewed after previous reading)
0 : LED1 interrupt signal inactive
1 : LED1 interrupt signal active
0 : LED1 old data (data is already read)
1 : LED1 new data (data is renewed after previous reading)
ALS interrupt signal inactive means that ALS measurement result is within threshold level set by ALS_TH register(56h,
57h, 58h, 59h). ALS interrupt signal active means measurement result is out of threshold level set by ALS_TH register. PS
interrupt signal active means each PS measurement result exceeds threshold level defined by PS_TH_LED register(53h,
54h, 55h). PS interrupt signal inactive means each PS measurement result does not exceed threshold level set by
PS_TH_LED register. When PS interrupt hysteresis( INTERRUPT register 52h<4>) is ‘H’, if once interrupt signal becomes
active, it is kept until measurement result becomes less than PS_TH_L_LED( 5Ch 5Dh 5Eh) register value. Regarding
ALS and LED1, it is possible to set persistence (5Bh).
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21/32
2011.06 - Rev.B
BH1771GLC
Technical Note
○ PS_DATA_LED ( 4Fh, 50h, 51h)
7
6
5
4
3
2
1
0
LED data
default value 00h
Register
LED1 data
LED2 data
LED3 data
○ INTERRUPT ( 52h )
7
X
Address
4Fh
50h
51h
6
5
Interrupt source
Bit
7:0
7:0
7:0
4
PS
Interrupt
hysteresis
Type
R
R
R
Description
PS measurement data for each
LED
3
2
1
Output
mode
Interrupt
polarity
Interrupt mode
0
default value 08h
Field
NA
Bit
7
Type
-
6:5
R
PS Interrupt
hysteresis
4
RW
Output mode
3
RW
Interrupt polarity
2
RW
1:0
RW
Interrupt source
Interrupt mode
Description
Ignored
00 : First interrupt triggered by ALS
01 : First interrupt triggered by LED1
10 : First interrupt triggered by LED2
11 : First interrupt triggered by LED3
0 : Use PS_TH_LED only.
1 : Use PS_TH_LED and PS_TH_L_LED for hysteresis
0 : INT pin is latched until INTERRUPT register is read.
1 : INT pin is updated after each measurement.
0 : INT pin is logic “L” when interrupt signal is active
1 : INT pin is logic “L” when interrupt signal is inactive
00 : INT pin is inactive.
01 : Triggered by only PS measurement
10 : Triggered by only ALS measurement
11 : Triggered by PS and ALS measurement
○ PS_TH_LED ( 53h, 54h, 55h)
7
6
5
4
3
2
1
0
LED threshold
default value FFh
Register
LED1 threshold
LED2 threshold
LED3 threshold
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Address
53h
54h
55h
Bit
7:0
7:0
7:0
22/32
Type
RW
RW
RW
Description
PS H threshold for each LED
2011.06 - Rev.B
BH1771GLC
Technical Note
○ ALS_TH_UP ( 56h, 57h )
7
6
5
4
3
2
1
0
ALS upper threshold data
default value FFh
Register
Address
Bit
Type
ALS TH upper LSBs
56h
7:0
RW
ALS TH upper MSBs
57h
7:0
RW
○ ALS_TH_LOW ( 58h, 59h )
7
6
5
4
3
2
Description
ALS interrupt upper threshold
(Low byte)
ALS interrupt upper threshold
(High byte)
1
0
ALS lower threshold data
default value 00h
Register
Address
Bit
Type
ALS TH lower LSBs
58h
7:0
RW
ALS TH lower MSBs
59h
7:0
RW
○ ALS_SENSITIVITY ( 5Ah )
7
6
5
4
3
2
Description
ALS interrupt lower threshold
(Low byte)
ALS interrupt lower threshold
(High byte)
1
0
ALS sensitivity data
default value 35h
Register
ALS sensitivity data
○ PERSISTENCE ( 5Bh )
7
6
ALS persistence
5
Bit
7:0
4
Type
RW
Description
ALS sensitivity adjustment register（refer to P27）
3
2
1
PS LED1 persistence
0
default value 11h
Field
ALS persistence
PS LED1 persistence
○ PS_TH_L_LED ( 5Ch, 5Dh, 5Eh)
7
6
LED L threshold
5
Bit
7:4
3:0
4
Type
RW
RW
Description
Persistence for ALS interrupt.
Persistence for PS LED1 interrupt.
3
2
1
0
default value 00h
Register
LED1 L threshold
LED2 L threshold
LED3 L threshold
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© 2011 ROHM Co., Ltd. All rights reserved.
Address
5Ch
5Dh
5Eh
Bit
7:0
7:0
7:0
23/32
Type
RW
RW
RW
Description
PS L threshold for each LED
2011.06 - Rev.B
BH1771GLC
Technical Note
●Current consumption
BH1771GLC can operate ALS and PS individually. Average current consumption is depend on each statuses and
measurement duration
(set by 45h, 46h register). Major elements which decide VCC current consumption are like following table.
Parameter
ALS part’s current
PS part’s current
PS current
during driving LED
ALS/PS
common ciruit current
1)
Symbol
Typ.
Units
IccALS
140
μA
Except for ALS/PS common circuit current.
Except for ALS/PS common circuit current.
Current flow for 1.4ms (in case of using one LED)
Current flow for 1.8ms (in case of using two LEDs)
Current flow for 2.2ms (in case of using three LEDs)
IccPS
250
μA
Icc3
6.5
mA
Icccmn
60
μA
Comment
Current consumption in case of operating only ALS
VCC current consumption can calculate according to following formula.
ICC(only ALS) = IccALS * ( 100ms / ALS meas rate ) +Icccmn
For example in case measurement rate is 500ms, the value is as following.
e. g. ) ICC(only ALS) = 140μA (100ms / 500ms) + 60μA = 88μA
2)
Current consumption in case of operating only PS
VCC current consumption can calculate according to following formula.
ICC(only PS) = IccPS * ( 1.4ms / PS meas rate ) +Icccmn + Icc3 * ( 200μs / PS meas rate* number of LEDs )
VDD_LED current consumption can calculate according to following formula.
IVDD_LED = (ILED1 + ILED2 + ILED3) * (200μs / PS meas rate)
For example in case it drives 50mA for only LED1 and measurement rate is 100ms, the value is as following.
e. g. ) ICC(only PS) = 250μA * ( 1.4ms / 100ms ) + 60μA + 6.5mA * ( 200μs / 100ms * 1 ) = 76.5μA
IVDD_LED = (50mA + 0 + 0) * (200μs / 100ms) = 100μA
For example in case it drive 200mA for LED1,2 and 3 and measurement rare is 10ms, the value is as following.
e. g. ) ICC(only PS) = 250μA * ( 2.2ms / 10ms ) + 60μA + 6.5mA * ( 200μs / 10ms * 3 ) = 505μA
IVDD_LED = ( 200mA + 200mA + 200mA ) * (200μs / 10ms) = 12mA
3)
Current consumption in case of operating ALS and PS at the same time.
VCC current consumption can calculate according to following formula.
ICC( ALS+PS) = Icc(only ALS) + Icc(only PS) - Icccmn
For example in case ALS measurement rate is 500ms and PS measurement rate is 100ms and it drives 50mA for only
LED1, the value is as following.
e.g. ) ICC(ALS+PS) = 88μA + 76.5μA - 60μA = 104.5μA
VDD_LED current consumption can calculate same as the case of operating only PS.
4)
2
I C bus High speed mode
BH1771GLC support I2C bus Hs mode. VCC current consumption increases approximately 80μA during
Hs- mode.
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24/32
2011.06 - Rev.B
BH1771GLC
Technical Note
A
8-bit Master code 00001xxx
t1
S
tH
SDAH
SCLH
1
7
6
2 to 5
8
9
F/S mode
7-bit SLA
Sr
A
R/W
n x (8-bit DATA + A/A)
Sr P
SDAH
SCLH
1
2 to 5
6
7
8
9
1
2 to 5
Hs-mode
6
7
8
9
tFS
If P then
F/S mode
If Sr (dotted lines)
then Hs mode
tH
= MCS current source pull-up
= Rp resistor pull-up
5)
Current consumption increases approximately 80uA
80μA in this term
In case of waiting trigger at forced mode
ALS/PScommon cucuit current （Icccmn） is flow.
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25/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●ALS Measurement mode explanation
Measurement Mode
H-Resolution mode
M-Resolution mode
Measurement Time
typ. 100ms.
typ.16ms.
Resolution
1 Lx
4 Lx
We recommend to use H-Resolution Mode.
Measurement time ( integration time ) of H-Resolution mode is so long that some kind of noise( including in 50Hz / 60Hz
noise ) is rejected. And H-Resolution mode is 1 l x resolution so that it is suitable for darkness.
●Regarding ALS measurement result
ALS measurement result is registered as following format
ALS DATA LSB ( 4Ch )
7
6
5
4
3
2
1
0
26
25
24
23
22
21
20
ALS DATA MSB ( 4Dh )
7
6
215
214
5
213
4
212
3
211
2
210
1
29
0
28
27
ALS Lux calculation example
ALS DATA LSB = ” 1001_0000 ”
ALS DATA MSB = ” 1000_0011 ”
( 215 + 29 + 28 + 27 + 24 ) ≒ 33680 [ lx ]
●Regarding PS measurement result
PS measurement result is converted to logarithm 8bit data and is registered as following format
PS_DATA_LED1 ( 4Fh ), PS_DATA_LED2 ( 50h ), PS_DATA_LED3 ( 51h )
7
6
5
4
3
2
1
7
6
5
4
3
2
2
2
2
2
2
2
21
The data seeing above registers are possible to change the irradiance.
Approximation formula is seeing in below.
Irradiance : 10 ^ (PS_DATA_LED * 0.0197) [μW/cm^2]
0
20
PS irradiance calculation example
PS_DATA_LED1 = ” 1000_0101 ”
10 ^ ( (27 + 22 + 20 ) x 0.0197) = 10^(133 x0.0197) ≒ 417 [μW/cm^2 ]
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26/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●ALS sensitivity adjustment function
BH1771GLC is possible to change ALS sensitivity. And it is possible to cancel the optical window influence ( difference with /
without optical window ) by using this function. Adjustment 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.
Sensitivity can be adjusted by ALS_SENSITIVITY(5Ah). For example, sensitivity 2 times when the value of the register is 2
times, and the measurement time 2 times, too.
The range of adjusting ALS_SENSITIVITY is below.
Adjustable range of
ALS_SENSITIVITY
binary
decimal
Min.
0001_1000
(sensitivity: default * 0.45 )
24
(sensitivity: default * 0.45 )
Typ.
0011_0101
default
53
default
Max.
1111_1110
(sensitivity: default * 4.79 )
254
(sensitivity: default * 4.79 )
It is possible to detect 0.21lx by using this function at H-resolution mode.
The below formula is to calculate illuminant per 1 count.
Illuminant per 1 count ( lx / count ) = 1 * 53 / X
53 : Default value of ALS_SENSITIVITY register (decimal)
X : ALS_SENSITIVITY register value (decimal)
Illuminant per 1 count is as following within adjustable range of ALS_SENSITIVITY.
ALS_SENSITIVITY register value
0001_1000
0011_0101
Illuminant per 1count(lx / count)
2.21
1.00
1111_1110
0.21
Please input the opecode at Power Down state to change ALS_SENSITIVITY register. There is a possibility of malfunction
when the opecode to change ALS_SENSITIVITY register is input while the illuminant measurement is on-going
In stand alone mode, if ALS measurement time exceeds the value defined ALS_MEAS_RATE register, ALS_MEAS_RATE
register value is ignored. Next measurement is started immediately after one measurement completion.
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27/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●Recommended land pattern
unit : mm
●Optical window design above the device
Sensing area; (0.55mm x 0.55mm)
1.4
Min. 0.55
Min. 0.55
Recommended light receiving area;
Please design the optical window
so that light can cover at least this area.
Min.
0.55
Min.
0.55
unit : mm
1.4
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© 2011 ROHM Co., Ltd. All rights reserved.
28/32
2011.06 - Rev.B
BH1771GLC
●
Technical Note
The method of distinguishing 1pin
There is the following methods of distinguishing 1pin.
①
Distinguishing by Pad design of top side.
There are 5 pads in the one side of a top side. There is a space between 2 pads and 3 pads.
②
Distinguishing by Die pattern.
1Pin
2 pads
A
①
B
3 pads
②Die pattern
Top View
③
Distinguishing by Pad design of bottom side.
1Pin
Bottom View
Pad of 1pin cuts the corner.
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29/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●Power on reset function
BH1771GLC has power on reset function. By operating this function, all of registers are reset when the power is supplied.
Please note followings and design the application.
①
Power on time : t1
BH1771GLC becomes operational after 2ms since VCC voltage crosses 1.9V from being less than 0.4V.
②
Power off time : t2
Before the power is supplied, VCC voltage should be less than 0.4V at least for 1ms.
1.9V
VCC
0.4V
t1
t2
t1
BH1771GLC
Don’t care
active
Don’t care
active
*”active state” means that BH1771GLC is correctly operational.
INT terminal is high impedance when VCC is supplied.
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30/32
2011.06 - Rev.B
BH1771GLC
Technical Note
●Cautions on use
1)
Absolute Maximum Ratings
An excess in the absolute maximum ratings, such as supply voltage ( Vccmax, VSDAmax, VSCLmax, VINTmax,
VGNDNCmax, VLEDmax ), temperature range of operating conditions ( Topr ), etc., can break down devices, thus making
impossible to identify breaking mode such as a short circuit or an open circuit. If any special mode exceeding the absolute
maximum ratings is assumed, consideration should be given to take physical safety measures including the use of fuses,
etc.
2) GND voltage
Make setting of the potential of the GND terminal and GND_LED terminal so that they will be maintained at the minimum in
any operating state. Furthermore, check to be sure no terminals are at a potential lower than the GND voltage including an
actual electric transient.
3) Short circuit between terminals and erroneous mounting
In order to mount ICs on a set PCB, pay thorough attention to the direction and offset of the ICs. Erroneous mounting can
break down the ICs. Furthermore, if a short circuit occurs due to foreign matters entering between terminals or between
the terminal and the power supply or the GND terminal, the ICs can break down.
4) Operation in strong electromagnetic field
Be noted that using ICs in the strong electromagnetic field can malfunction them.
5) Inspection with set PCB
On the inspection with the set PCB, if a capacitor is connected to a low-impedance IC terminal, the IC can suffer stress.
Therefore, be sure to discharge from the set PCB by each process. Furthermore, in order to mount or dismount the set
PCB to/from the jig for the inspection process, be sure to turn OFF the power supply and then mount the set PCB to the jig.
After the completion of the inspection, be sure to turn OFF the power supply and then dismount it from the jig. In addition,
for protection against static electricity, establish a ground for the assembly process and pay thorough attention to the
transportation and the storage of the set PCB.
6) Input terminals
In terms of the construction of IC, parasitic elements are inevitably formed in relation to potential. The operation of the
parasitic element can cause interference with circuit operation, thus resulting in a malfunction and then breakdown of the
input terminal. Therefore, pay thorough attention not to handle the input terminals; such as to apply to the input terminals a
voltage lower than the GND respectively, so that any parasitic element will operate. In addition, apply to the input terminals
a voltage within the guaranteed value of electrical characteristics.
7) Thermal design
Perform thermal design in which there are adequate margins by taking into account the power dissipation ( Pd ) in actual
states of use.
8) Treatment of package
Dusts or scratch on the photo detector may affect the optical characteristics. Please handle it with care.
9) RUSH current
When power is first supplied to the CMOS IC, it is possible that the internal logic may be unstable and rush current may
flow instantaneously. Therefore, give special consideration to power coupling capacitance, power wiring, width of GND
wiring, and routing of connections.
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31/32
2011.06 - Rev.B
BH1771GLC
Ordering part number
B
H
1
Part No.
7
7
1
G
Part No.
L
C
-
Package
GLC: WLGA010V28
E
2
Packaging and forming specification
E2:Embossed tape and reel
WLGA010V28
2.8±0.1
2.65±0.1(MOLD)
<Tape and Reel information>
Top View
0.9± 0.1 2.65±0.1(MOLD)
2.8± 0.1
8
1
4
9
6
Tape
Embossed carrier tape (with dry pack)
Quantity
3000pcs
Direction
of feed
E2
The direction is the 1pin of product is at the upper left when you hold
( reel on the left hand and you pull out the tape on the right hand
)
S
0.08 S
Bottom View
0.5
0.4 1.0
9
0.35 0.7 0.7 0.7 0.35
0.2
0.4 0.4
0.4
2.0
2.8± 0.1
1
6
0.5
0.4
2.8±0.1
4
0.2
●
Technical Note
1.0 0.4
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© 2011 ROHM Co., Ltd. All rights reserved.
1pin
(Unit : mm)
Reel
32/32
Direction of feed
∗ Order quantity needs to be multiple of the minimum quantity.
2011.06 - Rev.B
Notice
Notes
No copying or reproduction of this document, in part or in whole, is permitted without the
consent of ROHM Co.,Ltd.
The content specified herein is subject to change for improvement without notice.
The content specified herein is for the purpose of introducing ROHM's products (hereinafter
"Products"). If you wish to use any such Product, please be sure to refer to the specifications,
which can be obtained from ROHM upon request.
Examples of application circuits, circuit constants and any other information contained herein
illustrate the standard usage and operations of the Products. The peripheral conditions must
be taken into account when designing circuits for mass production.
Great care was taken in ensuring the accuracy of the information specified in this document.
However, should you incur any damage arising from any inaccuracy or misprint of such
information, ROHM shall bear no responsibility for such damage.
The technical information specified herein is intended only to show the typical functions of and
examples of application circuits for the Products. ROHM does not grant you, explicitly or
implicitly, any license to use or exercise intellectual property or other rights held by ROHM and
other parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the
use of such technical information.
The Products specified in this document are intended to be used with general-use electronic
equipment or devices (such as audio visual equipment, office-automation equipment, communication devices, electronic appliances and amusement devices).
The Products specified in this document are not designed to be radiation tolerant.
While ROHM always makes efforts to enhance the quality and reliability of its Products, a
Product may fail or malfunction for a variety of reasons.
Please be sure to implement in your equipment using the Products safety measures to guard
against the possibility of physical injury, fire or any other damage caused in the event of the
failure of any Product, such as derating, redundancy, fire control and fail-safe designs. ROHM
shall bear no responsibility whatsoever for your use of any Product outside of the prescribed
scope or not in accordance with the instruction manual.
The Products are not designed or manufactured to be used with any equipment, device or
system which requires an extremely high level of reliability the failure or malfunction of which
may result in a direct threat to human life or create a risk of human injury (such as a medical
instrument, transportation equipment, aerospace machinery, nuclear-reactor controller, fuelcontroller or other safety device). ROHM shall bear no responsibility in any way for use of any
of the Products for the above special purposes. If a Product is intended to be used for any
such special purpose, please contact a ROHM sales representative before purchasing.
If you intend to export or ship overseas any Product or technology specified herein that may
be controlled under the Foreign Exchange and the Foreign Trade Law, you will be required to
obtain a license or permit under the Law.
Thank you for your accessing to ROHM product informations.
More detail product informations and catalogs are available, please contact us.
ROHM Customer Support System
http://www.rohm.com/contact/
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© 2011 ROHM Co., Ltd. All rights reserved.
R1120A