Ambient Light Sensor IC Series
Analog Current Output Type
Ambient Light Sensor IC
BH1620FVC
No.09046EBT03
●Descriptions
BH1620FVC is an analog current output ambient light sensor. This IC is the most suitable to obtain the ambient light data for
adjusting LCD and Keypad backlight of Mobile phone for power saving and better visibility
●Features
1) Compact surface mount package 1.6
×
1.6 mm
2) Spectral sensitivity close to human eyes sensitivity.
3) Output current in proportion to brightness.
4) Supply voltage operates from 2.4V to 5.5V
5) Built-in shutdown function
6) 3 steps controllable output current gain.
7) 1.8V logic input interface
8) Low sensitivity variation (+/-15%)
●Applications
Mobile phone, LCD TV, PDP TV, Laptop PC, Portable game console, Digital camera, Digital video camera, Car navigation,
PDA, LCD display
●Absolute
Maximum Ratings
Parameter
Supply Voltage
Operating Temperature
Storage Temperature
Iout Current
Power Dissipation
Symbol
Vmax
Topr
Tstg
Ioutmax
Pd
Limits
7
-40~85
-40~100
7.5
165
※
Units
V
℃
℃
mA
mW
※
70mm
×
70mm
×
1.6mm glass epoxy board. Derating at 2.2 mW/℃ for operating above Ta=25℃.
●Operating
Conditions
Parameter
V
CC
Voltage
Symbol
Vcc
Min.
2.4
Typ.
3.0
Max.
5.5
Units
V
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© 2009 ROHM Co., Ltd. All rights reserved.
1/9
2009.04 - Rev.B
BH1620FVC
●Electrical
Characteristics ( V
CC
= 3.0V, Ta = 25℃, unless otherwise noted )
Parameter
Supply Current1 ( Operate )
Supply Current2 ( 0 lx )
Supply Current3 ( Shutdown )
IOUT Output Current1(Dark Current)
IOUT Output Current2
Peak Wave Length
Incandescent/Fluorescent
Light Current Ratio
Saturated Output Voltage
GC1,GC2 Input ‘L’ Voltage
GC1,GC2 Input ‘H’ Voltage1
GC1,GC2 Input ‘H’ Voltage2
Wake-up Time
Gain Ratio
H-Gain Mode/M-Gain Mode
Gain Ratio
M-Gain Mode/L-Gain Mode
※
White LED is used as optical source
Technical Note
Symbol
Icc1
Icc2
Icc3sd
Iout1
Iout2
λp
rIF
V
OMAX
V
IL
V
IH1
V
IH2
twu
rHM
rML
Min.
48.5
4.5
-
-
48.5
-
-
2.6
0
1.4
2.0
-
9.5
9.5
Typ.
71
9
0.2
-
57
560
1.0
2.9
-
-
-
45
10
10
Max.
97
13.5
0.4
0.2
65.5
-
-
3.0
0.4
Vcc
Vcc
128
10.5
10.5
Units
µA
µA
µA
µA
µA
nm
times
V
V
V
V
µs
times
times
Conditions
Ev=100 lx (H-Gain Mode)
※
Ev=0 lx (H-Gain Mode)
V
GC1
=V
GC2
=0 No Input Light
Ev=0 lx
Ev=100 lx (H-Gain Mode)
※
Ev=100 lx
Ev=100 lx, RL=220kΩ
(H-Gain Mode)
※
2.4V
≦
VCC
≦
3.6V
3.6V
＜
VCC
≦
5.5V
Shutdown
→
H-Gain Mode
Ev=100lx
※
Ev=100lx
※
Ev=100lx
※
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© 2009 ROHM Co., Ltd. All rights reserved.
2/9
2009.04 - Rev.B
BH1620FVC
●Reference
Data
100000
1.2
1.0
0.8
Technical Note
Fluorescent
Light
Incandescent
Light
Halogen Light
10000
1000
H-Gain
M-Gain
L-Gain
IOUT [ uA ]
100
10
1
0.1
0.01
Ratio
0.6
0.4
0.2
0.0
400
500
600
700
800
900
1000
1100
Kripton Light
Artifical Sun
Light
White LED
0.001
0
0.5
Wavelength [ nm ]
Ratio
1
1.5
2
0.01
0
1
100
10,000
1,000,000
Illuminance [ lx ]
Fig.1 Spectral Response
Fig.2 Light Source Dependency
( Fluorescent Light is set to '1' )
1.2
1
Fig.3 Illuminance – I
OUT
Characteristics
100
10
IOUT [ uA ]
1.2
1
1pin
0.8
-
+
受信指向角特性
0.8
暗電流温特
1pin
-
-
1
0.1
0.01
H-Gain
M-Gain
L-Gain
SD
Ratio
0.6
0.4
-
+
Ratio
0.6
0.4
0.2
0
0.2
0
-90
-60
-30
0
30
60
90
+
+
-90
-60
-30
0
30
60
90
0.001
-40 -20
0
20
40
60
80 100
Ta [ ℃ ]
Angle [ deg ]
Angle [ deg ]
Fig.4 Directional Characteristics 1
Fig.5 Directional Characteristics 2
Fig.6 Ta – I
OUT
( 0 lx )
100
1.4
1.4
1.2
1
0.8
10
H-Gain
M-Gain
L-Gain
Ratio
1.2
1
Ratio
ICC [ uA ]
1
0.8
0.6
0.4
0.1
SD
0.6
0.4
0.2
0
0.01
0.2
0.001
-40
-20
0
20
40
60
80
100
0
Ta [ ℃ ]
-40
-20
0
20
40
60
80
100
2
2.5
3
3.5
4
4.5
5
5.5
6
Ta [
℃
]
VCC [ V ]
Fig.7 Ta – I
CC
( 0 lx )
Fig.8 I
OUT
Temperature dependency
( 100 lx )
Fig.9 I
OUT VCC
dependency
10000
WakeupTime [ us ]
1000
100
10
1
100
1000
Illuminance [ lx ]
10000
L-Gain
M-Gain
H-Gain
Fig.10 Illuminance – Wake up Time
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© 2009 ROHM Co., Ltd. All rights reserved.
3/9
2009.04 - Rev.B
BH1620FVC
●Block
Diagram
Technical Note
VCC
GC1
GC2
Logic
PD
Current
Amp
IOUT
R1
C1
GND
●Block
Diagram Descriptions
・PD
Photo diode close to human eyes sensitivity.
・Current
AMP
To amplify Photo diode current ( H-Gain / M-Gain / L-Gain )
Gain controllable in 3 steps by input voltage from GC1 and GC2.
・Logic
Logic block for mode setting by input voltage from GC1 and GC2
●
Mode Setting
GC2
0
0
1
1
GC1
0
1
0
1
Mode
Shutdown
H-Gain Mode
M-Gain Mode
L-Gain Mode
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© 2009 ROHM Co., Ltd. All rights reserved.
4/9
2009.04 - Rev.B
BH1620FVC
●
External parts Setting
1) Gain setting of BH1620FVC
Please select the best gain controlled by 3 and 4pin based on the required illuminance range.
The reference is as follows.
Illuminance detection range [lx]
~1,000
~10,000
~100,000
Gain Mode
H-Gain Mode
M-Gain Mode
L-Gain Mode
Technical Note
This device will be mounted under the optical window in actual designing. Therefore, there is a possibility that the
illuminace to ALS( Ambient Light Sensor) will be less than the illuminance on the final product surface. Please consider the
attenuation of light through the optical window. Please set output resistance value( R1) within the range of 1 kΩ~1MΩ
which needs to be smaller than the input impedance of the next circuit.
2) Approximate formula of IOUT output voltage in each Gain Mode
(1) H-Gain mode
The output voltage is calculated as below.
-6
Viout= 0.57 x 10 x Ev x R1
Viout is IOUT output voltage [V]. Ev is an illuminance of the ALS surface [lx].
R1 is IOUT output resistor[Ω].
(For example) In case you want to convert the illuminance value up to 500 lx by ADC.
If the maximum voltage of ADC input is 2V, output resistor value will be as below.
-6
R1 = Viout/(0.57 x 10 x Ev)
-6
= 2 /(0.57 x 10 x 500) = 7018[Ω]
⇒6.8[kΩ]
(2) M-Gain mode
Viout= 0.057 x 10
-6
x Ev x R1
(3) L-Gain mode
-6
Viout= 0.0057 x 10 x Ev x R1
3) C1
(1) To reject the flicker light..
In case IOUT output is R1 only and an ALS receives the artificial lights such as fluorescent lamps and incandescent
lamps synchronized with 50/60 Hz of AC power supplies, the output current has a ripple. If you want to reject this ripple,
please add C1 to R1 in parallel. Please set it to C1 x R1 = about 0.1 as a time constant.
(2) To control backlight smoothly by using illuminance value.
C1 is effective to control backlight smoothly for a rapid changing of the illuminance. In this case, please set it to
C1 x R1 = about 1 ~ 10 as a time constant. It is not necessary if you average illuminance value with software to change
backlight smoothly.
Please note that the rise time becomes slow at power-on and recovery from shutdown mode to operation mode.
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© 2009 ROHM Co., Ltd. All rights reserved.
5/9
2009.04 - Rev.B
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