ISL29028 Datasheet, PDF (11/15 Pages) Intersil Corporation – Low Power Ambient Light and Proximity Sensor with Intelligent Interrupt

ISL29028
Suggested PCB Footprint
It is important that users check the “Surface Mount
Assembly Guidelines for Optical Dual FlatPack No Lead
(ODFN) Package” before starting ODFN product board
mounting.
(http://www.intersil.com/data/tb/TB477.pdf)
Layout Considerations
The ISL29028 is relatively insensitive to layout. Like
other I²C devices, it is intended to provide excellent
performance even in significantly noisy environments.
There are only a few considerations that will ensure best
performance.
Route the supply and I²C traces as far as possible from all
sources of noise. A 0.1µF and 1µF power supply decoupling
capacitors need to be placed close to the device.
R1
10kΩ
R2
R3
10kΩ 10kΩ
V_{I2C_PULL-UP}
V_DD
V_IR-LED
C1
1µF
C2
0.1µF
SLAVE_0
1 _{ADDR0 IRDR} 8
2 _VDD
3 _GND
4 _REXT
7
INT
SDA ⁶
SCL ⁵
REXT ISL29028
499kΩ
SLAVE_1
SDA
SCL
I²C SLAVE_n
SDA
SCL
FIGURE 5. ISL29028 TYPICAL CIRCUIT
I²C MASTER
MICROCONTROLLER
INT
SDA
SCL
Typical Performance Curves V_DD = 3.0V, R_EXT = 499kΩ
1.0
0.9
FLUORESCENT
0.8
0.7
0.6
HALOGEN
0.5
INCAND.
0.4
SUN
0.3
0.2
0.1
0
350
550
750
950
WAVELENGTH (nm)
FIGURE 6. SPECTRUM OF FOUR LIGHT SOURCES
NORMALIZED BY LUMINOUS INTENSITY
(LUX)
1.0
0.9
0.8 _ALS
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
300 400
HUMAN EYE
IR/PROX
500 600 700 800 900 1000 1100
WAVELENGTH (nm)
FIGURE 7. ISL29028 SENSITIVITY TO DIFFERENT
WAVELENGTHS
11
FN6780.1
March 2, 2010