DATASHEET

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MENDE 29044A
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ISL
Low Power Ambient Light and Proximity Sensor with
Internal IR-LED and Digital Output
ISL29044
Features
The ISL29044 is an integrated ambient and infrared
light-to-digital converter with a built-in IR LED and I2C Interface
(SMBus Compatible). This device uses two independent ADCs
for concurrently measuring ambient light and proximity in
parallel. The flexible interrupt scheme is designed for minimal
microcontroller utilization.
• Internal LED + Sensor = Complete Solution
For ambient light sensor (ALS) data conversions, an ADC
converts photodiode current (with a light sensitivity range up to
2000 Lux) in 100ms per sample. The ADC rejects 50Hz/60Hz
flicker noise caused by artificial light sources.
• Pb-Free (RoHS compliant)
For proximity sensor (Prox) data conversions, the built-in driver
turns on an internal infrared LED and the proximity sensor ADC
converts the reflected IR intensity to digital. This ADC rejects
ambient IR noise (such as sunlight) and has a 547μs
conversion time.
• Adjustable interrupt persistency
- 1/4/8/16 consecutive triggers required before interrupt
• Works under all light sources including sunlight
• Dual ADCs measure ALS/Prox concurrently
• <1.0μA Supply current when powered down
• Temperature compensated
Intelligent and Flexible Interrupts
• Independent ALS/Prox interrupt thresholds
Applications
• Display and keypad dimming adjustment and proximity
sensing for:
- Mobile devices: Smart phone, PDA, GPS
- Computing devices: Laptop PC, Netbook, Tablet PC
- Consumer devices: LCD-TV, digital picture frame, digital
camera
- Industrial and medical light and proximity sensing
The ISL29044 provides low power operation of ALS and
proximity sensing with a typical 133μA normal operation
current (108μA for sensors and internal circuitry, ~25μA for
LED) with 220mA current pulses for a net 100μs, repeating
every 800ms (or under).
The ISL29044 uses both a hardware pin and software bits to
indicate an interrupt event has occurred. An ALS interrupt is
defined as a measurement that is outside a set window. A
proximity interrupt is defined as a measurement over a
threshold limit. The user may also require that both ALS/Prox
interrupts occur at once, up to 16 times in a row before
activating the interrupt pin.
Related Literature
• See AN1436, “Proximity Sensors”
The ISL29044 is designed to operate from 2.25V to 3.63V over
the -40°C to +85°C ambient temperature range. It is
packaged in a clear, lead-free 8 Ld ODFN package.
V_PULLUP
I2C SLAVE 0
8 SDA
VDD 1
ISL29044
R1
RES1
C3
0.1µF
5 LED- LED+ 4
6 IRDR GND 3
7 INT
SCL 2
C1
0.1µF
100
R2
RES1
I2C MASTER
VDD
I2C SLAVE 1 I2C SLAVE_n
C2
SCL
SCL
1µF
SDA
SDA
2
I2C-DIAGRAM I C-DIAGRAM
FIGURE 1. TYPICAL APPLICATION
April 28, 2016
FN8305.2
90
80
R3
RES1
1
SCL
SDA
INT
CONTROLLER
70
FSR (%)
V_LED
220mA WHITE
60
50
110mA WHITE
40
30
20
10
0
0
220mA GREY
110mA GREY
20
40
60
80
100
DISTANCE (mm)
120
140
160
FIGURE 2. PROXIMITY RESPONSE vs DISTANCE
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC. 2012, 2016. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
ISL29044
ISL29044 Block Diagram
VDD
1
ALS PHOTODIODE
ARRAY
COMMAND
REGISTER
LIGHT DATA
PROCESS
ALS AND IR
IR PHOTODIODE
ARRAY
DUAL CHANNEL
ADCs
DATA
REGISTER
I2C
IREF
INTERRUPT
FOSC
IR DRIVER
3
4
LED+
GND
Pin Configuration
4
3 GND
INT
7
2 SCL
SDA
8
1 VDD
INT
6 IRDR
5
LED-
PIN# PIN NAME
LED+
IRDR 6
7
Pin Descriptions
ISL29044
(8 LD 2.36X3.94 (mm) OPTICAL CO-PACKAGE)
TOP VIEW
LED- 5
2 SCL
8 SDA
DESCRIPTIONS
1
VDD
Voltage supply 2.25V to 3.63V.
2
SCL
I2C clock line can be pulled from 1.7V to above VDD,
3.63V max.
3
GND
Ground
4
LED+
Anode of IR LED
5
LED-
Cathode of IR LED
6
IRDR
IR-LED driver pin - current flows into ISL29044 from
LED cathode.
7
INT
Interrupt pin; Logic output (open-drain) for interrupt.
8
SDA
I2C data line can be pulled from 1.7V to above VDD,
3.63V max.
Ordering Information
PART NUMBER
(Notes 1, 2, 3)
TEMP. RANGE
(°C)
ISL29044IROMZ-T7
-40 to +85
ISL29044IROMZ-EVALZ
PACKAGE
Tape & Reel
(Pb-free)
8 Ld Optical Co-package
PKG.
DWG. #
L8.2.36x3.94
Evaluation Board
NOTES:
1. Please refer to TB347 for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets: molding compounds, die attach materials, NiPdAu plate
(e4 termination finish), which are all RoHS compliant. The ISL29044 is compatible with limited SnPb and Pb-free soldering operations. The ISL29044
is MSL classified. See Tech Brief TB487 (Surface Mount Assembly Guidelines for Optical Co-Package Sensor and LED) for reflow profile and more
information.
3. For more information on MSL please see tech brief TB477.
2
FN8305.2
April 28, 2016
ISL29044
Absolute Maximum Ratings
Thermal Information
(TA = +25°C)
VDD Supply Voltage between VDD and GND . . . . . . . . . . . . . . . . . . . . . .4.0V
I2C Bus Pin Voltage (SCL, SDA). . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to 4.0V
I2C Bus Pin Current (SCL, SDA). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10mA
IRDR, LED+Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.5V
INT Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to 4.0V
INT Pin Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10mA
ESD Rating
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2kV
Thermal Resistance (Typical)
JA (°C/W) JC (°C/W)
8 Ld Optical Module Package (Notes 4, 5)
113
58
Maximum Die Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +90°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
Operating Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see TB487
http://www.intersil.com/pbfree/Pb-FreeReflow.asp
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product
reliability and result in failures not covered by warranty.
NOTES:
4. JA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
5. For JC, the “case temp” location is the center of the exposed metal pad on the package underside.
IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise
noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA
Electrical Specifications
PARAMETER
VDD
VDD = 3.0V, TA = +25°C.
DESCRIPTION
CONDITION
Power Supply Range
2.25
SR_VDD
Power Supply Slew Rate
VLED+
Voltage Supply for IR LED
IDD_OFF
Supply Current when Powered Down
ALS_EN = 0; PROX_EN = 0
Supply Current for ALS+Prox in Sleep Time
IDD_NORM
IDD_PRX_SLP
IDD_ALS
VDD Rising Edge between 0.4V and 2.25V
3.0
3.63
0.5
V
V/ms
5
V
0.05
0.8
µA
ALS_EN = 1; PROX_EN = 1
108
135
µA
Supply Current for Prox in Sleep Time
ALS_EN = 0; PROX_EN = 1
79
µA
Supply Current for ALS
ALS_EN = 1; PROX_EN = 0
94
µA
tINTGR_ALS
12-bit ALS Integration/Conversion Time
tINTGR_PROX
8-bit Prox Integration/Conversion Time
88
ALS Result when Dark
EAMBIENT = 0 lux, 2k Range
DATAALS_F
Full Scale ALS ADC Code
EAMBIENT > Selected Range Maximum Lux (Note 9)
1
DATAALS_1
Light Count Output with LSB of 0.0302 lux/count E = 48lux, Fluorescent (Notes 7,9), ALS_RANGE = 0
DATAALS_2
Light Count Output With LSB of 0.4824 lux/count E = 288lux, Fluorescent (Note 7,9), ALS_RANGE = 1
Prox Measurement w/o Object in Path
DATAPROX_F
Full Scale Prox ADC Code
112
ms
ms
3
Counts
4095 Counts
Count Output Variation Over Three Light Sources: Ambient Light Sensing
Fluorescent, Incandescent and Sunlight
DATAPROX_0
100
0.51
DATAALS_0
ΔDATA
DATA
MIN
MAX
(Note 6) TYP (Note 6) UNIT
447
15
%
1587
Counts
597
747
1
Counts
Counts
255
Counts
tr
Rise Time for IRDR Sink Current
RLOAD = 15 at IRDR pin, 20% to 80%
500
ns
tf
Fall Time for IRDR Sink Current
RLOAD = 15 at IRDR pin, 80% to 20%
400
ns
IIRDR_0
IRDR Sink Current
PROX_DR = 0; VIRDR = 0.5V
IIRDR_1
IRDR Sink Current
PROX_DR = 1; VIRDR = 0.5V
IRDR Leakage Current
PROX_EN = 0; VDD = 3.63V (Note 8)
VIRDR
Acceptable Voltage Range on IRDR Pin
Register bit PROX_DR = 0
tPULSE
Net IIRDR On Time Per PROX Reading
IIRDR_LEAK
FI2C
VI2C
85
3
125
208
0.001
0.5
1.7
mA
mA
1
µA
4.3
V
100
I2C Clock Rate Range
Supply Voltage Range for I2C Interface
105
µs
400
kHz
3.63
V
FN8305.2
April 28, 2016
ISL29044
Electrical Specifications
PARAMETER
VDD = 3.0V, TA = +25°C. (Continued)
DESCRIPTION
MIN
MAX
(Note 6) TYP (Note 6) UNIT
CONDITION
VIL
SCL and SDA Input Low Voltage
VIH
SCL and SDA Input High Voltage
ISDA
SDA Current Sinking Capability
VOL = 0.4V
3
5
mA
IINT
INT Current Sinking Capability
VOL = 0.4V
3
5
mA
(IIRDR)/(VIRDR)
PROX_DR = 0; VIRDR = 0.5V to 4.3V
5.8
mA/V
PSRRIRDR
0.55
V
1.25
V
NOTES:
6. Compliance to datasheet limits is assured by one or more methods: production test, characterization and/or design.
7. An LED is used in production test. The LED irradiance is calibrated to produce the same DATA count against a fluorescent light source of the same lux
level.
8. Ability to guarantee IIRDR leakage of ~1nA is limited by test hardware.
9. For ALS applications under light-distorting glass, please see the section titled “ALS Range 1 Considerations” on page 9.
IR-LED Specifications
TA = +25°C
PARAMETER
VF
DESCRIPTION
IR-LED Forward Voltage Drop
CONDITION
MIN
(Note 6)
TYP
MAX
(Note 6)
UNIT
IF = 200mA
2.0
V
IF = 100mA
1.8
V
IR
IR-LED Reverse-Bias Current
VR = 5.5V
λP
IR-LED Peak Output Wavelength
IF = 110mA
858
nm
Δλ
IR-LED Spectral Half-Width
IF = 110mA
39
nm
ΦE
IR-LED Radiant Power
IF = 110mA
30
mW
IR-LED Radiant Intensity (in 0.01sr) at 0°
IF = 110mA
128
mW/sr
I
I2C Electrical Specifications
PARAMETER
0.061
5
µA
For SCL and SDA unless otherwise noted, VDD = 3V, TA = +25°C (Note 10).
DESCRIPTION
CONDITION
MIN
(Note 6)
MAX
TYP (Note 6) UNIT
1.7
3.63
V
VI2C
Supply Voltage Range for I2C Interface
fSCL
SCL Clock Frequency
400
kHz
VIL
SCL and SDA Input Low Voltage
0.55
V
VIH
SCL and SDA Input High Voltage
Vhys
Hysteresis of Schmitt Trigger Input
VOL
Low-level Output Voltage (Open-drain) at 4mA Sink
Current
Ii
Input Leakage for each SDA, SCL Pin
1.25
V
0.05VDD
V
-10
0.4
V
10
µA
tSP
Pulse Width of Spikes that must be Suppressed by
the Input Filter
50
ns
tAA
SCL Falling Edge to SDA Output Data Valid
900
ns
1
pF
Ci
Capacitance for each SDA and SCL Pin
tHD:STA
Hold Time (Repeated) START Condition
After this period, the first clock pulse is
generated.
600
ns
tLOW
LOW Period of the SCL Clock
Measured at the 30% of VDD crossing.
1300
ns
tHIGH
HIGH period of the SCL Clock
600
ns
4
FN8305.2
April 28, 2016
ISL29044
I2C Electrical Specifications
PARAMETER
For SCL and SDA unless otherwise noted, VDD = 3V, TA = +25°C (Note 10). (Continued)
DESCRIPTION
CONDITION
MIN
(Note 6)
MAX
TYP (Note 6) UNIT
tSU:STA
Set-up Time for a Repeated START Condition
600
ns
tHD:DAT
Data Hold Time
30
ns
tSU:DAT
Data Set-up Time
100
ns
tR
Rise Time of both SDA and SCL Signals
(Note 11)
20 + 0.1xCb
ns
tF
Fall Time of both SDA and SCL Signals
(Note 11)
20 + 0.1xCb
ns
Set-up Time for STOP Condition
600
ns
Bus Free Time Between a STOP and START Condition
1300
ns
tSU:STO
tBUF
Cb
Capacitive Load for Each Bus Line
400
Maximum is determined by tR and tF
1
pF
Rpull-up
SDA and SCL System Bus Pull-up Resistor
k
tVD;DAT
Data Valid Time
0.9
µs
tVD:ACK
Data Valid Acknowledge Time
0.9
µs
VnL
Noise Margin at the Low Level
0.1VDD
V
VnH
Noise Margin at the High Level
0.2VDD
V
NOTES:
10. All parameters in I2C Electrical Specifications table are guaranteed by design and simulation.
11. Cb is the capacitance of the bus in pF.
FIGURE 3. I2C TIMING DIAGRAM
5
FN8305.2
April 28, 2016
ISL29044
Typical Performance Curves
VDD = 3.0V
100
1.0
90
FLUORESCENT
0.8
80
0.7
70
HALOGEN
0.5
INCAND.
SUN
0.4
60
FSR (%)
0.6
50
40
0.3
30
0.2
20
0.1
10
0
1100
1050
WAVELENGTH (nm)
1000
950
900
850
800
750
700
650
600
WAVELENGTH (nm)
550
500
450
950
400
750
350
550
300
0
350
FIGURE 5. ISL29044 SENSITIVITY TO DIFFERENT WAVELENGTHS
1.0
4500
ALS RANGE 125 READING (COUNTS)
FIGURE 4. SPECTRUM OF FOUR LIGHT SOURCES NORMALIZED BY
LUMINOUS INTENSITY (LUX)
SERIES1
0.8
0.6
0.4
0.2
4000
3500
3000
2500
1000
500
0
0
10
20
30
40
50 60 70 80
LUX METER (lux)
90 100 110 120 130
FIGURE 7. ALS TRANFER FUNCTION 2 LIGHT SOURCES
(125 LUX RANGE)
160
ALS+PROX (DURING PROX SLEEP)
90
140
70
MEASURED IDD (µA)
80
220mA WHITE
60
50
110mA WHITE
40
30
220mA GREY
20
0
0
WHITE LED
1500
100
10
HALOGEN
2000
90
80
70
60
50
40
30
20
10
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
FIGURE 6. ANGULAR SENSITIVITY OF ALS
FSR (%)
NORMALIZED INTENSITY
0.9
ALS-ONLY
120
100
80
PROX (DURING PROX SLEEP)
60
110mA GREY
20
40
60
80
100
120
140
DISTANCE (mm)
FIGURE 8. PROX COUNTS vs DISTANCE WITH 10cmx10cm
REFLECTORS
6
160
40
2.25
2.40
2.55
2.70
2.85 3.00 3.15
INPUT VDD (V)
3.30
3.45 3.60
FIGURE 9. VDD vs IDD FOR VARIOUS MODES OF OPERATION
FN8305.2
April 28, 2016
ISL29044
Typical Performance Curves
VDD = 3.0V (Continued)
0.02
240
220mA-MODE (PROX_DR = 1)
0.01
ALS % CHANGE
IIRDR (mA)
220
200
180
160
140
BOARD 7
0
-0.01
-0.02
120
100
110mA-MODE (PROX_DR = 0)
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
-0.03
-50 -40 -30 -20 -10 0
VIRDR (V)
TEMPERATURE (°C)
FIGURE 11. ALS RANGE1 OVER TEMP AT 75 LUX WHITE LED
FIGURE 10. IRDR PULSE AMPLITUDE vs VIRDR
1.0
9.00E-01
0.9
8.00E-01
0.8
7.00E-01
0.7
6.00E-01
0.6
WATTS
1.00E+00
WATTS
10 20 30 40 50 60 70 80 90 100
5.00E-01
4.00E-01
0.5
0.4
90
80
70
60
50
40
30
20
10
0
-10
-20
ANGULAR (°)
-30
-40
-50
-60
-70
-80
-90
90
80
70
60
50
40
30
20
10
0
-10
-20
-30
-40
-50
0
-60
0.1
0.00E+00
-70
0.2
1.00E-01
-80
0.3
2.00E-01
-90
3.00E-01
ANGULAR (°)
FIGURE 12. RADIATION EMISSION PATTERN IRLED TRANSVERSE
FIGURE 13. IR-LED LATERAL EMISSION PATTERN (NORMALIZED
INTENSITY vs ΘTRANS)
Lateral
Transverse
FIGURE 14. DEFINITION OF LATERAL AND TRANSVERSE AXES
7
FN8305.2
April 28, 2016
ISL29044
Principles of Operation
Photodiodes and ADCs
The ISL29044 contains two photodiode arrays, which convert
photons (light) into current. The ALS photodiodes are constructed
to mimic the human eye’s wavelength response curve to visible
light (see Figure 5). The ALS photodiodes’ current output is
digitized by a 12-bit ADC in 100ms. These 12 bits can be
accessed by reading from I2C registers 0x9 and 0xA when the
ADC conversion is completed.
The ALS converter is a charge-balancing, integrating 12-bit ADC.
Charge-balancing is best for converting small current signals in
the presence of periodic AC noise. Integrating over 100ms highly
rejects both 50Hz and 60Hz light flicker by picking the lowest
integer number of cycles for both 50Hz/60Hz frequencies.
ALS CONVERSION TIME =
100ms (FIXED)
SEVERAL µs BETWEEN
CONVERSIONS
When proximity sensing is enabled (PROX_EN = 1), the internal
IR LED is driven for 0.1ms by the built-in IR LED driver through
the IRDR pin. The amplitude of the IR LED current depends on
Register 1 bit 3: PROX_DR. If this bit is low, the load will see a
fixed 110mA current pulse. If this bit is high, the load on IRDR
will see a fixed 220mA current pulse, as seen in Figure 16.
LED+
INTERNAL IR-LED
LED-
PCB TRACE
100ms
100ms
100ms
100ms
100ms
TIME
0.54ms FOR PROX
CONVERSION
110mA
(PROX_DR = 0)
IRDR
(IRDR IS HI-Z WHEN
NOT DRIVING)
TIME
IRDR
(CURRENT
DRIVER)
Proximity Sensing
220mA
(PROX_DR = 1)
ALS
ACTIVE
PROX
SENSOR
ACTIVE
When the part is programmed for infrared (IR) sensing
(ALSIR_MODE = 1; ALS_EN = 1), infrared light is converted into a
current and digitized by the same ALS ADC. The result of an IR
conversion is strongly related to the amount of IR energy incident
on our sensor, but is unitless and is referred to in digital counts.
SERIES OF
CURRENT PULSES
TOTALING 0.1ms
TIME
SLEEP TIME
(PROX_SLP)
FIGURE 15. TIMING DIAGRAM FOR PROX/ALS EVENTS - NOT TO SCALE
FIGURE 16. CURRENT DRIVE MODE OPTIONS
When the IR from the LED reaches an object and gets reflected
back into the ISL29044, the reflected IR light is converted into
current as per the IR spectral response shown in Figure 5. One
entire proximity measurement takes 0.54ms for one conversion
(which includes 0.1ms spent driving the LED), and the period
between proximity measurements is decided by PROX_SLP
(sleep time) in Register 1 Bits 6:4.
Average LED driving current consumption is given by Equation 1.
The proximity sensor is an 8-bit ADC that operates in a similar
fashion. When proximity sensing is enabled, the IRDR pin will
drive the internal infrared LED, the emitted IR reflects off an object
(e.g., a human head) back into the ISL29044, and a sensor
converts the reflected IR wave to a current signal in 0.54ms. The
ADC subtracts the IR reading before and after the LED is driven
(to remove ambient IR such as sunlight), and converts this value
to a digital count stored in Register 0x8.
The ISL29044 is designed to run two conversions concurrently: a
proximity conversion and an ALS (or IR) conversion. Please note
that because of the conversion times, the user must let the ADCs
perform one full conversion first before reading from I2C
Registers PROX_DATA (wait 0.54ms) or ALSIR_DT1/2 (wait
100ms). The timing between ALS and Prox conversions is
arbitrary (as shown in Figure 15). The ALS runs continuously with
new data available every 100ms. The proximity sensor runs
continuously with a time between conversions decided by
PROX_SLP (Register 1 Bits [6:4]).
Ambient Light and IR Sensing
The ISL29044 is set for ambient light sensing when Register bit
ALSIR_MODE = 0 and ALR_EN = 1. The light-wavelength
response of the ALS appears as shown in Figure 5. ALS
measuring mode (as opposed to IR measuring mode) is set by
default.
8
I lRDR ;PEAK  100s
I lRDR ;AVG = -------------------------------------------------------t SLEEP
(EQ. 1)
A typical IRDR scheme is 220mA amplitude pulses every 800ms,
which yields 28μA DC.
Total Current Consumption
Total current consumption is the sum of IDD and IIRDR. The IRDR
pin sinks current (as shown in Figure 16) and the average IRDR
current can be calculated using Equation 1. IDD depends on
voltage and the mode-of-operation, as seen in Figure 9.
Interrupt Function
The ISL29044 has an intelligent interrupt scheme designed to
shift some logic processing away from intensive microcontroller
I2C polling routines (which consume power) and towards a more
independent light sensor, which can instruct a system to “wake
up” or “go to sleep”.
An ALS interrupt event (ALS_FLAG) is governed by Registers 5
through 7. The user writes a high and low threshold value to
these registers and the ISL29044 will issue an ALS interrupt flag
if the actual count stored in Registers 0x9 and 0xA are outside
the user’s programmed window. The user must write 0 to clear
the ALS_FLAG.
FN8305.2
April 28, 2016
ISL29044
A proximity interrupt event (PROX_FLAG) is governed by the high
and low thresholds in registers 3 and 4 (PROX_LT and PROX_HT).
PROX_FLAG is set when the measured proximity data is more
than the higher threshold X-times-in-a-row (X is set by user; see
following paragraph). The proximity interrupt flag is cleared when
the prox data is lower than the low proximity threshold
X-times-in-a-row, or when the user writes “0” to PROX_FLAG.
Interrupt persistency is another useful option available for both
ALS and proximity measurements. Persistency requires X-in-arow interrupt flags before the INT pin is driven low. Both ALS and
Prox have their own independent interrupt persistency options.
See ALS_PRST and PROX_PRST bits in Register 2.
The final interrupt option is the ability to AND or OR the two
interrupt flags using Register 2 Bit 0 (INT_CTRL). If the user
wants both ALS/Prox interrupts to happen at the same time
before changing the state of the interrupt pin, set this bit high. If
the user wants the interrupt pin to change state when either the
ALS or the Proximity interrupt flag goes high, leave this bit to its
default of 0.
ALS Range 1 Considerations
When measuring ALS counts higher than 1800 on range 1
(ALSIR_MODE = 0, ALS_RANGE = 0, ALS_DATA > 1800), switch
to range 2 (change the ALS_RANGE bit from “0” to “1”) and
re-measure ALS counts. This recommendation pertains only to
applications where the light incident upon the sensor is IR-heavy
and is distorted by tinted glass that increases the ratio of infrared
to visible light. For more information, please contact the factory.
VDD Power-up and Power Supply
Considerations
Upon power-up, please ensure a VDD slew rate of 0.5V/ms or
greater. After power-up, or if the user’s power supply temporarily
deviates from our specification (2.25V to 3.63V), Intersil
recommends the user write the following: write 0x00 to register
0x01, write 0x29 to register 0x0F, write 0x00 to register 0x0E,
and write 0x00 to register 0x0F. The user should then wait ~1ms
or more and then rewrite all registers to the desired values. If the
user prefers a hardware reset method instead of writing to test
registers: set VDD = 0V for 1 second or more, power back up at
the required slew rate, and write registers to the desired values.
Power-Down
To put the ISL29044 into a power-down state, the user can set
both PROX_EN and ALS_EN bits to 0 in Register 1 or more;
simply set all of Register 1 to 0x00.
9
Serial Interface
The ISL29044 supports the Inter-Integrated Circuit (I2C) bus data
transmission protocol. The I2C bus is a two wire serial
bidirectional interface consisting of SCL (clock) and SDA (data).
Both the wires are connected to the device supply via pull-up
resistors. The I2C protocol defines any device that sends data
onto the bus as a transmitter and the receiving device as the
receiver. The device controlling the transfer is a master and the
device being controlled is the slave. The transmitting device pulls
down the SDA line to transmit a “0” and releases it to transmit a
“1”. The master always initiates the data transfer, only when the
bus is not busy, and provides the clock for both transmit and
receive operations. The ISL29044 operates as a slave device in
all applications. The serial communication over the I2C interface
is conducted by sending the most significant bit (MSB) of each
byte of data first.
Start Condition
During data transfer, the SDA line must remain stable while the
SCL line is HIGH. All I2C interface operations must begin with a
START condition, which is a HIGH to LOW transition of SDA while
SCL is HIGH (refer to Figure 17). The ISL29044 continuously
monitors the SDA and SCL lines for the START condition and does
not respond to any command until this condition is met (refer to
Figure 17). A START condition is ignored during the power-up
sequence.
Stop Condition
All I2C interface operations must be terminated by a STOP
condition, which is a LOW-to-HIGH transition of SDA while SCL is
HIGH (refer to Figure 17). A STOP condition at the end of a
read/write operation places the device in its standby mode. If a
stop is issued in the middle of a Data byte, or before 1 full Data
byte + ACK is sent, then the serial communication of ISL29044
resets itself without performing the read/write. The contents of
the array are not affected.
Acknowledge
An acknowledge (ACK) is a software convention used to indicate
a successful data transfer. The transmitting device releases the
SDA bus after transmitting 8-bits. During the ninth clock cycle,
the receiver pulls the SDA line LOW to acknowledge the reception
of the eight bits of data (refer to Figure 17). The ISL29044
responds with an ACK after recognition of a START condition
followed by a valid Identification Byte, and once again, after
successful receipt of an Address Byte. The ISL29044 also
responds with an ACK after receiving a Data byte of a write
operation. The master must respond with an ACK after receiving
a Data byte of a read operation.
FN8305.2
April 28, 2016
ISL29044
8th
CLk
SCL FROM
MASTER
9th CLk
HIGH IMPEDANCE
SDA FROM
TRANSMITTER
SDA FROM
RECEIVER
DATA
STABLE
START
DATA
CHANGE
DATA
STABLE
ACK
STOP
FIGURE 17. START, DATA STABLE, ACKNOWLEDGE, AND STOP CONDITION
Device Addressing
BURST WRITE
Following a START condition, the master must output a Device
Address byte. The 7 MSBs of the Device Address byte are known as
the device identifier. The device identifier bits of ISL29044 are
internally hard-wired as “1000100”. The LSB of the Device Address
byte is defined as read or write (R/W) bit. When this R/W bit is a
“1”, a read operation is selected and when “0”, a write operation is
selected (refer to Figure 18). The master generates a START
condition followed by Device Address byte 1000100x (x as R/W)
and the ISL29044 compares it with the internal device identifier.
Upon a correct comparison, the device outputs an acknowledge
(LOW) on the SDA line (refer to Figure 17).
The ISL29044 has a burst write operation, which allows the
master to write multiple consecutive bytes from a specific
address location. It is initiated in the same manner as the byte
write operation, but instead of terminating the write cycle after
the first Data byte is transferred, the master can write to the
whole register array. After the receipt of each byte, the ISL29044
responds with an acknowledge, and the address is internally
incremented by one. The address pointer remains at the last
address byte written. When the counter reaches the end of the
register address list, it “rolls over” and goes back to the first
Register Address.
1
A7
D7
0
A6
D6
0
A5
D5
0
A4
D4
1
0
A3
A2
D3
D2
0
A1
D1
R/W
DEVICE
ADDRESS BYTE
A0
REGISTER
ADDRESS BYTE
D0
DATA BYTE
FIGURE 18. DEVICE ADDDRESS, REGISTER ADDRESS, & DATA BYTE
Write Operation
BYTE WRITE
In a byte write operation, ISL29044 requires the Device Address
byte, Register Address byte, and the Data byte. The master starts
the communication with a START condition. Upon receipt of the
Device Address byte, Register Address byte, and the Data byte,
the ISL29044 responds with an acknowledge (ACK). Following
the ISL29044 data acknowledge response, the master
terminates the transfer by generating a STOP condition. The
ISL29044 then begins an internal write cycle of the data to the
volatile memory. During the internal write cycle, the device inputs
are disabled and the SDA line is in a high impedance state, so the
device will not respond to any requests from the master (refer to
Figure 19).
SIGNAL FROM
MASTER DEVICE
SIGNAL AT SDA
SIGNALS FROM
SLAVE DEVICE
S
T
DEVICE ADDRESS
A
BYTE
R
T
ADDRESS BYTE
S
T
O
P
DATA BYTE
Read Operation
The ISL29044 has two basic read operations: Byte Read and
Burst Read.
BYTE READ
Byte read operations allow the master to access any register
location in the ISL29044. The Byte read operation is a two step
process. The master issues the START condition and the Device
Address byte with the R/W bit set to “0”, receives an
acknowledge, then issues the Register Address byte. After
acknowledging receipt of the register address byte, the master
immediately issues another START condition and the Device
Address byte with the R/W bit set to “1”. This is followed by an
acknowledge from the device and then by the 8-bit data word.
The master terminates the read operation by not responding with
an acknowledge and then issuing a stop condition (refer to
Figure 20).
BURST READ
Burst read operation is identical to the Byte Read operation.
After the first Data byte is transmitted, the master responds with
an acknowledge, indicating it requires additional data. The
device continues to output data for each acknowledge received.
The master terminates the read operation by not responding with
an acknowledge but issuing a STOP condition (refer to Figure 21).
For more information about the I2C standard, please consult the
Philips™ I2C specification documents.
1 0 0 0 1 0 0 0
A
C
K
A
C
K
A
C
K
FIGURE 19. BYTE WRITE SEQUENCE
10
FN8305.2
April 28, 2016
ISL29044
SIGNAL FROM
MASTER DEVICE
START
DEVICE ADDRESS
WRITE
ADDRESS BYTE
START
1 0 0 0 1 0 0 0
SIGNAL AT SDA
DATA BYTE
STOP
1 0 0 0 1 0 0 1
A
C
K
SIGNALS FROM
SLAVE DEVICE
DEVICE ADDRESS
READ
A
C
K
A
C
K
FIGURE 20. BYTE ADDRESS READ SEQUENCE
SIGNAL FROM
DEVICE ADDRESS
MASTER
WRITE
DEVICE START
SIGNAL AT
SDA
SIGNALS
FROM SLAVE
DEVICE
DEVICE ADDRESS
ADDRESS BYTE
READ
START
1 0 0 0 1 0 0 0
DATA BYTE 2
DATA BYTE 1
DATA BYTE n
STOP
1 0 0 0 1 0 0 1
A
C
K
A
C
K
A
C
K
A
C
K
A
C
K
(“n” is any integer
greater than 1)
FIGURE 21. BURST READ SEQUENCE
11
FN8305.2
April 28, 2016
ISL29044
Register Map
Following are detailed descriptions of the control registers related to the operation of the ISL29044 ambient light sensor device. These
registers are accessed by the I2C serial interface. For details on the I2C interface, refer to “Serial Interface” on page 9.
All the functionalities of the device are controlled by the registers. The ADC data can also be read. The following sections explain the
details of each register bit. All RESERVED bits must be set to zero, unless otherwise specified.
Register Descriptions
TABLE 1. ISL29044 REGISTERS AND REGISTER BITS
BIT
ADDR
REG NAME
7
6
5
4
3
2
1
0
DEFAULT
0x00
ChipID
1
1
0
1
0
0
0
0
0xB0
0x01
CONFIGURE
PROX EN
PROX_DR
ALS_EN
0x02
INTERRUPT
PROX_FLAG
0x03
PROX_LT
PROX_LT[7:0]
0x00
0x04
PROX_HT
PROX_HT[7:0]
0xFF
0x05
ALSIR_TH1
ALSIR_LT[7:0]
0x00
0x06
ALSIR_TH2
0x07
ALSIR_TH3
ALSIR_HT[11:4]
0xFF
0x08
PROX_DATA
PROX_DATA[7:0]
0x00
0x09
ALSIR_DT1
ALSIR_DATA[7:0]
0x00
0x0A
ALSIR_DT2
PROX_SLP[2:0]
PROX_PRST[1:0]
(Write 0)
RO
(Unused)
B7
B6
B5
B4
B3
B2
B1
B0
DFLT
(Hex)
1
1
0
1
0
0
0
0
0xB0
TABLE 4. ALS/IR DATA BIT
BIT 0
TABLE 3. CONFIGURE REGISTER ADDRESS
Configure
RW
0x01
B6
B5
PROX
_EN
PROX
_S2
PROX
_S1
B4
B3
B2
PROX PRO ALS/I
_X0 X_DR R_EN
OPERATION
0
Visible Spectrum ALS sensing data
1
IR Spectrum sensing data
FULL SCALE RANGE [B1]
Register Bits
B7
0x00
The ALS/IR data mode bit is a select mode for fetching data from
the data register (reg 0x09 and reg 0x0A). If B0 is set to 0, the
ALS/IR data register will contain visible spectrum ALS sensing
data. If B0 is set to 1, the ALS/IR data register will contain IR
spectrum sensing data.
Configure Register (Address: 0x01)
NAME
0x00
ALS/IR DATA BIT [B0]
This is a reserved register. Do not write or read
Reg.
Access Addr
(Hex)
0x00
0xF0
ALSIR_DATA[11:8]
Register Bits
0x00
INT_CTRL
ALSIR_LT[11:8]
TABLE 2. ChipID REGISTER ADDRESS
ChipID
ALS_PRST[1:0]
ALSIR_HT[3:0]
Register (Address: 0x00)
Reg.
Addr
NAME Access (Hex)
ALS_FLAG
ALS_RANGE ALSIR_MODE
B1
B0
ALS_
RANGE
ALS/IR
data
DFLT
(Hex)
0x00
The Full Scale Range (FSR) has two selectable ranges. Each
range has a maximum allowable lux value. The higher the range
value, the better the resolution and the wider the ALS lux value.
TABLE 5. RANGE REGISTER BITS
The Configure register consists all of control bits for both ALS
Sensing and Proximity Sensing. This register determines
operation mode. The register has one Enable Prox sensing bit,
three Proximity Sleep mode bits, one proximity current driver bit,
one Enable ALS/IR sensing bit, one ALS/IR range bit, and one
ALS/IR sensing data bits. The default register value is 0x00 at
power on.
12
BIT1
RANGE(k)
FSR (LUX) @ VISIBLE ALS SENSING
0
Range1
125
1
Range2
2000
ALS/IR_EN [B2]
The ALS/IR_EN bit[B2] is the enable bit for both ALS sensing and
IR sensing. If [B2] is 0, ALS sensing an IR sensing is disabled. If
[B2] is 1, ALS sensing and IR sensing is enabled.
FN8305.2
April 28, 2016
ISL29044
TABLE 6. RANGE REGISTER BITS
Interrupt Register (Address: 0x02)
OPERATION
TABLE 10. INTERRUP REGISTER ADDRESS
BIT 0
0
Disable ALS sensing and IR sensing
1
Enable ALS sensing and IR sensing
PROX_DR[B3]
NAME
Access
INTERRUPT
PROX_DR bit[B3] selects the IR driver current strength. The IR
driver sinks current through the LDR pin. The drive capability can
be programmed through [B3] either a pulse 110mA current sink
or 220mA pulse current sink. The higher the amplitude, the
better the range of detection.
TABLE 7. CURRENT DRIVER REGISTER BITS
BIT 0
OPERATION
0
110mA current sink
1
220mA current sink
PROX SLEEP MODE [B6,B5,B4]
ISL29044 is equipped with multiple sleep modes in proximity
sensing. It is a good power saving feature. The different sleep
modes can be selected by setting [B6-B4] bits on register 0x01.
When proximity sensing is enabled, the ADC converts for 0.54ms
and sleeps for 800ms by default.
Table 8 lists the possible operating sleep modes.
TABLE 8. SLEEP MODES BITS
B6
B5
B4
0
0
0
SLEEP TIME OPERATION
(msec)
RW
B6
B5
B4
B3
0x02
PROX_
FLAG
PROX_
PRST1
PROX_
PRST0
0
ALS/IR
_FLAG
1
0
200
0
1
1
100
1
0
0
75
1
0
1
50
1
1
0
12.5
1
1
1
0.0 (Sleep Mode Disabled)
PROX_EN[B7].
Proximity is enabled when PROX_EN[B7] is set to high.
0
Disable proximity sensing (Default)
1
Enable proximity sensing
0x00
OPERATION
ALS/IR INTERRUPT PERSIST BITS [B2,B1]
The interrupt persist bits[B2LOL, B1] provide control when
interrupts occur. There are four different selections for this
feature. A value of N (where N is 1, 4, 8, and 16) results in an
interrupt only if the value remains outside the threshold window
for N consecutive integration cycles. For example, if N is equal to
8 and the integration time is 100ms. An interrupt is generated
whenever the last conversion results in a value outside of the
programmed threshold window. Table 12 lists the possible
interrupt persist bits.
TABLE 12. INTERRUPT PERSIST BITS
TABLE 9. EN_PROXIMITY REGISTER BITS
CURRENT DRIVER OPERATION
ALS/IR ALS/IR_
INT_CTRL
_PRST1 PRSST0
DFLT
(Hex)
TABLE 11. INTERRUPT CONTROL REGISTER BITS
BIT 0
Logical AND
0
B0
INT_CTRL [B0] can be programmed to cause an interrupt when
either ALS_FLAG or PROX_FLAG go high or when both go high.
Writing ‘0’ will do a logical OR and a one will do a logical AND.
The INT pin is open-drain therefore, in this INT_CTRL bit, there are
two options to make the INT pin go low. Once the interrupt is
triggered, the INT pin goes low if the PROX_FLAG bit or ALS_FLAG
goes high in logic OR option. Otherwise, the interrupt is triggered
and the INT pin goes low if the PROX_FLAG bit and ALS_FLAG go
high in logic AND option. Both the INT pin and these interrupt
status bits are automatically cleared when writing ‘0’ to those
flag bits. Table 11 shows interrupt control bits.
Logical OR
400
B1
INT_CTRL[B0]
1
1
B2
The Interrupt register consists of all status bits. The ISL29044
has an interrupt scheme designed for both ALS/IR sensing and
Proximity logic detection sensing. The register has one proximity
sensing flag bit, two proximity sensing persistent bits, one
ALS/IR sensing flag bit and two ALS/IR persistent bits. The
default register value is 0x00.
0
0
13
B7
Register Bits
800 (Default)
0
BIT 0
Reg.
Addr
(Hex)
B2
B1
NUMBER OF INTEGRATION CYCLES (n)
0
0
1
0
1
4
1
0
8
1
1
16
FN8305.2
April 28, 2016
ISL29044
PROX_TL Registers (Address: 0x03)
ALS_FLAG BIT [B3]
The ALS_FLAG[B3] bit is a status bit for light intensity detection.
The bit is set to logic HIGH when the light intensity results at (reg
0x09, 0x0A), crosses the interrupt threshold’s window (register
address 0x05 - 0x07), and is set to logic LOW when its within the
interrupt threshold’s window. Once the interrupt is triggered, the
ALS_FLAG bit goes HIGH. The ALS/IR_FLAG bit is cleared by
writing ‘0’ to [B3]. Table 13 shows interrupt flag states.
TABLE 13. INTERRUPT FLAG BIT
BIT 3
OPERATION
0
Interrupt is cleared or not triggered yet
1
Interrupt is triggered
PROXIMITY INTERRUPT PERSIST BITS [B6,B5]
The interrupt persist bits provide control over when interrupts
occur. There are four different selections for this feature. A value
of N (where N is 1, 4, 8, and 16) results in an interrupt only if the
value remains above the PROX_HT (reg0x04) threshold for N
consecutive integration. At that moment, the PROX_FLAG is high
and remains asserted until cleared by writing the '0' to
PROX_FLAG bit or if the value is below PROX_LT (reg0x03)
threshold for N consecutive integration, it will also clear the
PROX_FLAG.
For example, if N is equal to 8, then an interrupt is generated
whenever the last conversion results in a value above the
PROX_HT threshold, then PROX_FLAG = 1. There are two ways of
clearing the PROX_FLAG. You can write a 0h to Reg0x02 to
manually clear the flag, or if the conversion results are less than
the PROX_LT value, upon completion of the measurement, the
Reg0x02 will be set to 0h and thus, the PROX_FLAG will be
automatically cleared.
TABLE 14. PROXIMITY LOGIC PERSIST BITS
TABLE 16. PROX_TL REGISTER BITS
Reg.
Addr
Access (Hex) B7
NAME
PROX_TL
RW
Register Bits
B6
B5
B4
B3
B2
DFLT
B0 (Hex)
B1
0x03 TL7 TL6 TL5 TL4 TL3 TL2 TL1 TL0 0x00
The lower interrupt threshold registers are used to set the lower
trigger point for interrupt generation. If the Prox value crosses
below or is equal to the lower threshold, it will be clear the last
state of Interrupt. For example, if PROX_FLAG is high at the last
state, then the proximity value is below the PROX_LT threshold
and the PROX_FLAG will go low at this moment. The register
defaults to 0x00 on power-up.
PROX_TH Registers (Address: 0x04)
TABLE 17. PROX_TH REGISTER BITS
Reg.
Addr
Access (Hex) B7
NAME
PROX_TH
RW
Register Bits
B6
B5
B4
B3
B2
B1
DFLT
B0 (Hex)
0x04 TH7 TH6 TH5 TH4 TH3 TH2 TH1 TH0 0xFF
The upper proximity threshold registers are used to set the upper
trigger point for Logic HIGH (Near). If the Prox value crosses
above or is equal to the upper threshold, a Logic HIGH (Far) is
asserted on the interrupt flag. Registers PROX_HT(0x04) are set
to upper threshold. 0x04 register is defaulted to 0xFF on
power-up.
ALS_TH1 and ALS_TH2 Registers (Address:
0x05 & 0x06[B3,B2,B1,B0])
TABLE 18. INTERRUPT THRESHOLD LOW REGISTER BITS
B2
B1
NUMBER OF INTEGRATION CYCLES (n)
0
0
1
0
1
4
1
0
8
ALS_TH2_MSB
RW
0x06
1
1
16
ALS_TH1_LSB
RW
0x05 TL7 TL6 TL5 TL4 TL3 TL2 TL1 TL0 0x00
PROX_FLAG BIT [B7]
PROX_FLAG bit [B7] is a status bit for IR light intensity detection.
[B7] is set to logic HIGH when the IR light intensity reflected from
the object to the sensor(reg 0x08) crosses the PROX_HT(register
address 0x04), and if [B7] is set to logic LOW when the IR light
intensity goes lower than PROX_LT (register address 0x03) or to
clear by writing ‘0’ to PROX_FLAG. Table 15 shows the interrupt
flag states.
NAME
Register Bits
Reg.
DFLT
Addr
Access (Hex) B7 B6 B5 B4 B3 B2 B1 B0 (Hex)
TL3 TL2 TL1 TL0 0x00
The lower interrupt threshold registers are used to set the lower
trigger point for interrupt generation. If the ALS value crosses
below or is equal to the lower threshold, an interrupt is asserted
on the interrupt flag. An 8-bit RW Register ALS_TH1(0x05) and a
nibble ALS_TH2(0x06[B3,B2,B1,B0]) provides the low and high
bytes, respectively, of the lower interrupt threshold. The high and
low bytes from each set of registers are combined to form a
12-bit threshold value. The interrupt threshold registers default
to 0x00 on power-up.
TABLE 15. INTERRUPT FLAG BIT
BIT 3
OPERATION
0
Logic Low (Far)
1
Logic High (Near)
14
FN8305.2
April 28, 2016
ISL29044
ALS_TH2 and ALS_TH3 Registers (Address:
0x06[B7,B6,B5,B4] & 0X07)
by the range bit ALS_RANGE (register 0x1 bit 1) and is
independent of the light source type.
TABLE 22. ALS SENSITIVITY AT DIFFERENT RANGES
TABLE 19. INTERRUPT THRESHOLD HIGH REGISTER BITS
Reg.
Addr
Access (Hex) B7
NAME
Register Bits
B6
B5
B4
B3
B2
B1
DFLT
B0 (Hex)
ALS_TH2_LSB
RW
0x06 TH7 TH6 TH5 TH4
0xF0
ALS_TH3_MSB
RW
0x07 TH7 TH6 TH5 TH4 TH3 TH2 TH1 TH0 0xFF
The upper interrupt threshold registers are used to set the upper
trigger point for interrupt generation. If the ALS value crosses
above or is equal to the upper threshold, an interrupt is asserted
on the interrupt pin and the interrupt flag. A nibble RW Register
ALS_TH(0x06[B7,B6,B5,B4]) and an 8-bit RW ALS_TH3(0x07)
provides the low and high bytes, respectively, of the upper
interrupt threshold. The high and low bytes from each set of
registers are combined to form a 12-bit threshold value. The
interrupt threshold registers default to 0xFF on power-up.
Data Registers (Addresses: 0x08)
TABLE 20. ADC REGISTER BITS
Register Bits
NAME ACCESS
REG.
ADDR
(HEX)
DFLT
B7 B6 B5 B4 B3 B2 B1 B0 (Hex)
DATA
0x08
D7 D6 D5 D4 D3 D2 D1 D0 0x00
RO
The ISL29044 has 8-bit read-only registers to hold the ADC value.
The registers are refreshed after every conversion cycle. The
default register value is 0x00 at power on.
Data Registers (Addresses: 0x09 & 0x0A)
TABLE 21. ADC REGISTER BITS
NAME
Register Bits
Reg. Addr
DFLT
Access
(Hex)
B7 B6 B5 B4 B3 B2 B1 B0 (Hex)
DATALSB
RO
0x09
DATAMSB
RO
0x0A
D7 D6 D5 D4 D3
D2 D1 D0 0x00
D11 D10 D9 D8 0x00
The ISL29044 has one 8-bit read-only register to hold the lower,
and one nibble (4-bit read only) to hold the upper of the ADC
value. The nibble (4-bit read only) is accessed at address 0x0A
and the lower byte is accessed at address 0x09. For 12-bit
resolution, the data is from D0 to D11. The registers are
refreshed after every conversion cycle. The default register value
is 0x00 at power on.
RANGE
ALS_RANGE
(Lux/Count)
0
0.0326
1
0.522
Table 22 shows two different scale factors: one for the low range
(ALS_RANGE = 0) and the other for the high range
(ALS_RANGE = 1).
Noise Rejection
Charge balancing ADC’s have excellent noise-rejection
characteristics for periodic noise sources whose frequency is an
integer multiple of the conversion rate. For instance, a 60Hz AC
unwanted signal’s sum from 0ms to k*16.66ms (k = 1,2...ki) is
zero. Similarly, setting the device’s integration time to be an
integer multiple of the periodic noise signal greatly improves the
light sensor output signal in the presence of noise. Since wall
sockets may output at 60Hz or 50Hz, our integration time is
100ms: the lowest common integer number of cycles for both
frequencies.
Proximity Detection of Various Objects
Proximity sensing relies on the amount of IR reflected back from
objects. A perfectly black object would absorb all light and reflect
no photons. The ISL29044 is sensitive enough to detect black ESD
foam, which reflects only 1% of IR. For biological objects, blonde
hair reflects more than brown hair and customers may notice that
skin tissue is much more reflective than hair. IR penetrates into
the skin and is reflected or scattered back from within. As a result,
the proximity count peaks at contact and monotonically decreases
as skin moves away. The reflective characteristics of skin are very
different from that of paper.
Soldering Considerations
Convection heating is recommended for reflow soldering;
direct-infrared heating is not recommended. The plastic ODFN
package requires a custom reflow soldering profile pursuant to
Figure 4 in TB487 (Surface Mount Assembly Guidelines for
Optical Co-Package Sensor and LED).
Applications Information
Calculating Lux
The ISL29044’s ADC output codes are directly proportional to lux
when in ALS mode (see ALSIR_MODE bit).
(EQ. 2)
E calc =  RANGE  OUT ADC
In Equation 2, Ecalc is the calculated lux reading and OUT
represents the ADC code. The constant  to plug in is determined
15
FN8305.2
April 28, 2016
ISL29044
Suggested PCB Footprint
Typical Circuit
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. However, this
device requires a special solder reflow profile as mentioned in
Figure 4 in TB487 (Surface Mount Assembly Guidelines for
Optical Co-Package Sensor and LED).
A typical application for the ISL29044 is shown in Figure 22. The
ISL29044’s I2C address is internally hardwired as 0b1000100. The
device can be tied onto a system’s I2C bus together with other I2C
compliant devices.
Layout Considerations
The ISL29044 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. 0.1µF and 1µF power supply decoupling
capacitors need to be placed close to the device.
V_LED
V_PULLUP
I2C SLAVE 0
5
6
7
8
LED-
LED+
IRDR
GND
INT
SDA
SCL
VDD
4
R1
RES1
C3
0.1µF
2
1
C1
0.1µF
R3
RES1
I2C MASTER
3
SCL
SDA
VDD
I2C SLAVE 1
ISL29044
R2
RES1
C2
1µF
I2C SLAVE_n
SCL
SCL
SDA
SDA
I2C-DIAGRAM
INT
CONTROLLER
I2C-DIAGRAM
FIGURE 22. ISL29044 TYPICAL CIRCUIT
16
FN8305.2
April 28, 2016
ISL29044
5-LEDK
4-LEDA
1.3400
3-GND
6-LDR
VSS
IRDR GROUND
SCL
1.0962
DIE ID:
7-INT
2-SCL
INT
YYYYY
YYYYYYY VDD
POWER
0.4888
SDA
8-SDA
1-VDD
0.4068
FIGURE 23. OPTICAL SENSOR LOCATION
17
FN8305.2
April 28, 2016
ISL29044
Revision History
The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make sure you
have the latest Rev.
DATE
REVISION
CHANGE
April 28, 2016
FN8305.2
Added Related Literature section.
April 21, 2016
FN8305.1
Removed the Related Literature section.
October 30, 2012
FN8305.0
Initial release.
Products
Intersil Corporation is a leader in the design and manufacture of high-performance analog semiconductors. The Company's products
address some of the industry's fastest growing markets, such as, flat panel displays, cell phones, handheld products, and notebooks.
Intersil's product families address power management and analog signal processing functions. Go to www.intersil.com/products for a
complete list of Intersil product families.
To report errors or suggestions for this datasheet, please go to: www.intersil.com/askourstaff
Reliability reports are available from our website at: http://rel.intersil.com/reports/search.php
For additional products, see www.intersil.com/product_tree
Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted
in the quality certifications found at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time
without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be
accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
18
FN8305.2
April 28, 2016
ISL29044
Package Outline Drawing
L8.2.36x3.94
8 LEAD OPTICAL CO-PACKAGE
Rev 0, 3/12
R0.4
Lens
R0.49
Aperture
0.58
0.18 0.6 0.8
0.6
5-LEDK
3.94
R0.4
0.72
4-LEDA
0.16
1.3
3-GND
0.6
0.9
0.97
1-VDD
1.56
2.36
6-LDR
7-INT
2-SCL
0.75
0.63
0.19
1.35
0.25
0.63
0.16
8-SDA
PIN 1
0.8 INDEX
AREA
BOTTOM VIEW
0.18
1.03
0.8
5-LEDK
6-LDR
3-GND
0.25
4-LEDA
7-INT
2-SCL
0.97
1.82
0.72
0.16
8-SDA
1-VDD
1.43
0.16
TOP VIEW
TYPICAL RECOMMENDED LAND PATTERN
NOTES:
19
1.
Dimensions are in millimeters.
Dimensions in ( ) for Reference Only.
2.
Dimensioning and tolerancing conform to ASME Y14.5m-1994.
3.
Unless otherwise specified, tolerance: Decimal ± 0.05
4.
Pin #1 identifier is a laser-etched dot on bottom surface.
FN8305.2
April 28, 2016
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