1
Low Power Ambient Light and Proximity Sensor with
Intelligent Interrupt and Sleep Modes
ISL29029
The ISL29029 is an integrated ambient and infrared light-to-digital
converter with a built-in IR LED driver 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.
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.
For proximity sensor (PROX) data conversions, the built-in driver
turns on an external 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 540μs conversion
time.
The ISL29029 provides low power operation of ALS and PROX
sensing with a typical 138μA normal operation current (110μA for
sensors and internal circuitry, ~28μA for external LED) with 220mA
current pulses for a net 100μs, repeating every 800ms (or under).
The ISL29029 uses both a hardware pin and software bits to
indicate an interrupt event has occurred. An ALS or PROX
interrupt is defined as a measurement which is outside a set
window. 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.
The ISL29029 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 lead ODFN package.
Applications
• Display and Keypad Dimming Adjustment and Proximity Sensing
for:
- Mobile Devices: Smart Phone, PDA, GPS
- Computing Devices: Laptop PC, Netbook
- Consumer Devices: LCD-TV, Digital Picture Frame, Digital
Camera
• Industrial and Medical Light and Proximity Sensing
Features
• Works Under All Light Sources Including Sunlight
• Dual ADCs Measure ALS/Prox Concurrently
• Intelligent Interrupt Scheme Simplifies μC Code
•0.5% Typical Nonlinearity
Ambient Light Sensing
• Simple Output Code Directly Proportional to lux
• 50Hz/60Hz Flicker Noise and IR Rejection
• Light Sensor Close to Human Eye Response
• Selectable 125/2000 Lux Range
Proximity Sensing
• Proximity Sensor with Broad IR Spectrum
- Can Use 850nm and 950nm External IR LEDs
•IR LED Driver with I
2C Programmable Sink Currents
-Net 100μs Pulse with 110mA or 220mA Amplitudes
- Periodic Sleep Time up to 800ms Between Pulses
• Ambient IR Noise Cancellation (Including Sunlight)
Intelligent and Flexible Interrupts
• Independent ALS/PROX Interrupt Thresholds
• Adjustable Interrupt Persistency
- 1/4/8/16 Consecutive Triggers Required Before Interrupt
Ultra Low Power
•138μA DC Typical Supply Current for ALS/Prox Sensing
-110μA for Sensors and Internal Circuitry
-28μA Typical Current for External IR LED (Assuming 220mA
for 100μs Every 800ms)
•<1.0μA Supply Current When Powered Down
Easy to Use
• Set Registers; Wait for Interrupt
•I
2C (SMBus Compatible) Output
• Temperature Compensated
• Tiny ODFN8 2.0x2.1x0.7 (mm) Package
Additional Features
• 1.7V to 3.63V Supply for I2C Interface
• 2.25V to 3.63V Sensor Power Supply
• Pb-Free (RoHS compliant)
•I
2C Address Selection Pin
November 23, 2010
FN7682.0
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 |Copyright Intersil Americas Inc. 2010. 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.
ISL29029
2FN7682.0
November 23, 2010
Block Diagram
Pin Configuration
ISL29029
8 LD ODFN (2.0x2.1x0.7mm)
TOP VIEW
VDD
REXT GND
SCL
IR PHOTODIODE
LIGHT DATA
43
5
2
FOSC
IREF
IRDR
ARRAY
ALS PHOTODIODE
PROCESS
ALS AND IR
ARRAY
DUAL CHANNEL
ADCs
8
INT
7
COMMAND
REGISTER
DATA
REGISTER
I2C
IR DRIVER
INTERRUPT
SDA
6
ADDR0
1
1
2
3
8
7
6
ADDR0
VDD
GND
IRDR
INT
SDA
4 5
REXT SCL
THERMAL
PAD
*THERMAL PAD CAN BE CONNECTED TO GND OR
ELECTRICALLY ISOLATED
Pin Descriptions
PIN
NUMBER
PIN
NAME DESCRIPTION
0 T.PAD Thermal Pad (connect to GND or float)
1 ADDR0 I2C address pin - pull high or low (do not float)
2 VDD Positive supply: 2.25V to 3.63V
3GNDGround
4 REXT External resistor (499kΩ; 1%) connects this pin
to ground
5SCLI
2C clock
line
The I2C bus lines can be pulled
from 1.7V to above VDD, 3.63V
max
6SDAI
2C data line
7INT
Interrupt pin; Logic output (open-drain) for
interrupt
8 IRDR IR LED driver pin - current flows into ISL29029
from LED cathode
Ordering Information
PART NUMBER
(Notes 1, 2, 3)
TEMP. RANGE
(°C)
PACKAGE
Tape & Reel
(Pb-free)
PKG.
DWG. #
ISL29029IROZ-T7 -40 to +85 8 Ld ODFN L8.2.1x2.0
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 and NiPdAu plate -
e4 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
3. For Moisture Sensitivity Level (MSL), please see device information page for ISL29029. For more information on MSL please see techbrief TB363.
ISL29029
3FN7682.0
November 23, 2010
Absolute Maximum Ratings (TA = +25°C) Thermal Information
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
REXT Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.5V to VDD + 0.5V
IRDR Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.5V
ADDR0 Pin Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.5V to VDD + 0.5V
INT Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to 4.0V
INT Pin Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10mA
ESD Rating
Human Body Model (Note 6). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2kV
Thermal Resistance (Typical) θJA (°C/W) θJC (°C/W)
8 Ld ODFN Package (Notes 4, 5) . . . . . . . . 88 10
Maximum Die Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+90°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +100°C
Operating Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see link below
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. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See Tech
Brief TB379.
5. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside.
6. ESD on all pins is 2kV except for IRDR, which is 1.5kV.
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 VDD = 3.0V, TA = +25°C, REXT = 499kΩ 1% tolerance.
PARAMETER DESCRIPTION CONDITION MIN TYP MAX UNIT
VDD Power Supply Range 2.25 3.0 3.63 V
SR_VDD Input Power-up Slew Rate VDD Rising Edge between 0.4V and 2.25V 0.5 V/ms
IDD_OFF Supply Current when Powered Down ALS_EN = 0; PROX_EN = 0 0.1 0.8 µA
IDD_NORM Supply Current for ALS+Prox in Sleep Time ALS_EN = 1; PROX_EN = 1 110 125 µA
IDD_PRX_SLP Supply Current for Prox in Sleep Time ALS_EN = 0; PROX_EN = 1 80 µA
IDD_ALS Supply Current for ALS ALS_EN = 1; PROX_EN = 0 96 µA
fOSC Internal Oscillator Frequency 5.25 MHz
tINTGR_ALS 12-bit ALS Integration/Conversion Time 88 100 112 ms
tINTGR_PROX 8-bit Prox Integration/Conversion Time 0.54 ms
Linearity ALS_1 Nonlinearity EAMBIENT = 0, 53, 90 Lux; ALS_RANGE = 0 (Notes
7, 11)
-6 0.5 +6 %
DATAALS_0 ALS Result when Dark EAMBIENT = 0 lux, 2k Range 1 3 Counts
DATAALS_F Full Scale ALS ADC Code EAMBIENT > Selected Range Maximum Lux (Note
11)
4095 Counts
ΔDATA
DATA
Count Output Variation Over Three Light Sources:
Fluorescent, Incandescent and Sunlight
Ambient Light Sensing ±10 %
DATAALS_1 Light Count Output with LSB of 0.0326 Lux/Count E = 53 lux, Fluorescent (Note 8),
ALS_RANGE = 0
1638 Counts
DATAALS_2 Light Count Output With LSB of 0.522 Lux/Count E = 320 lux, Fluorescent (Notes 8, 11),
ALS_RANGE = 1
503 614 725 Counts
DATAPROX_0 Prox Measurement w/o Object in Path 12Counts
DATAPROX_F Full Scale Prox ADC Code 255 Counts
DATAPROX_1 Prox Measurement Result (Note 9) 34 46 58 Counts
trRise Time for IRDR Sink Current RLOAD = 15Ω at IRDR pin, 20% to 80% 500 ns
tfFall time for IRDR Sink Current RLOAD = 15Ω at IRDR pin, 80% to 20% 500 ns
ISL29029
4FN7682.0
November 23, 2010
IIRDR_0 IRDR Sink Current PROX_DR = 0; VIRDR = 0.5V 90 110 130 mA
IIRDR_1 IRDR Sink Current PROX_DR = 1; VIRDR = 0.5V 220 mA
IIRDR_LEAK IRDR Leakage Current PROX_EN = 0; VDD = 3.63V (Note 10) 0.001 1 µA
VIRDR Acceptable Voltage Range on IRDR Pin Register bit PROX_DR = 0 0.5 4.3 V
tPULSE Net IIRDR On Time Per PROX Reading 100 µs
VREF Voltage of REXT Pin 0.51 V
FI2C I2C Clock Rate Range 400 kHz
VI2C Supply Voltage Range for I2C Interface 1.7 3.63 V
VIL SCL and SDA Input Low Voltage 0.55 V
VIH SCL and SDA Input High Voltage 1.25 V
ISDA SDA Current Sinking Capability VOL = 0.4V 3 5 mA
IINT INT Current Sinking Capability VOL = 0.4V 3 5 mA
PSRRIRDR (ΔIIRDR)/(ΔVIRDR) PROX_DR = 0; VIRDR = 0.5V to 4.3V 4 mA/V
NOTES:
7. Nonlinearity is defined as: [(Measured Counts at 53 lux)-(Expected Counts at 53 lux)]/4095. Expected counts are calculated using an endpoint linear-
fit trendline from measurements at 0 lux and 90 lux.
8. 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.
9. An 850nm infrared LED is used to test PROX/IR sensitivity in an internal test mode.
10. Ability to guarantee IIRDR leakage of ~1nA is limited by test hardware.
11. For ALS applications under light-distorting glass, please see the section titled ALS Range 1 Considerations.
Electrical Specifications VDD = 3.0V, TA = +25°C, REXT = 499kΩ 1% tolerance. (Continued)
PARAMETER DESCRIPTION CONDITION MIN TYP MAX UNIT
I2C Electrical Specifications For SCL and SDA unless otherwise noted, VDD = 3V, TA = +25°C, REXT = 499kΩ 1% tolerance
(Note 12).
PARAMETER DESCRIPTION CONDITION MIN TYP MAX UNIT
VI2C Supply Voltage Range for I2C Interface 1.7 3.63 V
fSCL SCL Clock Frequency 400 kHz
VIL SCL and SDA Input Low Voltage 0.55 V
VIH SCL and SDA Input High Voltage 1.25 V
Vhys Hysteresis of Schmitt Trigger Input 0.05VDD V
VOL Low-level output voltage (open-drain) at 4mA sink
current
0.4 V
IiInput Leakage for each SDA, SCL pin -10 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
CiCapacitance for each SDA and SCL pin 10 pF
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
tSU:STA Set-up Time for a Repeated START Condition 600 ns
tHD:DAT Data Hold Time 30 ns
ISL29029
5FN7682.0
November 23, 2010
tSU:DAT Data Set-up Time 100 ns
tRRise Time of both SDA and SCL Signals (Note 13) 20 + 0.1xCbns
tFFall Time of both SDA and SCL Signals (Note 13) 20 + 0.1xCbns
tSU:STO Set-up Time for STOP Condition 600 ns
tBUF Bus Free Time Between a STOP and START
Condition
1300 ns
CbCapacitive Load for Each Bus Line 400 pF
Rpull-up SDA and SCL system bus pull-up resistor Maximum is determined by tR and tF1kΩ
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:
12. All parameters in I2C Electrical Specifications table are guaranteed by design and simulation.
13. Cb is the capacitance of the bus in pF.
I2C Electrical Specifications For SCL and SDA unless otherwise noted, VDD = 3V, TA = +25°C, REXT = 499kΩ 1% tolerance
(Note 12). (Continued)
PARAMETER DESCRIPTION CONDITION MIN TYP MAX UNIT
FIGURE 1. I2C TIMING DIAGRAM
ISL29029
6FN7682.0
November 23, 2010
Register Map
There are ten 8-bit registers accessible via I2C. Registers 0x1 and 0x2 define the operation mode of the device. Registers 0x3 through 0x7
store the various ALS/IR/Prox thresholds which trigger interrupt events. Registers 0x8 through 0xA store the results of ALS/IR/Prox ADC
conversions.
Register Descriptions
TABLE 1. ISL29029 REGISTERS AND REGISTER BITS
ADDR REG NAME
BIT
7654321 0DEFAULT
0x00 (n/a) (Reserved) (n/a)
0x01 CONFIGURE PROX EN PROX_SLP[2:0] PROX_DR ALS_EN ALS_RANGE ALSIR_MODE 0x00
0x02 INTERRUPT PROX_FLAG PROX_PRST[1:0] (Write 0) ALS_FLAG ALS_PRST[1:0] INT_CTRL 0x00
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 ALSIR_HT[3:0] ALSIR_LT[11:8] 0xF0
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 (Unused) ALSIR_DATA[11:8] 0x00
0x0E TEST1 (Write as 0x00) 0x00
0x0F TEST2 (Write as 0x00) 0x00
TABLE 2. REGISTER 0x00 (RESERVED)
BIT # ACCESS DEFAULT NAME FUNCTION/OPERATION
7:0 RO (n/a) (n/a) Reserved - no need to read or write
TABLE 3. REGISTER 0x01 (CONFIGURE) - PROX/ALS CONFIGURATION
BIT # ACCESS DEFAULT NAME FUNCTION/OPERATION
7RW0x00 PROX_EN
(Prox Enable)
When = 0, proximity sensing is disabled
When = 1, continuous proximity sensing is enabled. Prox data will be ready 0.54ms after this
bit is set high
6:4 RW 0x00 PROX_SLP
(Prox Sleep)
For bits 6:4 = (see the following)
111; sleep time between prox IR LED pulses is 0.0ms (run continuously)
110; sleep time between prox IR LED pulses is 12.5ms
101; sleep time between prox IR LED pulses is 50ms
100; sleep time between prox IR LED pulses is 75ms
011; sleep time between prox IR LED pulses is 100ms
010; sleep time between prox IR LED pulses is 200ms
001; sleep time between prox IR LED pulses is 400ms
000; sleep time between prox IR LED pulses is 800ms
3RW0x00 PROX_DR
(Prox Drive)
When = 0, IRDR behaves as a pulsed 110mA current sink
When = 1, IRDR behaves as a pulsed 220mA current sink
2RW0x00 ALS_EN
(ALS Enable)
When = 0, ALS/IR sensing is disabled
When = 1, continuous ALS/IR sensing is enabled with new data ready every 100ms
1RW0x00
ALS_RANGE
(ALS Range)
When = 0, ALS is in low-lux range
When = 1, ALS is in high-lux range
0RW0x00
ALSIR_MODE
(ALSIR Mode)
When = 0, ALS/IR data register contains visible ALS sensing data
When = 1, ALS/IR data register contains IR spectrum sensing data
ISL29029
7FN7682.0
November 23, 2010
TABLE 4. REGISTER 0x02 (INTERRUPT) - PROX/ALS INTERRUPT CONTROL
BIT # ACCESS DEFAULT BIT NAME FUNCTION/OPERATION
7FLAG0x00
PROX_FLAG
(Prox Flag)
When = 0, no Prox interrupt event has occurred since power-on or last “clear”
When = 1, a Prox interrupt event occurred. Clearable by writing “0”
Writing “1” leaves previous state unchanged
6:5 RW 0x00 PROX_PRST
(Prox Persist)
For bits 6:5 = (see the following)
00; set PROX_FLAG if 1 conversion result trips the threshold value
01; set PROX_FLAG if 4 conversion results trip the threshold value
10; set PROX_FLAG if 8 conversion results trip the threshold value
11; set PROX_FLAG if 16 conversion results trip the threshold value
4RW0x00 Unused
(Write 0)
Unused register bit - write 0
3FLAG0x00 ALS_FLAG
(ALS FLAG)
When = 0, no ALS interrupt event has occurred since power-on or last “clear”
When = 1, an ALS interrupt event occurred. Clearable by writing “0”
Writing “1” leaves previous state unchanged
2:1 RW 0x00 ALS_PRST
(ALS Persist)
For bits 2:1 = (see the following)
00; set ALS_FLAG if 1 conversion is outside the set window
01; set ALS_FLAG if 4 conversions are outside the set window
10; set ALS_FLAG if 8 conversions are outside the set window
11; set ALS_FLAG if 16 conversions are outside the set window
0RW0x00INT_CTRL
(Interrupt Control)
When = 0, set INT pin low if PROX_FLAG or ALS_FLAG high (logical OR)
When = 1, set INT pin low if PROX_FLAG and ALS_FLAG high (logical AND)
TABLE 5. REGISTER 0x03 (PROX_LT) - INTERRUPT LOW THRESHOLD FOR PROXIMITY SENSOR
BIT # ACCESS DEFAULT BIT NAME FUNCTION/OPERATION
7:0 RW 0x00 PROX_LT
(Prox Threshold)
8-bit interrupt low threshold for
proximity sensing
TABLE 6. REGISTER 0x04 (PROX_HT) - INTERRUPT HIGH THRESHOLD FOR PROXIMITY SENSOR
BIT # ACCESS DEFAULT BIT NAME FUNCTION/OPERATION
7:0 RW 0xFF PROX_HT
(Prox Threshold) 8-bit interrupt high threshold for proximity sensing
TABLE 7. REGISTER 0x05 (ALSIR_TH1) - INTERRUPT LOW THRESHOLD FOR ALS/IR
BIT # ACCESS DEFAULT BIT NAME FUNCTION/OPERATION
7:0 RW 0x00 ALSIR_LT[7:0]
(ALS/IR Low Thr.) Lower 8 bits (of 12 bits) for ALS/IR low interrupt threshold
TABLE 8. REGISTER 0x06 (ALSIR_TH2) - INTERRUPT LOW/HIGH THRESHOLDS FOR ALS/IR
BIT # ACCESS DEFAULT BIT NAME FUNCTION/OPERATION
7:4 RW 0x0F ALSIR_HT[3:0]
(ALS/IR High Thr.) Lower 4 bits (of 12 bits) for ALS/IR high interrupt threshold
3:0 RW 0x00 ALSIR_LT[11:8]
(ALS/IR Low Thr.) Upper 4 bits (of 12 bits) for ALS/IR low interrupt threshold
TABLE 9. REGISTER 0x07 (ALSIR_TH3) - INTERRUPT HIGH THRESHOLD FOR ALS/IR
BIT # ACCESS DEFAULT BIT NAME FUNCTION/OPERATION
7:0 RW 0xFF ALSIR_HT[11:4]
(ALS/IR High Thr.) Upper 8 bits (of 12 bits) for ALS/IR high interrupt threshold
ISL29029
8FN7682.0
November 23, 2010
Principles of Operation
I2C Interface
The ISL29029’s I2C interface slave address is internally hardwired
as 0b100010<x>, where “0b” signifies binary notation and x
represents the logic level on pin ADDR0.
Figure 2 shows a sample one-byte read. The I2C bus master
always drives the SCL (clock) line, while either the master or the
slave can drive the SDA (data) line. Every I2C transaction begins
with the master asserting a start condition (SDA falling while SCL
remains high). The first transmitted byte is initiated by the
master and includes 7 address bits and a R/W bit. The slave is
responsible for pulling SDA low during the ACK bit after every
transmitted byte.
Each I2C transaction ends with the master asserting a stop
condition (SDA rising while SCL remains high).
For more information about the I2C standard, please consult the
Philips™ I2C specification documents.
Photodiodes and ADCs
The ISL29029 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 6). 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.
TABLE 10. REGISTER 0x08 (PROX_DATA) - PROXIMITY SENSOR DATA
BIT # ACCESS DEFAULT BIT NAME FUNCTION/OPERATION
7:0 RO 0x00 PROX_DATA
(Proximity Data) Results of 8-bit proximity sensor ADC conversion
TABLE 11. REGISTER 0x09 (ALSIR_DT1) - ALS/IR SENSOR DATA (LOWER 8 BITS)
BIT # ACCESS DEFAULT BIT NAME FUNCTION/OPERATION
7:0 RO 0x00 ALSIR_DATA
(ALS/IR Data) Lower 8 bits (of 12 bits) from result of ALS/IR sensor conversion
TABLE 12. REGISTER 0x0A (ALSIR_DT2) - ALS/IR SENSOR DATA (UPPER 4 BITS)
BIT # ACCESS DEFAULT BIT NAME FUNCTION/OPERATION
7:4 RO 0x00 (Unused) Unused bits
3:0 RO 0x00 ALSIR_DATA
(ALS/IR Data) Upper 4 bits (of 12 bits) from result of ALS/IR sensor conversion
TABLE 13. REGISTER 0x0E (TEST1) - TEST MODE
BIT # ACCESS DEFAULT BIT NAME FUNCTION/OPERATION
7:0 RW 0x00 (Write as 0x00) Test mode register. When 0x00, in normal operation
TABLE 14. REGISTER 0x0F (TEST2) - TEST MODE 2
BIT # ACCESS DEFAULT BIT NAME FUNCTION/OPERATION
7:0 RW 0x00 (Write as 0x00) Test mode register. When 0x00, in normal operation
FIGURE 2. I2C DRIVER TIMING DIAGRAM FOR MASTER AND SLAVE CONNECTED TO COMMON BUS
START WA A
A6 A5 A4 A3 A2 A1 A0 W A R7 R6 R5 R4 R3 R2 R1 R0 A A6 A5 A4 A3 A2 A1 A0 W A
A A A D7 D6D5D4 D3D2 D1D0
1357 1357 123456 9246
STOP START
SDA DRIVEN BY MASTER
DEVICE ADDRESS
SDA DRIVEN BY ISL29029
DATA BYTE0REGISTER ADDRESS
SLAVE
DEVICE ADDRESS
I2C DATA
SDA DRIVEN BY MASTER
SDA DRIVEN BY MASTER
2468
924689 78135789
I2C SDA
I2C SDA
I2C CLK
MASTER
(ISL29029)
ISL29029
9FN7682.0
November 23, 2010
The proximity sensor is an 8-bit ADC which operates in a similar
fashion. When proximity sensing is enabled, the IRDR pin will
drive a user-supplied infrared LED, the emitted IR reflects off an
object (i.e., a human head) back into the ISL29029, 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 ISL29029 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 3).
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]).
Changes from ISL29028
The ISL29029 is identical to the ISL29028 with a few small
changes: the x29 photodiode structure has been improved for better
ALS linearity in high-IR conditions, and the x29’s PROX interrupt
scheme behaves as an out-of-window comparator (compared to the
x28’s PROX level-comparator with hysteresis). If the internal
registers are of concern to the customer, please contact Intersil for a
list of changes (internal register changes are independent of part
performance).
Ambient Light and IR Sensing
The ISL29029 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 6. ALS measuring mode (as
opposed to IR measuring mode) is set by default.
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.
Proximity Sensing
When proximity sensing is enabled (PROX_EN = 1), the external
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 4.
When the IR from the LED reaches an object and gets reflected
back into the ISL29029, the reflected IR light is converted into
current as per the IR spectral response shown in Figure 7. 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.
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 4) and the average IRDR
ALS
ACTIVE
100ms 100ms 100ms
PROX
SENSOR
ACTIVE
IRDR
(CURRENT
DRIVER)
ALS CONVERSION TIME =
100ms (FIXED)
0.54ms FOR PROX
CONVERSION
SERIES OF
CURRENT PULSES
TOTALING 0.1ms
SLEEP TIME
(PROX_SLP)
100ms 100ms
SEVERAL µs BETWEEN
CONVERSIONS
TIME
TIME
TIME
FIGURE 3. TIMING DIAGRAM FOR PROX/ALS EVENTS - NOT TO SCALE
FIGURE 4. CURRENT DRIVE MODE OPTIONS
PIN 8 - IRDR
220mA
(PROX_DR = 1)
(IRDR IS HI-Z WHEN
NOT DRIVING)
110mA
(PROX_DR = 0)
IlRDR AVE;
IlRDR PEAK;100μs×
TSLEEP
-----------------------------------------------------
=(EQ. 1)
ISL29029
10 FN7682.0
November 23, 2010
current can be calculated using Equation 1. IDD depends on
voltage and the mode-of-operation as seen in Figure 11.
Interrupt Function
The ISL29029 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 (ALSTH1, ALSTH2, ALSTH3). The user writes high and low threshold
values to these registers and the ISL29029 will issue an ALS interrupt
flag if the measured ALS data from registers 0x9 and 0xA are outside
the user’s programmed threshold window X-times-in-a-row (X is set by
user; see “persistency” option below). The user must write 0 to clear
the ALS_FLAG.
A PROX interrupt event (PROX_FLAG) is governed by the high and
low thresholds in registers 3 and 4 (PROX_LT and PROX_HT). The
user writes high and low threshold values to these registers and the
ISL29029 will issue a PROX interrupt flag if the measured PROX data
from register 0x8 is outside the user’s programmed threshold window
X-times-in-a-row (X is set by user; see “persistency” option below). The
user must write 0 to clear the PROX_FLAG.
Writing “1” to either ALS_FLAG or PROX_FLAG bits does not
change the previous logic state of the bit.
Interrupt persistency is another useful option available for both
ALS and proximity measurements. Persistency requires X-in-a-
row 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
remeasure 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, see the separate ALS
Range 1 Considerations document.
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 ISL29029 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.
Calculating Lux
The ISL29029’s ADC output codes are directly proportional to lux
when in ALS mode (see ALSIR_MODE bit).
In Equation 2, Ecalc is the calculated lux reading and OUT
represents the ADC code. The constant α to plug in is determined
by the range bit ALS_RANGE (register 0x1 bit 1) and is
independent of the light source type.
Table 15 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 ISL29029 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.
Typical Circuit
A typical application for the ISL29029 is shown in Figure 5. The
ISL29029’s I2C address is internally hardwired as 0b100010<x>,
with x representing the logic state of input I2C address pin
ADDR0. The device can be tied onto a system’s I2C bus together
with other I2C compliant devices.
TABLE 15. ALS SENSITIVITY AT DIFFERENT RANGES
ALS_RANGE
αRANGE
(Lux/Count)
0 0.0326
1 0.522
Ecalc αRANGE OUTADC
×=(EQ. 2)
ISL29029
11 FN7682.0
November 23, 2010
Soldering Considerations
Convection heating is recommended for reflow soldering; direct-
infrared heating is not recommended. The plastic ODFN package
does not require a custom reflow soldering profile, and is qualified to
+260°C. A standard reflow soldering profile with a +260°C
maximum is recommended.
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 ISL29029 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.
ADDR0
1
GND
3
REXT
4
SDA
INT 7
IRDR 8
ISL29029
R1
10kΩ
R2
10kΩ
REXT
499kΩ
VDD
MICROCONTROLLER
INT
SDA
SLAVE_0 SLAVE_1 I2C SLAVE_n
I2C MASTER
SCL
SDA
SCL
SDA
VI2C_PULL-UP
6
R3
10kΩ
SCL
2VDD
5
C2
0.1µF
FIGURE 5. ISL29029 TYPICAL CIRCUIT
SCL
C1
1µF
VIR-LED
ISL29029
12 FN7682.0
November 23, 2010
Typical Performance Curves VDD = 3.0V, REXT = 499kΩ
FIGURE 6. SPECTRUM OF FOUR LIGHT SOURCES NORMALIZED
BY LUMINOUS INTENSITY (LUX)
FIGURE 7. ISL29029 SENSITIVITY TO DIFFERENT WAVELENGTHS
FIGURE 8. ANGULAR SENSITIVITY FIGURE 9. ALS LINEARITY OVER 3 LIGHT SOURCES (2000 LUX
RANGE)
FIGURE 10. PROX COUNTS vs DISTANCE WITH 10CM x 10CM
REFLECTOR (USING ISL29028 EVALUATION BOARD)
FIGURE 11. VDD vs IDD FOR VARIOUS MODES OF OPERATION
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
350 550 750 950
WAVELENGTH (nm)
NORMALIZED INTENSITY
FLUORESCENT
SUN
INCAND.
HALOGEN
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
300 400 500 600 700 800 900 1000 1100
WAVELENGTH (nm)
NORMALIZED RESPONSE
ALS
HUMAN EYE
IR/PROX
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
-90 -60 -30 0 30 60 90
ANGULAR OFFSET (°)
NORMALIZED SENSITIVITY
0
500
1000
1500
2000
2500
0 1000 2000 3000 4000 5000
ALS CODE (12-BIT)
HALOGEN
FLUORESCENT
INCANDESCENT
LUX METER READING (LX)
0
50
100
150
200
250
300
0 20 40 60 80 100 120 140 160 180 200
DISTANCE (mm)
PROX COUNTS (8-BIT)
WHITE COPY PAPER
220mA MODE
18% GREY CARD
110mA MODE
40
80
100
120
140
160
2.25 2.40 2.55 2.85 3.00 3.15 3.45
INPUT VDD (V)
MEASURED IDD (µA)
3.603.302.70
60
ALS+PROX (DURING PROX SLEEP)
ALS-ONLY
PROX (DURING PROX SLEEP)
ISL29029
13 FN7682.0
November 23, 2010
FIGURE 12. IRDR PULSE AMPLITUDE vs VIRDR FIGURE 13. STABILITY OF ALS COUNT OVER TEMP (AT 300 LUX)
FIGURE 14. STABILITY OF ALS COUNT OVER-TEMPERATURE (AT 0.00 LUX)
Typical Performance Curves VDD = 3.0V, REXT = 499kΩ (Continued)
100
120
140
160
180
200
220
240
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
220mA-MODE (PROX_DR = 1)
110mA-MODE (PROX_DR = 0)
VIRDR (V)
IIRDR (mA)
-50
-40
-30
-20
-10
0
10
20
30
40
50
-40 -15 10 35 60 85
ALS COUNT CHANGE FROM
+25°C MEASUREMENT (%)
TEMPERATURE (°C)
0
1
2
3
4
5
6
7
8
9
-40 10 60
TEMPERATURE (°C)
ALS CODE (12-BIT)
10
ISL29029
14 FN7682.0
November 23, 2010
FIGURE 15. 8 LD ODFN SENSOR LOCATION OUTLINE - DIMENSIONS IN mm
2.00
SENSOR OFFSET
0.43
0.50
2.10
1
2
3
4
8
7
6
5
0.42
ISL29029
15
Intersil products are manufactured, assembled and tested utilizing ISO9000 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
FN7682.0
November 23, 2010
For additional products, see www.intersil.com/product_tree
Products
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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
11/23/10 FN7682.0 Initial Release.
ISL29029
16 FN7682.0
November 23, 2010
Package Outline Drawing
L8.2.1x2.0
8 LEAD OPTICAL DUAL FLAT NO-LEAD PLASTIC PACKAGE (ODFN)
Rev 1, 12/09
located within the zone indicated. The pin #1 identifier may be
Unless otherwise specified, tolerance : Decimal ± 0.05
Tiebar shown (if present) is a non-functional feature.
The configuration of the pin #1 identifier is optional, but must be
between 0.25mm and 0.35mm from the terminal tip.
Dimension b applies to the metallized terminal and is measured
Dimensions in ( ) for Reference Only.
Dimensioning and tolerancing conform to ASME Y14.5m-1994.
6.
either a mold or mark feature.
3.
5.
4.
2.
Dimensions are in millimeters.1.
NOTES:
DETAIL "X"
SIDE VIEW
TYPICAL RECOMMENDED LAND PATTERN
TOP VIEW
(2X) 0.10
INDEX AREA
PIN 1
A
B
8X 0 . 35 ± 0 . 05
B0.10 AC
C
SEATING PLANE
BASE PLANE
0.08
0.10
SEE DETAIL "X"
C
C
6
0.20±0.05
1.50
0.50
0.75
1.50
M
0 . 00 MIN.
0 . 05 MAX.
0 . 2 REF
C5
0.70±0.05
2.10
2.00
(6x0.50)
(8x0.20)
(8x0.55)
(0.75)
(1.50)
2.10
2.50
(8x0.20)
INDEX AREA
PIN 1
6
BOTTOM VIEW
