1
Ultra-Low Lux, Low Power, Integrated Digital Ambient
Light Sensor with Interrupt Function
ISL29033
The ISL29033 is an integrated ambient and infrared light to
digital converter with I2C (SMBus Compatible) interface. Its
advanced, self-calibrated photodiode array emulates human
eye response with excellent IR rejection. The on-chip 16-bit
ADC is capable of rejecting 50Hz and 60Hz flicker caused by
artificial light sources. The lux range select feature allows
users to program the lux range for optimized counts/lux.
Power consumption can be reduced to less than 0.3µA when
powered down.
The ISL29033 supports a software and hardware interrupt that
remains asserted until the host clears it through the I2C
interface. The function of ADC conversion continues without
stopping after interrupt is asserted.
Designed to operate on supplies from 2.25V to 3.63V with an
I2C supply from 1.7V to 3.63V, the ISL29033 is specified for
operation over the -40°C to +85°C ambient temperature
range.
Related Literature
•See AN1422 “Light Sensor Applications”
Features
• Ambient Light Sensing
• Simple Output Code Directly Proportional to Lux
• Variable Conversion Resolution Up to 16 Bits
• Adjustable Sensitivity Up to 520 Counts Per Lux
• Measurement Range: 0.0019 to 8,000Lux with Four
Selectable Ranges
• Program Interrupt Feature
• Light Sensor Close to Human Eye Response
- Excellent Light Sensor IR and UV Rejection
•75μA Max Operating Current
-0.3μA Max Shutdown Current
• 6 Ld 2.0mmx2.1mmx0.7mm ODFN Package
Applications
• Display and Keypad Dimming Adjustment for:
- Mobile Devices: Smart Phone, PDA, GPS
- Computing Devices: Notebook PC, Webpad
- Consumer Devices: LCD-TV, Digital Picture Frame, Digital
Camera
• Industrial and Medical Light Sensing
VDD
REXT GND
SDA
SCL
COMMAND
REGISTER
INTEGRATION
ADC DATA
REGISTER
PHOTODIODE
LIGHT
3 2
5
6
1
fOSC
IREF
4
INT
PROCESS
ARRAY
DATA
I2C/SMBus
INTERRUPT
REGISTER
FIGURE 1. BLOCK DIAGRAM
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. 2011. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. I2C Bus is a registered trademark
owned by NXP Semiconductors Netherlands, B.V. All other trademarks mentioned are the property of their respective owners.
September 30, 2011
FN7656.1
ISL29033
2FN7656.1
September 30, 2011
Pin Configuration
ISL29033
(6 LD ODFN)
TOP VIEW
1
2
3
6
5
4
VDD
GND
REXT
SDA
SCL
INT
*EXPOSED PAD CAN BE CONNECTED TO GND OR
ELECTRICALLY ISOLATED
PD*
Pin Descriptions
PIN
NUMBER PIN NAME DESCRIPTION
PD PD Thermal Pad (connect to GND, or float)
1 VDD Positive supply: 2.25V to 3.63V
2GNDGround
3 REXT External resistor pin for ADC reference; connect
this pin to ground through a (nominal) 499kΩ
resistor.
4 INT Interrupt pin; low for interrupt alarming. INT pin
is open drain. INT remains asserted until the
interrupt flag status bit is reset.
5SCLI
2C serial clock
6SDAI
2C serial data
Ordering Information
PART NUMBER
(Notes 1, 2, 3, 4)
TEMP. RANGE
(°C)
PACKAGE
TAPE AND REEL
(Pb-free)
PKG.
DWG. #
ISL29033IROZ-T7 -40 to +85 6 Ld ODFN L6.2x2.1
ISL29033IROZ-EVALZ 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 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 ISL29033. For more information on MSL please see Tech Brief TB477.
4. The part marking is located on the bottom of the part.
ISL29033
3FN7656.1
September 30, 2011
Absolute Maximum Ratings (TA = +25°C) Thermal Information
VDD Supply Voltage between VDD and GND . . . . . . . . . . . . . . . . . . . . . .4.0V
I2C Bus Pin Voltage (SCL, SDA). . . . . . . . . . . . . . . . . . . . . . . . . -0.2V to 4.0V
I2C Bus Pin Current (SCL, SDA). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10mA
REXT Pin Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.2V to VDD + 0.5V
INT Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to VDD + 0.5V
INT Pin Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10mA
ESD Rating
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2kV
Thermal Resistance (Typical) θJA (°C/W)
6 Ld ODFN (Note 5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
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
Recommended Operating Conditions
Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.25V to 3.63V
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.
NOTE:
5. 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 TB477.
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, 16-bit ADC operation, unless otherwise
specified.
PARAMETER DESCRIPTION CONDITION
MIN
(Note 6) TYP
MAX
(Note 6) UNIT
VDD Power Supply Range 2.25 3.63 V
IDD Supply Current 65 75 µA
IDD1 Supply Current when Powered Down Software disabled or auto power-down 0.01 0.3 µA
VI2C Supply Voltage Range for I2C Interface 1.7 3.63 V
fOSC Internal Oscillator Frequency 600 670 740 kHz
tINT ADC Integration/Conversion Time 16-bit ADC data 100 ms
FI2C I2C Clock Rate Range 1 to
400
kHz
DATA_0 Count Output when Dark E = 0 lux, Range 1 (125 lux) 1 5 Counts
DATA_F Full Scale ADC Code 65535 Counts
ΔDATA
DATA
Count Output Variation Over Three Light
Sources: Fluorescent, Incandescent and
Sunlight
Ambient Light Sensing ±10 %
DATA_1 Light Count Output with LSB of
0.0019 lux/count
E = 37.5 lux, Fluorescent light (Note 7),
Ambient light sensing, Range 1 (125 lux)
16000 20000 24000 Counts
DATA_2 Light Count Output with LSB of
0.0075 lux/count
E = 37.5 lux, Fluorescent light (Note 7),
Ambient light sensing, Range 2 (500 lux)
5000 Counts
DATA_3 Light Count Output with LSB of 0.03 lux/count E = 37.5 lux, Fluorescent light (Note 7),
Ambient light sensing, Range 3 (2k lux)
1250 Counts
DATA_4 Light Count Output with LSB of 0.12 lux/count E = 37.5 lux, Fluorescent light (Note 7),
Ambient light sensing, Range 4 (8k lux)
312 Counts
DATA_IR1 Infrared Count Output E = 20 lux Solar light (Note 8),
Ambient light sensing, Range 1 (125 lux)
16000 20000 24000 Counts
DATA_IR2 Infrared Count Output E = 20 lux Solar light (Note 8),
Ambient light sensing, Range 2 (500 lux)
5000 Counts
ISL29033
4FN7656.1
September 30, 2011
DATA_IR3 Infrared Count Output E = 20 lux Solar light (Note 8),
Ambient light sensing, Range 3 (2000 lux)
1250 Counts
DATA_IR4 Infrared Count Output E = 20 lux Solar light (Note 8),
Ambient light sensing, Range 4 (8000 lux)
312 Counts
VREF Voltage of REXT Pin 0.52 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 4 5 mA
IINT INT Current Sinking Capability VOL = 0.4V 4 5 mA
Electrical Specifications VDD = 3.0V, TA = +25°C, REXT = 499kΩ 1% tolerance, 16-bit ADC operation, unless otherwise
specified. (Continued)
PARAMETER DESCRIPTION CONDITION
MIN
(Note 6) TYP
MAX
(Note 6) UNIT
Electrical Specifications VDD = 3.0V, TA = +25°C, REXT = 1MΩ 1% tolerance, 16-bit ADC operation,
unless otherwise specified.
PARAMETER DESCRIPTION CONDITION
MIN
(Note 6) TYP
MAX
(Note 6) UNIT
VDD Power Supply Range 2.25 3.63 V
IDD Supply Current 42 50 µA
IDD1 Supply Current when Powered Down Software disabled or auto power-down 0.01 0.3 µA
VI2C Supply Voltage Range for I2C Interface 1.7 3.63 V
fOSC Internal Oscillator Frequency 305 340 385 kHz
tINT ADC Integration/Conversion Time 16-bit ADC data 200 ms
FI2C I2C Clock Rate Range 1 to
400
kHz
DATA_0 Count Output when Dark E = 0 lux, Range 1 (125 lux) 1 10 Counts
DATA_F Full Scale ADC Code 65535 Counts
ΔDATA
DATA
Count Output Variation Over Three Light
Sources: Fluorescent, Incandescent and
Sunlight
Ambient Light Sensing ±10 %
DATA_1 Light Count Output with LSB
of 0.00095 lux/count
E = 18.75 lux, Fluorescent light (Note 7),
Ambient light sensing, Range 1 (62.5 lux)
15000 20000 25000 Counts
DATA_2 Light Count Output with LSB
of 0.000375 lux/count
E = 18.75 lux, Fluorescent light (Note 7),
Ambient light sensing, Range 2 (250 lux)
5000 Counts
DATA_3 Light Count Output with LSB
of 0.015 lux/count
E = 18.75 lux, Fluorescent light (Note 7),
Ambient light sensing, Range 3 (1k lux)
1250 Counts
DATA_4 Light Count Output with LSB
of 0.6 lux/count
E = 18.75 lux, Fluorescent light (Note 7),
Ambient light sensing, Range 4 (4k lux)
312 Counts
DATA_IR1 Infrared Count Output E = 10 lux Solar light (Note 8),
Ambient light sensing, Range 1 (62.5 lux)
15000 20000 25000 Counts
DATA_IR2 Infrared Count Output E = 10 lux Solar light (Note 8),
Ambient light sensing, Range 2 (250 lux)
5000 Counts
DATA_IR3 Infrared Count Output E = 10 lux Solar light (Note 8),
Ambient light sensing, Range 3 (1000 lux)
1250 Counts
DATA_IR4 Infrared Count Output E = 10 lux Solar light (Note 8),
Ambient light sensing, Range 4 (4000 lux)
312 Counts
VREF Voltage of REXT Pin 0.52 V
ISL29033
5FN7656.1
September 30, 2011
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 4 5 mA
IINT INT Current Sinking Capability VOL = 0.4V 4 5 mA
NOTES:
6. Compliance to datasheet limits is assured by one or more methods: production test, characterization and/or design.
7. A 550nm green LED is used in production test. The 550nm LED irradiance is calibrated to produce the same DATA count as a fluorescent light with
illuminance at the stated lux.
8. An 850nm IR LED is used in production test. The 850nm LED irradiance is calibrated to produce the same DATA_IR count as solar light with
illuminance at the stated lux.
I2C Electrical Specifications For SCL and SDA (Figure 2), unless otherwise noted, VDD = 3V, TA = +25°C, REXT = 499kΩ 1%
and 1MΩ 1% tolerance.
PARAMETER DESCRIPTION CONDITION
MIN
(Note 6) TYP
MAX
(Note 6) 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
tSU:DAT Data Set-up Time 100 ns
tRRise Time of both SDA and SCL Signals (Note 9) 20 +
0.1xCb
ns
tFFall Time of both SDA and SCL Signals (Note 9) 20 +
0.1xCb
ns
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
Electrical Specifications VDD = 3.0V, TA = +25°C, REXT = 1MΩ 1% tolerance, 16-bit ADC operation,
unless otherwise specified. (Continued)
PARAMETER DESCRIPTION CONDITION
MIN
(Note 6) TYP
MAX
(Note 6) UNIT
ISL29033
6FN7656.1
September 30, 2011
Principles of Operation
Photodiodes and ADC
The ISL29033 contains two photodiode arrays that convert light into
current. The spectral response for ambient light sensing and
infrared (IR) sensing is shown in Figure 8 in the “Typical
Performance Curves” section on page 12. After light is converted to
current during the light signal process, the current output is
converted to digital by a built-in 16-bit Analog-to-Digital Converter
(ADC). An I2C command reads the ambient light or IR intensity in
counts.
The converter is a charge-balancing integrating type 16-bit ADC. The
chosen method for conversion is best for converting small current
signals in the presence of an AC periodic noise. A 100ms integration
time, for instance, highly rejects 50Hz and 60Hz power line noise
simultaneously. See “Integration and Conversion Time” on page 9.
The built-in ADC offers user flexibility in integration time or
conversion time. There are two timing modes: Internal Timing Mode
and External Timing Mode. In Internal Timing Mode, integration time
is determined by an internal oscillator (fOSC) and the n-bit (n = 4, 8,
12, 16) counter inside the ADC. In External Timing Mode, integration
time is determined by the time between two consecutive I2C
External Timing Mode commands. A good balance of integration
time and resolution (depending on application) is required for
optimal results.
The ADC has I2C programmable range select to dynamically
accommodate various lighting conditions. For very dim conditions,
the ADC can be configured at its lowest range (Range 1) in the
ambient light sensing.
Low-Power Operation
The ISL29033 initial operation is at the power-down mode after a
supply voltage is provided. The data registers contain the default
value of 0. When the ISL29033 receives an I2C command to do a
one-time measurement from an I2C master, it starts ADC
conversion with light sensing. It goes to power-down mode
automatically after one conversion is finished and keeps the
conversion data available for the master to fetch anytime
afterwards. The ISL29033 continuously does ADC conversion
with light sensing if it receives an I2C command of continuous
measurement. It continuously updates the data registers with
the latest conversion data. It goes to power-down mode after it
receives the I2C command of power-down.
Ambient Light
There are four operational modes in ISL29033: Programmable ALS
once with auto power-down, programmable IR sensing once with
auto power-down, programmable continuous ALS sensing, and
programmable continuous IR sensing. These four modes can be
programmed in series to fulfill the application needs. The detailed
program configuration is shown in “BLOCK DIAGRAM” on page 1.
When the part is programmed for ambient light sensing, the
ambient light with wavelength within the “Ambient Light
Sensing” spectral response curve in Figure 8 is converted into
current. With ADC, the current is converted to an unsigned n-bit
(up to 16 bits) digital output.
When the part is programmed for infrared (IR) sensing, the IR
light with wavelength within the “IR Sensing” spectral response
curve in Figure 8 is converted into current. With ADC, the current
is converted to an unsigned n-bit (up to 16 bits) digital output.
Interrupt Function
The active low interrupt pin is an open drain pull-down
configuration. The interrupt pin serves as an alarm or monitoring
function to determine whether the ambient light level exceeds
the upper threshold or goes below the lower threshold. Note that
the function of ADC conversion continues without stopping after
interrupt is asserted. If the user needs to read the ADC count that
triggers the interrupt, reading should be done before the data
registers are refreshed by subsequent conversions. The user can
also configure the persistency of the interrupt pin. This reduces
the possibility of false triggers, such as noise or sudden spikes in
ambient light conditions. An unexpected camera flash, for
example, can be ignored by setting the persistency to eight
integration cycles.
ALS Ranges Considerations
When measuring ALS counts higher than 30000 counts on
Range 1 of the 16-bit ADC, switch to Range 2 (change [1 to 0]
bits of Register 1 from 00 to 01), and re-measure the ALS counts
and other data to change to Range 3 and Range 4. This
recommendation pertains only to applications in which light
incident on the sensor is IR-heavy and is distorted by tinted glass
that increases the ratio of infrared to visible light.
VDD Power-up and Power Supply
Considerations
Upon power-up, ensure a VDD slew rate of 0.5V/ms or greater.
After power-up, or if the power supply temporarily deviates from
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
NOTE:
9. Cb is the capacitance of the bus in pF.
I2C Electrical Specifications For SCL and SDA (Figure 2), unless otherwise noted, VDD = 3V, TA = +25°C, REXT = 499kΩ 1%
and 1MΩ 1% tolerance. (Continued)
PARAMETER DESCRIPTION CONDITION
MIN
(Note 6) TYP
MAX
(Note 6) UNIT
ISL29033
7FN7656.1
September 30, 2011
specification (2.25V to 3.63V), the following step is
recommended: write 0x00 to register 0x00. Wait a few seconds,
and then rewrite all registers to the desired values. A hardware
reset method can be used, if preferred, instead of writing to the
test registers. For this method, set VDD = 0V for 1 second or more,
power backup at the required slew rate, and write the registers to
the desired values.
Power-Down
To put the ISL29033 into a power-down state, the user can set
[7 to 5] bits to 0 in Register 0. Or more simply, set all of
Register 0 to 0x00.
I2C Interface
There are eight 8-bit registers available inside the ISL29033. The
two command registers define the operation of the device. The
command registers do not change until the registers are
overwritten. The two 8-bit data read-only registers are for the ADC
output. The data registers contain the ADC's latest digital output,
or the number of clock cycles in the previous integration period
(Figure 2).
The ISL29033 I2C interface slave address is internally hard-wired as
1000100. When 1000100x, with x as R or W, is sent after the Start
condition, the device compares the first 7 bits of this byte to its
address, and matches. Figure 3 shows a sample one-byte read, and
Figure 4 shows a sample one-byte write. 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 following byte is driven by the master and
includes the slave address and the read/write bit. The receiving
device is responsible for pulling SDA low during the
acknowledgement period. Every 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.
FIGURE 2. I2C TIMING DIAGRAM
FIGURE 3. I2C READ TIMING DIAGRAM SAMPLE
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 AD7D6D5D4D3D2D1D0
1357 1357 123456 9 2 4 6
STOP START
SDA DRIVEN BY MASTER
DEVICE ADDRESS
SDA DRIVEN BY ISL29033
DATA BYTE0REGISTER ADDRESS
OUT
DEVICE ADDRESSI2C DATA
SDA DRIVEN BY MASTER
SDA DRIVEN BY MASTER
2468
924689 78135789
I2C SDA
I2C SDA
I2C CLK
IN
ISL29033
8FN7656.1
September 30, 2011
Register Set
There are eight registers available in the ISL29033. Table 1
summarizes their functions.
Command Register I 00 (Hex)
The first command register has the following functions:
1. Operation Mode: Bits 7, 6, and 5. These three bits determine
the operation mode of the device (Table 2). Interrupt flag:
Bit 2. This is the status bit of the interrupt (Table 3). The bit is
set to logic high when the interrupt thresholds have been
triggered (out of threshold window), and to logic low when not
yet triggered. When activated and the interrupt is triggered,
the INT pin goes low, and the interrupt status bit goes high
until the status bit is polled through the I2C read command.
Both the INT output and the interrupt status bit are
automatically cleared at the end of the 8-bit (00h) command
register transfer.
FIGURE 4. I2C WRITE TIMING DIAGRAM SAMPLE
START W A A
A6 A5 A4 A3 A2 A1 A0 W A R7 R6 R5 R4 R3 R2 R1 R0 A B7 B6 B5 B4 B3 B2 B1 B0 A
A
12615948
STOP
SDA DRIVEN BY MASTER
FUNCTIONSREGISTER ADDRESSDEVICE ADDRESS
SDA DRIVEN BY MASTER SDA DRIVEN BY MASTER
I2C DATA
I2C SDA IN
I2C SDA OUT
I2C CLK IN
AA
345 789 234 678 123 567 9
A
TABLE 1. REGISTER SET
ADDR REG NAME
BIT
765 4 3210DEFAULT
00h COMMANDI OP2 OP1 OP0 0 0 FLAG PRST1 PRST0 00h
01h COMMANDII 0 0 0 0 RES1 RES0 RANGE1 RANGE0 00h
02h DATALSB D7 D6 D5 D4 D3 D2 D1 D0 00h
03h DATAMSB D15 D14 D13 D12 D11 D10 D9 D8 00h
04h INT_LT_LSB TL7 TL6 TL5 TL4 TL3 TL2 TL1 TL0 00h
05h INT_LT_MSB TL15 TL14 TL13 TL12 TL11 TL10 TL9 TL8 00h
06h INT_HT_LSB TH7 TH6 TH5 TH4 TH3 TH2 TH1 TH0 FFh
07h INT_HT_MSB TH15 TH14 TH13 TH12 TH11 TH10 TH9 TH8 FFh
TABLE 2. OPERATION MODE
BITS 7 TO 5 OPERATION
000 Power-down the device
001 Reserved (Do not use)
010 Reserved (Do not use)
100 Reserved (Do not use)
101 ALS continuous
110 IR continuous
111 Reserved (Do not use)
TABLE 3. INTERRUPT FLAG
BIT 2 OPERATION
0 Interrupt is cleared or not triggered yet
1 Interrupt is triggered
ISL29033
9FN7656.1
September 30, 2011
2. Interrupt Persist: Bits 1 and 0. The interrupt pin and the
interrupt flag are triggered or set when the data sensor
reading is out of the interrupt threshold window after m
consecutive number of integration cycles (Table 4). The
interrupt persist bits determine m.
Command Register II 01 (Hex)
The second command register has the following functions:
1. Resolution: Bits 3 and 2. Bits 3 and 2 determine the ADC
resolution and the number of clock cycles per conversion
(Table 5). Changing the number of clock cycles does more than
just change the resolution of the device; it also changes the
integration time, which is the period during which the
analog-to-digital (A/D) converter samples the photodiode
current signal for a measurement.
2. Range: Bits 1 and 0. The Full Scale Range (FSR) can be
adjusted through the I2C by using Bits 1 and 0. Table 6 lists
the possible values of FSR for the 499kΩ REXT resistor.
Data Registers (02 Hex and 03 Hex)
The device has two 8-bit read-only registers to hold the data from
LSB to MSB for the ADC (Table 7). The most significant bit (MSB)
is accessed at 03 hex, and the least significant bit (LSB) is
accessed at 02 hex. For 16-bit resolution, the data is from D0 to
D15; for 12-bit resolution, the data is from D0 to D11; for 8-bit
resolution, the data is from D0 to D7. The registers are refreshed
after every conversion cycle.
Interrupt Registers (04, 05, 06 and 07 Hex)
Registers 04 and 05 hex set the low (LO) threshold for the
interrupt pin and the interrupt flag. Register 04 hex is the LSB,
and Register 05 hex is the MSB. By default, the interrupt
threshold LO is 00 hex for both LSB and MSB.
Registers 06 and 07 hex set the high (HI) threshold for the
interrupt pin and the interrupt flag. Register 06 hex is the LSB,
and Register 07 hex is the MSB. By default, the interrupt
threshold HI is FF hex for both LSB and MSB.
Calculating Lux
The ISL29033 ADC output codes, DATA, are directly proportional
to lux in ambient light sensing, as shown in Equation 1.
In this equation, Ecal is the calculated lux reading. The constant,
a, is determined by the full scale range and the ADC maximum
output counts. The constant is independent of the light sources
(fluorescent, incandescent and sunlight) because the light source
IR component is removed during the light signal process. The
constant can also be viewed as the sensitivity (the smallest lux
measurement the device can measure), as shown in Equation 2.
In this equation, Range(k) is as defined in Table 6. Countmax is
the maximum output counts from the ADC.
The transfer function used for n-bits ADC is as shown in
Equation 3:
In this equation, n = 4, 8, 12 or 16 and is the number of ADC bits
programmed in the command register. The number 2n
represents the maximum number of counts possible from the
ADC output. Data is the ADC output stored in data
Registers 02 hex and 03 hex.
Integration and Conversion Time
ADC resolution and fOSC determine the integration time, tint, as
shown in Equation 4.
In this equation, n is the number of bits of resolution, and n = 4,
8, 12 or 16. Therefore, 2n is the number of clock cycles. The
value of n can be programmed at the command register, Register
01 (hex), Bits 3 and 2 (Table 8).
TABLE 4. INTERRUPT PERSIST
BIT 1:0 NUMBER OF INTEGRATION CYCLES
00 1
01 4
10 8
11 16
TABLE 5. ADC RESOLUTION DATA WIDTH
BITS 3:2 NUMBER OF CLOCK CYCLES n-BIT ADC
00 216 = 65,536 16
01 212 = 4,096 12
10 28 = 256 8
11 24 = 16 4
TABLE 6. RANGE/FSR LUX
BITS 1:0 k RANGE(k)
FSR (LUX) @ ALS
SENSING
00 1 Range1 125
01 2 Range2 500
10 3 Range3 2,000
11 4 Range4 8,000
TABLE 7. DATA REGISTERS
ADDRESS
(HEX) CONTENTS
02 D0 is LSB for 4-, 8-, 12- or 16-bit resolution; D3 is MSB for
4-bit resolution; D7 is MSB for 8-bit resolution
03 D15 is MSB for 16-bit resolution; D11 is MSB for 12-bit
resolution
Ecal αDATA×=(EQ. 1)
αRange k()
Countmax
---------------------------
=(EQ. 2)
(EQ. 3)
Ecal
Range k()
2n
-------------------------- DATA×=
tint 2n1
fOSC
------------
×2nREXT
655kHz 499kΩ×
-----------------------------------------------
×== (EQ. 4)
ISL29033
10 FN7656.1
September 30, 2011
External Scaling Resistor REXT for fOSC and
Range
The ISL29033 uses an external resistor, REXT, to fix its internal
oscillator frequency, fOSC, and the light sensing range, Range.
The fOSC and Range are inversely proportional to REXT. For ease
of use, the proportionality constant is referenced to 499kΩ.
Calculation for Range is shown in Equation 5 and for fOSC in
Equation 6.
Noise Rejection
In general, integrating-type ADCs have excellent noise rejection
characteristics for periodic noise sources for which frequency is
an integer multiple of the conversion rate. For example, 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.
ADC Output in IR Sensing
The ISL29033 ADC output codes, DATA, are directly proportional
to the IR intensity received in IR sensing, as shown in Equation 7.
In this equation, EIR is the received IR intensity. The constant, b,
changes with the spectrum of background IR noise, such as
sunlight and incandescent light. The constant, b, also changes
with ADC range and resolution selections.
Suggested PCB Footprint
It is important that users check Tech Brief 477, “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 ISL29033 is relatively insensitive to layout. Like other I2C
devices, it is intended to provide excellent performance even in
significantly noisy environments. Attention to a few
considerations will ensure best performance.
Route the supply and I2C traces as far as possible from all
sources of noise. Use two power-supply decoupling capacitors,
1µF and 0.1µF, placed close to the device.
Typical Circuit
A typical application for the ISL29033 is shown in Figure 5. The
ISL29033 I2C address is internally hardwired as 1000100. The
device can be tied onto a system’s I2C bus together with other
I2C compliant devices.
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; it is
qualified to +260°C. A standard reflow soldering profile with a
+260°C maximum is recommended.
ALS Sensor Window Layout
Special care should be taken to ensure that the sensor, as shown
in the sensor location outline (Figure 6), is uniformly illuminated.
Shadows from off-angle window openings can affect uniform
illumination, which in turn can affect measurement results.
TABLE 8. INTEGRATION TIME OF n-BIT ADC
REXT
(kΩ)
n = 16-BIT
(ms)
n = 12-BIT
(ms)
n = 8-BIT
(µs)
n = 4-BIT
(µs)
499 100 6.25 391 24
1000 200 12.5 782 48
(EQ. 5)
Range 499kΩ
REXT
-------------------Range k()×=
(EQ. 6)
fOSC
499kΩ
REXT
-------------------655×kHz=
DATAIR βEIR
×=(EQ. 7)
ISL29033
11 FN7656.1
September 30, 2011
FIGURE 5. ISL29033 TYPICAL CIRCUIT
VDD
1
GND
2
REXT
3INT 4
SCL 5
SDA 6
ISL29033
R1
10k
R2
10k
REXT
499kΩ
C2
0.1µF
C1
1µF
2.25V TO 3.63V
MICROCONTROLLER
SDA
SCL
I2C SLAVE_0 I2C SLAVE_1 I2C SLAVE_n
I2C MASTER
SCL
SDA
SCL
SDA
1.7V TO 3.63V
R3
RES1
INT
FIGURE 6. 6 LD ODFN SENSOR LOCATION OUTLINE
1
34
6
25
SENSOR OFFSET
0.54
0.37
0.40
ISL29033
12 FN7656.1
September 30, 2011
Typical Performance Curves VDD = 3.0V, REXT = 499kΩ
FIGURE 7. SPECTRUM OF FOUR LIGHT SOURCES NORMALIZED
BY LUMINOUS INTENSITY (LUX)
FIGURE 8. NORMALIZED SPECTRAL RESPONSE FOR AMBIENT
LIGHT SENSING
FIGURE 9. ANGULAR SENSITIVITY FIGURE 10. LINEARITY OVER RANGE 1
FIGURE 11. LOW LUX AT GREEN LED (500kΩ) FIGURE 12. LIGHT SOURCES AT RANGE 1, 500kΩ REXT
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 INCANDESCENT
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 SENSING
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0 10203040
ANGULAR OFFSET (°)
NORMALIZED SENSITIVITY
5
4
3
2
1
0
-1
-2
-3
-4
-5
ERROR PERCENT FULL SCALE (%)
0 20406080100120
LUX METER (LUX)
MAX
MIN
20
18
16
14
12
10
8
6
4
2
0
ADC READING (COUNTS)
LUX METER (LUX)
0 0.005 0.01 0.015 0.02
500kΩ
70000
60000
50000
40000
30000
20000
10000
0
0 102030405060708090100
LUX READING (LUX)
ADC READING (COUNTS)
FLUORESCENT LIGHT
INCANDESCENT LIGHT
HALOGEN
ISL29033
13 FN7656.1
September 30, 2011
FIGURE 13. 500kΩ ALS COUNT, 30 LUX NORMALIZED FIGURE 14. LOW LUX AT GREEN LED (1MΩ)
FIGURE 15. LIGHT SOURCES AT RANGE 1, 1MΩ REXT FIGURE 16. 1MΩ ALS COUNTS, 30 LUX NORMALIZED
FIGURE 17. SUPPLY CURRENT vs VDD ALS SENSING
Typical Performance Curves VDD = 3.0V, REXT = 499kΩ (Continued)
ALS OUTPUT CHANGE
FROM +25°C MEASUREMENT (%)
-60 0 60 100
TEMPERATURE (°C)
-40 -20 20 8040
10
6
2
-2
-6
-10
500k, 30LUX NORMALIZED
8
4
0
-4
-8
45
40
35
30
25
20
15
10
5
0
ADC READING (COUNTS)
LUX METER (LUX)
0 0.005 0.010 0.015 0.020
1MΩ
70000
60000
50000
40000
30000
20000
10000
0
0 1020304050
LUX READING (LUX)
ADC READING (COUNTS)
INCANDESCENT LIGHT
HALOGEN
FLUORESCENT LIGHT
ALS OUTPUT CHANGE
FROM +25°C MEASUREMENT (%)
TEMPERATURE (°C)
1M, 20 LUX NORMALIZED
-60 0 60 100-40 -20 20 8040
10
6
2
-2
-6
-10
8
4
0
-4
-8
90
80
70
60
50
40
30
20
10
0
IDD (µA)
VDD (V)
2.25 2.75 3.25 3.75
1MΩ
500kΩ
ISL29033
14
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
FN7656.1
September 30, 2011
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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
9/21/2011 FN7656.1 Changed Title on page 1 from “Integrated Digital Ambient Light Sensor with Interrupt Function” to “Ultra-Low
Lux, Low Power, Integrated Digital Ambient Light Sensor with Interrupt Function”
8/25/2011 FN7656.0 Initial Release
ISL29033
15 FN7656.1
September 30, 2011
Package Outline Drawing
L6.2x2.1
6 LEAD OPTICAL DUAL FLAT NO-LEAD PLASTIC PACKAGE (ODFN)
Rev 3, 5/11
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 0.15mm and 0.30mm from the terminal tip.
Dimension 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:
BOTTOM VIEW
DETAIL "X"
SIDE VIEW
TYPICAL RECOMMENDED LAND PATTERN
TOP VIEW
(4X) 0.10
INDEX AREA
PIN 1
A
BPIN #1
B0.10 MAC
C
SEATING PLANE
BASE PLANE
0.08
0.10
SEE DETAIL "X"
C
C
0 . 00 MIN.
0 . 05 MAX.
0 . 2 REF
C5
1
6
6
2.10
2.00
2.10
2.50
(1.35)
(6x0.30)
0.65
(6x0.55)
(6x0.20)
(4x0.65)
1.30 REF1.35
0.65
0.65
6x0.35 ± 0.05
PACKAGE
6X 0.30±0.05
INDEX AREA
OUTLINE
4
MAX 0.75
