FN6505 Rev 1.00 Page 1 of 11
August 20, 2009
FN6505
Rev 1.00
August 20, 2009
ISL29020
A Low Power, High Sensitivity, Light-to Digital Sensor With I2C Interface
DATASHEET
The ISL29020 is a low power, high sensitivity, integrated light
sensor with I2C (SMBus Compatible) interface. Its
state-of-the-art photodiode array provides close-to human
eye response and good IR rejection. This ADC is capable of
rejecting 50Hz and 60Hz flicker caused by artificial light
sources. The lux range select feature allows the user to
program the lux range for optimized counts/lux.
In normal operation, typical power consumption 55µA. In
order to further minimize power consumption, two
power-down modes have been provided. If polling is chosen
over continuous measurement of light, the auto-power-down
function shuts down the whole chip after each ADC
conversion for the measurement. The other power-down
mode is controlled by software via the I2C interface. The
power consumption can be reduced to less than 1µA when
powered down.
Designed to operate on supplies from 2.25V to 3.3V with I2C
supply from 1.7V to 3.6V, the ISL29020 is specified for
operation over the -40°C to +85°C ambient temperature range.
Block Diagram
Features
Low Power
- 65µA Max Operating Current
- 0.5µA Max Shutdown Current
- Software Shutdown and Automatic Shutdown
Ideal Spectral Response
- Close to Human Eye Response
- Excellent IR and UV Rejection
Easy to Use
- Simple Output Code Directly Proportional to lux
-I
2C (SMBus Compatible) Output
- No Complex Algorithms Needed
- Variable Conversion Resolution up to 16-bits
- Adjustable Sensitivity up to 65 Counts per lux
- Works Under Various Light Sources, Including Sunlight
- Selectable Range (via I2C)
- Range 1 = 0.015 lux to 1,000 lux
- Range 2 = 0.06 lux to 4,000 lux
- Range 3 = 0.24 lux to 16,000 lux
- Range 4 = 0.96 lux to 64,000 lux
- Temperature Compensated
- Integrated 50/60Hz Noise Rejection
Small Form Factor
- 2.0mmx2.1mmx0.7mm 6 Ld ODFN Package
Additional Features
-I
2C and SMBus Compatible
- 1.7V to 3.6V Supply for I2C Interface
- 2.25V to 3.3V Supply
- Address Selection Pin
Pb-Free (RoHS compliant)
Applications
Display and keypad dimming 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
Pinout
ISL29020
(6 LD ODFN)
TOP VIEW
Ordering Information
PART NUMBER
(Note)
PACKAGE
(Pb-Free)
PKG.
DWG. #
ISL29020IROZ-T7* 6 Ld ODFN L6.2x2.1
ISL29020IROZ-EVALZ Evaluation Board (Pb-free)
*Please refer to TB347 for details on reel specifications.
NOTE: 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.
VDD
REXT GND
SDA
SCL
COMMAND
REGISTER
INTEGRATING
ADC DATA
REGISTER
PHOTODIODE
LIGHT
3 2
5
6
1
f
OSC
IREF
COUNTER
2
16
GAIN/RANGE
EXT
SHDN
INT TIME
4
A0
ISL29020
TIMING
PROCESS
ARRAY
DATA
MODE
I2C/SMBus
1
2
3
6
5
4
VDD
GND
REXT
SDA
SCL
A0
*EXPOSED PAD CAN BE CONNECTED TO GND OR
ELECTRICALLY ISOLATED
ISL29020
FN6505 Rev 1.00 Page 2 of 11
August 20, 2009
Absolute Maximum Ratings (TA = +25°C) Thermal Information
VDD Supply Voltage between VDD and GND . . . . . . . . . . . . . 3.6V
I2C Bus Pin Voltage (SCL, SDA) . . . . . . . . . . . . . . . . . -0.2V to 3.6V
I2C Bus Pin Current (SCL, SDA) . . . . . . . . . . . . . . . . . . . . . . <10mA
REXT, A0 Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . . -0.2V to VDD
ESD Rating
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2kV
Thermal Resistance JA (°C/W)
6 Ld ODFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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
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.
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 = 3V, TA = +25°C, REXT = 500k1% tolerance, 16-bit ADC operation, unless otherwise specified.
PARAMETER DESCRIPTION CONDITION MIN TYP MAX UNIT
VDD Power Supply Range 2.25 3.3 V
IDD Supply Current 55 65 µA
IDD1 Supply Current when Powered Down Software disabled or auto power-down 0.01 0.5 µA
VI2CSupply Voltage Range for I2C Interface 1.7 3.6 V
fOSC Internal Oscillator Frequency 650 725 800 kHz
tint ADC Integration/Conversion Time 16-bit ADC data 90 ms
FI2CI2C Clock Rate Range 1 to 400 kHz
DATA_0 Count Output When Dark E = 0 lux, Range 1 (1k lux) 1 5 Counts
DATA_F Full Scale ADC Code 65535 Counts
DATA
DATA
Count Output Variation Over Three Light
Sources: Fluorescent, Incandescent
and Sunlight
Ambient light sensing ±10 %
DATA_1 Light Count Output With LSB of
0.015 lux/count
E = 300 lux, Fluorescent light (Note 1), Ambient light
sensing, Range 1 (1k lux)
15000 20000 25000 Counts
DATA_2 Light Count Output With LSB of
0.06 lux/count
E = 300 lux, Fluorescent light (Note 1), Ambient light
sensing, Range 2 (4k lux)
5000 Counts
DATA_3 Light Count Output With LSB of
0.24 lux/count
E = 300 lux, Fluorescent light (Note 1), Ambient light
sensing, Range 3 (16k lux)
1250 Counts
DATA_4 Light Count Output With LSB of
0.96 lux/count
E = 300 lux, Fluorescent light (Note 1), Ambient light
sensing, Range 4 (64k lux)
312 Counts
DATA_IR1 Infrared Count Output E = 210 lux, Sunlight (Note 2), IR sensing, Range 1 15000 20000 25000
DATA_IR2 Infrared Count Output E = 210 lux, Sunlight (Note 2), IR sensing, Range 2 5000
DATA_IR3 Infrared Count Output E = 210 lux, Sunlight (Note 2), IR sensing, Range 3 1250
DATA_IR4 Infrared Count Output E = 210 lux, Sunlight (Note 2), IR sensing, Range 4 312
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 4 5 mA
NOTES:
1. 550nm green LED is used in production test. The 550nm LED irradiance is calibrated to produce the same DATA count against an illuminance
level of 300 lux fluorscent light.
2. 850nm green LED is used in production test. The 850nm LED irradiance is calibrated to produce the same DATA_IR count against an illuminance
level of 210 lux sunlight at sea level.
ISL29020
FN6505 Rev 1.00 Page 3 of 11
August 20, 2009
Principles of Operation
Photodiodes and ADC
The ISL29020 contains two photodiode arrays which convert
light into current. The spectral response for ambient light
sensing and IR sensing is shown in Figure 8 in the “Typical
Performance Curves” on page 9. After light is converted to
current during the light signal process, the current output is
converted to digital by a single 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 Time or Conversion
Time” on page 6 and “Noise Rejection” on page 7.
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. See
“External Timing Mode” on page 6. A good balancing act of
integration time and resolution depending on the application is
required for optimal results.
The ADC has I2C programmable ranges to dynamically
accommodate various lighting conditions. For very dim
conditions, the ADC can be configured at its lower range
(Range 1). For bright conditions, the ADC can be configured at
its higher range (Range 2).
I2C Interface
There are three 8-bit registers available inside the ISL29020.
The command register defines the operation of the device. The
command register does not change until the register is
overwritten. The two data registers are Read-Only for 16-bit
ADC output or timer output. The data registers contain the
ADC's or timer’s latest digital output.
The ISL29020’s I2C interface slave address can be selected as
1000100 or 1000101 by connecting A0 pin to GND or VDD,
respectively. When 1000100x or 1000101x with x as R or W is
sent after the Start condition, this device compares the first
seven bits of this byte to its address and matches.
Figure 1 shows a sample one-byte read. Figure 2 shows a
sample one-byte write. Figure 3 shows a sync_I2C timing
diagram sample for externally controlled integration time. 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
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.
Low-Power Operation
The ISL29020 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 ISL29020 receives an I2C
command to do a one-time measurement from an I2C master,
it will start light sensing and ADC conversion. It will go to the
power-down mode automatically after one conversion is
finished and keep the conversion data available for the master
to fetch anytime afterwards. The ISL29020 will continuously do
light sensing and ADC conversion if it receives an I2C
command of continuous measurement. It will continuously
update the data registers with the latest conversion data. It will
go to the power-down mode after it receives the I2C command
of power-down.
Pin Descriptions
PIN NUMBER PIN NAME DESCRIPTION
1 VDD Positive supply; connect this pin to a 2.25V to 3.3V supply.
2 GND Ground pin.
3 REXT External resistor pin for ADC reference; connect this pin to ground through a (nominal) 500k resistor.
4A
0Bit 0 of I2C address; ground or tie this pin to VDD. No floating.
5SCLI
2C serial clock The I2C bus lines can be pulled from 1.7V to above VDD, 3.6V max.
6SDAI
2C serial data
ISL29020
FN6505 Rev 1.00 Page 4 of 11
August 20, 2009
FIGURE 1. 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 ISL29020
DATA BYTE0REGISTER ADDRESSDEVICE ADDRESSI2C DATA
SDA DRIVEN BY MASTER
SDA DRIVEN BY MASTER
2468
924689 78135789
I2C SDA IN
I2C SDA OUT
I
2
C CLK
FIGURE 2. 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
FIGURE 3. I2C SYNC_I2C TIMING DIAGRAM SAMPLE
A 6 A5 A4 A3 A2 A1 A0 W AR7R6R5R4R3R2R1R0 A
A
15 4
START W ASTOPREGISTER ADDRESSDEVICE ADDRESS AREGISTER ADDRESSREGISTER ADDRESSI2C DATA
I2C SDA IN
I2C SDA OUT
I2C CLK IN
SDA DRIVEN BY MASTER SDA DRIVEN BY MASTER A
234 6789123 56789
ISL29020
FN6505 Rev 1.00 Page 5 of 11
August 20, 2009
Register Set
There are three 8-bit registers in the ISL29020. Table 1 summarizes their functions.
Command Register (00 hex)
The Read/Write command register has five functions:
1. Enable: Bit 7. This bit enables the ISL29020 with logic 1 and
powers down ISL29020 with logic 0.
2. Measurement Mode: Bit 6. This bit controls the two
measurement modes of the device. A logic 0 puts the
device in the one-time measurement mode in which the
device is automatically shut-down after each measurement.
A logic 1 puts the device in the continuous measurement
mode in which data is collected continuously.
3. Light Sensing: Bit 5. This bit programs the device to do the
ambient light or the infrared (IR) light sensing. A logic 0,
requests for the ambient light sensing and a logic 1 requests
for the IR sensing.
4. Timing Mode and Resolution: Bits 4, 3 and 2. These three
bits determine whether the integration time is done
internally or externally, and the number of bits for ADC. 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, the
integration time is determined by the time between two
consecutive sync_I2C pulse commands.
With Bit 4 set to 0, the device is configured to run in the
Internal-Timing mode. For example, the command register
content should be 1xx000xx to request 16-bit ADC in the
internal-timing mode.
With Bit 4 set to 1, the device is configured to run in the
External-Timing mode. For the external timing, the command
1xx101xx needs to be sent to request the Timer data, the
number of clock cycles counted within the duration between the
two sync pulses (refer to Table 2). The Timer count is read from
register 01h (LSB) and 02h (MSB). The command 1xx100xx
needs to be sent to request the ADC conversion. The ADC data
is also read from register 01h (LSB) and 02h (MSB).
Bits 3 and 2 determine the number of clock cycles per
conversion in the Internal-Timing mode. Changing the
number of clock cycles does more than just change the
resolution of the device. It also changes the integration time,
which the ADC uses to sample the photodiode current signal
for a measurement.
TABLE 1. REGISTER SET
ADDR REG NAME
BIT
DEFAULT765 4 3210
00h COMMAND EN MODE LIGHT RES2 RES1 RES0 RANGE1 RANGE0 00h
01h DATALSB D7 D6 D5 D4 D3 D2 D1 D0 00h
02h DATAMSB D15 D14 D13 D12 D11 D10 D9 D8 00h
TABLE 2. WRITE ONLY REGISTERS
ADDRESS NAME FUNCTIONS/DESCRIPTION
b1xxx_xxxx sync_I2C Writing a logic 1 to this address bit
ends the current ADC-integration
and starts another. Used only with
External Timing Mode.
TABLE 3. ENABLE
BIT 7 OPERATION
0 Power-down the device
1 Enable the device
TABLE 4. MEASUREMENT MODE
BIT 6 OPERATION
0 One-time measurement
1 Continuous measurement
TABLE 5. LIGHT SENSING
BIT 5 OPERATION
0 Ambient light sensing
1 Infrared light sensing
TABLE 6. TIMING MODE AND RESOLUTION
BITS 4:3:2 MODE
0:0:0 Internal Timing, 16-bit ADC data output
0:0:1 Internal Timing, 12-bit ADC data output
0:1:0 Internal Timing, 8-bit ADC data output
0:1:1 Internal Timing, 4-bit ADC data output
1:0:0 External Timing, ADC data output
1:0:1 External Timing, Timer data output
1:1:0 Reserved
1:1:1 Reserved
ISL29020
FN6505 Rev 1.00 Page 6 of 11
August 20, 2009
.
5. Range: Bits 1 and 0. The Full Scale Range (FSR) can be
adjusted via I2C using Bits 1 and 0. Table 8 lists the possible
values of FSR for the 500kREXT resistor.
Data Registers (01 hex and 02 hex)
The device has two 8-bit read-only registers to hold a 16-bit
data from ADC or Timer. The most significant byte is accessed
at 02 hex, and the least significant byte is accessed at 01 hex.
The registers are refreshed after every conversion cycle.
Calculating Lux
The ISL29020’s ADC output codes, DATA, are directly
proportional to lux in the ambient light sensing, as shown in
Equation 1.
Here, Ecal is the calculated lux reading. The constant is
determined by the Full Scale Range and the ADC’s maximum
output counts. The constant can also be viewed as the
sensitivity: the smallest lux measurement the device can
measure, as shown in Equation 2.
Here, Range(k) is defined in Table 8. Countmax is the
maximum output counts from the ADC.
The transfer function used for each timing mode becomes:
INTERNAL TIMING MODE
Here, n = 4, 8, 12 or 16. This is the number of ADC bits
programmed in the command register. 2n represents the
maximum number of counts possible from the ADC output in
Internal-Timing mode. Data is the ADC output stored in the
data registers (01 hex and 02 hex).
EXTERNAL TIMING MODE
Here, Timer sets up the ADC’s maximum count reading and it
is the number of clock cycles accrued in the integration time
(set by sync_I2C pulses) in External-Timing mode. It is stored
in the data registers 01h and 02h when the command is coded
as 1xx101xx. Data is the ADC output. In this mode, the
command has to be sent out again with code 1xx100xx to
request the ADC output data from registers 01h and 02h.
External Scaling Resistor REXT for fOSC and Range
The ISL29020 uses an external resistor REXT to fix its internal
oscillator frequency, fOSC and the light sensing range, Range.
fOSC and Range are inversely proportional to REXT
. For user
simplicity, the proportionality constant is referenced to 500k:
Integration Time or Conversion Time
Integration time is the period during which the device’s analog-
to-digital ADC converter samples the photodiode current signal
for a measurement. Integration time, in other words, is the time
to complete the conversion of analog photodiode current into a
digital signal (number of counts).
Integration time affects the measurement resolution. For better
resolution, use a longer integration time. For short and fast
conversions, use a shorter integration time.
The ISL29020 offers user flexibility in the integration time to
balance resolution, speed and noise rejection. Integration time
can be set internally or externally by programming the bit 4 of the
command register 00(hex).
INTEGRATION TIME IN INTERNAL-TIMING MODE
Most applications will use the Internal-Timing mode. In this
mode, fOSC and ADC n-bits resolution determine the
integration time, tint, as shown in Equation 7.
where n is the number of bits of resolution and n = 4, 8, 12 or
16. 2n, therefore, is the number of clock cycles. n can be
programmed at the command register 00(hex) bits 3 and 2.
TABLE 7. RESOLUTION/WIDTH
BITS 3:2 NUMBER OF CLOCK CYCLES
0:0 216 = 65,536
0:1 212 = 4,096
1:0 28 = 256
1:1 24 = 16
TABLE 8. RANGE/FSR LUX
BITS
1:0 k RANGE(k)
FSR (LUX) @
ALS SENSING
FSR (LUX) @ IR
SENSING
0:0 1 Range1 1,000 Refer to page 2
0:1 2 Range2 4,000 Refer to page 2
1:0 3 Range3 16,000 Refer to page 2
1:1 4 Range4 64,000 Refer to page 2
TABLE 9. DATA REGISTERS
ADDRESS
(hex) CONTENTS
01 Least-significant byte of most recent ADC or Timer data.
02 Most-significant byte of most recent ADC or Timer data.
Ecal DATA=(EQ. 1)
Range k
Countmax
----------------------------
=(EQ. 2)
(EQ. 3)
ERange k
2n
--------------------------- DATA=
(EQ. 4)
ERange k
Timer
--------------------------- DATA=
(EQ. 5)
Range 500k
REXT
------------------ Range k=
(EQ. 6)
fOSC
500k
REXT
------------------ 725kHz=
tint 2n1
fOSC
--------------
2nREXT
725kHz 500k
----------------------------------------------
== (EQ. 7)
ISL29020
FN6505 Rev 1.00 Page 7 of 11
August 20, 2009
INTEGRATION TIME IN EXTERNAL TIMING MODE
The External Timing Mode is recommended when the
integration time is needed to synchronize to an external signal,
such as a PWM to eliminate noise.
The synchronization can be implemented by using I2C sync
command. The 1st I2C sync command starts the conversion.
The 2nd completes the conversion then starts over again to
commence the next conversion. The integration time, tint, is the
time interval between the two sync pulses:
where Timer is the number of internal clock cycles obtained from
data registers and fOSC is the internal oscillator frequency.
The internal oscillator, fOSC, operates identically in both the
internal and external timing modes. However, in External Timing
Mode, the number of clock cycles per integration is no longer
fixed at 2n. The number of clock cycles varies with the chosen
integration time, and is limited to 216 = 65,536. In order to avoid
erroneous readings the integration time must be short enough not
to allow an overflow in the counter register.
Noise Rejection
In general, integrating type ADCs 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.
Optical Design
Flat Window Lens Design
A window lens will surely limit the viewing angle of the
ISL29020. The window lens should be placed directly on top of
the device. The thickness of the lens should be kept at
minimum to minimize loss of power due to reflection and also
to minimize loss due to absorption of energy in the plastic
material. A thickness of t = 1mm is recommended for a window
lens design. The bigger the diameter of the window lens, the
wider the viewing angle is of the ISL29020. Table 11 shows the
recommended dimensions of the optical window to ensure
both 35° and 45° viewing angle. These dimensions are based
on a window lens thickness of 1.0mm and a refractive index of
1.59.
Window with Light Guide Design
If a smaller window is desired while maintaining a wide
effective viewing angle of the ISL29020, a cylindrical piece of
transparent plastic is needed to trap the light and then focus
and guide the light onto the device. Hence, the name light
guide or also known as light pipe. The pipe should be placed
directly on top of the device with a distance of D1 = 0.5mm to
achieve peak performance. The light pipe should have
minimum of 1.5mm in diameter to ensure that whole area of
the sensor will be exposed. See Figure 5.
TABLE 10. INTEGRATION TIME OF n-BIT ADC
REXT
(k n = 16-BIT n = 12-BIT n = 8-BIT n = 4-BIT
250 50ms 3.2ms 200µs 12.5µs
500** 100ms 6.25ms 390µs 24µs
1000 200ms 12.5ms 782µs 49µs
1500 300ms 18.8ms 1.17ms 73µs
2000 400ms 25ms 1.56ms 98µs
**Recommended REXT resistor value
tint
Timer
fOSC
-----------------
=(EQ. 8)
tint
65,535
fOSC
------------------
(EQ. 9)
TABLE 11. RECOMMENDED DIMENSIONS FOR A FLAT
WINDOW DESIGN
DTOTAL D1
DLENS @ 35°
VIEWING ANGLE
DLENS @ 45°
VIEWING ANGLE
1.5 0.50 2.25 3.75
2.0 1.00 3.00 4.75
2.5 1.50 3.75 5.75
3.0 2.00 4.30 6.75
3.5 2.50 5.00 7.75
t = 1 Thickness of lens
D1 Distance between ISL29020 and inner edge of lens
DLENS Diameter of lens
DTOTAL Distance constraint between the ISL29020 and lens
outer edge
* All dimensions are in mm.
DLENS
t
D1
DTOTAL
= VIEWING ANGLE
WINDOW LENS
ISL29020
FIGURE 4. FLAT WINDOW LENS
E = DATA
216 x 1000
ISL29020
FN6505 Rev 1.00 Page 8 of 11
August 20, 2009
Suggested PCB Footprint
It is important that the 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 ISL29020 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. Use one 0.01µF power-supply decoupling
capacitor, placed close to the device.
Typical Circuit
A typical application for the ISL29020 is shown in Figure 6. The
ISL29020’s I2C address is 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, and
is qualified to +260°C. A standard reflow soldering profile with a
+260°C maximum is recommended.
DLENS
t
L
DLENS
LIGHT PIPE
ISL29020
D2
D2 > 1.5mm
FIGURE 5. WINDOW WITH LIGHT GUIDE/PIPE
FIGURE 6. ISL29020 TYPICAL CIRCUIT
VDD
1
GND
2
REXT
3A
0
4
SCL 5
SDA 6
ISL29020
R1
10k
R2
10k
REXT
500k
C1
0.01µF
2.25V TO 3.3V
MICROCONTROLLER
SDA
SCL
I
2
C SLAVE_0
I
2
C SLAVE_1
I
2
C SLAVE_n
I
2
C MASTER
SCL
SDA
SCL
SDA
1.7V TO 3.6V
ISL29020
FN6505 Rev 1.00 Page 9 of 11
August 20, 2009
Typical Performance Curves (VDD = 3V, REXT = 500k
FIGURE 7. SPECTRAL RESPONSE OF LIGHT SOURCES FIGURE 8. SPECTRAL RESPONSE FOR AMBIENT LIGHT
SENSING AND IR SENSING
FIGURE 9. RADIATION PATTERN FIGURE 10. SENSITIVITY TO THREE LIGHT SOURCES
FIGURE 11. OUTPUT CODE FOR 0 LUX vs TEMPERATURE FIGURE 12. OUTPUT CODE vs TEMPERATURE
0
0.2
0.4
0.6
0.8
1.0
1.2
300 400 500 600 700 800 900 1000 1100
WAVELENGTH (nm)
NORMALIZED LIGHT INTENSITY
SUN
HALOGEN
INCANDESCENT
FLUORESCENT
-0.2
0
0.2
0.4
0.6
0.8
1.0
1.2
300 400 500 600 700 800 900 1000 1100
WAVELENGTH (nm)
NORMALIZED RESPONSE
HUMAN EYE
IR SENSING
AMBIENT LIGHT SENSING
RADIATION PATTERN
LUMINOSITY
ANGLE
RELATIVE SENSITIVITY
90°
80°
70°
60°
50°
40°
30°
20° 10° 10° 20°
30°
40°
50°
60°
70°
80°
90°
0.2 0.4 0.6 0.8 1.0
0
100
200
300
400
500
600
700
800
900
1000
0 100 200 300 400 500 600 700 800 900 1000
LUX METER READING (LUX)
CALCULATED ALS READING (LUX)
INCANDESCENT
HALOGEN
FLUORESCENT
ALS SENSING
RANGE 1 (1k Lux)
16-BIT ADC
ADC OUTPUT (COUNT)
0
32768
65535
1000 LUX
Ecal = 216 x DATA
OUTPUT CODE (COUNTS)
TEMPERATURE (°C)
0
2
4
6
8
10
-60 -20 20 60 100
0 lux
OUTPUT CODE RATIO (FROM +30°C)
TEMPERATURE (°C)
0.90
0.95
1.00
1.05
1.10
-60 -20 20 60 100
300 Lux FLUORESCENT LIGHT
ALS SENSING
RANGE 1 (1k Lux)
FN6505 Rev 1.00 Page 10 of 11
August 20, 2009
ISL29020
Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted
in the quality certifications found at www.intersil.com/en/support/qualandreliability.html
Intersil products are sold by description only. Intersil may modify the circuit design and/or specifications of products at any time without notice, provided that such
modification does not, in Intersil's sole judgment, affect the form, fit or function of the product. Accordingly, the reader is cautioned to verify that datasheets 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
For additional products, see www.intersil.com/en/products.html
© Copyright Intersil Americas LLC 2008-2009. All Rights Reserved.
All trademarks and registered trademarks are the property of their respective owners.
FIGURE 13. SUPPLY CURRENT vs TEMPERATURE
Typical Performance Curves (VDD = 3V, REXT = 500k (Continued)
SUPPLY CURRENT (µA)
TEMPERATURE (°C)
40
45
50
55
-50 -25 0 25 50 75 100 125
VDD = 2.25V
2.10
2.00
SENSOR OFFSET
0.59
0.34
16
5
2
4
3
0.23
FIGURE 14. SENSOR LOCATION OUTLINE
ISL29020
FN6505 Rev 1.00 Page 11 of 11
August 20, 2009
Package Outline Drawing
L6.2x2.1
6 LEAD OPTICAL DUAL FLAT NO-LEAD PLASTIC PACKAGE (ODFN)
Rev 0, 9/06
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 b applies to the metallized terminal and is measured
Dimensions in ( ) for Reference Only.
Dimensioning and tolerancing conform to AMSE Y14.5m-1994.
6.
either a mold or mark feature.
3.
5.
4.
2.
Dimensions are in millimeters.1.
NOTES:
(4X) 0.10
INDEX AREA
PIN 1
A
2.10
B
2.00
C
SEATING PLANE
BASE PLANE
0.08
0.10
SEE DETAIL "X"
C
C
0 . 00 MIN.
DETAIL "X"
0 . 05 MAX.
0 . 2 REF
C5
SIDE VIEW
TYPICAL RECOMMENDED LAND PATTERN
( 6X 0 . 30 )
( 6X 0 . 55 )
6
TOP VIEW
(0 . 65)
(1 . 95)
(0 . 65) (1 . 35)
BOTTOM VIEW
6X 0 . 35 ± 0 . 05
B0.10 MAC
1
1 . 35 1 . 30 REF
INDEX AREA
PIN 1
6
0.65
0 . 65
MAX 0.75
6X 0 . 30 ± 0 . 05