INTERSIL ISL29011

ISL29011
®
Data Sheet
May 14, 2009
Digital Ambient Light Sensor and
Proximity Sensor with Interrupt Function
The ISL29011 is an integrated ambient and infrared light to
digital converter with a built-in IR LED driver and I2C Interface
(SMBus Compatible). This device provides not only ambient
light sensing to allow robust backlight/display brightness
control but also infrared sensing to allow proximity estimation
featured with interrupt function.
For ambient light sensing, an internal ADC has been
designed based on the charge-balancing A/D conversion
technique. The ADC conversion time is nominally 90ms and
is user adjustable from 11µs to 90ms, depending on
oscillator frequency and ADC resolution. This ADC is
capable of rejecting 50Hz and 60Hz flicker noise caused by
artificial light sources. The lux-range-select feature allows
users to program the lux range for optimized counts/lux.
For proximity sensing, the ADC is used to digitize the output
signal from the photodiode array when the internal IR LED
driver is turned on and off for the programmed time periods
under user-selected modulation frequency to drive the
external IR LED. As this proximity sensor employs a noise
cancellation scheme to highly reject unwanted IR noise, the
digital output of proximity sensing decreases with distance.
The driver output current is user selectable up to 100mA to
drive different types of IR emitters LEDs.
Six different modes of operation can be selected via the I2C
interface: Programmable ALS once with auto power-down,
programmable IR sensing once, programmable proximity
sensing once, programmable continuous ALS sensing,
programmable continuous IR sensing and programmable
continuous proximity sensing. The programmable one-time
operation modes greatly reduce power because an immediate
automatic shutdown reduces overall supply current less than
0.5µA.
The ISL29011 supports both hardware and software
interrupts that remain asserted until the host clears it through
I2C interface for ambient light sensing and proximity
detection.
Designed to operate on supplies from 2.5V to 3.63V, the
ISL29011 is specified for operation over the -40°C to +85°C
ambient temperature range. It is packaged in a clear, Pb-free
8 Ld ODFN package.
FN6467.2
Features
Proximity Sensing
• Ambient IR Cancellation During Proximity Sensing
- Works Under Direct Sunlight
• IR LED Driver with Programmable Source Current
- Adjustable Current Drive from 100mA to 12.5mA
• Programmable LED current Modulation Frequency
• Variable Conversion Resolution
Ambient Light Sensing
• Simple Output Code Directly Proportional to lux
• Adjustable Sensitivity up to 65 Counts per lux
• 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
• Integrated 50/60Hz Noise Rejection
• Works Under Various Light Sources, Including Sunlight
Ideal Spectral Response for Light and Proximity Sensor
• Light Sensor Close to Human Eye Response
- Excellent Light Sensor IR and UV Rejection
• Proximity sensor range from 850nm to 950nm
- Can use either 850nm or 950nm LED solution
Ultra Low Power
• 90μA Max Operating Current
• Software Shutdown and Automatic Shutdown
- 0.5μA Max Shutdown Current
Easy to Use
• I2C (SMBus Compatible) Output
• No Complex Algorithms Needed
• Temperature Compensated
• Small Form Factor
- 8 Ld 2.0mmx2.1mmx0.7mm ODFN Package
Additional Features
• I2C and SMBus Compatible
• 1.7V to 3.63V Supply for I2C Interface
• 2.25V to 3.63V Sensor Power Supply
• Pb-Free (RoHS compliant)
Applications
• Display and Keypad Dimming Adjustment and Proximity
Sensing 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 and Proximity Sensing
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2009. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
ISL29011
Ordering Information
PART NUMBER
(Note)
TEMP. RANGE
(°C)
ISL29011IROZ-T7*
PACKAGE
(Pb-Free)
-40 to +85
ISL29011IROZ-EVALZ
8 Ld ODFN
PKG.
DWG. #
L8.2.1x2.0
Evaluation Board
*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.
Pinout
ISL29011
(8 LD ODFN)
TOP VIEW)
VDDD 1
8 IRDR
VDDA 2
7 INT
GND 3
6 SDA
REXT 4
5 SCL
EXPOSED PAD CAN BE CONNECTED TO GND OR
ELECTRICALLY ISOLATED
Pin Descriptions
PIN NUMBER PIN NAME
DESCRIPTION
1
VDDD
Positive digital supply: 2.5V to 3.63V.
2
VDDA
Positive analog supply: 2.5V to 3.63V, VDDA and VDDD should be externally shorted.
3
GND
Ground. The thermal pad is also connected to the GND pin.
4
REXT
External resistor pin setting the internal reference current and the conversion time. 499kΩ with 1% tolerance resistor
is recommended.
5
SCL
I2C serial clock line
6
SDA
I2C serial data line
7
INT
Interrupt pin; LO for interrupt/alarming. The INT pin is an open drain.
8
IRDR
The I2C bus lines can be pulled from 1.7V to above VDD, 3.63V max.
IR LED driver pin connecting to the anode of the external IR LED. The source current of the IR LED driver can be
programmed through I2C.
Exposed pad connected to ground or electrically isolated.
2
FN6467.2
May 14, 2009
ISL29011
Block Diagram
VDDD
1
VDDA
2
PHOTODIODE
ARRAY
COMMAND
REGISTER
LIGHT DATA
PROCESS
ALS AND IR
INTEGRATION
ADC
DATA
REGISTER
6
SDA
5
SCL
INTERRUPT
7
INT
IR DRIVER
8
IRDR
I2C
IR PHOTODIODE
ARRAY
IREF
FOSC
4
3
REXT
GND
ISL29011
3
FN6467.2
May 14, 2009
ISL29011
Absolute Maximum Ratings (TA = +25°C)
Thermal Information
VSUP(VDDD,VDDA) Supply Voltage between VDD and GND . . . . . .4V
VDDA Supply Voltage between VDDA and GND . . . . VDDD +/- 0.5V
I2C Bus (SCL, SDA) and INT Pin Voltage . . . . . . . . . . . . -0.2V to 4V
I2C Bus (SCL, SDA) and INT Pin Current . . . . . . . . . . . . . . . <10mA
IRDR Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . -0.2V to VDD + 0.5V
REXT Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . -0.2V to VDD + 0.5V
ESD Rating
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2kV
Thermal Resistance (Typical, Note 1)
θJA (°C/W)
8 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.
NOTE:
1. 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.
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
VSUP(VDDD,VDDA) = 3V, TA = +25°C, REXT = 499kΩ 1% tolerance, 16-bit ADC operation, unless otherwise
specified.
Electrical Specifications
PARAMETER
DESCRIPTION
CONDITION
VSUP
Power Supply Range for VDDD, VDDA
(Note 2)
Software disabled or auto power-down
MIN
ISUP(OFF)
Supply Current when Powered Down
Supply Current of Ambient Light and IR
Sensing
VI2C
Supply Voltage Range for I2C Interface
1.7
fOSC
Internal Oscillator Frequency
675
tint
ADC Integration/Conversion Time
FI2C
I2C Clock Rate Range
DATA_0
Count Output When Dark
16-bit ADC data
E = 0 lux
Full Scale ADC Code
ΔDATA
DATA
Count Output Variation Over Three Light
Sources: Fluorescent, Incandescent and
Sunlight
Ambient light sensing
DATA_1
Light Count Output With LSB of
0.015 lux/count
E = 300 lux, Fluorescent light (Note 3), Ambient light
sensing, Range 1 (1k lux)
DATA_2
Light Count Output With LSB of
0.06 lux/count
DATA_3
MAX
UNIT
3.63
V
0.1
0.5
µA
70
90
µA
3.63
V
825
kHz
2.25
ISUP(ON)
DATA_FS
TYP
750
90
ms
1 to 400
kHz
1
5
Counts
65535 Counts
±10
15000
%
20000
25000 Counts
E = 300 lux, Fluorescent light (Note 3), Ambient light
sensing, Range 2 (4k lux)
5000
Counts
Light Count Output With LSB of
0.24 lux/count
E = 300 lux, Fluorescent light (Note 3), 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 3), Ambient light
sensing, Range 4 (64k lux)
312
Counts
DATA_IR1
Infrared Count Output
E = 210 lux, Sunlight (Note 4), IR sensing, Range 1
DATA_IR2
Infrared Count Output
DATA_IR3
DATA_IR4
20000
25000 Counts
E = 210 lux, Sunlight (Note 4), IR sensing, Range 2
5000
Counts
Infrared Count Output
E = 210 lux, Sunlight (Note 4), IR sensing, Range 3
1250
Counts
Infrared Count Output
E = 210 lux, Sunlight (Note 4), IR sensing, Range 4
312
Counts
VREF
Voltage of REXT Pin
VIL
SCL and SDA Input Low Voltage
VIH
SCL and SDA Input High Voltage
4
15000
0.52
V
0.55
1.25
V
V
FN6467.2
May 14, 2009
ISL29011
Electrical Specifications
PARAMETER
VSUP(VDDD,VDDA) = 3V, TA = +25°C, REXT = 499kΩ 1% tolerance, 16-bit ADC operation, unless otherwise
specified. (Continued)
DESCRIPTION
CONDITION
ISDA, IINT
SDA and INT Current Sinking Capability
IIRDR1
IRDR Source Current
IS<1:0> = 0 (Note 5)
IIRDR2
IRDR Source Current
IS<1:0> = 1 (Note 5)
IIRDR3
IRDR Source Current
IS<1:0> = 2 (Note 5)
IIRDR4
IRDR Source Current
IS<1:0> = 3 (Note 5)
VIRLED
Voltage Head Room of IRDR Pin
MIN
4
15Ω at IRDR pin
44
TYP
MAX
UNIT
5
mA
100
mA
50
58
mA
25
mA
12.5
mA
VDD - 0.6
V
tr
Rise Time for IRDR Source Current
RLOAD = 15Ω at IRDR pin, 20% to 80%
35
ns
tf
Fall Time for IRDR Source Current
RLOAD = 15Ω at IRDR pin, 80% to 20%
10
ns
fIRLED1
IR LED Modulation Frequency
Freq = 0 (Note 5)
DC
kHz
fIRLED2
IR LED Modulation Frequency
Freq = 1 (Note 5)
360
kHz
ISUP (IRLED1) Supply Current of Proximity Sensing
IS<1:0> = 0, Freq = 0 (Note 5)
101
mA
ISUP (IRLED2) Supply Current of Proximity Sensing
IS<1:0> = 0, Freq = 1 (Note 5)
51
mA
Duty Cycle
Duty Cycle of IR LED Modulation
50
%
PROX-IR
PROX
Differential ADC Output of IR and Proximity IR and proximity sensing with Range 2 and Scheme 0;
Sensing With Object Far Away to Provide 15Ω @ IRDR pin, IS<1:0> = 0, Freq = 0; E = 210 lux,
No Reflection
Sunlight.
1.0
%
NOTES:
2. VSUP is the common voltage to VDDD and VDDA.
3. 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 fluorescent light.
4. 850nm infrared 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.
5. See “Register Set” on page 7.
Principles of Operation
Photodiodes and ADC
The ISL29011 contains two photodiode arrays which convert
light into current. The spectral response for ambient light
sensing and IR sensing is shown in Figure 6 in the performance
curves section. 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. Integration time is determined by an internal
oscillator (fOSC), and the n-bit (n = 4, 8, 12,16) counter inside
the ADC. A good balancing act of integration time and
resolution depending on the 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
5
(Range 1) in the ambient light sensing. For very bright
conditions, the ADC can be configured at its highest range
(Range 4) in the proximity sensing.
Low-Power Operation
The ISL29011 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 ISL29011 receives an I2C
command to do a one-time measurement from an I2C master,
it will start ADC conversion with light or proximity sensing. 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 ISL29011 will
continuously do ADC conversion with light or proximity
sensing 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.
Ambient Light, IR and Proximity Sensing
There are six operational modes in ISL29011: Programmable
ALS once with auto power-down, programmable IR sensing
once with auto power-down, programmable proximity sensing
once with auto power-down; programmable continuous ALS
sensing, programmable continuous IR sensing and
programmable continuous proximity sensing. These six
modes can be programmed in series to fulfill the application
FN6467.2
May 14, 2009
ISL29011
of the interrupt. 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 8 integration cycles.
needs. The detailed program configuration is listed in
“Register Set” on page 7.
When the part is programmed for ambient light sensing, the
ambient light with wavelength within the “Ambient Light
Sensing” spectral response curve in Figure 6 is converted
into current. With ADC, the current is converted to an
unsigned n-bit (up to 16 bits) digital output.
I2C Interface
There are eight 8-bit registers available inside the ISL29011.
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 and the Timer output. The data registers contain
the ADC's latest digital output, or the number of clock cycles in
the previous integration period. The four 8-bit interrupt registers
hold 16-bit interrupt high and low thresholds.
When the part is programmed for infrared (IR) sensing, the
IR light with wavelength within the “IR or Proximity Sensing”
spectral response curve on Figure 6 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 proximity sensing, the
external IR LED is turned on by the built-in IR LED driver
through the IRDR pin. The amplitude of the IR LED current
and the IR LED modulation frequency can be programmed
through Command Register II. When the IR from the LED
reaches an object and gets reflected back, the reflected IR
light with wavelength within the “IR or Proximity Sensing”
spectral response curve in Figure 6 is converted into current.
With ADC, the current is converted to an unsigned n-bit (up
to 16 bits) digital output. The output reading is inversely
proportional to the square of the distance between the
sensor and the object.
The ISL29011’s I2C interface slave address is internally
hard-wired as 1000100. When 1000100x 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. The I2C bus master always drives
the SCL (clock) line, while either the master or the slave can
drive the SDA (data) line. Figure 2 shows a sample write.
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).
Interrupt Function
The active low interrupt pin is an open drain pull-down
configuration. There is also an interrupt bit in the I2C register.
The interrupt serves as an alarm or monitoring function to
determine whether the ambient light level or the proximity
detection level exceeds the upper threshold or goes below the
lower threshold. The user can also configure the persistency
I2C DATA
I2C SDA
IN
I2C SDA
OUT
I2C CLK
DEVICE ADDRESS
START
For more information about the I2C standard, please consult
the Philips™ I2C specification documents.
REGISTER ADDRESS
W A
A6 A5 A4 A3 A2 A1 A0 W A R7 R6 R5 R4 R3 R2 R1 R0 A
1
2
3
4
5
6
SDA DRIVEN BY MASTER
A
SDA DRIVEN BY MASTER
7
8
9
1
2
3
4
5
6
DEVICE ADDRESS
STOP START
7
A
8
9
A6 A5 A4 A3 A2 A1 A0 W
SDA DRIVEN BY MASTER
1
2
3
4
5
6
DATA BYTE0
A
SDA DRIVEN BY ISL29011
A
A D7 D6 D5 D4 D3 D2 D1 D0
7
8
9
1
2
3
4
5
6
7
8
9
FIGURE 1. I2C READ TIMING DIAGRAM SAMPLE
6
FN6467.2
May 14, 2009
ISL29011
START
DEVICE ADDRESS
W
A
W
A
R7 R6 R5 R4 R3 R2 R1 R0
A
B7 B6 B5 B4 B3 B2 B1 B0
A
SDA DRIVEN BY MASTER
A
SDA DRIVEN BY MASTER
A
REGISTER ADDRESS
A
FUNCTIONS
STOP
I2C DATA
I2C SDA IN
A6 A5 A4 A3 A2 A1 A0
A
I2C SDA OUT
SDA DRIVEN BY MASTER
A
I2C CLK IN
1
3
2
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
FIGURE 2. I2C WRITE TIMING DIAGRAM SAMPLE
Register Set
There are eight registers that are available in the ISL29011. Table 1 summarizes their functions.
TABLE 1. REGISTER SET
BIT
ADDR
REG NAME
7
6
5
4
3
2
1
0
DEFAULT
00h
COMMANDI
OP2
OP1
OP0
0
0
FLAG
PRST1
PRST0
00h
01h
COMMANDII
Scheme
FREQ
IS1
IS0
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
Command Register I 00(hex)
The first command register has the following functions:
1. Operation Mode: Bits 7, 6, and 5.These three bits
determines the operation mode of the device.
TABLE 2. OPERATION MODE
BITS 7 TO 5
TABLE 3. INTERRUPT FLAG
BIT 2
OPERATION
0
Interrupt is cleared or not triggered yet
1
Interrupt is triggered
OPERATION
000
Power-down the device
001
ALS once
010
IR once
011
Proximity once
100
Reserved (Do not use)
101
ALS continuous
110
IR continuous
111
high. Both interrupt pin and the status bit are automatically
cleared at the end of Command Register I transfer.
Proximity continuous
2. Interrupt flag; Bit 2. This is the status bit of the interrupt.
The bit is set to logic high when the interrupt thresholds
have been triggered, and logic low when not yet triggered.
Once triggered, INT pin stays low and the status bit stays
7
3. Interrupt persist; Bits 1 and 0. The interrupt pin and the
interrupt flag is triggered/set when the data sensor
reading is out of the interrupt threshold window after m
consecutive number of integration cycles. The interrupt
persist bits determine m.
TABLE 4. INTERRUPT PERSIST
BITS 1 TO 0
NUMBER OF INTEGRATION CYCLES
00
1
01
4
10
8
11
16
FN6467.2
May 14, 2009
ISL29011
Command Register II 01(hex)
The second command register has the following functions:
1. Proximity Sensing Scheme: Bit 7. This bit programs the
function of the proximity detection. Logic 0 of this bit,
Scheme 0, makes full n (4, 8, 12, 16) bits (unsigned)
proximity detection. The range of Scheme 0 proximity
count is from 0 to 2n. Logic 1 of this bit, Scheme 1, makes
n-1 (3, 7, 11, 15) bits (2’s complementary)
proximity_less_ambient detection. The range of Scheme
1 proximity count is from -2(n-1) to 2(n-1). While Scheme
0 has wider dynamic range, Scheme 1 proximity
detection is less affected by the ambient IR noise
variation.
TABLE 5. PROXIMITY SENSING SCHEME
BIT 7
OPERATION
0
Sensing IR from LED and ambient
1
Sensing IR from LED with ambient IR rejection
2. Modulation Frequency: Bits 6. This bit sets the IR LED
driver’s modulation frequency.
TABLE 6. MODULATION FREQUENCY
BITS 6
MODULATION FREQUENCY
(kHz)
0
DC
1
360
TABLE 9. RANGE/FSR LUX
BITS
1:0
k
RANGE(k)
FSR (LUX) @
ALS SENSING
FSR @ IR
SENSING
00
1
Range1
1,000
Refer to page 4
01
2
Range2
4,000
Refer to page 4
10
3
Range3
16,000
Refer to page 4
11
4
Range4
64,000
Refer to page 4
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 ADC. 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.
TABLE 10. DATA REGISTERS
ADDRESS
(hex)
3. Amplitude of IR driver current: Bits 5 and 4. This device
provides current source to drive an external IR LED. The
drive capability can be programmed through Bits 5 and 4.
For example, the device sources 12.5mA out of the IRDR
pin if Bits 5 and 4 are 0.
TABLE 7. CURRENT SOURCE CAPABILITY AT IRDR PIN
BITS 5 TO 4
5. Range: Bits 1 and 0. The Full Scale Range (FSR) can be
adjusted via I2C using Bits 1 and 0. Table 9 lists the
possible values of FSR for the 499kΩ REXT resistor.
IRDR PIN SOURCE CURRENT
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
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. 04 hex is the LSB and 05
hex is the MSB. By default, the Interrupt threshold LO is 00
hex for both LSB and MSB.
00
12.5mA IR LED driver
01
25mA IR LED driver
10
50mA IR LED driver
Registers 06 and 07 hex set the high (HI) threshold for the
interrupt pin and the interrupt flag. 06 hex is the LSB and 07
hex is the MSB. By default, the Interrupt threshold HI is FF
hex for both LSB and MSB.
11
100mA IR LED driver
Calculating Lux
4. Resolution: Bits 3 and 2. Bits 3 and 2 determine the ADC’s
resolution and the number of clock cycles per conversion
in 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 is the
period the device’s analog-to-digital (A/D) converter
samples the photodiode current signal for a measurement.
.
TABLE 8. RESOLUTION/WIDTH
BITS 3 TO 2
NUMBER OF CLOCK CYCLES
n-BIT ADC
00
216 = 65,536
16
01
12
10
212 = 4,096
28 = 256
11
24 = 16
4
8
The ISL29011’s ADC output codes, DATA, are directly
proportional to lux in the ambient light sensing.
(EQ. 1)
E cal = α × DATA
Here, Ecal is the calculated lux reading. The constant α is
determined by the Full Scale Range and the ADC’s
maximum output counts. The constant is independent on the
light sources (fluorescent, incandescent and sunlight)
because of the light sources’ 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.
Range ( k )
α = ---------------------------Count max
(EQ. 2)
Here, Range(k) is defined in Table 9. Countmax is the
maximum output counts from the ADC.
8
FN6467.2
May 14, 2009
ISL29011
The transfer function used for n-bit ADC becomes
Equation 3:
Range ( k )
E cal = --------------------------- × DATA
n
2
(EQ. 3)
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.
Data is the ADC output stored in the data registers (02 hex
and 03 hex).
The ADC resolution and fOSC determines the integration
time, tint as shown in Equation 4.
R EXT
n
n
1
t int = 2 × -------------- = 2 × ---------------------------------------------725kHz × 499kΩ
f OSC
(EQ. 4)
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 01(hex) bits 3 and 2.
TABLE 11. INTEGRATION TIME OF n-BIT ADC
REXT
(kΩ)
n = 16-BIT
(ms)
n = 12-BIT
(ms)
n = 8-BIT
(µs)
n = 4-BIT
(µs)
250
45
2.812
175.5
10.8µs
499**
90
5.63
351
21.6µs
**Recommended REXT resistor value
External Scaling Resistor REXT for fOSC and
Range
The ISL29011 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 499kΩ as shown in Equations 5 and 6:
499kΩ
Range = ------------------ × Range ( k )
R EXT
(EQ. 5)
499kΩ
f OSC = ------------------ × 725 kHz
R EXT
(EQ. 6)
Noise Rejection
In general, integrating type 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.
ADC Output in IR Sensing
The ISL29011’s ADC output codes, DATA, are directly
proportional to the IR intensity received in the IR sensing.
(EQ. 7)
9
ADC Output in Proximity Sensing
In the proximity sensing, the ADC output codes, DATA, are
directly proportional to the total IR intensity from the
background IR noise and from the IR LED driven by the
ISL29011.
DATA PROX = β × E IR + γ × E LED
Integration and Conversion Time
DATA IR = β × E IR
Here, EIR is the received IR intensity. The constant β
changes with the spectrum of background IR noise like
sunlight and incandescent light. The β also changes with the
ADC’s range and resolution selections.
(EQ. 8)
Here, β and EIR have the same meanings as in Equation 7.
The constant γ depends on the spectrum of the used IR LED
and the ADC’s range and resolution selections. ELED is the
IR intensity which is emitted from the IR LED and reflected
by a specific objector to the ISL29011. ELED depends on the
current to the IR LED and the surface of the object. ELED
decreases with the square of the distance between the
object and the sensor.
If background IR noise is small, EIR can be neglected, and
the ADC output directly decreases with the distance. If there
is significant background IR noise, ISL29011 offers two
schemes to reduce the effect. The first way is do a proximity
sensing using Scheme 0, immediately followed by an IR
sensing. The differential reading of ADC outputs from the
proximity and IR sensing will then reduce the effect of
background IR noise and directly decrease with the distance
between the object and the sensor. The second way is to do
a proximity sensing using Scheme 1 to do on-chip
background IR noise subtraction. While Scheme 0 has wider
dynamic range, Scheme 1 proximity detection is faster but
with half the resolution. Please refer to “Typical Performance
Curves” on page 12 for ADC output versus distance using
Scheme 0 detection.
Figure 9 shows ISL29011 configured at 12-bit ADC
resolution and sensitivity range select at 16000 (range 3) for
the proximity reading. A 12.5mA external LED current at
360kHz modulation frequency detects three different sensing
objects: 92% brightness paper, 18% gray card and ESD
black foam. Figure 10 shows ISL29011 configured at 12-bit
ADC resolution and sensitivity range select at 1000
(range 1) for the proximity reading, with a programmed
external LED at 360kHz modulation frequency, detecting the
same sensing object: 18% gray card under four different
external LED current: 12.5mA, 25mA, 50mA and 100mA to
compare the proximity readout versus distance.
ISL29011 Proximity sensing relies on the amount of IR
reflected back from the objects to be detected. Clearly, it can
not detect an optically black object that reflects no light.
However, ISL29011 is sensitive enough to detect a black ESD
foam, which reflects slightly less than 1% of IR, as shown in
Figure 9 on page 12. For biological objects, blonde hair
reflects more than brunette hair, as expected and shown in
FN6467.2
May 14, 2009
ISL29011
Figure 11. Also 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. This characteristic is very different from that of a plain
paper reflector.
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
Interrupt Function
Depending on the mode of operation set by Bits 7, 6 and 5 of
command register 00 hex, the upper and lower interrupt
thresholds are for either ambient light level or proximity
detection. After each change of mode of operation, it is
expected a new set of thresholds are loaded to interrupt
registers 04, 05, 06 and 07 hex for proper interrupt detection.
Also, the interrupt persist counter will be reset to 0 when the
mode of operation is changed.
LED Modulation for Proximity Detection
ISL29011 offers two ways to modulate the LED in the
Proximity Detection mode - DC or 360kHz (with 50% duty
cycle) by bit 6 of register 01h. At the IRDR pin, there are four
different IRDR LED currents; 12.5, 25, 50, and 100mA
outputs selectable by bits 4 and 5 of register 01h. With the
LED running in the DC mode, the proximity detection is twice
as sensitive but consumes 2 times more current. The
sensitivity of LED 50mA, DC 50mA is identical to that of
100mA, 360kHz modulation. Please note that the ISL29011
does not include a LED.
Current Consumption Estimation
The low power operation is achieved through sequential
readout in the serial fashion, as shown in Figure 3, the
device requires three different phases in serial during the
entire detection cycle to do ambient light sensing, infrared
sensing and proximity sensing. The external IR LED will only
be turned on during the proximity sensing phase under user
program controlled current at modulated frequency depends
on user selections. Figure 3 also shows the current
consumption during each ALS, IR sensing and Proximity
sensing phase. For example, at 8-bit ADC resolution the
integration time is 0.4ms. If user programed 50mA current to
supply external IR LED at 360kHz modulated frequency,
during the entire operation cycle that includes ALS, IR
sensing and Proximity sensing three different serial phases,
the detection occurs once every 30ms, the average current
consumption including external IR LED drive current can be
calculated from Equation 9:
Layout Considerations
The ISL29011 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 two power-supply decoupling
capacitors 1uF and 0.1µF and place them close to the VDDA
and VDDD pins of the device.
Typical Circuit
A typical application for the ISL29011 is shown in Figure 4.
The ISL29011’s 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, and is qualified to +260°C. A standard reflow
soldering profile with a +260°C maximum is recommended.
[ ( 0.05mA + 0.05mA + 1mA + (50mA∗ 50%))∗ 0.4ms ) ]/30ms = 0.35mA
(EQ. 9)
If at a 12-bit ADC resolution where the integration time for
each serial phase becomes 7ms and the total detection time
becomes 100ms, the average current can be calculated from
Equation 10:
[ ( 0.05mA + 0.05mA + 1mA + (50mA∗ 50%))∗ 7 ms ) ]/100ms = 1.83mA
(EQ. 10)
10
FN6467.2
May 14, 2009
ISL29011
30ms
1µA
ALS
50µA
0.4ms
IR
50µA
0.4ms
PROXIMITY
0.4ms
1mA
IR LED
50mA
360 kHz
FIGURE 3. CURRENT CONSUMPTION FOR EACH INTEGRATION PHASE AND DETECTION CYCLE
1.7V TO 3.63V
R1
10kΩ
R2
10kΩ
I2C MASTER
R3
10kΩ
MICROCONTROLLER
INT
SDA
SCL
2.25V TO 3.63V
SLAVE_0
1
2
C1
1µF
C2
0.1µF
3
4
REXT
499k
VDDD
IRDR
VDDA
INT
GND
SDA
REXT
SCL
SLAVE_1
8
7
I2C SLAVE_n
SDA
SDA
SCL
SCL
6
5
ISL29011
FIGURE 4. ISL29011 TYPICAL CIRCUIT
11
FN6467.2
May 14, 2009
ISL29011
Typical Performance Curves
VSUP (VDDD, VDDA) = 3V, REXT = 499kΩ
1.2
SUN
1.0
INCANDESCENT
1.0
0.8
NORMALIZED RESPONSE
HALOGEN
0.6
FLUORESCENT
0.4
0.2
HUMAN EYE RESPONSE
IR AND
PROXIMITY
SENSING
0.8
0.6
0.4
0.2
0
0
300
400
500
600
700
800
WAVELENGTH (nm)
900
1000
-0.2
300
1100
20°
10°
0°
10°
20°
30°
40°
50°
50°
60°
60°
70°
70°
80°
80°
90°
0.2 0.4
0.6 0.8
RELATIVE SENSITIVITY
90°
1.0
CALCULATED ALS READING (LUX)
RADIATION PATTERN
LUMINOSITY
30°
ANGLE 40°
500
600
700
800
900
WAVELENGTH (nm)
1000
1100
1000
65535
VDD = 3V
RANGE = 1000 LUX
16-BIT ADC
900
800
700
INCANDESCENT
HALOGEN
600
500
32768
400
FLUORESCENT
300
200
Ecal =
100
0
0
1000 LUX
216
x DATA
0
100 200 300 400 500 600 700 800 900 1000
LUX METER READING (LUX)
FIGURE 7. RADIATION PATTERN
FIGURE 8. SENSITIVITY TO THREE LIGHT SOURCES
4500
DATAPROX-DATAIR (COUNT)
10000
92% BRIGHTNESS PAPER
1000
18% GRAY CARD
100
10
ESD BLACK FOAM
1
400
FIGURE 6. SPECTRAL RESPONSE FOR AMBIENT LIGHT
SENSING AND PROXIMITY SENSING
FIGURE 5. SPECTRUM OF FOUR LIGHT SOURCES
DATAPROX-DATAIR
AMBIENT
LIGHT
SENSING
ADC OUTPUT (COUNT)
NORMALIZED LIGHT INTENSITY
1.2
0
20
40
60
DISTANCE (mm)
80
100
FIGURE 9. ADC OUTPUT vs DISTANCE WITH DIFFERENT
OBJECTS IN PROXIMITY SENSING
12
4000
3500
IIRLED = 100mA
3000
IIRLED = 50mA
IIRLED = 25mA
2500
IIRLED = 12.5mA
2000
1500
1000
500
0
0
10
20
30
40
50
60
DISTANCE (mm)
70
80
90
FIGURE 10. ADC OUTPUT vs DISTANCE WITH DIFFERENT
LED CURRENT AMPLITUDES IN PROXIMITY
SENSING
FN6467.2
May 14, 2009
ISL29011
Typical Performance Curves
VSUP (VDDD, VDDA) = 3V, REXT = 499kΩ (Continued)
10
12-BIT ADC
RANGE 3
fLED = 328kHz
ILED = 12.5mA
4mm CENTER-TO-CENTER
FOR ISL29011 AND SFH4650,
ISOLATED BY BARRIER
AND BEHIND A 65%
IR TRANSMITTING GLASS
300
PIG'S SKIN
250
200
150
18% GRAY
130 CTS = 500 CTS x 65% x 65%
= 211 CTS
100
50
0
ALS SENSING
0 Lux
OUTPUT CODE (COUNTS)
DATAPROX - DATAIR (COUNT)
350
0
10
BLOND HAIR
BRUNETTE HAIR
20
40
30
50
8
6
4
2
0
-60
60
-20
DISTANCE (mm)
FIGURE 11. PROXIMITY DETECTIONS OF VARIOUS
BIOLOGICAL OBJECTS
60
100
FIGURE 12. OUTPUT CODE FOR 0 LUX vs TEMPERATURE
1.10
105.0
300 Lux FLUORESCENT LIGHT
ALS SENSING
IRDR OUTPUT CURRENT (mA)
104.5
1.05
1.00
0.95
0.90
-60
-20
20
TEMPERATURE (°C)
60
PROXIMITY SENSING
IS<1:0> = 0
104.0
103.5
103.0
102.5
102.0
101.5
101.0
100.5
100.0
-40
100
FIGURE 13. OUTPUT CODE vs TEMPERATURE
-20
0
20
40
60
TEMPERATURE (°C)
80
100
120
FIGURE 14. OUTPUT CURRENT vs TEMPERATURE IN
PROXIMITY SENSING
90
85
SUPPLY CURRENT (µA)
OUTPUT CODE RATIO (FROM +30°C)
20
TEMPERATURE (°C)
ALS SENSING
10,000 Lux
80
75
70
65
60
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 15. SUPPLY CURRENT vs TEMPERATURE IN ALS SENSING
13
FN6467.2
May 14, 2009
ISL29011
FIGURE 16. 8 LD ODFN SENSOR LOCATION OUTLINE
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed 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
14
FN6467.2
May 14, 2009
ISL29011
Package Outline Drawing
L8.2.1x2.0
8 LEAD OPTICAL DUAL FLAT NO-LEAD PLASTIC PACKAGE (ODFN)
Rev 0, 10/08
2.10
6
A
PIN #1
INDEX AREA
B
6
PIN 1
INDEX AREA
0.50
2.00
1.50
1.50
0.20±0.05
(2X)
0.10 M C A B
0.10
8X 0 . 35 ± 0 . 05
TOP VIEW
0.75
BOTTOM VIEW
SEE DETAIL "X"
0.10 C
0.70±0.05
C
BASE PLANE
SEATING PLANE
0.08 C
SIDE VIEW
(6x0.50)
(1.50)
(8x0.20)
C
0 . 2 REF
5
(8x0.55)
(0.75)
0 . 00 MIN.
0 . 05 MAX.
TYPICAL RECOMMENDED LAND PATTERN
DETAIL "X"
NOTES:
1. Dimensions are in millimeters.
Dimensions in ( ) for Reference Only.
2. Dimensioning and tolerancing conform to AMSE Y14.5m-1994.
3. Unless otherwise specified, tolerance : Decimal ± 0.05
4. Dimension b applies to the metallized terminal and is measured
between 0.25mm and 0.35mm from the terminal tip.
5. Tiebar shown (if present) is a non-functional feature.
6. The configuration of the pin #1 identifier is optional, but must be
located within the zone indicated. The pin #1 indentifier may be
either a mold or mark feature.
15
FN6467.2
May 14, 2009