ams AG

TAOS Inc.
is now
ams AG
The technical content of this TAOS datasheet is still valid.
Contact information:
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
r
r
TAOS147E − DECEMBER 2012
Features
PACKAGE
MODULE−8
(TOP VIEW)
D Ambient Light Sensing, Proximity
Detection, and IR LED in a Single Module
TMD2771 Series
D Ambient Light Sensing (ALS)
− Approximates Human Eye Response
− Programmable Analog Gain and
Integration Time
− 8,000,000:1 Dynamic Range
− Very High Sensitivity — Ideally Suited for
Operation Behind Dark Glass
Reduced Proximity Count Variation *
Programmable Offset *
Saturation Indicator *
Current Sink Driver for IR LED
16,000:1 Dynamic Range
Maskable ALS and Proximity Interrupt
− Programmable Upper and Lower
Thresholds with Persistence Filter
Power Management
− Low Power 2.2 mA Sleep State with UserSelectable Sleep-After-Interrupt Mode
− 90 mA Wait State with Programmable Wait
Time from 2.7 ms to > 8 seconds
I2C Fast Mode Compatible Interface
− Data Rates up to 400 kbit/s
− Input Voltage Levels Compatible with VDD
or 1.8-V Bus
3.94 mm 2.36 mm 1.35 mm Package
D
D
D
D
SCL 2
7 INT
GND 3
6 LDR
LEDA 4
5 LEDK
Package Drawing is Not to Scale
Applications
D
D
D
D
D
D
Display Backlight Control
Cell Phone Touch Screen Disable
Mechanical Switch Replacement
Industrial Process Control
Medical Diagnostics
Printer Paper Alignment
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−
−
−
−
−
8 SDA
lv
D Proximity Detection
VDD 1
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D Register Set- and Pin-Compatible with the
Description
D
D
D
D
D
D
Monitors, and PMP (Portable Media
Players)
Medical and Industrial Instrumentation
White Goods
Toys
Industrial/Commercial Lighting
Digital Signage
Printers
ca
* New or improved feature
End Products and Market Segments
D Mobile Handsets, Tablets, Laptops, HDTVs,
Te
ch
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The TMD2772 family of devices provides digital ambient light sensing (ALS), a complete proximity detection
system, and digital interface logic in a single 8-pin surface mount module. The devices are register-set and
pin-compatible with the TMD2771 family of devices and include new and improved ALS and proximity detection
features. The ALS enhancements include a reduced-gain mode that extends the operating range in sunlight.
Proximity detection includes improved signal-to-noise performance and more accurate factory calibration. A
proximity offset register allows compensation for optical system crosstalk between the IR LED and the sensor.
To prevent false proximity data measurement readings, a proximity saturation indicator bit signals that the
internal analog circuitry has reached saturation.
The TMD2772 ALS is based on the TAOS patented dual-diode technology that enables accurate results and
approximates human eye response to light intensity under a variety of lighting conditions. The proximity
detection system includes an LED driver and an IR LED, which are factory trimmed to eliminate the need for
end-equipment calibration due to component variations.
The LUMENOLOGY r Company
Copyright E 2012, TAOS Inc.
r
Texas Advanced Optoelectronic Solutions Inc.
1001 Klein Road S Suite 300 S Plano, TX 75074 S (972)
r 673-0759
www.taosinc.com
1
TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Functional Block Diagram
VDD
Interrupt
IR LED Constant
Current Sink
Prox Control
Prox
Integration
Prox
ADC
INT
Upper Limit
Prox
Data
Lower Limit
SCL
Upper Limit
CH0
ADC
CH0
Data
LEDK
ALS Control
Lower Limit
Channel 0
CH1
Data
SDA
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CH1
ADC
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Wait Control
I2C Interface
LEDA
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LDR
Channel 1
GND
Detailed Description
The light-to-digital device provides on-chip photodiodes, integrating amplifiers, ADCs, accumulators, clocks,
buffers, comparators, a state machine, and an I2C interface. Each device combines one photodiode (CH0),
which is responsive to both visible and infrared light, and a second photodiode (CH1), which is responsive
primarily to infrared light. Two integrating ADCs simultaneously convert the amplified photodiode currents to
a digital value providing up to 16-bits of resolution. Upon completion of the conversion cycle, the conversion
result is transferred to the Ch0 and Ch1 data registers. This digital output can be read by a microprocessor
where the luminance (ambient light level in lux) is derived using an empirical formula to approximate the human
eye response.
ni
ca
A fully integrated proximity detection solution is provided with an 850-nm IR LED, LED driver circuit, and
proximity detection engine. An internal LED driver pin (LDR) is externally connected to the LED cathode (LEDK)
to provide a controlled LED sink current. This is accomplished with a proprietary current calibration technique
that accounts for all variances in silicon, optics, package, and most important, IR LED output power. This
eliminates or greatly reduces the need for factory calibration that is required for most discrete proximity sensor
solutions. The device is factory calibrated to achieve a proximity count reading at a specified distance with a
specific number of pulses. In use, the number of proximity LED pulses can be programmed from 1 to 255 pulses,
which allows different proximity distances to be achieved. Each pulse has a 16 μs period with a 7.2 μs on time.
ch
Communication with the device is accomplished through a fast (up to 400 kHz), two-wire I2C serial bus for easy
connection to a microcontroller or embedded controller. The digital output of the device is inherently more
immune to noise when compared to an analog photodiode interface.
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The device provides a separate pin for level-style interrupts. When interrupts are enabled and a pre-set value
is exceeded, the interrupt pin is asserted and remains asserted until cleared by the controlling firmware. The
interrupt feature simplifies and improves system efficiency by eliminating the need to poll a sensor for a light
intensity or proximity value. An interrupt is generated when the value of an ALS or proximity conversion exceeds
either an upper or lower threshold. In addition, a programmable interrupt persistence feature allows the user
to determine how many consecutive exceeded thresholds are necessary to trigger an interrupt. Interrupt
thresholds and persistence settings are configured independently for both ALS and proximity.
Copyright E 2012, TAOS Inc.
The LUMENOLOGY r Company
r
r
2
www.taosinc.com
TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Terminal Functions
TERMINAL
NAME
NO.
TYPE
DESCRIPTION
GND
3
Power supply ground. All voltages are referenced to GND.
INT
7
O
Interrupt — open drain (active low).
LDR
6
O
LED driver input for proximity IR LED, constant current source LED driver.
LEDA
4
LEDK
5
SCL
2
I
SDA
8
I/O
VDD
1
LED anode.
I2C serial clock input terminal — clock signal for I2C serial data.
I2C serial data I/O terminal — serial data I/O for I2C .
lv
Supply voltage.
Available Options
ADDRESS
0x39
PACKAGE − LEADS
Module−8
TMD27723
0x39
Module−8
0x29
Module−8
0x29
Module−8
INTERFACE DESCRIPTION
ORDERING NUMBER
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DEVICE
TMD27721
TMD27725†
†
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LED cathode. Connect to LDR pin when using internal LED driver circuit.
TMD27727†
I2C Vbus = VDD Interface
I2C
TMD27721
Vbus = 1.8 V Interface
TMD27723
I2C Vbus = VDD Interface
I2C
TMD27725
Vbus = 1.8 V Interface
TMD27727
Contact TAOS for availability.
Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage, VDD (Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8 V
Digital I/O Voltage (except LDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 3.8 V
Max LEDA Voltage (TA=0 to 70C, 4.4V otherwise. Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8 V
Max LDR Voltage (TA=0 to 70C, 4.4V otherwise. Note 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8 V
Output terminal current (except LDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −1 mA to 20 mA
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . − 40°C to 85°C
ESD tolerance, human body model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000 V
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
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†
NOTES: 1. All voltages are with respect to GND.
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2. Maximum 4.8V DC over 7 years lifetime.
Maximum 5.0V spikes with up to 250s cumulative duration over 7 years lifetime.
Maximum 5.5V spikes with up to 10s (=1000* 10ms) cumulative duration over 7 years lifetime.
3. Maximum voltage with LDR = off.
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Recommended Operating Conditions
NOM
MAX
Supply voltage, VDD
2.2
3
3.6
V
−3
3
%
LED Supply Voltage (Max shown for TA=0 to 70C, 4.4V otherwise)
2.5
4.8
V
−30
85
°C
Te
MIN
Supply voltage accuracy, VDD total error including transients
Operating free-air temperature, TA (Note 2)
UNIT
NOTE 2: While the device is operational across the temperature range, functionality will vary with temperature. Specifications are stated only
at 25°C unless otherwise noted.
The LUMENOLOGY
Company
Copyright
www.taosinc.com
2012, TAOS Inc.
3
TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Operating Characteristics, VDD = 3 V, TA = 25 C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
Active — LDR pulse off
VOL
INT SDA output low voltage
INT,
I LEAK
Leakage current, SDA, SCL, INT pins
Sleep state — no I2C activity
Leakage current, LDR pin
VIH
SCL SDA input high voltage
SCL,
VIL
SCL SDA input low voltage
SCL,
UNIT
μA
2.2
4
3 mA sink current
0
0.4
6 mA sink current
0
0.6
−5
5
μA
5
μA
−5
TMD27721
0.7 VDD
V
1.25
TMD27723
V
0.3 VDD
TMD27721
V
0.54
TMD27723
lv
I LEAK
250
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Supply current
MAX
195
90
Wait state
IDD
TYP
PARAMETER
Dark ADC count value
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ALS Characteristics, VDD = 3 V, TA = 25 C, AGAIN = 16 , AEN = 1 (unless otherwise noted)
(Notes 1 ,2, 3)
TEST CONDITIONS
Ee = 0, AGAIN = 120×,
ATIME = 0xDB (100 ms)
ADC integration time step size
CHANNEL
MIN
TYP
MAX
CH0
0
1
5
CH1
0
1
5
2.58
2.73
ATIME = 0xFF
ADC number of integration steps
ADC counts per step
ADC count value
ADC count value
ms
steps
0
1024
counts
0
65535
counts
μW/cm2,
CH0
μW/cm2,
CH0
λp = 850 nm, Ee = 61.7
ATIME = 0xF6 (27 ms) (Note 3)
4000
5000
4000
5000
CH1
CH1
λp = 625 nm, ATIME = 0xF6 (27 ms) (Note 2)
λp = 850 nm, ATIME = 0xF6 (27 ms) (Note 3)
6000
950
6000
0.152
0.19
0.228
0.43
0.58
0.73
λp = 625 nm, ATIME = 0xF6 (27 ms)
(Note 2)
CH0
107.2
CH1
20.4
λp = 850 nm, ATIME = 0xF6 (27 ms)
(Note 3)
CH0
81.5
CH1
47.3
7.2
8.0
8.8
AGAIN = 16× and AGL = 0
14 4
14.4
16 0
16.0
17
17.6
6
ni
counts/
(μW/
cm2)
0.16
AGAIN = 8× and AGL = 0
AGAIN = 120× and AGL = 0
counts
2900
AGAIN = 1× and AGL = 1
Gain scaling, relative to 1× gain
setting
2.9
256
ATIME = 0xC0
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Irradiance responsivity
counts
ATIME = 0xFF
λp = 625 nm, Ee = 46.8
ATIME = 0xF6 (27 ms) (Note 2)
ADC count value ratio: CH1/CH0
Re
1
UNIT
108
120
×
132
Te
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NOTES: 1. Optical measurements are made using small-angle incident radiation from light-emitting diode optical sources. Red 625 nm and
infrared 850 nm LEDs are used for final product testing for compatibility with high-volume production.
2. The 625 nm irradiance Ee is supplied by an AlInGaP light-emitting diode with the following typical characteristics: peak wavelength
λp = 625 nm and spectral halfwidth Δλ½ = 20 nm.
3. The 850 nm irradiance Ee is supplied by a GaAs light-emitting diode with the following typical characteristics: peak wavelength
λp = 850 nm and spectral halfwidth Δλ½ = 42 nm.
Copyright
4
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2012, TAOS Inc.
www.taosinc.com
Company
TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Proximity Characteristics, VDD = VLEDA = 3 V, TA = 25C, PEN = 1 (unless otherwise noted)
PARAMETER
Supply current
MIN
LED On
TYP
MAX
3
LED On, PDRIVE = 0
100
LED On, PDRIVE = 1
50
LED On, PDRIVE = 2
25
ILEDA
LEDA current (Note 1)
PTIME
ADC conversion steps
PTIME
ADC conversion time
PTIME = 0xFF ( = 1 conversion step)
2.58
PTIME
ADC counts per step
PTIME = 0xFF ( = 1 conversion step)
0
PPULSE
LED pulses (Note 5)
LED On
LED pulse width
PPULSE = 1, PDRIVE = 0
LED pulse period
PPULSE = 2, PDRIVE = 0
Proximity response, no target
(offset)
PPULSE = 8, PDRIVE = 0, PGAIN = 4×, (Note 2)
Prox count, 100-mm target
(Note 3)
73 mm × 83 mm, 90% reflective Kodak Gray Card,
PGAIN = 4×, PPULSE = 8, PDRIVE = 0, PTIME = 0xFF
(Note 4)
LED On, PDRIVE = 3
UNIT
mA
mA
12.5
1
2.73
2.9
ms
counts
255
pulses
7.3
μs
16.0
μs
100
counts
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450
steps
1023
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0
256
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IDD
TEST CONDITIONS
520
590
counts
NOTES: 1. Value is factory-adjusted to meet the Prox count specification. Considerable variation (relative to the typical value) is possible after
adjustment.
2. Proximity offset varies with power supply characteristics and noise.
3. ILEDA is factory calibrated to achieve this specification. Offset and crosstalk directly sum with this value and is system dependent.
4. No glass or aperture above the module. Tested value is the average of 5 consecutive readings.
5. These parameters are ensured by design and characterization and are not 100% tested.
6. Proximity test was done using the following circuit. See the Application Information: Hardware section for recommended
application circuit.
VDD
VDD
4
1
TMD2772
1 mF
3
6
ca
GND
5
LEDA
LEDK
LDR
1 mF
22 mF
IR LED Characteristics, VDD = 3 V, TA = 25C
PARAMETER
TEST CONDITIONS
MIN
Forward Voltage
VR
Reverse Voltage
IR = 10 μA
5
PO
Radiant Power
IF = 20 mA
4.5
Δλ
TR
IF = 20 mA
TYP
MAX
1.4
1.5
UNIT
V
V
mW
Peak Wavelength
IF = 20 mA
850
Spectral Radiation Bandwidth
IF = 20 mA
40
Optical Rise Time
IF = 100 mA, TW = 125 ns, duty cycle = 25%
20
40
ns
Optical Fall Time
IF = 100 mA, TW = 125 ns, duty cycle = 25%
20
40
ns
Te
TF
ch
λp
ni
VF
The LUMENOLOGY r Company
nm
nm
Copyright E 2012, TAOS Inc.
r
r
www.taosinc.com
5
TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Wait Characteristics, VDD = 3 V, TA = 25C, WEN = 1 (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
Wait steps
TYP
1
Wait time
WTIME = 0xFF (= 1 wait step)
2.73
MAX
UNIT
256
steps
2.9
ms
AC Electrical Characteristics, VDD = 3 V, TA = 25C (unless otherwise noted)
(I2C
TEST CONDITIONS
MIN
UNIT
400
kHz
Clock frequency
t(BUF)
Bus free time between start and stop condition
1.3
t(HDSTA)
Hold time after (repeated) start condition. After
this period, the first clock is generated.
0.6
t(SUSTA)
Repeated start condition setup time
0.6
t(SUSTO)
Stop condition setup time
0.6
μs
t(HDDAT)
Data hold time
0
μs
t(SUDAT)
Data setup time
100
ns
t(LOW)
SCL clock low period
1.3
μs
t(HIGH)
SCL clock high period
0.6
μs
tF
Clock/data fall time
tR
Clock/data rise time
Ci
Input pin capacitance
μs
μs
μs
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0
MAX
f(SCL)
300
ns
300
ns
10
pF
Specified by design and characterization; not production tested.
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†
only)
TYP
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PARAMETER†
Copyright E 2012, TAOS Inc.
The LUMENOLOGY r Company
r
r
6
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
PARAMETER MEASUREMENT INFORMATION
t(LOW)
t(R)
t(F)
VIH
SCL
VIL
t(HDSTA)
t(BUF)
t(HIGH)
t(SUSTA)
t(HDDAT)
t(SUSTO)
t(SUDAT)
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VIH
SDA
VIL
P
Stop
Condition
S
S
Start
Condition
P
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Figure 1. Timing Diagrams
TYPICAL CHARACTERISTICS
NORMALIZED RESPONSIVITY vs.
ANGULAR DISPLACEMENT
SPECTRAL RESPONSIVITY
100%
1
Normalized Response (%)
0.6
0.4
0.2
Ch 1
ni
0
300
400
500
600
700
800
80%
Green LED
Both Axes
70%
60%
50%
40%
30%
20%
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Normalized Responsivity
0.8
90%
Ch 0
10%
0%
900 1000 1100
λ − Wavelength − nm
0
15
30 45
60
Angle of incident light (degrees)
75 90
Figure 3
Te
ch
Figure 2
-90 -75 -60 -45 -30 -15
The LUMENOLOGY
Company
Copyright
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2012, TAOS Inc.
7
TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
TYPICAL CHARACTERISTICS
TYPICAL LDR CURRENT
vs.
VOLTAGE
110%
PDRIVE = 00
LDR Current — mA
120
100
80
PDRIVE = 01
60
40
20
PDRIVE = 11
0
0.5
1
106%
104%
0C
102%
100%
50C
25C
75C
98%
96%
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PDRIVE = 10
108%
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140
lv
IDD — Active Current Normalized @ 3 V, 25C
160
0
NORMALIZED IDD
vs.
VDD and TEMPERATURE
1.5
2
2.5
3
94%
92%
2.7
2.8
2.9
LDR Voltage − V
3
3.1
3.2
3.3
VDD — V
Figure 5
Te
ch
ni
ca
Figure 4
Copyright E 2012, TAOS Inc.
The LUMENOLOGY r Company
r
r
8
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
PRINCIPLES OF OPERATION
System State Machine
An internal state machine provides system control of the ALS, proximity detection, and power management
features of the device. At power up, an internal power-on-reset initializes the device and puts it in a low-power
Sleep state.
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When a start condition is detected on the I2C bus, the device transitions to the Idle state where it checks the
Enable register (0x00) PON bit. If PON is disabled, the device will return to the Sleep state to save power.
Otherwise, the device will remain in the Idle state until a proximity or ALS function is enabled. Once enabled,
the device will execute the Prox, Wait, and ALS states in sequence as indicated in Figure 5. Upon completion
and return to Idle, the device will automatically begin a new prox−wait−ALS cycle as long as PON and either
PEN or AEN remain enabled.
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If the Prox or ALS function generates an interrupt and the Sleep-After-Interrupt (SAI) feature is enabled, the
device will transition to the Sleep state and remain in a low-power mode until an I2C command is received. See
the Interrupts section for additional information.
Sleep
I2C
Start
!PON
Idle
INT & SAI
INT & SAI
PEN
!PEN &
!WEN
& AEN
!WEN
& !AEN
Prox
ca
!WEN
& AEN
ni
WEN
!PEN &
WEN &
AEN
!AEN
ALS
Wait
AEN
Figure 6. Simplified State Diagram
ch
Photodiodes
Conventional ALS detectors respond strongly to infrared light, which the human eye does not see. This can lead
to significant error when the infrared content of the ambient light is high (such as with incandescent lighting).
Te
This problem is overcome through the use of two photodiodes. The Channel 0 photodiode, referred to as the
CH0 channel, is sensitive to both visible and infrared light, while the Channel 1 photodiode, referred to as CH1,
is sensitive primarily to infrared light. Two integrating ADCs convert the photodiode currents to digital outputs.
The ADC digital outputs from the two channels are used in a formula to obtain a value that approximates the
human eye response in units of lux.
The LUMENOLOGY r Company
Copyright E 2012, TAOS Inc.
r
r
www.taosinc.com
9
TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
ALS Operation
ATIME(r 1)
2.73 ms to 699 ms
CH0
ALS
CH0
Data
C0DATAH(r0x15), C0DATA(r0x14)
ALS Control
CH1
Data
C1DATAH(r0x17), C1DATA(r0x16)
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CH1
ADC
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CH0
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The ALS engine contains ALS gain control (AGAIN) and two integrating analog-to-digital converters (ADC), one
for the CH0 and one for the CH1 photodiodes. The ALS integration time (ATIME) impacts both the resolution
and the sensitivity of the ALS reading. Integration of both channels occurs simultaneously and upon completion
of the conversion cycle, the results are transferred to the data registers (C0DATA and C1DATA). This data is
also referred to as channel count. The transfers are double-buffered to ensure data integrity.
CH1
AGAIN(r0x0F, b1:0)
1, 8, 16, 120 Gain
Figure 7. ALS Operation
The registers for programming the integration and wait times are a 2’s compliment values. The actual time can
be calculated as follows:
ATIME = 256 − Integration Time / 2.73 ms
Inversely, the time can be calculated from the register value as follows:
Integration Time = 2.73 ms × (256 − ATIME)
In order to reject 50/60-Hz ripple strongly present in fluorescent lighting, the integration time needs to
be programmed in multiples of 10 / 8.3 ms or the half cycle time. Both frequencies can be rejected with a
programmed value of 50 ms (ATIME = 0xED) or multiples of 50 ms (i.e. 100, 150, 200, 400, 600).
The registers for programming the AGAIN hold a two-bit value representing a gain of 1×, 8×, 16×, or 120×. The
gain, in terms of amount of gain, will be represented by the value AGAINx, i.e. AGAINx = 1, 8, 16, or 120. With
the AGL bit set, the gains will be lowered to 1/6, 8/6, 16/6, and 20×, allowing for up to 60k lux.
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Lux Equation
ch
ni
The lux calculation is a function of CH0 channel count (C0DATA), CH1 channel count (C1DATA), ALS gain
(AGAINx), and ALS integration time in milliseconds (ATIME_ms). If an aperture, glass/plastic, or a light pipe
attenuates the light equally across the spectrum (300 nm to 1100 nm), then a scaling factor referred to as glass
attenuation (GA) can be used to compensate for attenuation. For a device in open air with no aperture or
glass/plastic above the device, GA = 1. If it is not spectrally flat, then a custom lux equation with new coefficients
should be generated. (See TAOS application note).
Te
Counts per Lux (CPL) needs to be calculated only when ATIME or AGAIN is changed, otherwise it remains a
constant. The first segment of the equation (Lux1) covers fluorescent and incandescent light. The second
segment (Lux2) covers dimmed incandescent light. The final lux is the maximum of Lux1, Lux2, or 0.
CPL = (ATIME_ms × AGAINx) / 20
Lux1 = (C0DATA − 1.75 × C1DATA) / CPL
Lux2 = (0.63 × C0DATA − 1.00 × C1DATA) / CPL
Lux = MAX(Lux1, Lux2, 0)
Copyright E 2012, TAOS Inc.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Proximity Detection
Proximity detection is accomplished by measuring the amount of IR energy, from the internal IR LED, reflected
off an object to determine its distance. The internal proximity IR LED is driven by the integrated proximity LED
current driver as shown in Figure 8.
IR
LED
PDL(r0x0D,b0)
PPULSE(r0x0E)
PDRIVE(r0x0F, b7:6)
LEDK
PGAIN(r0x0F, b3:2)
POFFSET(r0x1E)
PTIME(r0x02)
Prox LED
Current Driver
LDR
PVALID(r0x13, b1)
PSAT(r0x13, b6)
Prox Control
Prox
Data
PDATAH(r0x019)
PDATAL(r0x018)
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Prox
ADC
lv
Prox
Integration
PDIODE(r0x0F, b5:4)
Object
al
id
LEDA
CH1
CH0
Background Energy
Figure 8. Proximity Detection
The LED current driver, output on the LDR terminal, provides a regulated current sink that eliminates the need
for an external current limiting resistor. The combination of proximity LED drive strength (PDRIVE) and proximity
drive level (PDL) determine the drive current. PDRIVE sets the drive current to 116 mA, 58 mA, 29 mA, or
14.5 mA when PDL is not asserted. However, when PDL is asserted, the drive current is reduced by a factor
of 9.
Referring to the Detailed State Machine figure, the LED current driver pulses the IR LED as shown in Figure 9
during the Prox Accum state. Figure 9 also illustrates that the LED On pulse has a fixed width of 7.3 μs and
period of 16.0 μs. So, in addition to setting the proximity drive current, 1 to 255 proximity pulses (PPULSE) can
be programmed. When deciding on the number of proximity pulses, keep in mind that the signal increases
proportionally to PPULSE, while noise increases by the square root of PPULSE.
ni
ca
Reflected IR LED +
Background Energy
LED On
Background
Energy
LED Off
7.3 ms
Te
ch
16.0 ms
The LUMENOLOGY r Company
IR LED Pulses
Figure 9. Proximity LED Current Driver Waveform
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Figure 8 illustrates light rays emitting from the internal IR LED, reflecting off an object, and being absorbed by
the CH0 and CH1 photodiodes. The proximity diode selector (PDIODE) determines which of the two
photodiodes is used for a given proximity measurement. Note that neither photodiode is selected when the
device first powers up, so PDIODE must be set for proximity detection to work.
al
id
Referring again to Figure 9, the reflected IR LED and the background energy is integrated during the LED On
time, then during the LED Off time, the integrated background energy is subtracted from the LED On time
energy, leaving the IR LED energy to accumulate from pulse to pulse. The proximity gain (PGAIN) determines
the integration rate, which can be programmed to 1×, 2×, 4×, or 8× gain. At power up, PGAIN defaults to 1×
gain, which is recommended for most applications. For reference, PGAIN equal to 8× is comparable to the
TMD2771’s 1× gain setting. During LED On time integration, the proximity saturation bit in the Status register
(0x13) will be set if the integrator saturates. This condition can occur if the proximity gain is set too high for the
lighting conditions, such as in the presence of bright sunlight. Once asserted, PSAT will remain set until a special
function proximity interrupt clear command is received from the host (see command register).
am
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lv
After the programmed number of proximity pulses have been generated, the proximity ADC converts and scales
the proximity measurement to a 16-bit value, then stores the result in two 8-bit proximity data (PDATAx)
registers. ADC scaling is controlled by the proximity ADC conversion time (PTIME) which is programmable from
1 to 256 2.73-ms time units. However, depending on the application, scaling the proximity data will equally scale
any accumulated noise. Therefore, in general, it is recommended to leave PTIME at the default value of one
2.73-ms ADC conversion time (0xFF).
In many practical proximity applications, a number of optical system and environmental conditions can produce
an offset in the proximity measurement result. To counter these effects, a proximity offset (POFFSET) is
provided which allows the proximity data to be shifted positive or negative. Additional information on the use
of the proximity offset feature is provided in available TAOS application notes.
Once the first proximity cycle has completed, the proximity valid (PVALID) bit in the Status register will be set
and remain set until the proximity detection function is disabled (PEN).
Te
ch
ni
ca
For additional information on using the proximity detection function behind glass and for optical system design
guidance, please see available TAOS application notes.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Interrupts
The interrupt feature simplifies and improves system efficiency by eliminating the need to poll the sensor for
light intensity or proximity values outside of a user-defined range. While the interrupt function is always enabled
and its status is available in the status register (0x13), the output of the interrupt state can be enabled using the
proximity interrupt enable (PIEN) or ALS interrupt enable (AIEN) fields in the enable register (0x00).
al
id
Four 16-bit interrupt threshold registers allow the user to set limits below and above a desired light level and
proximity range. An interrupt can be generated when the ALS CH0 data (C0DATA) falls outside of the desired
light level range, as determined by the values in the ALS interrupt low threshold registers (AILTx) and ALS
interrupt high threshold registers (AIHTx). Likewise, an out-of-range proximity interrupt can be generated when
the proximity data (PDATA) falls below the proximity interrupt low threshold (PILTx) or exceeds the proximity
interrupt high threshold (PIHTx).
lv
It is important to note that the thresholds are evaluated in sequence, first the low threshold, then the high
threshold. As a result, if the low threshold is set above the high threshold, the high threshold is ignored and only
the low threshold is evaluated.
am
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To further control when an interrupt occurs, the device provides a persistence filter. The persistence filter allows
the user to specify the number of consecutive out-of-range ALS or proximity occurrences before an interrupt
is generated. The persistence filter register (0x0C) allows the user to set the ALS persistence filter (APERS)
and the proximity persistence filter (PPERS) values. See the persistence filter register for details on the
persistence filter values. Once the persistence filter generates an interrupt, it will continue until a special function
interrupt clear command is received (see command register).
Prox
Integration
Prox
ADC
PIHTH(r0x0B), PIHTL(r0x0A)
PPERS(r0x0C, b7:4)
Upper Limit
Prox Persistence
Prox
Data
Lower Limit
PILTH(r09), PILTL(r08)
CH1
AIHTH(r07), AIHTL(r06)
Upper Limit
ALS Persistence
CH0
Data
ca
CH0
ADC
APERS(r0x0C, b3:0)
Lower Limit
AILTH(r05), AILTL(r04)
Figure 10. Programmable Interrupt
Te
ch
ni
CH0
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
System State Machine Timing
The system state machine shown in Figure 5 provides an overview of the states and state transitions that
provide system control of the device. This section highlights the programmable features, which affect the state
machine cycle time, and provides details to determine system level timing.
al
id
When the proximity detection feature is enabled (PEN), the state machine transitions through the Prox Init, Prox
Accum, Prox Wait, and Prox ADC states. The Prox Init and Prox Wait times are a fixed 2.73 ms, whereas the
Prox Accum time is determined by the number of proximity LED pulses (PPULSE) and the Prox ADC time is
determined by the integration time (PTIME). The formulas to determine the Prox Accum and Prox ADC times
are given in the associated boxes in Figure 10. If an interrupt is generated as a result of the proximity cycle, it
will be asserted at the end of the Prox ADC state and transition to the Sleep state if SAI is enabled.
lv
When the power management feature is enabled (WEN), the state machine will transition in turn to the Wait
state. The wait time is determined by WLONG, which extends normal operation by 12× when asserted, and
WTIME. The formula to determine the wait time is given in the box associated with the Wait state in Figure 9.
am
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When the ALS feature is enabled (AEN), the state machine will transition through the ALS Init and ALS ADC
states. The ALS Init state takes 2.73 ms, while the ALS ADC time is dependent on the integration time (ATIME).
The formula to determine ALS ADC time is given in the associated box in Figure 9. If an interrupt is generated
as a result of the ALS cycle, it will be asserted at the end of the ALS ADC state and transition to the Sleep state
if SAI is enabled.
Prox
Time: 2.73 ms
Sleep
Prox
Init
!PON
PEN
I2C Start
INT & SAI
PPULSE: 0 ~ 255 pulses
Time: 16.0 μs/pulse
Range: 0 ~ 4.1 ms
Time: 2.73 ms
Prox
Accum
ALS
Idle
INT & SAI
ALS
ADC
!WEN &
!AEN
Prox
Wait
!AEN
!PEN & !WEN
& AEN
!PEN & WEN
& AEN
ca
ALS
Init
ch
Time: 2.73 ms
!WEN &
AEN
Prox
ADC
ni
PTIME: 1 ~ 256 steps
Time: 2.73 ms/step
Range: 2.73 ms ~ 699 ms
ATIME: 1 ~ 256 steps
Time: 2.73 ms/step
Range: 2.73 ms ~ 699 ms
AEN
WEN
Wait
Time:
Range:
WTIME: 1 ~ 256 steps
WLONG = 0
WLONG = 1
2.73 ms/step
32.8 ms/step
2.73 ms ~ 699 ms
32.8 ms ~ 8.39s
Te
Note: PON, PEN, WEN, AEN, and SAI are fields in the Enable register (0x00).
Copyright E 2012, TAOS Inc.
Figure 11. Detailed State Diagram
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Power Management
Power consumption can be managed with the Wait state, because the Wait state typically consumes only 90 μA
of IDD current. An example of the power management feature is given below. With the assumptions provided
in the example, average IDD is estimated to be 176 μA.
Table 1. Power Management
PROGRAMMABLE
PARAMETER
PROGRAMMED VALUE
DURATION
PPULSE
0x04
0.064 ms
Prox Init
2.73 ms
Prox Accum
Prox Accum − LED On
0.029 ms (Note 1)
Prox Accum − LED OFF
0.035 ms (Note 2)
2.73 ms
Prox ADC
ALS Init
ALS ADC
0xFF
WTIME
0xEE
WLONG
0
103 mA
0.195 mA
0.195 mA
2.73 ms
0.195 mA
49 2 ms
49.2
0 090 mA
0.090
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st
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Wait
PTIME
0.195 mA
lv
Prox Wait
TYPICAL
CURRENT
al
id
SYSTEM STATE MACHINE
STATE
ATIME
0xEE
2.73 ms
0.195 mA
49.2 ms
0195 mA
NOTES: 1. Prox Accum − LED On time = 7.3 μs per pulse × 4 pulses = 29.3μs = 0.029 ms
2. Prox Accum − LED Off time = 8.7 μs per pulse × 4 pulses = 34.7μs = 0.035 ms
Average IDD Current = ((0.029 × 103) + (0.035 x 0.195) + (2.73 × 0.195) +
(49.2 × 0.090) + (49.2 × 0.195) + (2.73 × 0.195 × 3)) / 109 176 μA
Keeping with the same programmed values as the example, Table 2 shows how the average IDD current is
affected by the Wait state time, which is determined by WEN, WTIME, and WLONG. Note that the worst-case
current occurs when the Wait state is not enabled.
Table 2. Average IDD Current
0
1
1
1
WLONG
WAIT STATE
AVERAGE IDD CURRENT
n/a
n/a
0 ms
245 μA
0xFF
0
2.73 ms
238 μA
0xEE
0
49.2 ms
175 μA
0x00
0
699 ms
102 μA
0x00
1
8389 ms
91 μA
Te
ch
ni
1
WTIME
ca
WEN
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
I2C Protocol
Interface and control are accomplished through an I2C serial compatible interface (standard or fast mode) to
a set of registers that provide access to device control functions and output data. The devices support the 7-bit
I2C addressing protocol.
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The I2C standard provides for three types of bus transaction: read, write, and a combined protocol (Figure 13).
During a write operation, the first byte written is a command byte followed by data. In a combined protocol, the
first byte written is the command byte followed by reading a series of bytes. If a read command is issued, the
register address from the previous command will be used for data access. Likewise, if the MSB of the command
is not set, the device will write a series of bytes at the address stored in the last valid command with a register
address. The command byte contains either control information or a 5-bit register address. The control
commands can also be used to clear interrupts.
...
Acknowledge (0)
Not Acknowledged (1)
Stop Condition
Read (1)
Start Condition
Repeated Start Condition
Write (0)
Continuation of protocol
Master-to-Slave
Slave-to-Master
1
am
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st
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A
N
P
R
S
Sr
W
lv
The I2C bus protocol was developed by Philips (now NXP). For a complete description of the I2C protocol, please
review the NXP I2C design specification at http://www.i2c−bus.org/references/.
7
S
1
Slave Address
W
1
8
A
1
Command Code
8
A
1
Data Byte
A
8
1
1
...
P
I2C Write Protocol
1
7
S
1
Slave Address
R
1
8
A
1
Data
A
Data
1
...
A
P
I2C Read Protocol
1
S
Slave Address
W
1
8
1
1
7
1
1
Command Code
A
Sr
Slave Address
R
A
ca
7
A
8
1
Data
A
8
Data
1
A
1
...
P
I2C Read Protocol — Combined Format
Figure 12. I2C Protocols
Te
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1
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E− DECEMBER 2012
Register Set
The device is controlled and monitored by data registers and a command register accessed through the serial
interface. These registers provide for a variety of control functions and can be read to determine results of the
ADC conversions. The register set is summarized in Table 1.
Table 3. Register Address
ADDRESS
RESISTER NAME
R/W
−−
COMMAND
W
REGISTER FUNCTION
0x00
ENABLE
R/W
Enables states and interrupts
0x01
ATIME
R/W
ALS time
0x02
PTIME
R/W
Proximity time
0x03
WTIME
R/W
Wait time
0x04
AILTL
R/W
ALS interrupt low threshold low byte
0x05
AILTH
R/W
ALS interrupt low threshold high byte
0x06
AIHTL
R/W
ALS interrupt high threshold low byte
0x07
AIHTH
R/W
ALS interrupt high threshold high byte
0x08
PILTL
R/W
Proximity interrupt low threshold low byte
0x00
RESET VALUE
0x00
al
id
Specifies register address
0x00
0xFF
0xFF
0xFF
lv
0x00
0x00
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0x00
0x00
0x09
PILTH
R/W
Proximity interrupt low threshold high byte
0x00
0x0A
PIHTL
R/W
Proximity interrupt high threshold low byte
0x00
0x0B
PIHTH
R/W
Proximity interrupt high threshold high byte
0x00
0x0C
PERS
R/W
Interrupt persistence filters
0x00
0x0D
CONFIG
R/W
Configuration
0x00
0x0E
PPULSE
R/W
Proximity pulse count
0x00
0x0F
CONTROL
R/W
Control register
0x00
0x11
REVISION
R
Die revision number
0x12
ID
R
Device ID
0x13
STATUS
R
Device status
0x00
0x14
C0DATA
R
CH0 ADC low data register
0x00
0x15
C0DATAH
R
CH0 ADC high data register
0x00
0x16
C1DATA
R
CH1 ADC low data register
0x00
0x17
C1DATAH
R
CH1 ADC high data register
0x00
0x18
PDATAL
R
Proximity ADC low data register
0x00
Proximity ADC high data register
0x00
Proximity offset register
0x00
PDATAH
R
POFFSET
R/W
ID
ni
ca
0x19
0x1E
Rev Num.
Te
ch
The mechanics of accessing a specific register depends on the specific protocol used. See the section on I2C
protocols on the previous pages. In general, the COMMAND register is written first to specify the specific
control/status register for following read/write operations.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Command Register
The command registers specifies the address of the target register for future write and read operations.
Table 4. Command Register
COMMAND
FIELD
BITS
COMMAND
7
TYPE
6:5
4
3
TYPE
2
1
0
Reset
0x00
ADD
DESCRIPTION
Select Command Register. Must write as 1 when addressing COMMAND register.
Selects type of transaction to follow in subsequent data transfers:
FIELD VALUE
DESCRIPTION
00
Repeated byte protocol transaction
01
Auto-increment protocol transaction
10
Reserved — Do not use
11
Special function — See description below
lv
COMMAND
5
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6
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7
Transaction type 00 will repeatedly read the same register with each data access.
Transaction type 01 will provide an auto-increment function to read successive register bytes.
ADD
4:0
Address field/special function field. Depending on the transaction type, see above, this field either
specifies a special function command or selects the specific control-status-register for following write and
read transactions. The field values listed below apply only to special function commands:
FIELD VALUE
DESCRIPTION
00000
Normal — no action
00101
Proximity interrupt clear
00110
ALS interrupt clear
00111
Proximity and ALS interrupt clear
other
Reserved — Do not write
Te
ch
ni
ca
ALS/Proximity Interrupt Clear clears any pending ALS/Proximity interrupt. This special function is self
clearing.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Enable Register (0x00)
The ENABLE register is used to power the device on/off, enable functions, and interrupts.
Table 5. Enable Register
6
5
4
3
2
1
0
Reserved
SAI
PIEN
Resv
AIEN
WEN
PEN
AEN
PON
Reset
0x00
al
id
ENABLE
7
BITS
DESCRIPTION
Reserved
7
Reserved. Write as 0.
SAI
6
Sleep after interrupt. When asserted, the device will power down at the end of a proximity or ALS cycle if an
interrupt has been generated.
PIEN
5
Proximity interrupt mask. When asserted, permits proximity interrupts to be generated.
AIEN
4
ALS interrupt mask. When asserted, permits ALS interrupts to be generated.
WEN
3
Wait Enable. This bit activates the wait feature. Writing a 1 activates the wait timer. Writing a 0 disables the
wait timer.
PEN
2
Proximity enable. This bit activates the proximity function. Writing a 1 enables proximity. Writing a 0
disables proximity.
AEN
1
PON
0
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lv
FIELD
ALS Enable. This bit actives the two channel ADC. Writing a 1 activates the ALS. Writing a 0 disables
the ALS.
Te
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ni
ca
Power ON. This bit activates the internal oscillator to permit the timers and ADC channels to operate.
Writing a 1 activates the oscillator. Writing a 0 disables the oscillator.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
ALS Time Register (0x01)
The ALS time register controls the internal integration time of the ALS channel ADCs in 2.73 ms increments.
Upon power up, the ALS time register is set to 0xFF.
Table 6. ALS Integration Time Register
7:0
DESCRIPTION
VALUE
INTEG_CYCLES
TIME
0xFF
1
2.73 ms
0xF6
10
27.3 ms
0xDB
37
101 ms
0xC0
64
175 ms
0x00
256
699 ms
MAX COUNT
al
id
BITS
1024
10240
37888
65535
65535
lv
FIELD
ATIME
Proximity Time Register (0x02)
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The proximity time register controls the integration time of the proximity ADC in 2.73 ms increments. Upon power
up, the proximity time register is set to 0xFF. It is recommended that this register be programmed to a value of
0xFF (1 integration cycle).
Table 7. Proximity Integration Time Control Register
FIELD
BITS
PTIME
7:0
DESCRIPTION
VALUE
INTEG_CYCLES
TIME
MAX COUNT
0xFF
1
2.73 ms
1023
Wait Time Register (0x03)
Wait time is set 2.73 ms increments unless the WLONG bit is asserted in which case the wait times are 12×
longer. WTIME is programmed as a 2’s complement number. Upon power up, the wait time register is set to
0xFF.
Table 8. Wait Time Register
WTIME
7:0
DESCRIPTION
REGISTER VALUE
WAIT TIME
TIME (WLONG = 0)
TIME (WLONG = 1)
0xFF
1
2.73 ms
0.033 sec
0xB6
74
202 ms
2.4 sec
0x00
256
699 ms
8.4 sec
ca
BITS
ni
FIELD
Te
ch
NOTE: The Proximity Wait Time Register should be configured before PEN and/or AEN is/are asserted.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
ALS Interrupt Threshold Registers (0x04 − 0x07)
The ALS interrupt threshold registers provides the values to be used as the high and low trigger points for the
comparison function for interrupt generation. If C0DATA crosses below the low threshold specified, or above
the higher threshold, an interrupt is asserted on the interrupt pin.
Table 9. ALS Interrupt Threshold Registers
BITS
0x04
7:0
ALS low threshold lower byte
DESCRIPTION
AILTH
0x05
7:0
ALS low threshold upper byte
AIHTL
0x06
7:0
ALS high threshold lower byte
AIHTH
0x07
7:0
ALS high threshold upper byte
al
id
ADDRESS
AILTL
lv
REGISTER
Proximity Interrupt Threshold Registers (0x08 − 0x0B)
am
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The proximity interrupt threshold registers provide the values to be used as the high and low trigger points for
the comparison function for interrupt generation. If the value generated by proximity channel crosses below the
lower threshold specified, or above the higher threshold, an interrupt is signaled to the host processor.
Table 10. Proximity Interrupt Threshold Registers
ADDRESS
BITS
PILTL
0x08
7:0
Proximity low threshold lower byte
DESCRIPTION
PILTH
0x09
7:0
Proximity low threshold upper byte
PIHTL
0x0A
7:0
Proximity high threshold lower byte
PIHTH
0x0B
7:0
Proximity high threshold upper byte
Te
ch
ni
ca
REGISTER
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Persistence Filter Register (0x0C)
The persistence filter register controls the interrupt capabilities of the device. Configurable filtering is provided
to allow interrupts to be generated after every ADC cycle or if the ADC cycle has produced a result that is outside
of the values specified by threshold register for some specified amount of time. Separate filtering is provided
for proximity and ALS functions. ALS interrupts are generated using C0DATA.
6
PERS
5
4
3
PPERS
BITS
7:4
3:0
0
Reset
0x00
APERS
DESCRIPTION
Proximity interrupt persistence filter. Controls rate of proximity interrupt to the host processor.
FIELD VALUE
MEANING
0000
−−−
0001
1
INTERRUPT PERSISTENCE FUNCTION
Every proximity cycle generates an interrupt
1 proximity value out of range
0010
2
2 consecutive proximity values out of range
...
...
...
1111
15
15 consecutive proximity values out of range
ALS Interrupt persistence filter. Controls rate of ALS interrupt to the host processor.
FIELD VALUE
MEANING
0000
Every
0001
1
1 value outside of threshold range
0010
2
2 consecutive values out of range
INTERRUPT PERSISTENCE FUNCTION
Every ALS cycle generates an interrupt
0011
3
3 consecutive values out of range
0100
5
5 consecutive values out of range
0101
10
10 consecutive values out of range
0110
15
15 consecutive values out of range
0111
20
20 consecutive values out of range
1000
25
25 consecutive values out of range
1001
30
30 consecutive values out of range
1010
35
35 consecutive values out of range
1011
40
40 consecutive values out of range
1100
45
45 consecutive values out of range
1101
50
50 consecutive values out of range
1110
55
55 consecutive values out of range
1111
60
60 consecutive values out of range
Te
ch
ni
ca
APERS
1
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st
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FIELD
PPERS
2
lv
7
al
id
Table 11. Persistence Filter Register
Copyright E 2012, TAOS Inc.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Configuration Register (0x0D)
The configuration register sets the proximity LED drive level, wait long time, and ALS gain level.
Table 12. Configuration Register
6
5
CONFIG
4
3
Reserved
2
1
0
AGL
WLONG
PDL
Reset
0x00
al
id
7
FIELD
BITS
Reserved
7:3
DESCRIPTION
AGL
2
ALS gain level. When asserted, the 1× and 8× ALS gain (AGAIN) modes are scaled by 0.16. Otherwise,
AGAIN is scaled by 1. Do not use with AGAIN greater than 8×.
WLONG
1
Wait Long. When asserted, the wait cycles are increased by a factor 12× from that programmed in the
WTIME register.
PDL
0
Proximity drive level. When asserted, the proximity LDR drive current is reduced by 9.
am
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lv
Reserved. Write as 0.
Proximity Pulse Count Register (0x0E)
The proximity pulse count register sets the number of proximity pulses that the LDR pin will generate during the
Prox Accum state. The pulses are generated at a 62.5-kHz rate.
Table 13. Proximity Pulse Count Register
7
PPULSE
6
5
4
3
2
1
PPULSE
BITS
7:0
Reset
0x00
DESCRIPTION
Proximity Pulse Count. Specifies the number of proximity pulses to be generated.
Te
ch
ni
ca
FIELD
PPULSE
0
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Control Register (0x0F)
The Control register provides eight bits of miscellaneous control to the analog block. These bits typically control
functions such as gain settings and/or diode selection.
Table 14. Control Register
6
FIELD
BITS
7:6
3:2
1:0
AGAIN
DESCRIPTION
LED STRENGTH — PDL = 0
Reset
0x00
LED STRENGTH — PDL = 1
00
100 mA
11.1 mA
01
50 mA
5.6 mA
10
25 mA
2.8 mA
11
12.5 mA
1.4 mA
Proximity Diode Selector.
DIODE SELECTION
00
Proximity uses neither diode
01
Proximity uses the CH0 diode
10
Proximity uses the CH1 diode
11
Reserved — Do not write
Proximity Gain.
FIELD VALUE
AGAIN
0
PGAIN
FIELD VALUE
PGAIN
1
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5:4
2
Proximity LED Drive Strength.
FIELD VALUE
PDIODE
3
ResvPDIODE
PDRIVE
PDRIVE ((Note 1))
4
lv
CONTROL
5
al
id
7
PROXIMITY GAIN VALUE
00
1× gain
01
2× gain
10
4× gain
11
8× gain
ALS Gain.
FIELD VALUE
ALS GAIN VALUE
00
1× gain
01
8× gain
10
16× gain
ca
120× gain
11
Te
ch
ni
NOTE 1: LED STRENGTH values (italic) are nominal operating values. Specifications can be found in the Proximity Characteristics table.
Copyright E 2012, TAOS Inc.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Revision Register (0x11)
The Revision register shows the silicon revision number. It is a read-only register and shows the revision level
of the silicon used internally.
Table 15. Revision Register
6
REVISION
5
4
3
2
Reserved
1
0
Reset
Rev Num
DIE_REV
al
id
7
BITS
7:4
Reserved
DESCRIPTION
Bits read as 0
DIE_REV
3:0
Die revision number
Die revision number
lv
FIELD
Reserved
ID Register (0x12)
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The ID Register provides the value for the part number. The ID register is a read-only register.
Table 16. ID Register
7
6
ID
5
4
3
2
1
0
ID
FIELD
BITS
ID
7:0
Reset
ID
DESCRIPTION
0x30 = TMD27721
Part number identification
0x39 = TMD27723
Status Register (0x13)
The Status Register provides the internal status of the device. This register is read only.
Table 17. Status Register
7
Reserved
BIT
Reserved
7
PSAT
PINT
PSAT
PINT
Resv
AINT
3
2
Reserved
1
0
PVALID
AVALID
Reset
0x00
DESCRIPTION
Reserved. Bit reads as 0.
6
Proximity Saturation. Indicates that the proximity measurement saturated.
5
Proximity Interrupt. Indicates that the device is asserting a proximity interrupt.
4
ALS Interrupt. Indicates that the device is asserting an ALS interrupt.
ch
AINT
4
ni
FIELD
5
ca
STATUS
6
3:2
PVALID
1
Proximity Valid. Indicates that the proximity channel has completed an integration cycle after PEN has been
asserted.
0
ALS Valid. Indicates that the ALS channels have completed an integration cycle after AEN has been
asserted.
Te
Reserved
AVALID
Reserved. Bits read as 0.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
ADC Channel Data Registers (0x14 − 0x17)
ALS data is stored as two 16-bit values. To ensure the data is read correctly, a two-byte read I2C transaction
should be used with auto increment protocol bits set in the command register. With this operation, when the
lower byte register is read, the upper eight bits are stored in a shadow register, which is read by a subsequent
read to the upper byte. The upper register will read the correct value even if additional ADC integration cycles
end between the reading of the lower and upper registers.
ADDRESS
BITS
C0DATA
0x14
7:0
ALS CH0 data low byte
DESCRIPTION
C0DATAH
0x15
7:0
ALS CH0 data high byte
C1DATA
0x16
7:0
ALS CH1 data low byte
C1DATAH
0x17
7:0
ALS CH1 data high byte
lv
REGISTER
al
id
Table 18. ADC Channel Data Registers
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Proximity Data Registers (0x18 − 0x19)
Proximity data is stored as a 16-bit value. To ensure the data is read correctly, a two-byte read I2C transaction
should be utilized with auto increment protocol bits set in the command register. With this operation, when the
lower byte register is read, the upper eight bits are stored into a shadow register, which is read by a subsequent
read to the upper byte. The upper register will read the correct value even if the next ADC cycle ends between
the reading of the lower and upper registers.
Table 19. Proximity Data Registers
REGISTER
ADDRESS
BITS
PDATAL
0x18
7:0
Proximity data low byte
DESCRIPTION
PDATAH
0x19
7:0
Proximity data high byte
Proximity Offset Register (0x1E)
ni
ca
The 8-bit proximity offset register provides compensation for proximity offsets caused by device variations,
optical crosstalk, and other environmental factors. Proximity offset is a sign-magnitude value where the sign
bit, bit 7, determines if the offset is negative (bit 7 = 0) or positive (bit 7 = 1). At power up, the register is set to
0x00. The magnitude of the offset compensation depends on the proximity gain (PGAIN), proximity LED drive
strength (PDRIVE), and the number of proximity pulses (PPULSE). Because a number of environmental factors
contribute to proximity offset, this register is best suited for use in an adaptive closed-loop control system. See
available TAOS application notes for proximity offset register application information.
ch
Table 20. Proximity Offset Register
7
POFFSET
5
SIGN
4
3
SIGN
7
MAGNITUDE
6:0
Copyright E 2012, TAOS Inc.
2
1
DESCRIPTION
Proximity Offset Sign. The offset sign shifts the proximity data negative when equal to 0 and positive when
equal to 1.
Proximity Offset Magnitude. The offset magnitude shifts the proximity data positive or negative, depending
on the proximity offset sign. The actual amount of the shift depends on the proximity gain (PGAIN), proximity
LED drive strength (PDRIVE), and the number of proximity pulses (PPULSE).
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r
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26
0
Reset
0x00
MAGNITUDE
BIT
Te
FIELD
6
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
APPLICATION INFORMATION: HARDWARE
LED Driver Pin with Proximity Detection
al
id
In a proximity sensing system, the included IR LED can be pulsed with more than 100 mA of rapidly switching
current, therefore, a few design considerations must be kept in mind to get the best performance. The key goal
is to reduce the power supply noise coupled back into the device during the LED pulses. Averaging of multiple
proximity samples is recommended to reduce the proximity noise.
The first recommendation is to use two power supplies; one for the device VDD and the other for the IR LED.
In many systems, there is a quiet analog supply and a noisy digital supply. By connecting the quiet supply to
the VDD pin and the noisy supply to the LEDA pin, the key goal can be met. Place a 1-μF low-ESR decoupling
capacitor as close as possible to the VDD pin and another at the LEDA pin, and at least 10-μF of bulk capacitance
to supply the 100-mA current surge. This may be distributed as two 4.7 μF capacitors.
Voltage
Regulator
LDR
RP
RP
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1 mF
C*
GND
Voltage
Regulator
LEDK
VDD
lv
VBUS
TMD2772
RPI
INT
SCL
LEDA
10 mF
SDA
1 mF
* Cap Value Per Regulator Manufacturer Recommendation
Figure 13. Proximity Sensing Using Separate Power Supplies
If it is not possible to provide two separate power supplies, the device can be operated from a single supply.
A 22-Ω resistor in series with the VDD supply line and a 1-μF low ESR capacitor effectively filter any power supply
noise. The previous capacitor placement considerations apply.
VBUS
Voltage
Regulator
22 W
LEDK
VDD
LDR
1 mF
GND
TMD2772
RP
RP
RPI
INT
SCL
LEDA
SDA
ni
ca
10 mF
ch
1 mF
Figure 14. Proximity Sensing Using Single Power Supply
Te
VBUS in the above figures refers to the I2C bus voltage which is either VDD or 1.8 V. Be sure to apply the specified
I2C bus voltage shown in the Available Options table for the specific device being used.
The I2C signals and the Interrupt are open-drain outputs and require pull−up resistors. The pull-up resistor (RP)
value is a function of the I2C bus speed, the I2C bus voltage, and the capacitive load. The TAOS EVM running
at 400 kbps, uses 1.5-kΩ resistors. A 10-kΩ pull-up resistor (RPI) can be used for the interrupt line.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
APPLICATION INFORMATION: HARDWARE
PCB Pad Layout
0.60 0.05
0.80 0.05
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lv
0.72 0.05
al
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Suggested PCB pad layout guidelines for the surface mount module are shown in Figure 15. Flash Gold is
recommended surface finish for the landing pads.
0.25 0.05
NOTES: A. All linear dimensions are in mm.
B. This drawing is subject to change without notice.
Te
ch
ni
ca
Figure 15. Suggested Module PCB Layout
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
PACKAGE INFORMATION
MODULE
Dual Flat No-Lead
TOP VIEW
SIDE VIEW
al
id
Detector
1.0
3.94
0.2
2.40
3.73
0.1
lv
0.9
LED
0.58
END VIEW
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1.18
2.36 0.2
1.35
0.2
2.10 0.1
BOTTOM VIEW
0.80
ca
0.60
0.25
ch
ni
0.72
0.05
Lead Free
All linear dimensions are in millimeters. Dimension tolerance is ± 0.05 mm unless otherwise noted.
Contacts are copper with NiPdAu plating.
This package contains no lead (Pb).
This drawing is subject to change without notice.
Te
NOTES: A.
B.
C.
D.
Pb
The LUMENOLOGY r Company
Figure 16. Module Packaging Configuration
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
CARRIER TAPE AND REEL INFORMATION
TOP VIEW
8.00
1.75
4.00
1.50
al
id
2.00 0.05
B
5.50 0.05
B
1.00
0.05
Unit Orientation
A
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DETAIL A
A
lv
+ 0.30
12.00
− 0.10
DETAIL B
6 Max
8 Max
0.29
0.02
2.70
Ao
Bo
Ko
ca
All linear dimensions are in millimeters. Dimension tolerance is ± 0.10 mm unless otherwise noted.
The dimensions on this drawing are for illustrative purposes only. Dimensions of an actual carrier may vary slightly.
Symbols on drawing Ao, Bo, and Ko are defined in ANSI EIA Standard 481−B 2001.
Each reel is 330 millimeters in diameter and contains 2500 parts.
TAOS packaging tape and reel conform to the requirements of EIA Standard 481−B.
In accordance with EIA standard, device pin 1 is located next to the sprocket holes in the tape.
This drawing is subject to change without notice.
ni
NOTES: A.
B.
C.
D.
E.
F.
G.
4.30
1.70
Te
ch
Figure 17. Module Carrier Tape
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
SOLDERING INFORMATION
The module has been tested and has demonstrated an ability to be reflow soldered to a PCB substrate.
Table 21. Solder Reflow Profile
PARAMETER
REFERENCE
DEVICE
Average temperature gradient in preheating
tsoak
2 to 3 minutes
Time above 217°C (T1)
t1
Max 60 sec
Time above 230°C (T2)
Time above Tpeak −10°C (T3)
Peak temperature in reflow
t2
Max 50 sec
t3
Max 10 sec
lv
Soak time
2.5°C/sec
260°C
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Tpeak
Temperature gradient in cooling
Max −5°C/sec
Not to scale — for reference only
T3
T2
t3
t2
tsoak
t1
Figure 18. Solder Reflow Profile Graph
Te
ch
Time (sec)
ni
Temperature (C)
T1
ca
Tpeak
al
id
The solder reflow profile describes the expected maximum heat exposure of components during the solder
reflow process of product on a PCB. Temperature is measured on top of component. The components should
be limited to a maximum of three passes through this solder reflow profile.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
STORAGE INFORMATION
Moisture Sensitivity
al
id
Optical characteristics of the device can be adversely affected during the soldering process by the release and
vaporization of moisture that has been previously absorbed into the package. To ensure the package contains
the smallest amount of absorbed moisture possible, each device is baked prior to being dry packed for shipping.
Devices are dry packed in a sealed aluminized envelope called a moisture-barrier bag with silica gel to protect
them from ambient moisture during shipping, handling, and storage before use.
Shelf Life
The calculated shelf life of the device in an unopened moisture barrier bag is 12 months from the date code on
the bag when stored under the following conditions:
lv
Shelf Life: 12 months
Ambient Temperature: < 40°C
Relative Humidity: < 90%
Floor Life
am
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st
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Rebaking of the devices will be required if the devices exceed the 12 month shelf life or the Humidity Indicator
Card shows that the devices were exposed to conditions beyond the allowable moisture region.
The module has been assigned a moisture sensitivity level of MSL 3. As a result, the floor life of devices removed
from the moisture barrier bag is 168 hours from the time the bag was opened, provided that the devices are
stored under the following conditions:
Floor Life: 168 hours
Ambient Temperature: < 30°C
Relative Humidity: < 60%
If the floor life or the temperature/humidity conditions have been exceeded, the devices must be rebaked prior
to solder reflow or dry packing.
Rebaking Instructions
Te
ch
ni
ca
When the shelf life or floor life limits have been exceeded, rebake at 50°C for 12 hours.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
PRODUCTION DATA — information in this document is current at publication date. Products conform to
specifications in accordance with the terms of Texas Advanced Optoelectronic Solutions, Inc. standard
warranty. Production processing does not necessarily include testing of all parameters.
LEAD-FREE (Pb-FREE) and GREEN STATEMENT
al
id
Pb-Free (RoHS) TAOS’ terms Lead-Free or Pb-Free mean semiconductor products that are compatible with the current
RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous
materials. Where designed to be soldered at high temperatures, TAOS Pb-Free products are suitable for use in specified
lead-free processes.
Green (RoHS & no Sb/Br) TAOS defines Green to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and
Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material).
am
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lv
Important Information and Disclaimer The information provided in this statement represents TAOS’ knowledge and
belief as of the date that it is provided. TAOS bases its knowledge and belief on information provided by third parties,
and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate
information from third parties. TAOS has taken and continues to take reasonable steps to provide representative
and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and
chemicals. TAOS and TAOS suppliers consider certain information to be proprietary, and thus CAS numbers and other
limited information may not be available for release.
NOTICE
Texas Advanced Optoelectronic Solutions, Inc. (TAOS) reserves the right to make changes to the products contained in this
document to improve performance or for any other purpose, or to discontinue them without notice. Customers are advised
to contact TAOS to obtain the latest product information before placing orders or designing TAOS products into systems.
TAOS assumes no responsibility for the use of any products or circuits described in this document or customer product
design, conveys no license, either expressed or implied, under any patent or other right, and makes no representation that
the circuits are free of patent infringement. TAOS further makes no claim as to the suitability of its products for any particular
purpose, nor does TAOS assume any liability arising out of the use of any product or circuit, and specifically disclaims any
and all liability, including without limitation consequential or incidental damages.
ca
TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS, INC. PRODUCTS ARE NOT DESIGNED OR INTENDED FOR
USE IN CRITICAL APPLICATIONS IN WHICH THE FAILURE OR MALFUNCTION OF THE TAOS PRODUCT MAY
RESULT IN PERSONAL INJURY OR DEATH. USE OF TAOS PRODUCTS IN LIFE SUPPORT SYSTEMS IS EXPRESSLY
UNAUTHORIZED AND ANY SUCH USE BY A CUSTOMER IS COMPLETELY AT THE CUSTOMER’S RISK.
Te
ch
ni
LUMENOLOGY, TAOS, the TAOS logo, and Texas Advanced Optoelectronic Solutions are registered trademarks of Texas Advanced
Optoelectronic Solutions Incorporated.
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TMD2772
DIGITAL ALS
and PROXIMITY MODULE
Te
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TAOS147E − DECEMBER 2012
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