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TMD2772/
TMD2772WA
Digital ALS and Proximity Module
General Description
The TMD2772/TMD2772WA 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 and are
available with 25° and 50° fields of view. 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/TMD2772WA ALS is based on the ams 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.
Ordering Information and Content Guide appear at end of
datasheet.
Key Benefits & Features
The benefits and features of TMD2772/TMD2772WA, Digital ALS
and Proximity Module are listed below:
Figure 1:
Added Value of Using TMD2772/TMD2772WA
Benefits
Features
• Minimizes board space requirements
• Ambient light sensing, proximity detection, and IR LED
in a single module
• Approximates human eye response over a
wide variety of lighting conditions. Achieves
accurate sensing behind spectrally dark glass.
• Ambient light sensing (ALS)
• Wide variety of programmable features which
enable 8,000,000:1 dynamic range with very high
sensitivity
ams Datasheet
[v1-21] 2016-Feb-16
Page 1
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TMD2772/ TMD2772WA − General Description
Benefits
Features
• Eliminates need for customer end-product
calibration.
• Reduces the proximity noise
• Control of system crosstalk and offset
• Prevents false proximity detection in bright
light
• Selectable IR power-level without external
resistor
• Enables wide operating range
• Proximity detection
• Calibrated and trimmed to provide consistent
reading
• Reduced proximity count variation (1)
• Programmable offset (1)
• Saturation indicator bit (1)
• Programmable driver for IR LED
• 16,000:1 dynamic range
• Reduces external processor burden
• Maskable ALS and proximity interrupt
• Programmable upper and lower thresholds with
persistence filter
• Enables dynamic power dissipation control
• Power management
• Programmable average power consumption
• Programmable wait time from 2.7 ms to > 8
seconds
• Industry standard two-wire interface
• I²C fast mode compatible interface
• Data rates up to 400 kbit/s
• Input voltage levels compatible with VDD or 1.8V
bus
• Small foot-print module
• 3.94 mm x 2.36 mm x 1.35 mm package
• Optimize ambient light sensing angle
• Available with standard 25° (TMD2772) and wide 50°
(TMD2772WA)
Note(s):
1. New or Improved feature.
Applications
The TMD2772 applications include:
• Display Backlight Control
• Cell Phone Touch Screen Disable
• Mechanical Switch Replacement
• Industrial Process Control
• Medical Diagnostics
• Printer Paper Alignment
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − General Description
Block Diagram
The functional blocks of this device are shown below:
Figure 2:
TMD2772/TMD2772WA Block Diagram
LEDA LEDK
VDD
LDR
IR
LED
Programmable
Current Sink
CH0 ADC
CH0
INT
CH1 ADC
CH1
I²C Interface
Control
SCL
SDA
TMD2772/TMD2772WA
ams Datasheet
[v1-21] 2016-Feb-16
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TMD2772/ TMD2772WA − Pin Assignment
This is a Package Module - 8 pin diagram. Package drawing is
not to scale.
Pin Assignment
Figure 3:
Pin Diagram (Top View)
TMD2772
TMD2772WA
VDD
1
8
SDA
VDD
1
8
SDA
SCL
2
7
INT
SCL
2
7
INT
GND 3
6
LDR
GND 3
6
LDR
LEDA 4
5 LEDK
LEDA 4
5 LEDK
Figure 4:
Pin Description
Pin Number
Pin Name
1
VDD
Power
Supply voltage.
2
SCL
Input
I²C serial clock input terminal — clock signal for I²C
serial data.
3
GND
Power
Power supply ground. All voltages are referenced
to GND.
4
LEDA
LED anode.
5
LEDK
LED cathode. Connect to LDR pin when using
internal LED driver circuit.
6
LDR
LED driver input for proximity IR LED, constant
current source LED driver.
7
INT
Output
Interrupt — open drain (active low).
8
SDA
Input / Output
I²C serial data I/O terminal — serial data I/O for I²C.
Page 4
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Pin Type
Description
ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Absolute Maximum Ratings
Absolute Maximum Ratings
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. These are stress
ratings only. 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 rating conditions for extended periods may affect
device reliability.
Figure 5:
Absolute Maximum Ratings
Symbol
VDD (1)
VLDR (2)
Parameter
Min
Supply Voltage
Voltage on LDR signal with LDR = off.
• TA between
0° C - 70° C
• TA between
LED supply voltage on LEDA input
• TA between
0° C - 70° C
• TA between
-30° C - 70° C
• TA outside of
-30° C - 85° C
VIO
Digital I/O Voltage except LDR
IOut
Unit
3.8
V
4.8
4.6
4.4
-30° C - 70° C
• TA outside of -30° C - 85° C
VLEDA (3)
Max
4.8
4.6
4.4
V
V
-0.5
3.8
V
Output terminal current except LDR
-1
20
mA
Tstg
Storage temperature range
-40
85
°C
TA
Operating free-air temperature
-30
85
°C
ISCR
Input Current
(latch up immunity)
JEDEC JESD78D Nov 2011
CLASS 1 µA
ESDHBM
Electrostatic Discharge HBM
JS-001-2014
± 2000
V
ESDCDM
Electrostatic Discharge CDM
JEDEC JESD22-C101F Oct 2013
± 500
V
Note(s):
1. All voltages are with respect to GND.
2. Maximum voltage with LDR = off.
3. 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.
ams Datasheet
[v1-21] 2016-Feb-16
Page 5
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TMD2772/ TMD2772WA − Electrical Characteristics
All limits are guaranteed. The parameters with min and max
values are guaranteed with production tests or SQC (Statistical
Quality Control) methods.
Electrical Characteristics
Figure 6:
Recommended Operating Conditions
Symbol
Parameter
Min
Typ
Max
Unit
Supply voltage
2.2
3
3.6
V
Supply voltage accuracy, VDD total error
including transients
-3
3
%
TA
Operating free-air temperature (1)
-30
85
°C
VLEDA
LED supply voltage on LEDA input
• TA between 0-70° C
2.5
2.5
4.8
4.4
V
VDD
• TA outside of 0-70° C
Note(s):
1. While the device is operational across the temperature range, functionality will vary with temperature. Specifications are stated
only at 25°C unless otherwise noted.
Figure 7:
Operating Characteristics VDD = 3V, TA = 25°C (unless otherwise noted)
Symbol
IDD
VOL
ILEAK
VIH
VIL
Parameter
Supply current
Conditions
Min
Typ
Max
Active — LDR pulse off
195
250
Wait state
90
Sleep state — no I²C
activity
2.2
Units
μA
4
3 mA sink current
0
0.4
6 mA sink current
0
0.6
Leakage current, SDA,
SCL, INT pins
-5
5
μA
Leakage current, LDR pin
-5
5
μA
INT, SDA output low
voltage
SCL, SDA input high
voltage
SCL, SDA input low
voltage
Page 6
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V
TMD27721, TMD27725,
TMD27721WA
0.7 VDD
V
TMD27723, TMD27727,
TMD27723WA
TMD27721, TMD27725,
TMD27721WA
1.25
0.3 VDD
V
TMD27723, TMD27727,
TMD27723WA
0.54
ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Electrical Characteristics
Figure 8:
ADC Characteristics, VDD = 3V, TA = 25°C, AGAIN = 16x, AEN = 1 (unless otherwise noted)
Parameter
Dark ADC count value
ADC Integration time
step size
Test Conditions
Ee = 0, AGAIN = 120×,
ATIME = 0xDB (100ms)
ATIME = 0xFF
ADC number of
integration steps
Channel
Min
Typ
Max
Unit
CH0
0
1
5
CH1
0
1
5
2.58
2.73
2.9
ms
1
256
steps
counts
ADC counts per step
ATIME = 0xFF
0
1023
counts
ADC count value
ATIME = 0xC0
0
65535
counts
ams Datasheet
[v1-21] 2016-Feb-16
Page 7
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TMD2772/ TMD2772WA − Electrical Characteristics
Figure 9:
ALS Characteristics, V DD = 3V, TA = 25°C, AGAIN = 16x, AEN = 1 (unless otherwise noted)
Parameter
Test Conditions (1), (2), (3), (4)
λp = 625 nm, Ee = 46.8 μW/cm2
ADC count value
TMD2772 (25°)
λp = 850 nm, Ee = 61.7 μW/cm2
λp = 625 nm, Ee = 129.5 μW/cm2
ADC count value
TMD2772WA (50°)
λp = 850 nm, Ee = 181.2 μW/cm2
ADC count value
ratio: CH1/CH0
Re Irradiance
responsivity
TMD2772 (25°)
Re Irradiance
responsivity
TMD2772WA (50°)
Channel
Min
Typ
Max
CH0
4000
5000
6000
counts
CH1
CH0
950
4000
5000
6000
counts
CH1
CH0
2900
4000
5000
6000
counts
CH1
CH0
950
4000
5000
6000
counts
CH1
2900
λp = 625 nm
0.152
0.19
0.228
λp = 850 nm
0.43
0.58
0.73
CH0
107.2
CH1
20.4
CH0
81.5
CH1
47.3
CH0
38.6
CH1
7.3
CH0
27.6
CH1
16.0
λp = 625 nm
counts
/(μW/
cm2)
λp = 850 nm
λp = 625 nm
counts
/(μW/
cm2)
λp = 850 nm
AGAIN = 1× and AGL = 1
Gain scaling,
relative to 1× gain
setting
Unit
0.16
AGAIN = 8× and AGL = 0
7.2
8.0
8.8
AGAIN = 16× and AGL = 0
14.4
16.0
17.6
AGAIN = 120× and AGL = 0
108
120
132
x
Note(s):
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.
4. Unless otherwise specified, measurements are taken with ATIME= 0xF6 (27 ms).
Page 8
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Electrical Characteristics
Figure 10:
Proximity Characteristics, VDD = LEDA = 3V, TA = 25°C, PEN = 1 (unless otherwise noted)
Parameter
I DD Supply current
I LEDA LEDA current (1)
Test Conditions
Min
LED On
Typ
Max
3
LED On, PDRIVE = 0
100
LED On, PDRIVE = 1
50
LED On, PDRIVE = 2
25
LED On, PDRIVE = 3
12.5
Units
mA
mA
PTIME ADC conversion steps
1
256
steps
2.9
ms
PTIME ADC conversion time
PTIME = 0xFF
(= 1 conversion step)
2.58
PTIME ADC counts per step
PTIME = 0xFF
(= 1 conversion step)
0
1023
counts
0
255
pulses
PPULSE LED pulses (2)
2.73
LED On LED pulse width
PPULSE = 1, PDRIVE = 0
7.3
μs
LED pulse period
PPULSE = 2, PDRIVE = 0
16.0
μs
Proximity response, no
target (offset)
PPULSE = 8, PDRIVE = 0,
PGAIN = 4×, (3)
100
counts
Prox count, 100mm target,
TMD2772 devices (4)
73 mm × 83 mm, 90% reflective
Kodak Gray Card, PGAIN = 4×,
PPULSE = 8, PDRIVE = 0,
PTIME = 0xFF (5)
450
520
590
counts
Prox count, 100mm target,
TMD2772WA devices (4)
73 mm × 83 mm, 90% reflective
Kodak Gray Card, PGAIN = 4×,
PPULSE = 8, PDRIVE = 0,
PTIME = 0xFF (5)
235
275
315
counts
Note(s):
1. Value is factory-adjusted to meet the Prox count specification. Considerable variation (relative to the typical value) is possible after
adjustment.
2. These parameters are ensured by design and characterization and are not 100% tested.
3. Proximity offset varies with power supply characteristics and noise.
4. ILEDA is factory calibrated to achieve this specification. Offset and crosstalk directly sum with this value and is system dependent.
5. No glass or aperture above the module. Tested value is the average of 5 consecutive readings.
6. Proximity test was done using the circuit shown in Figure 12. See PCB Pad Layout for recommended application circuit.
ams Datasheet
[v1-21] 2016-Feb-16
Page 9
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TMD2772/ TMD2772WA − Electrical Characteristics
Figure 11:
Proximity Test Circuit
Figure 12:
IR LED Characteristics, VDD = 3V, TA = 25°C
Parameter
Test Conditions
Min
Typ
Max
Unit
VF Forward Voltage
IF = 100 mA
1.5
2.2
V
VR Reverse Voltage
IR = 10 μA
5
V
PO Radiant Power
IF = 20 mA
4.5
mW
λp Peak Wavelength
IF = 20 mA
850
nm
Δλ Spectral Radiation
Bandwidth
IF = 20 mA
40
nm
Figure 13:
Wait Characteristics, VDD = 3V, TA = 25°C, WEN = 1 (unless otherwise noted)
Parameter
Conditions
Wait steps
Wait time
Page 10
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Min
Typ
1
WTIME = 0xFF (= 1 wait step)
2.73
Max
Units
256
steps
2.9
ms
ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Timing Characteristics
Timing Characteristics
Figure 14:
AC Electrical Characteristics, VDD = 3V, TA = 25°C (unless otherwise noted)
Parameter (1)
Conditions
Min
Max
Unit
0
400
kHz
fSCL
Clock frequency (I²C only)
tBUF
Bus free time between start and stop condition
1.3
μs
tHD;STA
Hold time after (repeated) start condition.
After this period, the first clock is generated.
0.6
μs
tSU;STA
Repeated start condition setup time
0.6
μs
tSU;STO
Stop condition setup time
0.6
μs
tHD;DAT
Data hold time
10
ns
tSU;DAT
Data setup time
100
ns
tLOW
SCL clock low period
1.3
μs
tHIGH
SCL clock high period
0.6
μs
tF
Clock/data fall time
300
ns
tR
Clock/data rise time
300
ns
Ci
Input pin capacitance
10
pF
Note(s):
1. Specified by design and characterization; not production tested.
Timing Diagrams
Figure 15:
Parameter Measurement Information
tHIGH
tR
tLOW
tF
VIH
SCL
VIL
tHD; STA
tSU; DAT
tHD; DAT
tSU; STA
tSU; STO
tBUF
SDA
VIH
VIL
STOP
ams Datasheet
[v1-21] 2016-Feb-16
START
START
STOP
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TMD2772/ TMD2772WA − Typical Operating Characteristics
Typical Operating
Characteristics
Figure 16:
Spectral Responsivity
Figure 17:
Normalized IDD vs. VDD and Temperature
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Typical Operating Characteristics
Figure 18:
Normalized Responsivity vs. Angular Displacement for Non-WA and WA Devices
Both axes
for
TMD2772
Both axes for
TMD2772WA
ams Datasheet
[v1-21] 2016-Feb-16
Page 13
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TMD2772/ TMD2772WA − Typical Operating Characteristics
Figure 19:
Proximity Response of TMD2772 and TMD2772WA Modules
Proximity Response of TMD2772 and TMD2772WA
Conditions; PPULSE =8, PDRIVE = 0, PGAIN = 4x
1200
Proximity Count
1000
800
600
TMD2772
TMD2772WA
400
200
0
0
25
50
75
100
125
150
175
Distance in milimeters
(Response to 73mm x 83mm, 90% reflective Kodak Gray card)
Figure 20:
Typical LDR Current vs. Voltage
Page 14
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − 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.
Detailed Description
Figure 21:
Detailed Block Diagram of TMD2772/TMD2772WA
VDD
LDR
IR LED Constant
Current Sink
Prox Control
INT
Interrupt
Upper Limit
Prox
Prox ADC Prox Data
Integration
SCL
Lower Limit
LEDA
Upper Limit
CH0 ADC CH0 Data
LEDK
Lower Limit
Channel 0
I²C Interface
Wait Control
SDA
ALC Control
CH1 ADC CH1 Data
Channel 1
TMD2772
GND
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
ams Datasheet
[v1-21] 2016-Feb-16
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TMD2772/ TMD2772WA − Detailed Description
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.
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.
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.
Page 16
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Principles of Operation
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.
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 22. 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.
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 Interrupts for additional
information.
Figure 22:
Simplified State Diagram
ams Datasheet
[v1-21] 2016-Feb-16
Page 17
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TMD2772/ TMD2772WA − Principles of Operation
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).
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.
ALS Operation
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.
Figure 23:
ALS Operation
Page 18
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Principles of 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.
Lux Equation
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 ams application note).
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.
Lux formula for TMD2772:
CPL = (ATIME_ms × AGAINx) / 20
Lux1 = (C0DATA – (1.75 × C1DATA)) / CPL
Lux2 = ((0.63 × C0DATA) – (1.00 × C1DATA)) / CPL
Lux = MAX(Lux1, Lux2, 0)
Lux formula for TMD2772WA:
CPL = (ATIME_ms × AGAINx) / 1.16
Lux1 = (C0DATA - (1.8422 x C1DATA)) / CPL
Lux2 = ((0.4106 x C0DATA) - (0.667 x C1DATA)) / CPL
Lux = MAX(Lux1, Lux2, 0)
ams Datasheet
[v1-21] 2016-Feb-16
Page 19
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TMD2772/ TMD2772WA − Principles of Operation
Proximity Detection
Proximity detection is accomplished by measuring the amount
of I R 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 24.The proximity detector will see light reflected from
the intended target as well as light reflected through any path.
Both surfaces of a transparent cover will reflect some of the IR
LEDs energy. An air gap of less the 0.5mm between the top of
the module and the cover is recommended. For a detailed
explanation of the of the effects of an air gap see ams
application note; Application Note DN58: Proximity Detection
Behind Glass for a detailed discussion of optical design
considerations.
Figure 24:
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
100%, 50%, 25%, or 12.5% 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 25 during the Prox
Accum state. Figure 25 also illustrates that the LED On pulse has
a fixed width of 7.3μs and period of 16.0μs. So, in addition to
setting the proximity drive current, 1 to 255 proximity pulses
(PPULSE) can be programmed. When deciding on the number
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TMD2772/ TMD2772WA − Principles of Operation
of proximity pulses, keep in mind that the signal increases
proportionally to PPULSE, while noise increases by the square
root of PPULSE.
Figure 25:
Proximity LED Current Driver Waveform
Figure 24 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.
Referring again to Figure 25, 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 4× 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
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
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TMD2772/ TMD2772WA − Principles of Operation
is programmable from 1 to 256 2.73ms 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 2.73ms
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 ams 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).
For additional information on using the proximity detection
function behind glass and for optical system design guidance,
please see available ams application notes.
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).
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).
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.
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
Interrupt register (0x0C) allows the user to set the ALS
persistence filter (APERS) and the proximity persistence filter
(PPERS) values. See the Interrupt Register (0x0C) 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
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TMD2772/ TMD2772WA − Principles of Operation
Figure 26:
Programmable Interrupt
System State Machine Timing
The system state machine shown in Figure 27 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.
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 27. 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.
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 27.
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TMD2772/ TMD2772WA − Principles of Operation
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 27. 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.
Figure 27:
Detailed State Machine
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TMD2772/ TMD2772WA − Principles of Operation
Power Management
Power consumption can be managed with the Wait state,
because the Wait state typically consumes only 90μA of I DD
current. An example of the power management feature is given
below. With the assumptions provided in the example, average
I DD is estimated to be 176μA.
Figure 28:
Power Management
System State
Machine State
Programmable
Parameter
Programmed
Value
Prox Init
Prox Accum
PPULSE
0x04
Duration
Typical
Current
2.73 ms
0.195 mA
0.064 ms
Prox Accum − LED On
0.029 ms (1)
103 mA
Prox Accum − LED OFF
0.035 ms (2)
0.195 mA
2.73 ms
0.195 mA
2.73 ms
0.195 mA
49 2 ms
0 090 mA
2.73 ms
0.195 mA
49 2 ms
0.195 mA
Prox Wait
Prox ADC
PTIME
0xFF
WTIME
0xEE
Wait
WLONG
ALS Init
ALS ADC
ATIME
0xEE
Note(s):
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
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TMD2772/ TMD2772WA − Principles of Operation
Average I DD 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,
Figure 29 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.
Figure 29:
Average IDD Current
WEN
WTIME
WLONG
WAIT State
Average IDD Current
0
n/a
n/a
0 ms
245 μA
1
0xFF
0
2.73 ms
238 μA
1
0xEE
0
49.2 ms
175 μA
1
0x00
0
699 ms
102 μA
1
0x00
1
8389 ms
91 μA
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TMD2772/ TMD2772WA − Principles of Operation
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.
The I²C standard provides for three types of bus transaction:
read, write, and a combined protocol (Figure 30). 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.
The I²C bus protocol was developed by Phillips (now NXP). For
a complete description of the I²C protocol, please review the
NXP I²C design specification at
http://www.i2c-bus.org/references/
Figure 30:
I²C Protocols
7
1
S Slave Address
1
1
8
1
8
1
1
W
A
Command Code
A
Data Byte
A
P
I2C Write Protocol
1
7
S Slave Address
1
1
8
1
8
1
1
R
A
Data
A
Data
A
P
I2C Read Protocol
1
S
7
Slave Address
1
1
W A
8
1
1
7
1
1
Command Code
A
Sr
Slave Address
R
A
8
1
8
1
1
Data
A
Data
A
P
I2C Read Protocol – Combined Format
A
N
P
R
S
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Acknowledge (0)
Not Acknowledged (1)
Stop Condition
Read (1)
Start Condition
Sr
W
…
Repeated Start Condition
Write (0)
Communication of Protocol
Master-to-Slave
Slave-to-Master
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TMD2772/ TMD2772WA − Register Description
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 Figure 31.
Register Description
Figure 31:
Register Map
Address
Register Name
R/W
---
COMMAND
W
0x00
ENABLE
0x01
Register Function
Reset Value
Specifies register address
0x00
R/W
Enables states and interrupts
0x00
ATIME
R/W
Integration time
0xFF
0x02
PTIME
R/W
Proximity ADC time
0xFF
0x03
WTIME
R/W
Wait time
0xFF
0x04
AILTL
R/W
ALS interrupt low threshold low byte
0x00
0x05
AILTH
R/W
ALS interrupt low threshold high byte
0x00
0x06
AIHTL
R/W
ALS interrupt high threshold low byte
0x00
0x07
AIHTH
R/W
ALS interrupt high threshold high byte
0x00
0x08
PILTL
R/W
Proximity interrupt low threshold low byte
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
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Rev Num
0x39
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TMD2772/ TMD2772WA − Register Description
Address
Register Name
R/W
Register Function
Reset Value
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
0x19
PDATAH
R
Proximity ADC high data register
0x00
0x1E
POFFSET
R/W
Proximity offset register
0x00
The mechanics of accessing a specific register depends on the
specific protocol used (see I²C Protocol). 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/ TMD2772WA − Register Description
Command Register
The Command Register specifies the address of the target
register for future write and read operations. The command
register defaults to 0x00 at power-on.
Figure 32:
Command Register
7
6
COMMAND
5
4
TYPE
3
2
1
0
ADD
Field
Bits
Description (Reset value = 0x00)
COMMAND
7
Select Command Register. Must write as 1 when addressing COMMAND register.
Selects type of transaction to follow in subsequent data transfers:
Field Value
TYPE
Description
00
Repeated byte protocol transaction
01
Auto-increment protocol transaction
10
Reserved — Do not use
11
Special function – See description below
6:5
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.
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
ADD
4:0
Description
00000
Normal — no action
00101
Proximity interrupt clear
00110
ALS interrupt clear
00111
Proximity and ALS interrupt clear
other
Reserved — Do not write
ALS/Proximity Interrupt Clear clears any pending ALS/Proximity interrupt. This
special function is self clearing.
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TMD2772/ TMD2772WA − Register Description
Enable Register (0x00)
The Enable Register is used to power the device on/off, enable
functions, and interrupts.
Figure 33:
Enable Register
7
6
5
4
3
2
1
0
Reserved
SAI
PIEN
AIEN
WEN
PEN
AEN
PON
Field
Bits
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 interrupt 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
ALS Enable. This bit activates the two channel ADC. Writing a 1 activates the
ALS. Writing a 0 disables the ALS.
PON
0
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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Description (Reset value = 0x00)
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TMD2772/ TMD2772WA − Register Description
ALS Time Register (0x01)
The ALS Time Register controls the internal integration time of
the ALS channel ADS’s in 2.73ms increments. Time is expressed
as a 2’s complement number.
To calculate the value:
1. Determine the number of 2.73ms intervals required
2. Take the 2’s complement
For a 1 x 2.73ms interval, 0xFF should be written. For 2 x 2.73ms
intervals, 0xFE should be written. The maximum integration
time is 699ms (0x00).
Figure 34:
ALS Time Register
7
6
5
4
3
2
1
0
ATIME
Description (Reset value = 0xFF)
Field
ATIME
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Bits
7:0
Value
Cycles
Time
Max Count
0xFF
1
2.73 ms
1024
0xF6
10
27.3 ms
10240
0xDB
37
101 ms
37888
0xC0
64
175 ms
65535
0x00
256
699 ms
65535
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TMD2772/ TMD2772WA − Register Description
Proximity Time Register (0x02)
The Proximity Time Register controls the integration time of the
proximity ADC in 2.73 ms increments. Time is expressed as a 2’s
complement number. It is recommended that this register be
programmed to a value of 0xFF (1 integration cycle).
Figure 35:
Proximity Time Register
7
6
5
4
3
2
1
0
PTIME
Description (Reset value = 0xFF)
Field
Bits
PTIME
7:0
Value
Cycles
Time
Max Count
0xFF
1
2.73 ms
1023
Wait Time Register (0x03)
Wait time is set in 2.73 ms increments unless the WLONG bit is
asserted in which case the wait times are 12x longer. WTIME is
programmed as a 2’s complement number.
Figure 36:
Wait Time Register
7
6
5
4
3
2
1
0
WTIME
Description (Reset value = 0xFF)
Field
WTIME
Bits
7:0
Register Value
Wait Time
Time
(WLONG=0)
Time
(WLONG=1)
0xFF
1
2.73 ms
0.033 s
0xB6
74
202 ms
2.4 s
0x00
256
699 ms
8.4 s
Note(s):
1. The Proximity Wait Time Register should be configured before PEN and/or AEN is/are asserted.
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TMD2772/ TMD2772WA − Register Description
ALS Interrupt Threshold Register (0x04 − 0x07)
The ALS Interrupt Threshold Registers provide the values to be
used as the high and low trigger points for the comparison
function for interrupt generation. If C0DATA is not between the
low and high thresholds and the persistence criteria is met, an
interrupt is asserted on the interrupt pin.
Figure 37:
ALS Interrupt Threshold Registers
Register
Address
Bits
Description (Reset value = 0x00)
AILTL
0x04
7:0
ALS low threshold lower byte
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
Proximity Interrupt Threshold Register (0x08 −
0x0B)
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 is not between the low and high thresholds
and the persistence criteria is met, an interrupt is signaled to
the host processor.
Figure 38:
Proximity Interrupt Threshold Registers
Register
Address
Bits
PILTL
0x08
7:0
Proximity low threshold lower byte
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
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Description (Reset value = 0x00)
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TMD2772/ TMD2772WA − Register Description
Interrupt Register (0x0C)
The Interrupt Register controls the filtering interrupt
capabilities of the device. Configurable filtering is provided to
allow interrupts to be generated after each ADC integration
cycle or if the ADC integration 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 by looking only at the C0DATA
ADC integration results.
Figure 39:
Interrupt Register
7
6
5
4
3
2
PPERS
Field
1
0
APERS
Bits
Description (Reset value = 0x00)
Proximity interrupt persistence filter. Controls rate of proximity interrupt to the
host processor.
PPERS
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7:4
Field Value
Meaning
Interrupt Persistence
0000
Every
0001
1
1 proximity value outside of threshold
range
0010
2
2 consecutive proximity values out of
range
…
…
…
1111
15
15 consecutive proximity values out of
range
Every proximity cycle generates an
interrupt
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TMD2772/ TMD2772WA − Register Description
Field
Bits
Description (Reset value = 0x00)
ALS Interrupt persistence filter. Controls rate of interrupt to the host processor.
APERS
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Field Value
Persistence
Interrupt Persistence
0000
Every
0001
1
1 value outside of threshold range
0010
2
2 consecutive values out of range
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
Every ALS cycle generates an interrupt
3:0
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TMD2772/ TMD2772WA − Register Description
Configuration Register (0x0D)
The Configuration Register sets the proximity LED drive level,
wait long time, and ALS gain level
Figure 40:
Configuration Register.
7
6
5
4
3
Reserved
2
1
0
AGL
WLONG
PDL
Field
Bits
Description (Reset value = 0x00)
Reserved
7:3
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. Should be set = 0
anytime AGAIN is greater than 8x, or if using a TMD module.
WLONG
1
Wait Long. When asserted, the wait cycles are increased by a factor 12x
from that programmed in the WTIME register.
PDL
0
Proximity drive level. When asserted, the proximity LDR drive current is
reduced by 9.
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 62.5kHz rate.
Figure 41:
Proximity Pulse Count Register
7
6
5
4
3
2
1
0
PPULSE
Field
Bits
Description
PPULSE
7:0
Proximity Pulse Count. Specifies the number of proximity pulses
to be generated.
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TMD2772/ TMD2772WA − Register Description
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.
Figure 42:
Control Register
7
6
5
PDRIVE
Field
4
3
PDIODE
2
1
0
PGAIN
Bits
AGAIN
Description (Reset value = 0x00)
Proximity LED Drive Strength.
PDRIVE (1)
Field Value
LED Strength – PDL=0
LED Strength – PDL=1
00
100 %
11.1 %
01
50 %
5.6 %
10
25 %
2.8 %
11
12.5 %
1.4 %
7:6
Proximity Diode Selector.
PDIODE
Field Value
Diode Selection
00
Proximity uses neither diode
01
Proximity uses the CH0 diode
10
Proximity uses the CH1 diode
11
Reserved — Do not write
5:4
Proximity Gain.
PGAIN
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Field Value
Proximity Gain Value
00
1x gain
01
2x gain
10
4x gain
11
8x gain
3:2
ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Register Description
Field
Bits
Description (Reset value = 0x00)
ALS Gain
AGAIN
Field Value
ALS Gain Value
00
1X Gain
01
8X Gain
10
16X Gain
11
120X Gain
1:0
Note(s):
1. LED STRENGTH values are nominal operating values. Specifications can be found in the Proximity Characteristics table.
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.
Figure 43:
Revision Register
7
6
5
4
3
Reserved
1
0
DIE_REV
Field
Bits
RESERVED
7:4
Reserved.
DIE_REV
3:0
Die revision number
ams Datasheet
[v1-21] 2016-Feb-16
2
Description (Reset value = Rev Num)
Page 39
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TMD2772/ TMD2772WA − Register Description
ID Register (0x12)
The ID Register provides the value for the part number. The ID
register is a read-only register whose value never changes.
Figure 44:
ID Register
7
6
5
4
3
2
1
0
ID
Field
Bit
Description (Reset value = ID)
TMD27721 = 0x30
TMD27723 = 0x39
TMD27725 = 0x30
ID
7:0
TMD27727 = 0x39
TMD27721WA = 0x30
TMD27723WA = 0x39
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Register Description
Status Register (0x13)
The Status Register provides the internal status of the device.
This register is read only.
Figure 45:
Status Register
7
6
5
4
Reserved
PSAT
PINT
AINT
3
2
Reserved
1
0
PVALID
AVALID
Field
Bits
Description (Reset value = 0x00)
Reserved
7
Reserved. Bit reads as 0.
PSAT
6
Proximity Saturation. Indicates the proximity measurement saturated.
PINT
5
Proximity Interrupt. Indicates that the device is asserting a proximity
interrupt.
AINT
4
ALS Interrupt. Indicates that the device is asserting an ALS interrupt.
Reserved
3:2
PVALID
1
Proximity Valid. Indicates that the Proximity channel has completed
an integration cycle after the PEN bit has been asserted.
AVALID
0
ALS Valid. Indicates that the ALS channels have completed an
integration cycle after AEN has been asserted.
Reserved. Bits read as 0.
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.
Figure 46:
ADC Channel Data Registers
Register
Address
Bits
C0DATA
0x14
7:0
ALS CH0 data low byte
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
ams Datasheet
[v1-21] 2016-Feb-16
Description (Reset value = 0x00)
Page 41
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TMD2772/ TMD2772WA − Register Description
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.
Figure 47:
Proximity Data Registers
Register
Address
Bits
PDATAL
0x18
7:0
Proximity data low byte
PDATAH
0x19
7:0
Proximity data high byte
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Description (Reset value = 0x00)
ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Register Description
Proximity Offset Register (0x1E)
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). 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 ams application
notes for proximity offset register application information.
The default value on power up is factory trimmed to provide a
typical proximity offset of 100. This is achieved with no glass or
reflective object above the sensor, and PPULSE=08, PGAIN=10,
PDRIVE=00. If the value is changed during use but power is
removed it will return to the default value on power up.
Figure 48:
Proximity Offset Register
7
6
5
SIGN
4
3
2
1
0
MAGNITUDE
Field
Bits
SIGN
7
MAGNITUDE
ams Datasheet
[v1-21] 2016-Feb-16
6:0
Description (Reset value = trimmed value)
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).
Page 43
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TMD2772/ TMD2772WA − Application Information
Application Information
LED Driver Pin with Proximity Detection
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 V DD 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 1μF low-ESR
decoupling capacitor as close as possible to the VDD pin and
another at the LEDA pin, and at least 10μF of bulk capacitance
to supply the 100mA current surge. This may be distributed as
two 4.7μF capacitors.
Figure 49:
Proximity Sensing Using Separate Power Supplies
VBUS
Voltage
Regulator
VDD
1µF
GND
TMD2772
Or
TMD2772WA
RP
RP
RPI
INT
SCL
Voltage
Regulator
LEDA
SDA
1µF
LEDK
LDR
If it is not possible to provide two separate power supplies, the
device can be operated from a single supply. A 22Ω resistor in
series with the V DD supply line and a 1μF low ESR capacitor
effectively filter any power supply noise. The previous capacitor
placement considerations apply.
Page 44
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Application Information
Figure 50:
Proximity Sensing Using Single Power Supply
VBUS
22
Voltage
Regulator
VDD
1µF
Per
regulator
datasheet
GND
TMD2772
Or
TMD2772WA
RP
RP
RPI
INT
SCL
LEDA
SDA
1µF
LEDK
LDR
V BUS in the above figures refers to the I²C bus voltage which is
either V DD or 1.8V. 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 ams EVM running at 400 kbps, uses 1.5kΩ
resistors. A 10kΩ pull-up resistor (RPI) can be used for the
interrupt line.
ams Datasheet
[v1-21] 2016-Feb-16
Page 45
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TMD2772/ TMD2772WA − PCB Pad Layout
PCB Pad Layout
Suggested PCB pad layout guidelines for the surface mount
module are shown below. Flash Gold is recommended surface
finish for the landing pads.
This footprint is recommended for both the TMD2772 and the
TMD2772WA.
Figure 51:
Suggested Module PCB Layout
Note(s):
1. All linear dimensions are in millimeters.
2. Dimension tolerances are ±0.05mm unless otherwise noted.
3. This drawing is subject to change without notice.
Page 46
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Packaging Mechanical Data
Packaging Mechanical Data
Figure 52:
TMD2772 Module Dimensions
RoHS
Green
Note(s):
1. All linear dimensions are in millimeters.
2. Dimension tolerance is ± 0.05 mm unless otherwise noted.
3. Contacts are copper with NiPdAu plating.
4. This package contains no lead (Pb).
5. This drawing is subject to change without notice.
ams Datasheet
[v1-21] 2016-Feb-16
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TMD2772/ TMD2772WA − Packaging Mechanical Data
Figure 53:
TMD2772WA Module Dimensions
RoHS
Green
Note(s):
1. All linear dimensions are in millimeters.
2. Dimension tolerance is ± 0.05 mm unless otherwise noted.
3. Contacts are copper with NiPdAu plating.
4. This package contains no lead (Pb).
5. This drawing is subject to change without notice.
Page 48
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Carrier Tape & Reel Information
Carrier Tape & Reel Information
Figure 54:
TMD2772 Module Carrier Tape
Note(s):
1. All linear dimensions are in millimeters. Dimension tolerance is ± 0.10mm unless otherwise noted.
2. The dimensions on this drawing are for illustrative purposes only. Dimensions of an actual carrier may vary slightly.
3. Symbols on drawing Ao, Bo, and Ko are defined in ANSI EIA Standard 481−B 2001.
4. Each reel is 330 millimeters in diameter and contains 2500 parts.
5. ams packaging tape and reel conform to the requirements of EIA Standard 481−B.
6. In accordance with EIA standard, device pin 1 is located next to the sprocket holes in the tape.
7. This drawing is subject to change without notice.
ams Datasheet
[v1-21] 2016-Feb-16
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TMD2772/ TMD2772WA − Carrier Tape & Reel Information
Figure 55:
TMD2772WA Module Carrier Tape
Note(s):
1. All linear dimensions are in millimeters. Dimension tolerance is ± 0.10mm unless otherwise noted.
2. The dimensions on this drawing are for illustrative purposes only. Dimensions of an actual carrier may vary slightly.
3. Symbols on drawing Ao, Bo, and Ko are defined in ANSI EIA Standard 481−B 2001.
4. Each reel is 330 millimeters in diameter and contains 2500 parts.
5. ams packaging tape and reel conform to the requirements of EIA Standard 481−B.
6. In accordance with EIA standard, device pin 1 is located next to the sprocket holes in the tape.
7. This drawing is subject to change without notice.
Page 50
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Manufacturing Information
Manufacturing Information
The module has been tested and has demonstrated an ability
to be reflow soldered to a PCB substrate.
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.
Figure 56:
Solder Reflow Profile
Parameter
Reference
Average temperature gradient in preheating
Soak time
Device
2.5°C/s
tsoak
2 to 3 minutes
Time above 217°C (T1)
t1
Max 60 s
Time above 230°C (T2)
t2
Max 50 s
Time above 250°C (T3)
t3
Max 10 s
Peak temperature in reflow
260°C
Tpeak
Temperature gradient in cooling
Max −5°C/s
Figure 57:
Solder Reflow Profile Graph
Tpeak
Not to scale — for reference only
T3
T2
Temperature (5C)
T1
Time (sec)
(s)
t3
t2
tsoak
ams Datasheet
[v1-21] 2016-Feb-16
t1
Page 51
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TMD2772/ TMD2772WA − Storage Information
Storage Information
Moisture Sensitivity
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:
• Shelf Life: 12 months
• Ambient Temperature: < 40°C
• Relative Humidity: < 90%
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.
Floor Life
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
When the shelf life or floor life limits have been exceeded,
rebake at 50°C for 12 hours.
Page 52
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Ordering & Contact Information
Ordering & Contact Information
Figure 58:
Configuration and Ordering Information
Ordering
Code
Description
Package
− Leads
ID (0x12)
I²C
Address
Angular
Response
TMD27721
I²C VBUS = VDD Interface
Module − 8
0x30
0x39
± 25°
TMD27723
I²C VBUS = 1.8V Interface
Module − 8
0x39
0x39
± 25°
TMD27725 (1)
I²C VBUS = VDD Interface
Module − 8
0x30
0x29
± 25°
TMD27727 (1)
I²C VBUS = 1.8V Interface
Module − 8
0x39
0x29
± 25°
TMD27721WA (1)
I²C VBUS = VDD Interface
Module − 8
0x30
0x39
± 50°
TMD27723WA
I²C VBUS = 1.8V Interface
Module − 8
0x39
0x39
± 50°
Note(s):
1. Contact ams for availability.
Buy our products or get free samples online at:
www.ams.com/ICdirect
Technical Support is available at:
www.ams.com/Technical-Support
Provide feedback about this document at:
www.ams.com/Document-Feedback
For further information and requests, e-mail us at:
[email protected]
For sales offices, distributors and representatives, please visit:
www.ams.com/contact
Headquarters
ams AG
Tobelbaderstrasse 30
8141 Premstaetten
Austria, Europe
Tel: +43 (0) 3136 500 0
Website: www.ams.com
ams Datasheet
[v1-21] 2016-Feb-16
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TMD2772/ TMD2772WA − RoHS Compliant & ams Green Statement
RoHS Compliant & ams Green
Statement
RoHS: The term RoHS compliant means that ams AG products
fully comply with current RoHS directives. Our semiconductor
products do not contain any chemicals for all 6 substance
categories, including the requirement that lead not exceed
0.1% by weight in homogeneous materials. Where designed to
be soldered at high temperatures, RoHS compliant products are
suitable for use in specified lead-free processes.
ams Green (RoHS compliant and no Sb/Br): ams Green
defines that in addition to RoHS compliance, our products are
free of Bromine (Br) and Antimony (Sb) based flame retardants
(Br or Sb do not exceed 0.1% by weight in homogeneous
material).
Important Information: The information provided in this
statement represents ams AG knowledge and belief as of the
date that it is provided. ams AG 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. ams AG 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. ams AG
and ams AG suppliers consider certain information to be
proprietary, and thus CAS numbers and other limited
information may not be available for release.
Page 54
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ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Copyrights & Disclaimer
Copyrights & Disclaimer
Copyright ams AG, Tobelbader Strasse 30, 8141 Premstaetten,
Austria-Europe. Trademarks Registered. All rights reserved. The
material herein may not be reproduced, adapted, merged,
translated, stored, or used without the prior written consent of
the copyright owner.
Devices sold by ams AG are covered by the warranty and patent
indemnification provisions appearing in its General Terms of
Trade. ams AG makes no warranty, express, statutory, implied,
or by description regarding the information set forth herein.
ams AG reserves the right to change specifications and prices
at any time and without notice. Therefore, prior to designing
this product into a system, it is necessary to check with ams AG
for current information. This product is intended for use in
commercial applications. Applications requiring extended
temperature range, unusual environmental requirements, or
high reliability applications, such as military, medical
life-support or life-sustaining equipment are specifically not
recommended without additional processing by ams AG for
each application. This product is provided by ams AG “AS IS”
and any express or implied warranties, including, but not
limited to the implied warranties of merchantability and fitness
for a particular purpose are disclaimed.
ams AG shall not be liable to recipient or any third party for any
damages, including but not limited to personal injury, property
damage, loss of profits, loss of use, interruption of business or
indirect, special, incidental or consequential damages, of any
kind, in connection with or arising out of the furnishing,
performance or use of the technical data herein. No obligation
or liability to recipient or any third party shall arise or flow out
of ams AG rendering of technical or other services.
ams Datasheet
[v1-21] 2016-Feb-16
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TMD2772/ TMD2772WA − Document Status
Document Status
Document Status
Product Preview
Preliminary Datasheet
Datasheet
Datasheet (discontinued)
Page 56
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Product Status
Definition
Pre-Development
Information in this datasheet is based on product ideas in
the planning phase of development. All specifications are
design goals without any warranty and are subject to
change without notice
Pre-Production
Information in this datasheet is based on products in the
design, validation or qualification phase of development.
The performance and parameters shown in this document
are preliminary without any warranty and are subject to
change without notice
Production
Information in this datasheet is based on products in
ramp-up to full production or full production which
conform to specifications in accordance with the terms of
ams AG standard warranty as given in the General Terms of
Trade
Discontinued
Information in this datasheet is based on products which
conform to specifications in accordance with the terms of
ams AG standard warranty as given in the General Terms of
Trade, but these products have been superseded and
should not be used for new designs
ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Revision Information
Revision Information
Changes from 1-20 (2014-Jul-21) to current revision 1-21 (2016-Feb-16)
Page
Updated Figure 5
5
Updated Figure 58
53
Note(s):
1. Page and figure numbers for the previous version may differ from page and figure numbers in the current revision.
2. Correction of typographical errors is not explicitly mentioned.
ams Datasheet
[v1-21] 2016-Feb-16
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TMD2772/ TMD2772WA − Content Guide
Content Guide
Page 58
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1
1
2
3
General Description
Key Benefits & Features
Applications
Block Diagram
4
5
6
Pin Assignment
Absolute Maximum Ratings
Electrical Characteristics
11
11
Timing Characteristics
Timing Diagrams
12
15
Typical Operating Characteristics
Detailed Description
17
17
18
18
19
20
22
23
25
27
Principles of Operation
System State Machine
Photodiodes
ALS Operation
Lux Equation
Proximity Detection
Interrupts
System State Machine Timing
Power Management
I²C Protocol
28
30
31
32
33
33
34
34
35
37
37
38
39
40
41
41
42
43
Register Description
Command Register
Enable Register (0x00)
ALS Time Register (0x01)
Proximity Time Register (0x02)
Wait Time Register (0x03)
ALS Interrupt Threshold Register (0x04 − 0x07)
Proximity Interrupt Threshold Register (0x08 − 0x0B)
Interrupt Register (0x0C)
Configuration Register (0x0D)
Proximity Pulse Count Register (0x0E)
Control Register (0x0F)
Revision Register (0x11)
ID Register (0x12)
Status Register (0x13)
ADC Channel Data Registers (0x14 − 0x17)
Proximity Data Registers (0x18 − 0x19)
Proximity Offset Register (0x1E)
ams Datasheet
[v1-21] 2016-Feb-16
TMD2772/ TMD2772WA − Content Guide
ams Datasheet
[v1-21] 2016-Feb-16
44
44
Application Information
LED Driver Pin with Proximity Detection
46
47
49
51
PCB Pad Layout
Packaging Mechanical Data
Carrier Tape & Reel Information
Manufacturing Information
52
52
52
52
52
Storage Information
Moisture Sensitivity
Shelf Life
Floor Life
Rebaking Instructions
53
54
55
56
57
Ordering & Contact Information
RoHS Compliant & ams Green Statement
Copyrights & Disclaimer
Document Status
Revision Information
Page 59
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