TAOS TSL25717

TSL2571
LIGHT-TO-DIGITAL CONVERTER
r
r
TAOS117A − FEBRUARY 2011
Features
PACKAGE FN
DUAL FLAT NO-LEAD
(TOP VIEW)
D Ambient Light Sensing (ALS)
−
−
−
−
D
D
D
D
Approximates Human Eye Response
Programmable Analog Gain
Programmable Integration Time
Programmable Interrupt Function with
Upper and Lower Threshold
− Resolution Up to 16 Bits
− Very High Sensitivity — Operates Well
Behind Darkened Glass
− Up to 1,000,000:1 Dynamic Range
Programmable Wait Timer
− Programmable from 2.72 ms
to > 8 Seconds
− Wait State — 65 mA Typical Current
I2C Interface Compatible
− Up to 400 kHz (I2C Fast Mode)
− Dedicated Interrupt Pin
Small 2 mm 2 mm ODFN Package
Sleep Mode — 2.5 mA Typical Current
VDD 1
6 SDA
SCL 2
5 INT
GND 3
4 NC
Applications
D
D
D
D
D
D
Display Management
Backlight Control
Portable Device Power Optimization
Cell Phones, PDA, GPS
Notebooks and Monitors
LCD TVs
Description
The TSL2571 family of devices provides ambient light sensing (ALS) that approximates human eye response
to light intensity under a variety of lighting conditions and through a variety of attenuation materials. While useful
for general purpose light sensing, the device is particularly useful for display management with the purpose of
extending battery life and providing optimum viewing in diverse lighting conditions. Display panel and keyboard
backlighting can account for up to 30 to 40 percent of total platform power. The ALS features are ideal for use
in notebook PCs, LCD monitors, flat-panel televisions, and cell phones.
Functional Block Diagram
Interrupt
GND
INT
Wait Control
CH0
Data
ALS Control
CH0
CH1
ADC
CH1
Data
Lower Limit
I2C Interface
Upper Limit
CH0
ADC
VDD
SCL
SDA
CH1
The LUMENOLOGY r Company
Copyright E 2011, 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
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TSL2571
LIGHT-TO-DIGITAL CONVERTER
TAOS117A − FEBRUARY 2011
Detailed Description
The TSL2571 light-to-digital device includes on-chip photodiodes, integrating amplifiers, ADCs, accumulators,
clocks, buffers, comparators, a state machine, and an I2C interface. The device combines one photodiode
(CH0), which is responsive to both visible and infrared light, and one photodiode (CH1), which is responsive
primarily to infrared light. Two integrating ADCs simultaneously convert the amplified photodiode currents into
a digital value providing up to 16 bits of resolution. Upon completion of the conversion cycle, the conversion
result is transferred to the data registers. This digital output can be read by a microprocessor through which the
illuminance (ambient light level) in lux is derived using an empirical formula to approximate the human eye
response.
Communication to 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 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 value. An interrupt is generated when the value of an ALS 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.
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TSL2571
LIGHT-TO-DIGITAL CONVERTER
TAOS117A − FEBRUARY 2011
Terminal Functions
TERMINAL
TYPE
NAME
NO.
GND
3
INT
5
NC
4
SCL
2
I
SDA
6
I/O
VDD
1
DESCRIPTION
Power supply ground. All voltages are referenced to GND.
O
Interrupt — open drain (active low).
Do not connect.
I2C serial clock input terminal — clock signal for I2C serial data.
I2C serial data I/O terminal — serial data I/O for I2C .
Supply voltage.
Available Options
DEVICE
PACKAGE − LEADS
INTERFACE DESCRIPTION
ORDERING NUMBER
TSL25711
0x39
FN−6
I2C
Vbus = VDD Interface
TSL25711FN
TSL25713
0x39
FN−6
I2C Vbus = 1.8 V Interface
TSL25713FN
TSL25715†
0x29
FN−6
I2C Vbus = VDD Interface
TSL25715FN
FN−6
I2C
TSL25717FN
TSL25717†
†
ADDRESS
0x29
Vbus = 1.8 V Interface
Contact TAOS for availability.
Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage, VDD (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8 V
Digital output voltage range, VO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 3.8 V
Digital output current, IO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −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.
NOTE 1: All voltages are with respect to GND.
Recommended Operating Conditions
MIN
NOM
MAX
Supply voltage, VDD
2.6
3
3.6
V
Operating free-air temperature, TA
−30
70
°C
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LIGHT-TO-DIGITAL CONVERTER
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Operating Characteristics, VDD = 3 V, TA = 25C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
Active
IDD
Supply current
VOL
INT SDA output low voltage
INT,
I LEAK
Leakage current, SDA, SCL, INT pins
VIH
SCL SDA input high voltage
SCL,
VIL
SCL SDA input low voltage
SCL,
TYP
MAX
175
250
Wait mode
65
Sleep mode — no I2C activity
2.5
μA
4
3 mA sink current
0
0.4
6 mA sink current
0
0.6
−5
5
TSL25711, TSL25715
0.7 VDD
TSL25713, TSL25717
1.25
UNIT
V
μA
V
TSL25711, TSL25715
0.3 VDD
TSL25713, TSL25717
0.54
V
ALS Characteristics, VDD = 3 V, TA = 25C, Gain = 16, AEN = 1 (unless otherwise noted)
(Notes 1 ,2, 3)
PARAMETER
TEST CONDITIONS
Dark ADC count value
Ee = 0, AGAIN = 120×,
ATIME = 0xDB (100 ms)
ADC integration time step size
ATIME = 0xFF
CHANNEL
MIN
TYP
MAX
CH0
0
1
5
CH1
0
1
5
2.58
2.72
2.9
ADC Number of integration steps
ADC counts per step
ATIME = 0xFF
ADC count value
ATIME = 0xC0
ADC count value
ADC count value ratio: CH1/CH0
Re
Irradiance responsivity
G i scaling,
Gain
li
relative
l ti to
t 1× gain
i
setting
CH0
λp = 850 nm, Ee = 219.7 μW/cm2,
ATIME = 0xF6 (27 ms) See note 3.
CH0
ms
256
steps
0
1024
counts
65535
counts
4000
CH1
5000
6000
790
4000
CH1
5000
6000
counts
2800
λp = 625 nm
nm, ATIME = 0xF6 (27 ms) See note 2
2.
10 8
10.8
15 8
15.8
20.8
20 8
λp = 850 nm
nm, ATIME = 0xF6 (27 ms) See note 3
3.
41
56
68
λp = 625 nm, ATIME = 0xF6 (27 ms)
See note 2.
CH0
29.1
CH1
4.6
λp = 850 nm, ATIME = 0xF6 (27 ms)
See note 3.
CH0
22.8
CH1
12.7
%
counts/
(μW/
cm2)
8×
−10
10
16×
−10
10
10
−10
10
120×
counts
1
0
λp = 625 nm, Ee = 171.6 μW/cm2,
ATIME = 0xF6 (27 ms) See note 2.
UNIT
%
NOTES: 1. Optical measurements are made using small-angle incident radiation from light-emitting diode optical sources. Visible 625 nm LEDs
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.
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TSL2571
LIGHT-TO-DIGITAL CONVERTER
TAOS117A − FEBRUARY 2011
Wait Characteristics, VDD = 3 V, TA = 25C, WEN = 1 (unless otherwise noted)
PARAMETER
TEST CONDITIONS
Wait step size
CHANNEL
WTIME = 0xFF
Wait number of integration steps
MIN
TYP
2.58
2.72
1
MAX
UNIT
2.9
ms
256
steps
AC Electrical Characteristics, VDD = 3 V, TA = 25C (unless otherwise noted)
PARAMETER†
†
(I2C
TEST CONDITIONS
MIN
only)
TYP
0
MAX
UNIT
400
kHz
f(SCL)
Clock frequency
t(BUF)
Bus free time between start and stop condition
1.3
μs
t(HDSTA)
Hold time after (repeated) start condition. After
this period, the first clock is generated.
0.6
μs
t(SUSTA)
Repeated start condition setup time
0.6
μs
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
300
ns
tR
Clock/data rise time
300
ns
Ci
Input pin capacitance
10
pF
Specified by design and characterization; not production tested.
PARAMETER MEASUREMENT INFORMATION
t(LOW)
t(R)
t(F)
VIH
SCL
VIL
t(HDSTA)
t(BUF)
t(HIGH)
t(HDDAT)
t(SUSTA)
t(SUSTO)
t(SUDAT)
VIH
SDA
VIL
P
Stop
Condition
S
S
Start
Condition
Start
P
Stop
t(LOWSEXT)
SCLACK
SCLACK
t(LOWMEXT)
t(LOWMEXT)
t(LOWMEXT)
SCL
SDA
Figure 1. Timing Diagrams
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TYPICAL CHARACTERISTICS
SPECTRAL RESPONSIVITY
NORMALIZED IDD
vs.
VDD and TEMPERATURE
110%
1
Ch 0
108%
75C
IDD Normalized @ 3 V, 25C
Normalized Responsivity
0.8
0.6
0.4
Ch 1
106%
104%
50C
25C
102%
100%
0.2
0C
98%
96%
94%
0
300
400
500
600
700
800
92%
2.7
900 1000 1100
2.8
2.9
λ − Wavelength − nm
3
3.1
3.2
3.3
VDD — V
Figure 2
Figure 3
NORMALIZED RESPONSIVITY
vs.
ANGULAR DISPLACEMENT
1.0
Optical Axis
Normalized Responsivity
0.8
0.6
0.4
0.2
0
−90
-Q
+Q
90
−60
−30
0
30
60
Q − Angular Displacement − °
Figure 4
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LIGHT-TO-DIGITAL CONVERTER
TAOS117A − FEBRUARY 2011
PRINCIPLES OF OPERATION
System State Machine
The device provides control of ALS and power management functionality through an internal state machine
(Figure 5). After a power-on-reset, the device is in the sleep mode. As soon as the PON bit is set, the device
will move to the start state. It will then continue through the Wait and ALS states. If these states are enabled,
the device will execute each function. If the PON bit is set to 0, the state machine will continue until all
conversions are completed and then go into a low power sleep mode.
Sleep
PON = 1 (r 0:b0)
PON = 0 (r 0:b0)
Start
ALS
Wait
Figure 5. Simplified State Diagram
NOTE: In this document, the nomenclature uses the bit field name in italic followed by the register number and
bit number to allow the user to easily identify the register and bit that controls the function. For example, the
power on (PON) is in register 0, bit 0. This is represented as PON (r0:b0).
Photodiodes
Conventional silicon 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)
due to the difference between the silicon detector response and the brightness perceived by the human eye.
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.
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ALS Operation
The ALS engine contains ALS gain control (AGAIN) and two integrating analog-to-digital converters (ADC) for
the Channel 0 and Channel 1 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.
ATIME(r 1)
2.72 ms to 696 ms
CH0
ALS
CH0
Data
C0DATAH(r 0x15), C0DATA(r 0x14)
ALS Control
CH0
CH1
ADC
CH1
Data
C1DATAH(r 0x17), C1DATA(r 0x16)
CH1
AGAIN(r 0x0F, b1:0)
1, 8, 16, 120 Gain
Figure 6. 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 / 2.72 ms
Inversely, the time can be calculated from the register value as follows:
Integration Time = 2.72 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.
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 TAOS 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.
CPL = (ATIME_ms × AGAINx) / (GA × 53)
Lux1 = (C0DATA − 2 × C1DATA) / CPL
Lux2 = (0.6 × C0DATA − C1DATA) / CPL
Lux = MAX(Lux1, Lux2, 0)
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Interrupts
The interrupt feature simplifies and improves system efficiency by eliminating the need to poll the sensor for
light intensity values outside of a user-defined range. While the interrupt function is always enabled and it’s
status is available in the status register (0x13), the output of the interrupt state can be enabled using the ALS
interrupt enable (AIEN) field in the enable register (0x00).
Two 16-bit interrupt threshold registers allow the user to set limits below and above a desired light level 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). It is important to note that the low threshold value must be less than the high
threshold value for proper operation.
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 occurrences before an interrupt is generated.
The persistence register (0x0C) allows the user to set the ALS persistence (APERS) value. See the persistence
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).
AIHTH(r 07), AIHTL(r 06)
Upper Limit
CH0
ADC
APERS(r 0x0C, b3:0)
ALS Persistence
CH0
Data
Lower Limit
CH0
AILTH(r 05), AILTL(r 04)
Figure 7. Programmable Interrupt
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State Diagram
Figure 8 shows a more detailed flow for the state machine. The device starts in the sleep mode. The PON bit
is written to enable the device. A 2.72-ms delay will occur before entering the start state.
If the WEN bit is set, the state machine will then cycle through the wait state. If the WLONG bit is set, the wait
cycles are extended by 12× over normal operation. When the wait counter terminates, the state machine will
step to the ALS state.
The AEN should always be set. In this case, a minimum of 1 integration time step should be programmed. The
ALS state machine will continue until it reaches the terminal count at which point the data will be latched in
the ALS register and the interrupt set, if enabled.
1 to 256 steps
Step: 2.72 ms
Time: 2.72 ms − 696 ms
120 Hz Minimum − 8 ms
100 Hz Minimum − 10 ms
Sleep
PON = 1
PON = 0
Start
ALS
ALS
Check
AEN = 1
Wait
Check
ALS
Delay
2.72 ms
WEN = 1
Wait
WLONG = 0
1 to 256 steps
Step: 2.72 ms
Time: 2.72 ms − 696 ms
Minimum − 2.72 ms
WLONG = 1
1 to 256 steps
Step: 32.64 ms
Time: 32.64 ms − 8.35 s
Minimum − 32.64 ms
Figure 8. Expanded State Diagram
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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 17).
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 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/.
A
N
P
R
S
S
W
...
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
S
7
Slave Address
1
W
1
A
8
1
Command Code
8
A
1
Data Byte
A
8
1
1
...
P
I2C Write Protocol
1
S
7
Slave Address
1
R
1
A
8
1
Data
A
Data
A
1
...
P
I2C Read Protocol
1
7
1
1
8
1
1
7
1
1
S
Slave Address
W
A
Command Code
A
S
Slave Address
R
A
8
Data
1
8
A
Data
1
A
1
...
P
I2C Read Protocol — Combined Format
Figure 9. I2C Protocols
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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 1. Register Address
ADDRESS
RESISTER NAME
R/W
−−
COMMAND
W
0x00
ENABLE
0x01
0x03
0x04
0x05
0x06
REGISTER FUNCTION
RESET VALUE
Specifies register address
0x00
R/W
Enables states and interrupts
0x00
ATIME
R/W
ALS ADC time
0xFF
WTIME
R/W
Wait time
0xFF
AILTL
R/W
ALS interrupt low threshold low byte
0x00
AILTH
R/W
ALS interrupt low threshold high byte
0x00
AIHTL
R/W
ALS interrupt high threshold low byte
0x00
0x07
AIHTH
R/W
ALS interrupt high threshold high byte
0x00
0x0C
PERS
R/W
Interrupt persistence filters
0x00
0x0D
CONFIG
R/W
Configuration
0x00
0x0F
CONTROL
R/W
Control register
0x00
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
ID
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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Command Register
The command registers specifies the address of the target register for future write and read operations.
Table 2. Command Register
7
6
COMMAND
COMMAND
FIELD
BITS
COMMAND
7
TYPE
6:5
5
4
3
TYPE
2
1
0
−−
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
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 register/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
00110
ALS interrupt clear
other
Reserved — do not write
ALS interrupt clear — clears any pending ALS interrupt. This special function is self clearing.
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Enable Register (0x00)
The ENABLE register is used to power the device on/off, enable functions, and interrupts.
Table 3. Enable Register
7
6
5
Reserved
ENABLE
4
3
2
1
0
AIEN
WEN
Reserved
AEN
PON
Address
0x00
FIELD
BITS
DESCRIPTION
Reserved
7:5
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.
Reserved
2
Reserved. Write as 0.
AEN
1
ALS Enable. Writing a 1 activates the ALS. Writing a 0 disables the ALS.
PON 1
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.
Reserved. Write as 0.
NOTE 1: A minimum interval of 2.72 ms must pass after PON is asserted before ALS can be initiated. This required time is enforced by the
hardware in cases where the firmware does not provide it.
ALS Timing Register (0x01)
The ALS timing register controls the internal integration time of the ALS ADCs in 2.72-ms increments.
Table 4. ALS Timing Register
FIELD
BITS
ATIME
7:0
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DESCRIPTION
VALUE
INTEG_CYCLES
TIME
0xFF
1
2.72 ms
1024
0xF6
10
27.2 ms
10240
0xDB
37
101 ms
37888
0xC0
64
174 ms
65535
0x00
256
696 ms
65535
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Wait Time Register (0x03)
Wait time is set 2.72 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.
Table 5. Wait Time Register
FIELD
BITS
WTIME
7:0
DESCRIPTION
REGISTER VALUE
WAIT TIME
TIME (WLONG = 0)
TIME (WLONG = 1)
0xFF
1
2.72 ms
0.032 sec
0xB6
74
201 ms
2.4 sec
0x00
256
696 ms
8.3 sec
NOTE: The Wait Time Register should be configured before AEN is asserted.
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 6. ALS Interrupt Threshold Registers
REGISTER
ADDRESS
BITS
AILTL
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
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Persistence Register (0x0C)
The persistence 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.
ALS interrupts are generated using C0DATA.
Table 7. Persistence Register
7
6
PERS
5
4
3
2
Reserved
1
0
Address
0x0C
APERS
FIELD
BITS
Reserved
7:4
Reserved
DESCRIPTION
APERS
3:0
Interrupt persistence. Controls rate of interrupt to the host processor.
FIELD VALUE
MEANING
0000
Every
INTERRUPT PERSISTENCE FUNCTION
0001
1
1 value outside of threshold range
0010
2
2 consecutive values out of range
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
Configuration Register (0x0D)
The configuration register sets the wait long time.
Table 8. Configuration Register
7
6
5
CONFIG
4
3
2
Reserved
0
WLONG
Reserved
Address
0x0D
FIELD
BITS
Reserved
7:2
WLONG
1
Wait Long. When asserted, the wait cycles are increased by a factor 12× from that programmed in the
WTIME register.
Reserved
0
Reserved. Write as 0.
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DESCRIPTION
Reserved. Write as 0.
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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 9. Control Register
7
6
5
CONTROL
4
3
2
1
0
Reserved
FIELD
BITS
Reserved
7:2
Reserved. Write bits as 0
AGAIN
1:0
ALS Gain Control.
Address
0x0F
AGAIN
DESCRIPTION
FIELD VALUE
ALS GAIN VALUE
00
1× gain
01
8× gain
10
16× gain
11
120× gain
ID Register (0x12)
The ID Register provides the value for the part number. The ID register is a read-only register.
Table 10. ID Register
7
6
5
4
ID
3
2
1
0
Address
0x12
ID
FIELD
BITS
ID
7:0
DESCRIPTION
0x04 = TSL25711 & TSL25715
Part number identification
0x0D = TSL25713 & TSL25717
Status Register (0x13)
The Status Register provides the internal status of the device. This register is read only.
Table 11. Status Register
7
STATUS
6
5
Reserved
FIELD
BIT
Reserved
7:5
AINT
4
Reserved
3:1
AVALID
0
4
3
AINT
2
1
Reserved
0
AVALID
Address
0x13
DESCRIPTION
Reserved. Write as 0.
ALS Interrupt. Indicates that the device is asserting an ALS interrupt.
Reserved.
ALS Valid. Indicates that the ALS CH0 / CH1 channels have completed an integration cycle.
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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.
Table 12. ADC Channel Data Registers
Copyright E 2011, TAOS Inc.
REGISTER
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
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APPLICATION INFORMATION: HARDWARE
Typical Hardware Application
A typical hardware application circuit is shown in Figure 10. A 1-μF low-ESR decoupling capacitor should be
placed as close as possible to the VDD pin.
VDD
VBUS
VDD
RP
1 mF
TSL2571
RP
RPI
INT
SCL
GND
SDA
Figure 10. Typical Application Hardware Circuit
VBUS in Figure 10 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.
PCB Pad Layout
Suggested PCB pad layout guidelines for the Dual Flat No-Lead (FN) surface mount package are shown in
Figure 11.
2500
Note: Pads can be
extended further if hand
soldering is needed.
1000
1000
400
650
1700
650
400
NOTES: A. All linear dimensions are in micrometers.
B. This drawing is subject to change without notice.
Figure 11. Suggested FN Package PCB Layout
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MECHANICAL DATA
PACKAGE FN
Dual Flat No-Lead
TOP VIEW
466 10
PIN OUT
TOP VIEW
PIN 1
466
10
2000 100
2000
100
VDD 1
6 SDA
SCL 2
5 INT
GND 3
4 NC
Photodiode Array Area
END VIEW
SIDE VIEW
295
Nominal
650 50
203 8
650
300
50
BOTTOM VIEW
CL of Photodiode Array Area
(Note B)
CL of Solder Contacts
20 Nominal
140 Nominal
CL of Solder Contacts
CL of Photodiode Array Area (Note B)
PIN 1
Pb
750 150
NOTES: A.
B.
C.
D.
E.
F.
Lead Free
All linear dimensions are in micrometers. Dimension tolerance is ± 20 μm unless otherwise noted.
The die is centered within the package within a tolerance of ± 3 mils.
Package top surface is molded with an electrically nonconductive clear plastic compound having an index of refraction of 1.55.
Contact finish is copper alloy A194 with pre-plated NiPdAu lead finish.
This package contains no lead (Pb).
This drawing is subject to change without notice.
Figure 12. Package FN — Dual Flat No-Lead Packaging Configuration
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MECHANICAL DATA
TOP VIEW
2.00 0.05
1.75
4.00
1.50
4.00
B
+ 0.30
8.00
− 0.10
3.50 0.05
1.00
0.25
A
B
A
DETAIL B
DETAIL A
5 Max
5 Max
0.254
0.02
2.18 0.05
NOTES: A.
B.
C.
D.
E.
F.
G.
2.18 0.05
0.83 0.05
Ao
Bo
Ko
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 178 millimeters in diameter and contains 3500 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.
Figure 13. Package FN Carrier Tape
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MANUFACTURING INFORMATION
The FN package 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.
Table 13. Solder Reflow Profile
PARAMETER
REFERENCE
DEVICE
Average temperature gradient in preheating
Soak time
2.5°C/sec
tsoak
2 to 3 minutes
Time above 217°C (T1)
t1
Max 60 sec
Time above 230°C (T2)
t2
Max 50 sec
Time above Tpeak −10°C (T3)
t3
Max 10 sec
Peak temperature in reflow
Tpeak
260°C
Temperature gradient in cooling
Tpeak
Max −5°C/sec
Not to scale — for reference only
T3
T2
Temperature (C)
T1
Time (sec)
t3
t2
tsoak
t1
Figure 14. Solder Reflow Profile Graph
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MANUFACTURING 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 dry-baked prior to being packed for shipping.
Devices are 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.
The FN package has been assigned a moisture sensitivity level of MSL 3 and the devices should be stored under
the following conditions:
Temperature Range
Relative Humidity
Total Time
Opened Time
5°C to 50°C
60% maximum
12 months from the date code on the aluminized envelope — if unopened
168 hours or fewer
Rebaking will be required if the devices have been stored unopened for more than 12 months or if the aluminized
envelope has been open for more than 168 hours. If rebaking is required, it should be done at 50°C for 12 hours.
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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
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).
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.
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.
LUMENOLOGY, TAOS, the TAOS logo, and Texas Advanced Optoelectronic Solutions are registered trademarks of Texas Advanced
Optoelectronic Solutions Incorporated.
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