TSL2550T - Texas Advanced Optoelectronic Solutions

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

The LUMENOLOGY r Company r

www.taosinc.com

DConverts Light Intensity to Digital Signal

DInfrared Compensation to Approximate

Human Eye Response

DCompanding A/D for Wide Dynamic Range

DRejects 50 Hz/60 Hz Lighting Ripple

DTwo-Wire SMBus Serial Interface

DSingle Supply Operation (2.7 V to 5.5 V)

DLow Active Power (1 mW typ)

DPower Down Mode

DLow-Profile Surface-Mount Packages

DRoHS Compliant

Description

The TSL2550 is a digital-output light sensor with

a two-wire, SMBus serial interface. It combines

two photodiodes and a companding analog-to-

digital converter (ADC) on a single CMOS

integrated circuit to provide light measurements

over an effective 12-bit dynamic range with a

response similar to that of the human eye.

The TSL2550 is designed for use with broad wavelength light sources. One of the photodiodes (channel 0) is

sensitive to visible and infrared light, while the second photodiode (channel 1) is sensitive primarily to infrared

light. An integrating ADC converts the photodiode currents to channel 0 and channel 1 digital outputs. Channel

1 digital output is used to compensate for the effect of the infrared component of ambient light on channel 0

digital output. The ADC digital outputs of the two channels are used to obtain a value that approximates the

human eye response in the commonly used unit of Lux.

This device is intended primarily for use in applications in which measurement of ambient light is used to control

display backlighting such as laptop computers, PDAs, camcorders, and GPS systems. Other applications

include contrast control in LED signs and displays, camera exposure control, lighting controls, etc. The

integrating conversion technique used by the TSL2550 effectively eliminates the effect of flicker from

AC-powered lamps, increasing the stability of the measurement.

Functional Block Diagram

SMBCLK

Two-Wire Serial Interface

Integrating

A/D Converter

Control Logic Output Registers

SMBData

VDD = 2.7 V to 5.5 V

Channel 0

Photodiode

Channel 1

Photodiode

Texas Advanced Optoelectronic Solutions Inc.

1001 Klein Road S Suite 300 S Plano, TX 75074 S (972) 673-0759

8 SMBData

7 NC

6 NC

5 SMBCLK

PACKAGE D

8-LEAD SOIC

(TOP VIEW)

VDD 1

NC 2

NC 3

GND 4

PACKAGE T

4-LEAD SMD

(TOP VIEW)

VDD 1

GND 2

4 SMBData

3 SMBCLK

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

www.taosinc.com

Terminal Functions

TERMINAL

NAME D PKG

NO.

T PKG

NO.

TYPE DESCRIPTION

GND 4 2 Power supply ground. All voltages are referenced to GND.

SMBCLK 5 3 I SMBus serial clock input terminal — clock signal for SMBus serial data.

SMBData 8 4 I/O SMBus serial data I/O terminal — serial data I/O for SMBus.

VDD 1 1 Supply voltage.

Available Options

DEVICE TAPACKAGE − LEADS PACKAGE DESIGNATOR ORDERING NUMBER

TSL2550 −40°C to 85°SOIC−8 D TSL2550D

TSL2550 −40°C to 85°T−4 T TSL2550T

Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted)†

Supply voltage, VDD (see Note 1) 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Digital output voltage range, VO −0.3 V to +6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Digital output current, IO ±10 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SMBus input/output current, I(SMBIN) −1 mA to 20 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating free-air temperature range, TA −40°C to 85°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Storage temperature range, Tstg −40°C to 85°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ESD tolerance, human body model 2000 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Solder conditions in accordance with JEDEC J−STD−020A, maximum temperature (see Note 2) 260°C. . .

†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.

NOTES: 1. All voltage values are with respect to GND.

2. Package D only: The device may be hand soldered provided that heat is applied only to the solder pad and no contact is made

between the tip of the solder iron and the device lead. The maximum time heat should be applied to the device is 5 seconds.

Recommended Operating Conditions

MIN MAX UNIT

Supply voltage, VDD 2.7 5.5 V

Operating free-air temperature, TA0 70 °C

SMBus input low voltage @ VDD = 3.3 V ± 5%, VIL 0.8 V

SMBus input high voltage @ VDD = 3.3 V ± 5%, VIH 2.1 V

SMBus operating frequency, f(SMBCLK) 10 100 kHz

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

The LUMENOLOGY r Company r

www.taosinc.com

Electrical Characteristics over recommended operating free-air temperature range (unless

otherwise noted)

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

SMBus output low voltage

IO = 50 μA 0.01

VOL SMBus output low voltage IO = 4 mA 0.4 V

Supply current

Active, VSMBCLK and VSMDATA = VDD,

VDD = 3.3 V ± 5% 0.35 0.6 mA

IDD Supply current Power down, VSMBCLK and VSMDATA =

VDD, VDD = 3.3 V ± 5% 10 μA

IIH High level input current VI = VDD 5μA

IIL Low level input current VI = 0 −5μA

Operating Characteristics, VDD = 3.3 V, TA = 25C (unless otherwise noted) (see Notes 2, 3, 4)

PARAMETER TEST CONDITIONS CHANNEL MIN TYP MAX UNIT

E 0

Ch0 1

Ee = 0 Ch1 1

ADC count value standard mode

= 640 nm Ch0 639 799 959

counts

ADC count value, standard mode

λp = 640 nm

Ee = 72 μW/cm2Ch1 85 counts

= 940 nm Ch0 511 799 1039

λp = 940 nm

Ee = 140 μW/cm2Ch1 703

E 0

Ch0 1

Ee = 0 Ch1 1

ADC count value extended mode

= 640 nm Ch0 155

counts

ADC count value, extended mode

λp = 640 nm

Ee = 72 μW/cm2Ch1 16 counts

= 940 nm Ch0 155

λp = 940 nm

Ee = 140 μW/cm2Ch1 139

ADC count value ratio: Ch1/Ch0, λp = 640 nm, Ee = 72 μW/cm20.070 0.106 0.175

ADC count value ratio: Ch1/Ch0

standard mode λp = 940 nm, Ee = 140 μW/cm20.70 0.88 1.20

= 640 nm Ch0 11.1

Irradiance responsivity standard mode

λp = 640 nm

Ee = 72 μW/cm2Ch1 1.2 counts/

(μW/

ReIrradiance responsivity, standard mode

= 940 nm Ch0 5.7 (μW/

)

λp = 940 nm

Ee = 140 μW/cm2Ch1 5

cm2)

Fluorescent light source: 300 Lux

Ch0 2.8

Illuminance responsivity standard mode

Fluorescent light source: 300 Lux Ch1 0.23 counts/

RvIlluminance responsivity, standard mode

Incandescent light source: 50 Lux

Ch0 19

counts/

lux

Incandescent light source: 50 Lux Ch1 13

(Sensor Lux) / (actual Lux), standard mode Fluorescent light source: 300 Lux 0.65 1 1.35

(Sensor Lux) / (actual Lux)

standard mode

(Note 5) Incandescent light source: 50 Lux 0.5 1 1.5

NOTES: 3. Optical measurements are made using small-angle incident radiation from light-emitting diode optical sources. Visible 640 nm LEDs

and infrared 940 nm LEDs are used for final product testing for compatibility with high volume production.

4. The 640 nm irradiance Ee is supplied by an AlInGaP light-emitting diode with the following characteristics: peak wavelength

λp = 640 nm and spectral halfwidth Δλ½ = 17 nm.

5. The 940 nm irradiance Ee is supplied by a GaAs light-emitting diode with the following characteristics: peak wavelength

λp = 940 nm and spectral halfwidth Δλ½ = 40 nm.

6. The sensor Lux is calculated using the empirical formula shown on p. 11 of this data sheet based on measured Ch0 and Ch1 ADC

count values for the light source specified. Actual Lux is obtained with a commercial luxmeter. The range of the (sensor Lux) / (actual

Lux) ratio is estimated based on the variation of the 640 nm and 940 nm optical parameters. Devices are not 100% tested with

fluorescent or incandescent light sources.

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

www.taosinc.com

AC Electrical Characteristics, VDD = 3.3 V, TA = 25C (unless otherwise noted)

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

t(CONV) Conversion time, per channel, standard mode 400 ms

t(CONV) Conversion time, per channel, extended mode 80 ms

f(SMBCLK) Clock frequency 100 kHz

t(BUF) Bus free time between start and stop condition 4.7 μs

t(HDSTA)

Hold time after (repeated) start condition. After

this period, the first clock is generated. 4μs

t(SUSTA) Repeated start condition setup time 4.7 μs

t(SUSTO) Stop condition setup time 4μs

t(HDDAT) Data hold time 300 ns

t(SUDAT) Data setup time 250 ns

t(LOW) SMBCLK clock low period 4.7 μs

t(HIGH) SMBCLK clock high period 4μs

t(TIMEOUT) Detect clock/data low timeout 25 35 ms

tFClock/data fall time 300 ns

tRClock/data rise time 1000 ns

CiInput pin capacitance 10 pF

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

The LUMENOLOGY r Company r

www.taosinc.com

PARAMETER MEASUREMENT INFORMATION

SMBDATA

SMBCLK

StopStart

SMBCLKACK

t(LOWMEXT) t(LOWMEXT)

t(LOWSEXT)

SMBCLKACK

t(LOWMEXT)

Start

Condition

Stop

Condition

SMBDATA

t(SUSTO)

t(SUDAT)

t(HDDAT)

t(BUF)

VIH

VIL

SMBCLK

t(SUSTA)

t(HIGH)

t(F)

t(R)

t(HDSTA)

t(LOW)

VIH

VIL

PSS

Figure 1. SMBus Timing Diagrams

A0A1A2A3A4A5A6

SMBCLK

Start by

Master

SMBDATA

1919

D1D2D3D4D5D6D7 D0R/W

Frame 1 SMBus Slave Address Byte Frame 2 Command Byte

ACK by

TSL2550

Stop by

Master

ACK by

TSL2550

Figure 2. SMBus Timing Diagram for Send Byte Format

A0A1A2A3A4A5A6

SMBCLK

Start by

Master

SMBDATA

1919

D1D2D3D4D5D6D7 D0R/W

Frame 1 SMBus Slave Address Byte Frame 2 Data Byte From TSL2550

ACK by

TSL2550

Stop by

Master

NACK by

Master

Figure 3. SMBus Timing Diagram for Receive Byte Format

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

www.taosinc.com

TYPICAL CHARACTERISTICS

SPECTRAL RESPONSIVITY

λ − Wavelength − nm

Figure 4

400

0.2

0.4

0.6

0.8

500 600 700 800 900 1000 1100

Relative Responsivity

Channel 1

Photodiode

Channel 0

Photodiode

Figure 5

NORMALIZED ADC OUTPUT

vs.

SUPPLY VOLTAGE

VDD − Supply Voltage − V

Normalized ADC Output

2.5 3 3.5 4 4.5 5 5.5 6

0.2

0.4

0.6

0.8

1.2

1.4

1.6

1.8

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

The LUMENOLOGY r Company r

www.taosinc.com

PRINCIPLES OF OPERATION

Analog-to-Digital Converter

The TSL2550 contains an integrating analog-to-digital converter (ADC) that integrates a photodiode current.

First it integrates channel 0 photodiode current and then it integrates channel 1 photodiode current. At the end

of the conversion cycle for each channel, the conversion result is transferred to the appropriate channel 0 or

channel 1 ADC register. The transfer is double-buffered to ensure that invalid data is not read during the transfer.

After the data is transferred, the TSL2550 automatically begins the next conversion cycle. A VALID bit is used

to indicate that data has been written to the ADC register after ADC is enabled.

Interface to the ADC and control of other device functions is accomplished using the standard 2-wire System

Management Bus (SMBus) interface. Both versions 1.1 and 2.0 of the SMBus are supported.

The ADC has two operating modes: standard and extended. In standard mode, the integration time is 400 mS

for each channel or 800 mS for both channel 0 and channel 1. Extended mode shortens the integration time

by a factor of five with a corresponding decrease in responsivity of 5×. The extended range allows the device

to operate at higher light levels, extending the overall dynamic range by a factor of five.

Digital Interface

The TSL2550 contains an 8-bit command register that can be written and read via the SMBus. The command

converted value of each of the two ADC channels. The SMBus slave address is hardwired internally as 0111001

(MSB to LSB, A6 to A0).

Both the send byte protocol and the receive byte protocol are implemented in the TSL2550. The send byte

protocol allows single bytes of data to be written to the device (see Figure 6). The written byte is called the

COMMAND byte. The receive byte protocol allows single bytes of data to be read from the device (see Figure

7). The receive data can be either the previously written COMMAND byte or the data from one of the ADC

channels. In Figure 6 and Figure 7, the clear area represents data sent by the host and the shaded area

represents data returned by the ambient light sensor or slave device.

Data ByteSlave AddressS

APA

811 11

S = Start Condition P = Stop Condition Shaded = Slave Transmission

Figure 6. Send Byte Protocol

Data ByteSlave AddressS

APA

811 11

S = Start Condition P = Stop Condition Shaded = Slave Transmission

Figure 7. Receive Byte Protocol

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

www.taosinc.com

Command Register

The command register is used primarily to:

DSelect which ADC register will be read during a read cycle

DSwitch the dynamic range of the device between standard and extended range modes

DPower the device up for operation or power it down for minimum power consumption

Table 1 shows the six primary commands used to control the TSL2550.

Table 1. Command Summary

COMMAND FUNCTION

0x00h Power-down state

0x03h Power-up state/Read command register

0x1Dh Write command to assert extended range mode

0x18h Write command to reset or return to standard range mode

0x43h Read ADC channel 0

0x83h Read ADC channel 1

The content of the command register defaults to 0x00h when power is applied to the device, placing the device

into the power-down mode.

Once the TSL2550 is set to the standard range mode (0x18h) or the extended range mode (0x1Dh), the device

remains in that mode until it is powered down or the mode is changed via the command register.

The 0x03h command has two purposes: It is used to power up the device and can also be used to check that

the device is communicating properly. The value returned during a read cycle should be 0x03h.

ADC Register

The TSL2550 contains two ADC registers (channel 0 and channel 1). Each ADC register contains two

component fields that are used to determine the logarithmic ADC count value: CHORD bits and STEP bits. The

CHORD bits correspond to the most significant portion of the ADC value and specifies a segment of the

piece-wise linear approximation. The STEP bits correspond to the least significant portion of the ADC count

value and specifies a linear value within a segment. CHORD and STEP bits all equal to 0 corresponds to a

condition in which the light level is below the detection limit of the sensor. CHORD and STEP bits all equal to

1 corresponds to an overflow condition.

Each of the two ADC value registers contain seven data bits and a valid bit as described in Table 2.

Table 2. ADC Register Data Format

VALID CHORD BITS STEP BITS

B7 B6 B5 B4 B3 B2 B1 B0

VALID C2 C1 C0 S3 S2 S1 S0

FIELD BITS DESCRIPTION

VALID 7 ADC channel data is valid. One indicates that the ADC has written data into the

channel data register, since ADCEN was asserted in the COMMAND register.

CHORD 6 to 4 CHORD number.

STEP 3 to 0 STEP number.

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

The LUMENOLOGY r Company r

www.taosinc.com

The specific ADC value register read depends on the last read command written to the command register, as

described above and in the Operation section, below.

The MSB of the ADC register (VALID bit B7) is used to indicate that data has been written to the ADC register

after the device is powered up as described in Command Register section.

Bits 6 through 0 contain the 7-bit code representing the ADC count value, which is proportional to a

photodetector current. In this code, the ADC count value is represented by a piece-wise linear approximation

to a log function. The transfer function is broken into 8 chords of 16 steps each. (This code is very similar to μ-law

code used in audio compression — it differs in that it does not have a sign bit and it is not inverted.) Table 3 shows

the relationship between the CHORD and STEP bits and the CHORD and STEP numbers and values. These

are used to calculate the ADC count value.

Table 3. CHORD and STEP Numbers and Values vs Register Bits

CHORD

BITS

B6, B5, B4

C, CHORD

NUMBER

CHORD

VALUE

(Note A)

STEP

VALUE

(Note B)

STEP

BITS

B3, B2, B1, B0

S, STEP

NUMBER

000 0 0 1 0000 0

001 1 16 2 0001 1

010 2 49 4 0010 2

011 3 115 8 0011 3

100 4 247 16 0100 4

101 5 511 32 0101 5

110 6 1039 64 0110 6

111 7 2095 128 0111 7

1000 8

1001 9

1010 10

1011 11

1100 12

1101 13

1110 14

1111 15

NOTES: A. CHORD VALUE = INT (16.5 × ((2C) − 1))

B. STEP VALUE = 2C

The ADC count value is obtained by adding the CHORD VALUE and the product of the STEP NUMBER and

STEP VALUE (which depends on CHORD NUMBER).

ADC Count Value +((Chord Value) )(Step Value) (Step Number))

The ADC count value can also be expressed as a formula:

ADC Count Value +(INT (16.5 ((2C*1))) )(S (2C))

where:

C is the CHORD NUMBER (0 to 7)

S is the STEP NUMBER (0 to 15)

as defined in Table 3.

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

www.taosinc.com

Operation

After applying VDD, the device will initially be in the power down state. To operate the device, issue an SMBus

Send Byte protocol with the device address and the appropriate command byte to read ADC channel 0 or ADC

channel 1 (see Table 1). To obtain the conversion result, issue an SMBus Receive Byte protocol with the device

address. The data byte received will correspond to the value in the ADC register (0 or 1) specified by the previous

command. If a conversion has not been completed since power up (either through VDD or power up command),

the valid bit will be 0, and the data will not be valid. If there is a valid conversion result available, the valid bit

will be set (1), and the remaining 7 bits will represent valid data from the previously selected ADC register. Data

may be read repeatedly from the currently selected ADC register, and although it will remain valid, the ADC

serial 400 ms per channel conversion times in standard mode). Note also that the command register itself may

be read, as a check to be sure that the device is communicating properly.

To power down the device for reduced power consumption, issue an SMBus Send Byte protocol with the device

address followed by 0 as indicated in Table 1.

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

The LUMENOLOGY r Company r

www.taosinc.com

APPLICATION INFORMATION

The TSL2550 is intended for use in ambient light detection applications, such as display backlight control, where

adjustments are made to display brightness or contrast based on the brightness of the ambient light, as

perceived by the human eye. 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 in the TSL2550 through the use of two photodiodes. One of the photodiodes

(channel 0) is sensitive to both visible and infrared light, while the second photodiode (channel 1) is sensitive

primarily to infrared light. An integrating ADC converts the photodiode currents to channel 0 and channel 1 digital

outputs. Channel 1 digital output is used to compensate for the effect of the infrared component of light on the

channel 0 digital output. The ADC digital outputs from the two channels are used in a formula to obtain a value

that approximates the human eye response in the commonly used Illuminance unit of Lux. For standard mode:

Light Level (lux) +(Ch0 *Ch1) 0.39 e(*0.181R2)

where:

R = Ch1 Counts / (Ch0 Counts − Ch1 Counts)

The formula above was obtained by optical testing with fluorescent and incandescent light sources. The light

level calculated from the formula will be slightly higher than the actual light level for sunlight and will be slightly

lower than the actual light level for composite fluorescent and incandescent light sources.

NOTE:

Please see TAOS application notes for additional information, including implementing a display

brightness control system with the TSL2550, and for a simple implementation of the equation shown

above suitable for use in embedded microcontrollers.

Table 4 contains a summary of the typical sensor outputs for several common light sources.

Table 4. Sensor Output Summary (Standard Mode)

LIGHT SOURCE ILLUMINANCE

(LUX)

CHANNEL 0

(COUNTS)

CHANNEL 1

(COUNTS)

RATIO:

CH1/CH0

LUX per CH0

COUNT

Fluorescent 297 831 68 0.082 0.36

Daylight (shade) 201 895 343 0.383 0.22

Incandescent 42 959 671 0.7 0.04

Light from 50 or 60 Hz sources, and especially fluorescent lighting, has a high harmonic content. Since the

TSL2550 integrates the ambient light over an approximately 400 millisecond interval (per channel), this light

ripple is typically reduced to less than ¼ LSB.

Power Supply Decoupling

The power supply lines must be decoupled with a 0.1 μF capacitor placed as close to the device package as

possible. The bypass capacitor should have low effective series resistance (ESR) and effective series

inductance (ESI), such as the common ceramic types, which provide a low impedance path to ground at high

frequencies to handle transient currents caused by internal logic switching.

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

www.taosinc.com

APPLICATION INFORMATION

PCB Pad Layout

Suggested PCB pad layout guidelines for the D package and T package are shown in Figure 8 and Figure 9.

2.25

6.90

4.65

1.27

0.50

NOTES: A. All linear dimensions are in millimeters.

B. This drawing is subject to change without notice.

Figure 8. Suggested D Package PCB Layout

1.50

2.90

0.90

1.00

NOTES: A. All linear dimensions are in millimeters.

B. This drawing is subject to change without notice.

Figure 9. Suggested T Package PCB Layout

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

The LUMENOLOGY r Company r

www.taosinc.com

MECHANICAL DATA

PACKAGE D Plastic Small-Outline

PIN 1

6  1.27

0.510

0.330

8

 2.8 TYP

CLEAR WINDOW

NOTE B

1.75

1.35

0.50

0.25

4.00

3.80

6.20

5.80

45

0.88 TYP TOP OF

SENSOR DIE

5.00

4.80

5.3

MAX

1.27

0.41 0.25

0.10

0.25

0.19

DETAIL A

TOP VIEW

END VIEW

SIDE VIEW

PIN 1

BOTTOM VIEW

NOTES: A. All linear dimensions are in millimeters.

B. The center of the 1234 μm by 282 μm photo-active area is typically located in the center of the package in the long dimension and

269 μm off center in the short dimension.

C. Package is molded with an electrically nonconductive clear plastic compound having an index of refraction of 1.55.

D. This drawing is subject to change without notice.

Figure 10. Package D — Plastic Small Outline IC Packaging Configuration

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

www.taosinc.com

MECHANICAL DATA

PACKAGE T Four-Lead Surface Mount Device

TOP VIEW

SIDE VIEW

BOTTOM VIEW

3.80

2.60

1.35

3.10 2  7

0.35

1.50

0.55

DETAIL A: TYPICAL PACKAGE TERMINAL

0.78

0.90

1.23

0.67

0.281.46

PHOTODIODE ACTIVE AREA LOCATION

0.50

0.10

0.78

R 0.25

PIN 4

PIN 1

PIN 4

PIN 1

NOTES: A. All linear dimensions are in millimeters.

B. Terminal finish is gold.

C. Dimension tolerance is ± 0.15 mm.

D. This drawing is subject to change without notice.

Figure 11. Package T — Four-Lead Surface Mount Device Packaging Configuration

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

The LUMENOLOGY r Company r

www.taosinc.com

MECHANICAL DATA

0.292  0.013

[0.0115  0.0005]

2.11  0.10 [0.083  0.004]

2  0.05

[0.079 

0.002]

4  0.1

[0.157 

0.004]

1.75  0.10

[0.069  0.004]

12 + 0.3 − 0.1

[0.472 + 0.12 − 0.004]

SIDE VIEW

TOP VIEW END VIEW

DETAIL B

5.50  0.05

[0.217  0.002]

8  0.1

[0.315 

0.004]

 1.50

6.45  0.10

[0.254  0.004]

5.13  0.10

[0.202  0.004]

DETAIL A

AoBo

NOTES: A. All linear dimensions are in millimeters [inches].

B. The dimensions on this drawing are for illustrative purposes only. Dimensions of an actual carrier may vary slightly.

C. Symbols on drawing Ao, Bo, and Ko are defined in ANSI EIA Standard 481−B 2001.

D. Each reel is 178 millimeters in diameter and contains 1000 parts.

E. TAOS packaging tape and reel conform to the requirements of EIA Standard 481−B.

F. In accordance with EIA standard, device pin 1 is located next to the sprocket holes in the tape.

G. This drawing is subject to change without notice.

Figure 12. Package D Carrier Tape

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

www.taosinc.com

MECHANICAL DATA

0.30  0.050 2.10

4  0.100

2  0.100

8 Typ

1.75  0.100

5.50

 0.100

12  0.100

R 0.20 TYP

 1.50

SIDE VIEW

TOP VIEW

END VIEW

3.09 MAX

2.90  0.100 Ao

R 0.20 TYP

1.80 Ko

4.29 MAX

4.10  0.100 Bo

DETAIL B

DETAIL A

R 0.20 TYP

NOTES: A. All linear dimensions are in millimeters.

B. The dimensions on this drawing are for illustrative purposes only. Dimensions of an actual carrier may vary slightly.

C. Symbols on drawing Ao, Bo, and Ko are defined in ANSI EIA Standard 481−B 2001.

D. Each reel is 178 millimeters in diameter and contains 1000 parts.

E. TAOS packaging tape and reel conform to the requirements of EIA Standard 481−B.

F. In accordance with EIA standard, device pin 1 is located next to the sprocket holes in the tape.

G. This drawing is subject to change without notice.

Figure 13. Package T Carrier Tape

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

The LUMENOLOGY r Company r

www.taosinc.com

MANUFACTURING INFORMATION

The D and T packages have been tested and have demonstrated an ability to be reflow soldered to a PCB

substrate. The process, equipment, and materials used in these test are detailed below.

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 5. TSL2550 Solder Reflow Profile

PARAMETER REFERENCE TSL2550D/TSL2550T

Average temperature gradient in preheating 2.5°C/sec

Soak time tsoak 2 to 3 minutes

Time above 217°C t1Max 60 sec

Time above 230°C t2Max 50 sec

Time above Tpeak −10°C t3Max 10 sec

Peak temperature in reflow Tpeak 260° C (−0°C/+5°C)

Temperature gradient in cooling Max −5°C/sec

tsoak

Tpeak

Not to scale — for reference only

Time (sec)

Temperature (C)

Figure 14. TSL2550D/TSL2550T Solder Reflow Profile Graph

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

www.taosinc.com

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 molding compound.

Package D

To ensure the package molding compound contains the smallest amount of absorbed moisture possible, all

devices shipped in carrier tape have been pre-baked and shipped in a sealed moisture-barrier bag. No further

action is necessary if these devices are processed through solder reflow within 24 hours of the seal being broken

on the moisture-barrier bag.

However, for all devices shipped in tubes or if the seal on the moisture barrier bag has been broken for 24 hours

or longer, it is recommended that the following procedures be used to ensure the package molding compound

contains the smallest amount of absorbed moisture possible.

For devices shipped in tubes:

1. Remove devices from tubes

2. Bake devices for 4 hours, at 90°C

3. After cooling, load devices back into tubes

4. Perform solder reflow within 24 hours after bake

Bake only a quantity of devices that can be processed through solder reflow in 24 hours. Devices can be

re-baked for 4 hours, at 90°C for a cumulative total of 12 hours (3 bakes for 4 hours at 90°C).

For devices shipped in carrier tape:

1. Bake devices for 4 hours, at 90°C in the tape

2. Perform solder reflow within 24 hours after bake

Bake only a quantity of devices that can be processed through solder reflow in 24 hours. Devices can be

re−baked for 4 hours in tape, at 90°C for a cumulative total of 12 hours (3 bakes for 4 hours at 90°C).

Package T

To ensure the package molding compound 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

with silica gel to protect them from ambient moisture during shipping, handling, and storage before use.

The T package has been assigned a moisture sensitivity level of MSL 3 and the devices should be stored under

the following conditions:

Temperature Range 5°C to 50°C

Relative Humidity 60% maximum

Total Time 6 months from the date code on the aluminized envelope — if unopened

Opened Time 168 hours or fewer

Rebaking will be required if the devices have been stored unopened for more than 6 months or if the aluminized

envelope has been open for more than 168 hours. If rebaking is required, it should be done at 90°C for 4 hours.

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007

The LUMENOLOGY r Company r

www.taosinc.com

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.

TSL2550

AMBIENT LIGHT SENSOR

WITH SMBus INTERFACE

TAOS029L − OCTOBER 2007