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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
r
r
TAOS145B − SEPTEMBER 2012
PACKAGE FN
DUAL FLAT NO-LEAD
(TOP VIEW)
D RGB and Clear Color Sensing and
D
D
D
D
D
− Low Power — 2.5-mA Sleep State
− 65-mA Wait State withProgrammable Wait
State Time from 2.4 ms to > 7 Seconds
2
I C Fast Mode Compatible Interface
− Data Rates up to 400 kbit/s
− Input Voltage Levels Compatible with VDD
or 1.8 V Bus
Register Set and Pin Compatible with the
TCS3x71 Series
Small 2 mm 2.4 mm Dual Flat No-Lead
(FN) Package
Description
6 SDA
SCL 2
5 INT
GND 3
4 LDR
Package Drawing Not to Scale
Applications
D
D
D
D
D
D
RGB LED Backlight Control
Ambient Light Color Temperature Sensing
Cell Phone Touch Screen Disable
Mechanical Switch Replacement
Industrial Process Control
Medical Diagnostics
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D Power Management
VDD 1
lv
D
Proximity Detection in a Single Device
Color Light Sensing with IR-Blocking Filter
− Programmable Analog Gain and
Integration Time
− 3,800,000:1 Dynamic Range
− Very High Sensitivity — Ideally Suited for
Operation Behind Dark Glass
Proximity Detection
− Ambient Light Rejection
− Programmable Integration Time
− Current Sink Driver for External IR LED
Maskable Light and Proximity Interrupt
− Programmable Upper and Lower
Thresholds with Persistence Filter
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Features
End Products and Market Segments
D HDTVs, Mobile Handsets, Tablets, and
D
D
D
Portable Media Payers
Medical and Commercial Instrumentation
Toys
Solid State and General Lighting
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The TCS3772 device family provides red, green, blue, and clear (RGBC) light sensing and, when coupled with
an external IR LED, proximity detection. These devices detect light intensity under a variety of lighting conditions
and through a variety of attenuation materials, including dark glass. The proximity detection feature allows a
large dynamic range of operation for accurate short distance detection, such as in a cell phone, for detecting
when the user positions the phone close to their ear. An internal state machine provides the ability to put the
device into a low power state in between proximity and RGBC measurements providing very low average power
consumption.
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The color sensing feature is useful in applications such as LED RGB backlight control, solid state lighting,
reflected LED color sampler, or fluorescent light color temperature detection. With the addition of an IR blocking
filter, the device is an excellent ambient light sensor, color temperature monitor, and general purpose color
sensor.
The LUMENOLOGY r Company
Copyright E 2012, TAOS Inc.
r
Texas Advanced Optoelectronic Solutions Inc.
1001 Klein Road S Suite 300 S Plano, TX 75074 S (972)
r 673-0759
www.taosinc.com
1
TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
Functional Block Diagram
Interrupt
IR LED Constant
Current Sink
VDD
Prox Control
Upper Limit
GND
Prox
Integration
Prox
ADC
INT
Prox
Data
Lower Limit
SCL
Red
Clear Data
Red ADC
Red Data
Green ADC
Green Data
Lower Limit
SDA
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Green
Clear ADC
Upper Limit
lv
RGBC Control
I2C Interface
Wait Control
Clear
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LDR
Blue ADC
Blue Data
Blue
Detailed Description
The TCS3772 is a next-generation digital color light sensor device containing four integrating analog-to-digital
converters (ADCs) that integrate currents from photodiodes. The device contains a 3 × 4 photodiode array used
for color measurements and a 1 × 4 photodiode array used for proximity measurements. Integration of all color
sensing channels occurs simultaneously. Upon completion of the conversion cycle, the conversion result is
transferred to the corresponding data registers. The transfers are double-buffered to ensure that the integrity
of the data is maintained. 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.
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The device provides a separate pin for level-style interrupts. The interrupt feature simplifies and improves
system efficiency by eliminating the need to poll a sensor for a light intensity value. When interrupts are enabled,
an interrupt is generated when the value of a clear channel or proximity conversion is greater than an upper
threshold or less than a lower threshold. Once the interrupt is asserted, it remains asserted until cleared by the
controlling firmware. In addition, a programmable interrupt persistence filter allows the user to set the number
of consecutive clear channel or proximity conversions outside of the threshold region that are necessary to
trigger an interrupt. Interrupt thresholds and persistence filter settings are configured independently for both
clear and proximity.
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Proximity detection requires only a single external IR LED. An internal LED driver can be configured to provide
a constant current sink of 12.5 mA, 25 mA, 50 mA, or 100 mA of current. No external current limiting resistor
is required. The number of proximity LED pulses can be programmed from 1 to 255 pulses. Each pulse has a
14-μs period.
Copyright E 2012, TAOS Inc.
The LUMENOLOGY r Company
r
r
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
Terminal Functions
TERMINAL
NO.
TYPE
DESCRIPTION
GND
3
Power supply ground. All voltages are referenced to GND.
INT
5
O
Interrupt — open drain (active low).
LDR
4
O
LED driver for proximity emitter — open drain.
SCL
2
I
I2C serial clock input terminal — clock signal for I2C serial data.
SDA
6
I/O
VDD
1
I2C serial data I/O terminal — serial data I/O for I2C .
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NAME
Supply voltage.
Available Options
0x39
PACKAGE − LEADS
INTERFACE DESCRIPTION
FN−6
I2C Vbus = VDD Interface
TCS37723†
0x39
FN−6
I2C
TCS37725†
0x29
FN−6
I2C Vbus = VDD Interface
TCS37727
0x29
FN−6
I2C Vbus = 1.8 V Interface
Vbus = 1.8 V Interface
ORDERING NUMBER
lv
ADDRESS
TCS37721FN
TCS37723FN
TCS37725FN
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†
DEVICE
TCS37721†
TCS37727FN
Contact TAOS for availability.
Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage, VDD (Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8 V
Input terminal voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 3.8 V
Output terminal voltage (except LDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 3.8 V
Output terminal voltage (LDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 3.8 V
Output terminal current (except LDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −1 mA to 20 mA
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40°C to 85°C
ESD tolerance, human body model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000 V
†
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: All voltages are with respect to GND.
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Recommended Operating Conditions
NOM
MAX
2.7
3
3.6
2.7
3
3.3
V
Operating free-air temperature, TA
−30
70
°C
UNIT
V
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MIN
Supply voltage, VDD (TCS37721 & TCS37725) (I2C Vbus = VDD)
Supply voltage, VDD (TCS37723 & TCS37727) (I2C Vbus = 1.8 V)
The LUMENOLOGY r Company
Copyright E 2012, TAOS Inc.
r
r
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3
TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
Operating Characteristics, VDD = 3 V, TA = 25C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
Active — LDR pulses off
Supply current
VOL
INT SDA output low voltage
INT,
I LEAK
Leakage current, SDA, SCL, INT pins
I LEAK
Leakage current, LDR pin
VIH
SCL SDA input high voltage
SCL,
VIL
SCL SDA input low voltage
SCL,
MAX
235
330
Wait state
65
Sleep state — no I2C activity
2.5
UNIT
μA
10
3 mA sink current
0
0.4
6 mA sink current
0
0.6
−5
5
μA
5
μA
−5
TCS37721 & TCS37725
0.7 VDD
TCS37723 & TCS37727
1.25
V
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IDD
TYP
V
0.3 VDD
TCS37721 & TCS37725
V
0.54
lv
TCS37723 & TCS37727
PARAMETER
Irradiance
responsivity
Red Channel
TEST
CONDITIONS
λD = 465 nm
Note 2
Re
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Optical Characteristics, VDD = 3 V, TA = 25C, AGAIN = 16, ATIME = 0xF6 (unless otherwise noted)
(Note 1)
λD = 525 nm
Note 3
λD = 615 nm
Note 4
MIN
TYP
Green Channel
MAX
MIN
0%
15%
4%
80%
TYP
Blue Channel
MAX
MIN
10%
42%
25%
60%
110%
0%
TYP
Clear Channel
MAX
MIN
TYP
MAX
65%
88%
11.0
13.8
16.6
85%
10%
45%
13.2
16.6
20.0
14%
5%
24%
15.6
19.5
23.4
UNIT
counts/
μW/
cm2
NOTES: 1. The percentage shown represents the ratio of the respective red, green, or blue channel value to the clear channel value.
2. The 465 nm input irradiance is supplied by an InGaN light-emitting diode with the following characteristics:
dominant wavelength λD = 465 nm, spectral halfwidth Δλ½ = 22 nm.
3. The 525 nm input irradiance is supplied by an InGaN light-emitting diode with the following characteristics:
dominant wavelength λD = 525 nm, spectral halfwidth Δλ½ = 35 nm.
4. The 615 nm input irradiance is supplied by a AlInGaP light-emitting diode with the following characteristics:
dominant wavelength λD = 615 nm, spectral halfwidth Δλ½ = 15 nm.
RGBC Characteristics, VDD = 3 V, TA = 25C, AGAIN = 16, AEN = 1 (unless otherwise noted)
TEST CONDITIONS
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PARAMETER
Dark ADC count value
ADC integration time step size
Ee = 0, AGAIN = 60×, ATIME = 0xD6 (100 ms)
ATIME = 0xFF
ADC number of integration steps
(Note 5)
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G i scaling,
Gain
li
relative
l ti to
t 1× gain
i
setting
TYP
MAX
UNIT
0
1
5
counts
2.27
2.4
2.56
ms
256
steps
0
1024
counts
0
65535
counts
1
ADC counts per step (Note 5)
ADC count value (Note 5)
MIN
ATIME = 0xC0 (153.6 ms)
4×
3.8
4
4.2
16×
15
16
16.8
16 8
58
60
63
60×
Te
NOTE 5: Parameter ensured by design and is not tested.
Copyright E 2012, TAOS Inc.
The LUMENOLOGY r Company
r
r
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
Proximity Characteristics, VDD = 3 V, TA = 25C, PEN = 1 (unless otherwise noted)
PARAMETER
LDR pulse on
ADC conversion time step size
PTIME = 0xFF
PTIME = 0xFF
ADC count value
λp = 850 nm, Ee = 770.1
PPULSE = 1 (Note 3)
ADC output responsivity
λp = 850 nm, PTIME = 0xFF, PPULSE = 1 (Note 3)
Noise (Notes 1,
1 2,
2 3)
μW/cm2,
Ee = 0,
0 PTIME = 0xFF,
0xFF PPULSE = 8 (Note 6)
PTIME = 0xFB,
mA
ms
1
256
steps
0
1023
counts
1350
1900
counts
0.247
counts/
μW/cm2
0.211
2
% FS
255
14.0
LED pulse width — LED on time
6.3
PDRIVE = 0
80
106
Maximum operating distance
(Notes 1, 4, 5)
pulses
μs
μs
132
50
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PDRIVE = 1
ISINK sink current @ 1.6 V,
LDR pin
UNIT
2.56
0
LED pulse period
NOTES: 1.
2.
3.
4.
2.4
0.175
LED pulse count (Note 1)
LED drive current
2.27
MAX
3
ADC number of integration steps
(Note 1)
ADC counts per step (Note 1)
TYP
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Supply current
MIN
lv
IDD
TEST CONDITIONS
PDRIVE = 2
25
PDRIVE = 3
12.5
PDRIVE = 0 (100 mA), PPULSE = 64
Emitter: λp = 850 nm, 20° half angle, and 60 mW/sr
Object: 16 × 20-inch, 90% reflective Kodak Gray Card
(white surface)
Optics: Open view (no glass, no optical attenuation)
mA
30
inches
Parameter is ensured by design or characterization and is not tested.
Proximity noise is defined as one standard deviation of 600 samples.
Proximity noise typically increases as √PPULSE
Greater operating distances are achievable with appropriate optical system design considerations. See available TAOS application
notes for additional information.
5. Maximum operating distance is dependent upon emitter and the reflective properties of the object’s surface.
6. Proximity noise test was done using the following circuit:
VDD
22 W
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VDD
15.0 W
1
1 mF
TCS3772
3
4
LDR
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GND
ch
Wait Characteristics, VDD = 3 V, TA = 25C, WEN = 1 (unless otherwise noted)
PARAMETER
Wait step size
TEST CONDITIONS
CHANNEL
WTIME = 0xFF
TYP
MAX
2.27
2.4
2.56
ms
256
steps
1
Te
Wait number of steps (Note 7)
MIN
UNIT
NOTE 7: Parameter ensured by design and is not tested.
The LUMENOLOGY r Company
Copyright E 2012, TAOS Inc.
r
r
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5
TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
AC Electrical Characteristics, VDD = 3 V, TA = 25C (unless otherwise noted)
PARAMETER†
(I2C
TEST CONDITIONS
MIN
UNIT
400
kHz
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
t(SUDAT)
Data setup time
100
t(LOW)
SCL clock low period
1.3
t(HIGH)
SCL clock high period
0.6
tF
Clock/data fall time
tR
Clock/data rise time
Ci
Input pin capacitance
μs
ns
μs
μs
lv
0
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0
MAX
f(SCL)
300
ns
300
ns
10
pF
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†
only)
TYP
Specified by design and characterization; not production tested.
PARAMETER MEASUREMENT INFORMATION
t(LOW)
VIH
SCL
VIL
t(R)
t(F)
t(HDSTA)
t(BUF)
t(HIGH)
t(HDDAT)
t(SUSTA)
t(SUSTO)
t(SUDAT)
VIH
SDA
VIL
P
S
S
P
Start
Condition
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Stop
Condition
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Figure 1. Timing Diagrams
Copyright E 2012, TAOS Inc.
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
TYPICAL CHARACTERISTICS
PHOTODIODE SPECTRAL RESPONSIVITY
RGBC
PHOTODIODE SPECTRAL RESPONSIVITY
PROXIMITY
1
1
Normalized to
Clear
@ 605 nm
0.8
TA = 25°C
0.7
Relative Responsivity
Relative Responsivity
0.8
0.9
Red
0.6
Green
0.5
0.4
Blue
0.3
0.7
0.6
0.5
0.4
0.3
0.2
0.1
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0.2
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0.9
lv
Clear
0.1
0
300
500
700
900
λ − Wavelength − nm
0
300
1100
500
700
900
λ − Wavelength − nm
Figure 2
Figure 3
NORMALIZED RESPONSIVITY
vs.
ANGULAR DISPLACEMENT
1.0
ch
-Q
0.6
0.4
0.2
+Q
−60
−30
0
30
60
Q − Angular Displacement − °
Te
Optical Axis
Normalized Responsivity
Optical Axis
ca
0.4
ni
Normalized Responsivity
0.8
0.6
0
−90
NORMALIZED RESPONSIVITY
vs.
ANGULAR DISPLACEMENT
1.0
0.8
0.2
1100
90
0
−90
-Q
Figure 4
The LUMENOLOGY r Company
+Q
−60
−30
0
30
60
Q − Angular Displacement − °
90
Figure 5
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
TYPICAL CHARACTERISTICS
TYPICAL LDR CURRENT
vs.
VOLTAGE
NORMALIZED IDD
vs.
VDD and TEMPERATURE
110%
160
140
100 mA
106%
120
25C
102%
50C
100%
0C
98%
100
lv
LDR Current — mA
104%
80
50 mA
60
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IDD Normalized @ 3 V, 25C
108%
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75C
40
96%
25 mA
20
94%
12.5 mA
92%
2.7
2.8
2.9
3
3.1
3.2
0
3.3
0
0.5
1
1.5
2
2.5
3
LDR Voltage − V
VDD — V
Figure 6
Figure 7
RESPONSIVITY TEMPERATURE
COEFFICIENT
ca
Temperature Coefficient — ppm/ C
10,000
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1000
Copyright E 2012, TAOS Inc.
100
400
500
600
700
800
900
1000
λ − Wavelength − nm
Figure 8
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r
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
PRINCIPLES OF OPERATION
System State Machine
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The TCS3772 provides control of RGBC, proximity detection, and power management functionality through an
internal state machine (Figure 9). 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 Prox, Wait, and RGBC 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 0x00:b0)
PON = 0
(r0x 00:b0)
Prox
lv
Start
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RGBC
Wait
Figure 9. Simplified State Diagram
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NOTE: In this document, the nomenclature uses the bit field name in italics 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 (r0x00:b0).
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
RGBC Operation
ATIME(r0x01)
2.4 ms to 700 ms
AGAIN(r 0x0F, b1:0)
1, 4, 16, 60 Gain
RGBC Control
Clear ADC
Clear Data
CDATAH(r 0x15), CDATA(r 0x14)
Red ADC
Red Data
RDATAH(r 0x17), RDATA(r 0x16)
Green ADC
Green Data
GDATAH(r 0x19), GDATA(r 0x18)
Red
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Green
lv
Clear
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The RGBC engine contains RGBC gain control (AGAIN) and four integrating analog-to-digital converters (ADC)
for the RGBC photodiodes. The RGBC integration time (ATIME) impacts both the resolution and the sensitivity
of the RGBC reading. Integration of all four channels occurs simultaneously and upon completion of the
conversion cycle, the results are transferred to the color data registers. This data is also referred to as channel
count. The transfers are double-buffered to ensure that invalid data is not read during the transfer. After the
transfer, the device automatically moves to the next state in accordance with the configured state machine.
Blue ADC
Blue Data
BDATAH(r 0x1B), BDATA(r 0x1A)
Blue
Figure 10. RGBC 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 / 2.4 ms
Inversely, the time can be calculated from the register value as follows:
Integration Time = 2.4 ms × (256 − ATIME)
For example, if a 100-ms integration time is needed, the device needs to be programmed to:
256 − (100 / 2.4) = 256 − 42 = 214 = 0xD6
Te
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Conversely, the programmed value of 0xC0 would correspond to:
(256 − 0xC0) × 2.4 = 64 × 2.4 = 154 ms
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
Proximity Detection
Proximity detection is accomplished by measuring the amount of light energy, generally from an IR LED,
reflected off an object to determine its distance. The proximity light source, which is external to the TCS3772
device, is driven by the integrated proximity LED current driver as shown in Figure 6.
External IR
LED
PTIME(r0x02)
Prox LED
Current Driver
LDR
Prox Control
Prox
ADC
PVALID(r0x13, b1)
Prox
Data
PDATAH(r0x019)
PDATAL(r0x018)
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Prox
Integration
Object
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PPULSE(r0x0E)
PDRIVE(r0x0F, b7:6)
VDD
Background Energy
Figure 11. 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. PDRIVE sets the drive current to 100 mA, 50 mA, 25 mA. To drive an
external light source with more than 100 mA or to minimize on-chip ground bounce, LDR can be used to
drive an external p-type transistor, which, in turn, drives the light source.
Referring to the Detailed State Machine figure, the LED current driver pulses the external IR LED as shown in
Figure 12 during the Prox Accum state. Figure 12 also illustrates that the LED On pulse has a fixed width of
6.3 μs and period of 14.0 μs. So, in addition to setting the proximity drive current, 1 to 255 proximity pulses
(PPULSE) can be programmed. When deciding on the number of proximity pulses, keep in mind that the signal
increases proportionally to PPULSE, while noise increases by the square root of PPULSE.
Te
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Reflected IR LED +
Background Energy
LED On
Background
Energy
LED Off
6.3 ms
14.0 ms
IR LED Pulses
Figure 12. Proximity LED Current Driver Waveform
Figure 11 illustrates light rays emitting from an external IR LED, reflecting off an object, and being absorbed by
the proximity photodiode.
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TAOS145B − SEPTEMBER 2012
Referring again to Figure 12, 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 external IR LED energy to accumulate from pulse to pulse.
al
id
After the programmed number of proximity pulses have been generated, the proximity ADC converts and scales
the proximity measurement to a 16-bit value, then stores the result in two 8-bit proximity data (PDATAx)
registers. ADC scaling is controlled by the proximity ADC conversion time (PTIME) which is programmable from
1 to 256 2.4-ms time units. However, depending on the application, scaling the proximity data will equally scale
any accumulated noise. Therefore, in general, it is recommended to leave PTIME at the default value of one
2.4-ms ADC conversion time (0xFF).
Once the first proximity cycle has completed, the proximity valid (PVALID) bit in the Status register will be set
and remain set until the proximity detection function is disabled (PEN).
Te
ch
ni
ca
am
lc s
on A
te G
nt
st
il
lv
For additional information on using the proximity detection function behind glass and for optical system design
guidance, please see available TAOS application notes.
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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 it’s status is available in the status register (0x13), the output of the interrupt state can be enabled using
the proximity interrupt enable (PIEN) or Clear interrupt enable (AIEN) fields in the enable register (0x00).
al
id
Four 16-bit interrupt threshold registers allow the user to set limits below and above a desired light level and
proximity range. An interrupt can be generated when the Clear data (CDATA) is less than the Clear interrupt
low threshold registers (AILTx) or greater than the Clear interrupt high threshold registers (AIHTx). Likewise,
an out-of-range proximity interrupt can be generated when the proximity data (PDATA) falls below the proximity
interrupt low threshold (PILTx) or exceeds the proximity interrupt high threshold (PIHTx).
lv
It is important to note that the thresholds are evaluated in sequence, first the low threshold, then the high
threshold. As a result, if the low threshold is set above the high threshold, the high threshold is ignored and only
the low threshold is evaluated.
am
lc s
on A
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nt
st
il
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 Clear or proximity occurrences before an interrupt
is generated. The persistence register (0x0C) allows the user to set the Clear persistence (APERS) and the
proximity persistence (PPERS) values. 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).
Prox
Integration
Prox
ADC
PIHTH(r 0x0B), PIHTL(r 0x0A)
PPERS(r 0x0C, b7:4)
Upper Limit
Prox Persistence
Prox
Data
Lower Limit
PILTH(r 0x09), PILTL(r0x 08)
AIHTH(r0x 07), AIHTL(r0x 06)
Upper Limit
Clear Persistence
Clear
Data
ca
Clear
ADC
APERS(r 0x0C, b3:0)
Lower Limit
AILTH(r 0x05), AILTL(r0x 04)
Figure 13. Programmable Interrupt
Te
ch
ni
Clear
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COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
System Timing
The system state machine shown in Figure 9 provides an overview of the states and state transitions that
provide system control of the device. This section highlights the programmable features, which affect the state
machine cycle time, and provides details to determine system level timing.
al
id
When the proximity detection feature is enabled (PEN), the state machine transitions through the Prox Accum,
Prox Wait, and Prox ADC states. The Prox Wait time is a fixed 2.4 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 14. If an interrupt is generated as a result of the proximity cycle, it will be asserted
at the end of the Prox ADC state.
lv
When the power management feature is enabled (WEN), the state machine will transition in turn to the Wait
state. The wait time is determined by WLONG, which extends normal operation by 12× when asserted, and
WTIME. The formula to determine the wait time is given in the box associated with the Wait state in Figure 14.
am
lc s
on A
te G
nt
st
il
When the RGBC feature is enabled (AEN), the state machine will transition through the RGBC Init and RGBC
ADC states. The RGBC Init state takes 2.4 ms, while the RGBC ADC time is dependent on the integration time
(ATIME). The formula to determine RGBC ADC time is given in the associated box in Figure 14. If an interrupt
is generated as a result of the RGBC cycle, it will be asserted at the end of the RGBC ADC.
Sleep
!PON
I2C
Start
(Note 1)
Prox
PPULSE: 0 ~ 255 pulses
Time: 14.0 μs/pulse
Range: 0 ~ 3.6 ms
Prox
Accum
PEN
RGBC
Idle
RGBC
ADC
Time: 2.4 ms
!WEN &
!AEN
Prox
Wait
!AEN
!PEN & !WEN
& AEN
ca
!PEN & WEN
& AEN
ch
RGBC
Init
Time: 2.4 ms
!WEN &
AEN
Prox
ADC
AEN
WEN
ni
PTIME: 1 ~ 256 steps
Time: 2.4 ms/step
Range: 2.4 ms ~ 614 ms
ATIME: 1 ~ 256 steps
Time: 2.4 ms/step
Range: 2.4 ms ~ 614 ms
Wait
Time:
Range:
WTIME: 1 ~ 256 steps
WLONG = 0
WLONG = 1
2.4 ms/step
28.8 ms/step
2.4 ms ~ 614 ms
28.8 ms ~ 7.37s
Te
Notes: 1. There is a 2.4 ms warm-up delay if PON is enabled. If PON is not enabled, the device will return to the Sleep state as shown.
2. PON, PEN, WEN, and AEN are fields in the Enable register (0x00).
Copyright E 2012, TAOS Inc.
Figure 14. Detailed State Diagram
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Power Management
Power consumption can be managed with the Wait state, because the Wait state typically consumes only 65 μA
of IDD current. An example of the power management feature is given below. With the assumptions provided
in the example, average IDD is estimated to be 186 μA.
Table 1. Power Management
PROGRAMMABLE
PARAMETER
PROGRAMMED VALUE
PPULSE
0x04
Prox Accum
DURATION
0.056 ms
Prox Accum − LED On
0.025 ms (Note 1)
Prox Accum − LED Off
0.031 ms (Note 2)
Prox Wait
2.40 ms
Wait
PTIME
0xFF
WTIME
0xEE
WLONG
0
2.40 ms
0.235 mA
0.235 mA
0.235 mA
43 1 ms
43.1
0 065 mA
0.065
2.40 ms
0.235 mA
am
lc s
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nt
st
il
ALS Init
ALS ADC
109 mA
lv
Prox ADC
TYPICAL
CURRENT
al
id
SYSTEM STATE MACHINE
STATE
ATIME
0xEE
43.1 ms
0.235 mA
NOTES: 1. Prox Accum − LED On time = 6.3 μs per pulse × 4 pulses = 25.2μs = 0.025 ms
2. Prox Accum − LED Off time = 7.7 μs per pulse × 4 pulses = 30.9μs = 0.031 ms
Average IDD Current = ((0.025 × 109) + (0.031 × 0.235) + (2.40 × 0.235) +
(43.1 × 0.065) + (43.1 × 0.263) + (2.40 × 0.235 × 2)) / 93 186 μA
Keeping with the same programmed values as the example, Table 2 shows how the average IDD current is
affected by the Wait state time, which is determined by WEN, WTIME, and WLONG. Note that the worst-case
current occurs when the Wait state is not enabled.
Table 2. Average IDD Current
0
1
1
1
WLONG
WAIT STATE
AVERAGE IDD CURRENT
n/a
n/a
0 ms
289 μA
0xFF
0
2.40 ms
279 μA
0xEE
0
43.1 ms
186 μA
0x00
0
613 ms
82 μA
7.36 s
67 μA
0x00
1
Te
ch
ni
1
WTIME
ca
WEN
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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.
al
id
The I2C standard provides for three types of bus transaction: read, write, and a combined protocol (Figure 15).
During a write operation, the first byte written is a command byte followed by data. In a combined protocol, the
first byte written is the command byte followed by reading a series of bytes. If a read command is issued, the
register address from the previous command will be used for data access. Likewise, if the MSB of the command
is not set, the device will write a series of bytes at the address stored in the last valid command with a register
address. The command byte contains either control information or a 5-bit register address. The control
commands can also be used to clear interrupts.
...
Acknowledge (0)
Not Acknowledged (1)
Stop Condition
Read (1)
Start Condition
Repeated Start Condition
Write (0)
Continuation of protocol
Master-to-Slave
Slave-to-Master
1
am
lc s
on A
te G
nt
st
il
A
N
P
R
S
Sr
W
lv
The I2C bus protocol was developed by Philips (now NXP). For a complete description of the I2C protocol, please
review the NXP I2C design specification at http://www.i2c−bus.org/references/.
7
S
1
Slave Address
W
1
8
A
1
Command Code
8
A
1
Data Byte
A
8
1
1
...
P
I2C Write Protocol
1
7
S
1
Slave Address
R
1
8
A
1
Data
A
Data
1
...
A
P
I2C Read Protocol
1
S
Slave Address
W
1
8
1
1
7
1
1
Command Code
A
Sr
Slave Address
R
A
ca
7
A
8
1
Data
A
8
Data
1
A
1
...
P
I2C Read Protocol — Combined Format
Figure 15. I2C Protocols
Te
ch
ni
1
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Register Set
The TCS3772 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 3.
Table 3. Register Address
ADDRESS
RESISTER NAME
R/W
−−
COMMAND
W
REGISTER FUNCTION
0x00
ENABLE
R/W
Enables states and interrupts
0x01
ATIME
R/W
RGBC time
0x02
PTIME
R/W
Proximity time
0x03
WTIME
R/W
Wait time
0x04
AILTL
R/W
Clear interrupt low threshold low byte
0x05
AILTH
R/W
Clear interrupt low threshold high byte
0x06
AIHTL
R/W
Clear interrupt high threshold low byte
0x07
AIHTH
R/W
Clear interrupt high threshold high byte
0x08
PILTL
R/W
Proximity interrupt low threshold low byte
0x00
RESET VALUE
0x00
al
id
Specifies register address
0x00
0xFF
0xFF
0xFF
lv
0x00
0x00
am
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nt
st
il
0x00
0x00
0x09
PILTH
R/W
Proximity interrupt low threshold high byte
0x00
0x0A
PIHTL
R/W
Proximity interrupt high threshold low byte
0x00
PIHTH
R/W
Proximity interrupt high threshold high byte
0x00
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
Gain control register
0x00
0x12
ID
R
Device ID
0x13
STATUS
R
Device status
0x00
0x14
CDATA
R
Clear ADC data low byte
0x00
0x15
CDATAH
R
Clear ADC data high byte
0x00
0x16
RDATA
R
Red ADC data low byte
0x00
0x17
RDATAH
R
Red ADC data high byte
0x00
0x18
GDATA
R
Green ADC data low byte
0x00
0x19
GDATAH
R
Green ADC data high byte
0x00
0x1A
BDATA
R
Blue ADC data low byte
0x00
0x1B
BDATAH
R
Blue ADC data high byte
0x00
0x1C
PDATA
R
Proximity ADC data low byte
0x00
0x1D
PDATAH
R
Proximity ADC data high byte
0x00
ni
ca
0x0B
0x0C
ID
Te
ch
The mechanics of accessing a specific register depends on the specific protocol used. See the section on I2C
protocols on the previous pages. In general, the COMMAND register is written first to specify the specific
control/status register for following read/write operations.
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Command Register
The command registers specifies the address of the target register for future write and read operations.
Table 4. Command Register
FIELD
CMD
5
4
3
TYPE
CMD
7
6:5
1
0
Reset
0x00
ADDR/SF
BITS
TYPE
2
DESCRIPTION
Select Command Register. Must write as 1 when addressing COMMAND register.
Selects type of transaction to follow in subsequent data transfers:
FIELD VALUE
INTEGRATION TIME
00
Repeated byte protocol transaction
01
Auto-increment protocol transaction
10
Reserved — Do not use
11
Special function — See description below
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id
COMMAND
6
am
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lv
7
Byte protocol will repeatedly read the same register with each data access.
Block protocol will provide auto-increment function to read successive bytes.
ADDR/SF
4:0
Address field/special function field. Depending on the transaction type, see above, this field either
specifies a special function command or selects the specific control−status−register for following write
and read transactions. The field values listed below apply only to special function commands:
FIELD VALUE
READ VALUE
00101
Proximity interrupt clear
00110
Clear channel interrupt clear
00111
Proximity and Clear interrupt clear
other
Reserved — Do not write
Te
ch
ni
ca
The ALS and Proximity interrupt clear special functions clear any pending interrupt(s) and are self
clearing.
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Enable Register (0x00)
The Enable register is used primarily to power the TCS3772 device on and off, and enable functions and
interrupts as shown in Table 5.
Table 5. Enable Register
6
Reserved
ENABLE
5
4
3
2
1
0
PIEN
Resv
AIEN
WEN
PEN
AEN
PON
Reset
0x00
al
id
7
FIELD
BITS
Reserved
7:6
PIEN
5
Proximity interrupt enable. When asserted, permits proximity interrupts to be generated.
AIEN
4
Clear channel interrupt enable. When asserted, permits Clear interrupts to be generated.
WEN
3
Wait enable. This bit activates the wait feature. Writing a 1 activates the wait timer. Writing a 0 disables the
wait timer.
PEN
2
Proximity enable. This bit activates the proximity function. Writing a 1 enables proximity. Writing a 0
disables proximity.
AEN
1
PON
0
DESCRIPTION
am
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nt
st
il
lv
Reserved. Write as 0.
RGBC enable. This bit actives the two-channel ADC. Writing a 1 activates RGBC. Writing a 0 disables
RGBC.
Te
ch
ni
ca
Power ON. This bit activates the internal oscillator to permit the timers and ADC channels to operate.
Writing a 1 activates the oscillator. Writing a 0 disables the oscillator. During reads and writes over the I2C
interface, this bit is temporarily overridden and the oscillator is enabled, independent of the state of PON.
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RGBC Time Register (0x01)
The RGBC timing register controls the internal integration time of the RGBC clear and IR channel ADCs in
2.4-ms increments. Upon power up, the RGBC time register is set to 0xFF.
Table 6. RGBC Time Register
7:0
DESCRIPTION
VALUE
INTEG_CYCLES
TIME
0xFF
1
2.4 ms
0xF6
10
24 ms
0xD6
42
101 ms
0xAD
64
154 ms
0x00
256
614 ms
MAX COUNT
al
id
BITS
1024
10240
43008
65535
65535
lv
FIELD
ATIME
Proximity Time Register (0x02)
am
lc s
on A
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nt
st
il
The proximity timing register controls the integration time of the proximity ADC in 2.4 ms increments. Upon
power up, the proximity time register is set to 0xFF. It is recommended that this register be programmed to a
value of 0xFF (1 integration cycle).
Max Prox Count = ((256 − PTIME) × 1024)) − 1
up to a maximum of 65535
Table 7. Proximity Time Register
FIELD
BITS
PTIME
7:0
DESCRIPTION
VALUE
INTEG_CYCLES
TIME
MAX COUNT
0xFF
1
2.4 ms
1023
Wait Time Register (0x03)
Wait time is set 2.4 ms increments unless the WLONG bit is asserted in which case the wait times are 12× longer.
WTIME is programmed as a 2’s complement number. Upon power up, the wait time register is set to 0xFF.
BITS
7:0
REGISTER VALUE
DESCRIPTION
WAIT TIME
TIME (WLONG = 0)
TIME (WLONG = 1)
0xFF
1
2.4 ms
0.029 sec
0xAB
85
204 ms
2.45 sec
0x00
256
614 ms
7.4 sec
ch
ni
FIELD
WTIME
ca
Table 8. Wait Time Register
Te
NOTE: The Proximity Wait Time Register should be configured before PEN and/or AEN is/are asserted.
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Clear Interrupt Threshold Registers (0x04 − 0x07)
The Clear interrupt threshold registers provides the values to be used as the high and low trigger points for the
comparison function for interrupt generation. If the value generated by the clear channel crosses below the
lower threshold specified, or above the higher threshold, an interrupt is asserted on the interrupt pin.
Table 9. Clear Interrupt Threshold Registers
BITS
0x04
7:0
Clear channel low threshold lower byte
DESCRIPTION
AILTH
0x05
7:0
Clear channel low threshold upper byte
AIHTL
0x06
7:0
Clear channel high threshold lower byte
AIHTH
0x07
7:0
Clear channel high threshold upper byte
al
id
ADDRESS
AILTL
lv
REGISTER
Proximity Interrupt Threshold Registers (0x08 − 0x0B)
am
lc s
on A
te G
nt
st
il
The proximity interrupt threshold registers provide the values to be used as the high and low trigger points for
the comparison function for interrupt generation. If the value generated by proximity channel crosses below the
lower threshold specified, or above the higher threshold, an interrupt is signaled to the host processor.
Table 10. Proximity Interrupt Threshold Registers
ADDRESS
BITS
PILTL
0x08
7:0
Proximity ADC channel low threshold lower byte
DESCRIPTION
PILTH
0x09
7:0
Proximity ADC channel low threshold upper byte
PIHTL
0x0A
7:0
Proximity ADC channel high threshold lower byte
PIHTH
0x0B
7:0
Proximity ADC channel high threshold upper byte
Te
ch
ni
ca
REGISTER
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Persistence Filter Register (0x0C)
The persistence filter register controls the filtering interrupt capabilities of the device. Configurable filtering is
provided to allow interrupts to be generated after each integration cycle or if the integration has produced a result
that is outside of the values specified by the threshold register for some specified amount of time. Separate
filtering is provided for proximity and the clear channel.
6
PERS
5
4
3
2
PPERS
FIELD
BITS
PPERS
7:4
Reset
0x00
DESCRIPTION
Proximity interrupt persistence. Controls rate of proximity interrupt to the host processor.
INTERRUPT PERSISTENCE FUNCTION
Every proximity cycle generates an interrupt
0001
1 proximity value out of range
am
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on A
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nt
st
il
0000
0010
2 consecutive proximity values out of range
...
...
1111
3:0
0
APERS
FIELD VALUE
APERS
1
lv
7
al
id
Table 11. Persistence Filter Register
15 consecutive proximity values out of range
Clear Interrupt persistence. Controls rate of Clear channel interrupt to the host processor.
FIELD VALUE
INTERRUPT PERSISTENCE FUNCTION
Every RGBC cycle generates an interrupt
0001
1 clear channel value outside of threshold range
0010
2 clear channel consecutive values out of range
0011
3 clear channel consecutive values out of range
0100
5 clear channel consecutive values out of range
0101
10 clear channel consecutive values out of range
0110
15 clear channel consecutive values out of range
0111
20 clear channel consecutive values out of range
1000
25 clear channel consecutive values out of range
1001
30 clear channel consecutive values out of range
1010
35 clear channel consecutive values out of range
1011
40 clear channel consecutive values out of range
ca
0000
45 clear channel consecutive values out of range
1101
50 clear channel consecutive values out of range
1110
55 clear channel consecutive values out of range
1111
60 clear channel consecutive values out of range
Te
ch
ni
1100
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Configuration Register (0x0D)
The configuration register sets the wait long time.
Table 12. Configuration Register
7
6
5
CONFIG
4
3
2
0
WLONG
Reserved
Reset
0x00
al
id
Reserved
1
FIELD
BITS
Reserved
7:2
DESCRIPTION
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.
lv
Reserved. Write as 0.
am
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nt
st
il
Proximity Pulse Count Register (0x0E)
The proximity pulse count register sets the number of proximity pulses that will be transmitted.
Table 13. Proximity Pulse Count Register
7
PPULSE
6
5
4
3
2
1
PPULSE
BITS
PPULSE
7:0
Reset
0x00
DESCRIPTION
Proximity Pulse Count. Specifies the number of proximity pulses to be generated.
Te
ch
ni
ca
FIELD
0
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Control Register (0x0F)
The Control register provides eight bits of miscellaneous control to the analog block.
Table 14. Control Register
6
CONTROL
5
4
PDRIVE
FIELD
BITS
PDRIVE
7:6
3
2
0
Reserved
Reset
0x00
AGAIN
DESCRIPTION
Proximity LED Drive Strength.
LED STRENGTH
00
100 mA
01
50 mA
10
25 mA
11
12.5 mA
5:2
Reserved.
AGAIN
1:0
RGBC Gain Control.
Write bits as 0
am
lc s
on A
te G
nt
st
il
Reserved
lv
FIELD VALUE
FIELD VALUE
ID Register (0x12)
1
al
id
7
RGBC GAIN VALUE
00
1× gain
01
4× gain
10
16× gain
11
60× gain
The ID Register provides the value for the part number. The ID register is a read-only register.
Table 15. ID Register
7
ID
6
5
4
3
2
1
Reset
ID
ID
ID
7:0
DESCRIPTION
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BITS
0x40 = TCS37721 & TCS37725
Part number identification
0x49 = TCS37723 & TCS37727
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FIELD
0
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
Status Register (0x13)
The Status Register provides the internal status of the device. This register is read only.
Table 16. Status Register
STATUS
6
Reserved
5
4
PINT
Resv
AINT
3
2
Reserved
1
0
PVALID
AVALID
Reset
0x00
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7
FIELD
BIT
Reserved
7:6
DESCRIPTION
PINT
5
Proximity Interrupt.
AINT
4
Clear channel Interrupt.
Reserved
3:2
PVALID
1
Proximity Valid. Indicates that a proximity cycle has completed since PEN was asserted.
AVALID
0
RGBC Valid. Indicates that the RGBC cycle has completed since AEN was asserted.
Reserved.
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Reserved.
RGBC Channel Data Registers (0x14 − 0x1B)
Clear, red, green, and blue data is stored as 16-bit values. To ensure the data is read correctly, a two-byte read
I2C transaction should be used with a read word protocol bit 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 additional ADC
integration cycles end between the reading of the lower and upper registers.
Table 17. ADC Channel Data Registers
REGISTER
ADDRESS
BITS
CDATA
0x14
7:0
Clear data low byte
DESCRIPTION
CDATAH
0x15
7:0
Clear data high byte
RDATA
0x16
7:0
Red data low byte
RDATAH
0x17
7:0
Red data high byte
0x18
7:0
Green data low byte
0x19
7:0
Green data high byte
BDATA
0x1A
7:0
Blue data low byte
7:0
Blue data high byte
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GDATA
GDATAH
BDATAH
0x1B
ni
Proximity Data Registers (0x1C − 0x1D)
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Proximity data is stored as a 16-bit value. To ensure the data is read correctly, a two-byte read I2C transaction
should be used with a read word protocol bit 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 additional ADC integration cycles end
between the reading of the lower and upper registers.
Table 18. PDATA Registers
REGISTER
ADDRESS
BITS
PDATA
0x1C
7:0
Proximity data low byte
PDATAH
0x1D
7:0
Proximity data high byte
The LUMENOLOGY r Company
DESCRIPTION
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
APPLICATION INFORMATION: HARDWARE
LED Driver Pin with Proximity Detection
In a proximity sensing system, the IR LED can be pulsed by the TCS3772 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.
Voltage
Regulator
VDD
1 mF
RP
GND
Voltage
Regulator
RP
RPI
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VBUS
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The first recommendation is to use two power supplies; one for the device VDD and the other for the IR LED.
In many systems, there is a quiet analog supply and a noisy digital supply. By connecting the quiet supply to
the VDD pin and the noisy supply to the LED, the key goal can be meet. Place a 1-μF low-ESR decoupling
capacitor as close as possible to the VDD pin and another at the LED anode, and a 22-μF capacitor at the output
of the LED voltage regulator to supply the 100-mA current surge.
TCS3772
INT
SCL
LDR
22 mF
1 mF
SDA
IR LED
* Cap Value Per Regulator Manufacturer Recommendation
Figure 16. Proximity Sensing Using Separate Power Supplies
If it is not possible to provide two separate power supplies, the device can be operated from a single supply.
A 22-Ω resistor in series with the VDD supply line and a 1-μF low ESR capacitor effectively filter any power supply
noise. The previous capacitor placement considerations apply.
VBUS
Voltage
Regulator
22 W
VDD
1 mF
22 mF
RP
ca
GND
1 mF
TCS3772
RP
RPI
INT
SCL
LDR
SDA
ni
IR LED
ch
Figure 17. Proximity Sensing Using Single Power Supply
Te
VBUS in the above figures refers to the I2C bus voltage which is either VDD or 1.8 V. Be sure to apply the specified
I2C bus voltage shown in the Available Options table for the specific device being used.
The I2C signals and the Interrupt are open-drain outputs and require pull−up resistors. The pull-up resistor (RP)
value is a function of the I2C bus speed, the I2C bus voltage, and the capacitive load. The TAOS EVM running
at 400 kbps, uses 1.5-kΩ resistors. A 10-kΩ pull-up resistor (RPI) can be used for the interrupt line.
Copyright E 2012, TAOS Inc.
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
APPLICATION INFORMATION: HARDWARE
PCB Pad Layout
Suggested land pattern based on the IPC−7351B Generic Requirements for Surface Mount Design and Land
Pattern Standard (2010) for the small outline no-lead (SON) package is shown in Figure 18.
1.20
0.35 6
lv
0.65
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2.70
1.20
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0.65
TOP VIEW
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
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Figure 18. Suggested FN Package PCB Layout
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
PACKAGE INFORMATION
PACKAGE FN
Dual Flat No-Lead
TOP VIEW
496 10
PIN OUT
TOP VIEW
PIN 1
VDD 1
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2400 75
SCL 2
5 INT
lv
406
10
6 SDA
4 LDR
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GND 3
2000
75
END VIEW
Photodiode Active Area
SIDE VIEW
295
Nominal
650 50
BOTTOM VIEW
650
BSC
CL of Solder Contacts and
Photodiode Array Area (Note B)
300
50
(Note C)
125 Nominal
ni
Pb
Lead Free
All linear dimensions are in micrometers.
The die is centered within the package within a tolerance of ± 75 μm.
Double-Half Etch (DHE) is 97 ± 20 μm. Non-DHE is 203 ± 8 μm.
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.
Te
NOTES: A.
B.
C.
D.
E.
F.
G.
CL of Photodiode Array Area (Note B)
750 100
ch
PIN 1
ca
CL of Solder Contacts
Figure 19. Package FN — Dual Flat No-Lead Packaging Configuration
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
CARRIER TAPE AND REEL INFORMATION
TOP VIEW
2.00 0.05
1.75
1.50
4.00
al
id
4.00
B
+ 0.30
8.00
− 0.10
0.50
0.05
B
A
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A
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3.50 0.05
DETAIL B
DETAIL A
5 Max
5 Max
0.254
0.02
2.21 0.05
Ao
2.61 0.05
0.83 0.05
Bo
ni
ca
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.
Te
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NOTES: A.
B.
C.
D.
E.
F.
G.
The LUMENOLOGY r Company
Figure 20. Package FN Carrier Tape
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
SOLDERING INFORMATION
The FN package has been tested and has demonstrated an ability to be reflow soldered to a PCB substrate.
Table 19. Solder Reflow Profile
PARAMETER
REFERENCE
TCS3772
Average temperature gradient in preheating
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
Tpeak
260°C
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Peak temperature in reflow
Temperature gradient in cooling
Tpeak
lv
Soak time
2.5°C/sec
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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.
Max −5°C/sec
Not to scale — for reference only
T3
T2
ca
Temperature (C)
T1
Time (sec)
t3
ni
t2
t1
Figure 21. Solder Reflow Profile Graph
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tsoak
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
STORAGE INFORMATION
Moisture Sensitivity
al
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Optical characteristics of the device can be adversely affected during the soldering process by the release and
vaporization of moisture that has been previously absorbed into the package. To ensure the package contains
the smallest amount of absorbed moisture possible, each device is baked prior to being dry packed for shipping.
Devices are dry packed in a sealed aluminized envelope called a moisture-barrier bag with silica gel to protect
them from ambient moisture during shipping, handling, and storage before use.
Shelf Life
The calculated shelf life of the device in an unopened moisture barrier bag is 12 months from the date code on
the bag when stored under the following conditions:
lv
Shelf Life: 12 months
Ambient Temperature: < 40°C
Relative Humidity: < 90%
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Rebaking of the devices will be required if the devices exceed the 12 month shelf life or the Humidity Indicator
Card shows that the devices were exposed to conditions beyond the allowable moisture region.
Floor Life
The FN package has been assigned a moisture sensitivity level of MSL 3. As a result, the floor life of devices
removed from the moisture barrier bag is 168 hours from the time the bag was opened, provided that the devices
are stored under the following conditions:
Floor Life: 168 hours
Ambient Temperature: < 30°C
Relative Humidity: < 60%
If the floor life or the temperature/humidity conditions have been exceeded, the devices must be rebaked prior
to solder reflow or dry packing.
Rebaking Instructions
Te
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When the shelf life or floor life limits have been exceeded, rebake at 50°C for 12 hours.
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TCS3772
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS145B − SEPTEMBER 2012
PRODUCTION DATA — information in this document is current at publication date. Products conform to
specifications in accordance with the terms of Texas Advanced Optoelectronic Solutions, Inc. standard
warranty. Production processing does not necessarily include testing of all parameters.
LEAD-FREE (Pb-FREE) and GREEN STATEMENT
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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).
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Important Information and Disclaimer The information provided in this statement represents TAOS’ knowledge and
belief as of the date that it is provided. TAOS bases its knowledge and belief on information provided by third parties,
and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate
information from third parties. TAOS has taken and continues to take reasonable steps to provide representative
and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and
chemicals. TAOS and TAOS suppliers consider certain information to be proprietary, and thus CAS numbers and other
limited information may not be available for release.
NOTICE
Texas Advanced Optoelectronic Solutions, Inc. (TAOS) reserves the right to make changes to the products contained in this
document to improve performance or for any other purpose, or to discontinue them without notice. Customers are advised
to contact TAOS to obtain the latest product information before placing orders or designing TAOS products into systems.
TAOS assumes no responsibility for the use of any products or circuits described in this document or customer product
design, conveys no license, either expressed or implied, under any patent or other right, and makes no representation that
the circuits are free of patent infringement. TAOS further makes no claim as to the suitability of its products for any particular
purpose, nor does TAOS assume any liability arising out of the use of any product or circuit, and specifically disclaims any
and all liability, including without limitation consequential or incidental damages.
ca
TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS, INC. PRODUCTS ARE NOT DESIGNED OR INTENDED FOR
USE IN CRITICAL APPLICATIONS IN WHICH THE FAILURE OR MALFUNCTION OF THE TAOS PRODUCT MAY
RESULT IN PERSONAL INJURY OR DEATH. USE OF TAOS PRODUCTS IN LIFE SUPPORT SYSTEMS IS EXPRESSLY
UNAUTHORIZED AND ANY SUCH USE BY A CUSTOMER IS COMPLETELY AT THE CUSTOMER’S RISK.
Te
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LUMENOLOGY, TAOS, the TAOS logo, and Texas Advanced Optoelectronic Solutions are registered trademarks of Texas Advanced
Optoelectronic Solutions Incorporated.
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