S i 11 3 2
U V I
NDEX
Features
Pin Assignments
AND
A
M B I E N T
L
I G H T
S
E NS O R
I C
WITH
I
2
C I
NT ERF ACE
Integrated UV index sensor
UV Index register that can
be read through I
2
C interface
Factory calibration to address
part-to-part variation
Digital
Industry's lowest power
consumption
1.71
Integrated ambient light sensor
100
mlx resolution possible,
2
allowing operation under dark
I C Serial communications
glass
Up to 3.4 Mbps data rate
1 to 128 klx dynamic range
Slave mode hardware address
possible across two ADC range
decoding
settings
Small-outline 10-lead 2x2 mm
Accurate lux measurements with
QFN
IR correction algorithm
to 3.6 V supply voltage
< 500 nA standby current
Internal and external wake support
Built-in voltage supply monitor and
power-on reset controller
DNC
SDA
SCL
V
DD
INT
1
2
3
4
10
9
8
7
6
V
DD
GND
V
DD
V
DD
QFN-10
5
DNC
Temperature Range
–40
to +85 °C
Applications
Fitness/health electronics
Smart watches
Smartphone handsets
Description
Tablets
Portable consumer electronics
Display-backlighting control
The Si1132 is a low-power, ultraviolet (UV) index, and ambient light
sensor with I
2
C digital interface and programmable-event interrupt output.
This sensor IC includes an analog-to-digital converter, integrated high-
sensitivity visible and infrared photodiodes, and digital signal processor.
The Si1132 offers excellent performance under a wide dynamic range
and a variety of light sources including direct sunlight. The Si1132 can
also work under dark glass covers. The photodiode response and
associated digital conversion circuitry provide excellent immunity to
artificial light flicker noise and natural light flutter noise. The Si1132
devices are provided in a 10-lead 2x2 mm QFN package and are capable
of operation from 1.71 to 3.6 V over the –40 to +85 °C temperature range.
Rev. 1.2 12/14
Copyright © 2014 by Silicon Laboratories
Si1132
Si1132
Functional Block Diagram
VDD
Regulator
Temp
A
M
U
X
ADC
Filter
Visible
INT
SCL
SDA
Infrared
Digital Sequencer & Control Logic
I
2
C
Registers
Oscillator
GND
3.3 V
Host
SDA
SCL
Si1132
SDA
SCL
VDD
INT
0.1 uF
INT
VDD
GND
VDD
VDD
Figure 1. Si1132 Application
2
Rev. 1.2
Si1132
T
ABLE O F
C
ONTENTS
1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
1.1. Performance Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
1.2. Typical Performance Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
2. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
2.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
2.2. Ambient Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
2.3. Ultraviolet (UV) Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.4. Host Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3. Operational Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1. Off Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2. Initialization Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.3. Standby Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.4. Forced Conversion Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.5. Autonomous Operation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
4. Programming Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1. Command and Response Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2. Command Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.3. Resource Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.4. Signal Path Software Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.5. I
2
C Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.6. Parameter RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
5. Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
6. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
7. Package Outline: 10-Pin QFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
8. Suggested PCB Land Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Rev. 1.2
3
Si1132
1. Electrical Specifications
1.1. Performance Tables
Table 1. Recommended Operating Conditions
Parameter
V
DD
Supply Voltage
V
DD
OFF Supply Voltage
V
DD
Supply Ripple Voltage
Operating Temperature
SCL, SDA, Input High Logic
Voltage
SCL, SDA Input Low Logic
Voltage
Operation under Direct Sunlight
Start-Up Time
T
I
2
C
VIH
I
2
C
VIL
Edc
V
DD
above 1.71 V
Symbol
V
DD
V
DD_OFF
OFF mode
V
DD
= 3.3 V
1 kHz–10 MHz
Test Condition
Min
1.71
–0.3
—
–40
V
DD
x0.7
0
—
25
—
25
—
—
—
—
Typ
—
Max
3.6
1.0
50
85
V
DD
V
DD
x0.3
128
—
Unit
V
V
mVpp
°C
V
V
klx
ms
Table 2. Performance Characteristics
1
Parameter
I
DD
OFF Mode
I
DD
Standby Mode
Symbol
I
off
I
sb
Test Condition
V
DD
< V
DD_OFF
(leakage from SCL,
SDA, and INT not included)
No ALS Conversions
No I
2
C Activity
V
DD
= 1.8 V
No ALS Conversions
No I
2
C Activity
V
DD
=3.3 V
V
DD
= 3.3 V
V
DD
= 3.3 V
UV or ALS VIS + ALS IR
Min
—
—
Typ
240
150
Max
1000
500
Unit
nA
nA
I
DD
Standby Mode
I
sb
—
1.4
—
µA
I
DD
Actively Measuring
INT, SCL, SDA
Leakage Current
Actively Measuring Time
2
I
active
—
–1
—
4.3
—
285
5.5
1
—
mA
µA
µs
Notes:
1.
Unless specifically stated in "Conditions", electrical data assumes ambient light levels < 1 klx.
2.
Represents the time during which the device is drawing a current equal to I
active
for power estimation purposes.
Assumes default settings.
4
Rev. 1.2
Si1132
Table 2. Performance Characteristics
1
(Continued)
Parameter
Visible Photodiode
Response
Symbol
Test Condition
Sunlight
ALS_VIS_ADC_GAIN=0
VIS_RANGE=0
2500K incandescent bulb
ALS_VIS_ADC_GAIN=0
VIS_RANGE=0
“Cool white” fluorescent
ALS_VIS_ADC_GAIN=0
VIS_RANGE=0
Infrared LED (875 nm)
ALS_VIS_ADC_GAIN=0
VIS_RANGE=0
Small Infrared Photodiode
Response
Sunlight
ALS_IR_ADC_GAIN=0
IR_RANGE=0
2500K incandescent bulb
ALS_IR_ADC_GAIN=0
IR_RANGE=0
“Cool white” fluorescent
ALS_IR_ADC_GAIN=0
IR_RANGE=0
Infrared LED (875 nm)
ALS_IR_ADC_GAIN=0
IR_RANGE=0
Visible Photodiode Noise
All gain settings
Min
—
Typ
0.282
Max
—
Unit
ADC
counts/
lux
ADC
counts/
lux
ADC
counts/
lux
ADC
counts.
m
2
/W
ADC
counts/
lux
ADC
counts/
lux
ADC
counts/
lux
ADC
counts.
m
2
/W
ADC
counts
RMS
ADC
counts
RMS
—
0.319
—
—
0.146
—
—
8.277
—
—
2.44
—
—
8.46
—
—
0.71
—
—
452.38
—
—
7
—
Small Infrared Photodiode
Noise
All gain settings
—
1
—
Notes:
1.
Unless specifically stated in "Conditions", electrical data assumes ambient light levels < 1 klx.
2.
Represents the time during which the device is drawing a current equal to I
active
for power estimation purposes.
Assumes default settings.
Rev. 1.2
5