Si 7 0 3 4 - A1 0
D
IGITA L
I
2
C H
UMIDITY AND
T
EMPERATURE
S
ENSOR
Features
Precision Relative Humidity Sensor
± 4% RH (max), 0–80% RH
High Accuracy Temperature Sensor
±0.4 °C (max), –10 to 85 °C
0 to 100% RH operating range
–40 to +125 °C operating range
Low Voltage Operation
Low Power Consumption
50 nA, standby current
Factory-calibrated
I
2
C Interface
Integrated on-chip heater
2x2 mm QFN package
Excellent long term stability
Applications
Mobile smartphones and tablets
Consumer electronics
HVAC/R
Respiratory therapy
White goods
Asset and goods tracking
Thermostats/humidistats
Micro-environments/data centers
Indoor weather stations
Ordering Information:
See page 23.
Pin Assignments
Description
The Si7034 I
2
C Humidity and Temperature Sensor is a monolithic CMOS IC
integrating humidity and temperature sensor elements, an analog-to-digital
converter, signal processing, calibration data, and an I
2
C interface. The patented
use of industry-standard low-K polymeric dielectrics for sensing humidity enables
the construction of low-power, monolithic CMOS Sensor ICs with low drift and
hysteresis, and excellent long-term stability.
The humidity and temperature sensors are factory-calibrated and the calibration
data is stored in the on-chip non-volatile memory. This ensures that the sensors
are fully interchangeable, with no calibration or software changes required.
The Si7034 is available in a 2x2 mm DFN package and is reflow solderable. It can
be used as a hardware- and software-compatible drop-in upgrade for existing RH/
temperature sensors in 2x2 mm QFN-6 packages. The Si7034 offers an accurate,
low-power, factory-calibrated digital solution ideal for measuring humidity, dew
point, and temperature in applications ranging from HVAC/R and asset tracking to
industrial and consumer platforms.
DNC
6
VDD
1
5
GND
SCL
2
3
4
SDA
DNC
Top View
Patent Protected. Patents pending
Rev. 1.0 8/15
Copyright © 2015 by Silicon Laboratories
Si7034-A10
Si7034-A10
Functional Block Diagram
Vdd
Si7034
Humidity
Sensor
1.25V
Ref
Calibration
Memory
Control Logic
ADC
Temp
Sensor
I
2
C
Interface
SDA
SCL
GND
2
Rev. 1.0
Si7034-A10
T
ABLE O F
C
ONTENTS
Section
Page
1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2. Typical Application Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
3. Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.1. Relative Humidity Sensor Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.2. Hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.3. Prolonged Exposure to High Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
4.4. PCB Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.5. Protecting the Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.6. Bake/Hydrate Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.7. Long Term Drift/Aging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5. I2C Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1. Issuing a Measurement Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.2. Reading and Writing User Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.3. Measuring Relative Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.4. Measuring Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.5. Firmware Revision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.6. Electronic Serial Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
5.7. Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6. Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
7. Pin Descriptions: Si7034 (Top View) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
9. Package Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
9.1. Package Outline: 2x2 6-pin QFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10. PCB Land Pattern and Solder Mask Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
11. Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
11.1. Si7034 Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
11.2. Top Marking Explanation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
12. Additional Reference Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Rev. 1.0
3
Si7034-A10
1. Electrical Specifications
Unless otherwise specified, all min/max specifications apply over the recommended operating conditions.
Table 1. Recommended Operating Conditions
Parameter
Power Supply
Operating Temperature
Symbol
V
DD
T
A
Test Condition
Min
1.67
–40
Typ
—
—
Max
1.98
+125
Unit
V
°C
Table 2. General Specifications
1.67
V
DD
1.98 V; T
A
= –40 to +125 °C unless otherwise noted.
Parameter
Input Voltage High
Input Voltage Low
Input Voltage Range
Input Leakage
Output Voltage Low
Current Consumption
Symbol
V
IH
VIL
VIN
IIL
VOL
I
DD
Test Condition
SCL, SDA pins
SCL, SDA pins
SCL, SDA pins with respect to GND
SCL, SDA pins
SDA pin; IOL = 1.5 mA
Normal Mode, Temperature conversion in
progress
1
Normal Mode, RH conversion in progress
1
Fast Mode, parallel temperature and RH
conversion in progress
2
Fast Mode, RH conversion in progress
3
Standby, –40 to +85 °C
5
Standby, –40 to +125 °C
5
Peak IDD during powerup
6
Peak IDD during I
2
C operations
7
After writing to user registers
8
Min
0.7xVDD
—
0.0
—
—
—
—
—
—
—
—
—
—
—
—
Typ
—
—
—
—
—
245
106
337
106
0.05
0.05
4
3.5
11.6
6.4 to 53.5
Max
—
0.3xVDD
VDD+2
1
0.4
288
145
398
145
0.56
5.2
5.1
4
17
—
Unit
V
V
V
μA
V
μA
μA
μA
μA
μA
μA
mA
mA
µA
mA
Heater Current
9
I
HEAT
Notes:
1.
In Normal Mode, a temperature conversion is performed first, followed by an RH conversion.
2.
In Fast Mode, both a temperature conversion and an RH conversion are initiated at the same time and occur in parallel.
3.
Current consumption of RH conversion after the temperature conversion has finished. In Fast Mode, the temperature
conversion finishes before the RH conversion.
4.
Additional time for RH conversion after the temperature conversion has finished.
5.
No conversion or I
2
C transaction in progress. Typical values measured at 25 °C.
6.
Occurs once during powerup. Duration is <5 msec.
7.
Occurs during I
2
C commands for Reset, Read/Write User Registers, Read EID, and Read Firmware Version. Duration
is <100
μs
when I
2
C clock speed is >100 kHz (>200 kHz for 2-byte commands).
8.
IDD after a user register write. Initiating any other subsequent I
2
C transaction on the same bus (such as a user register
read, starting an RH measurement, or traffic directed at other I
2
C devices) will transition the device to standby mode.
9.
Additional current consumption when HTRE bit enabled.
4
Rev. 1.0
Si7034-A10
Table 2. General Specifications (Continued)
1.67
V
DD
1.98 V; T
A
= –40 to +125 °C unless otherwise noted.
Parameter
Conversion Time
Symbol
t
CONV
Test Condition
Normal Mode, RH conversion
1
Normal Mode, Temperature conversion
1
Fast Mode, parallel Temp and RH conver-
sion
2
Fast Mode, additional RH conversion
time
4
Min
Typ
5.8
3.7
0.9
1.6
Max
8.5
6
1.5
2.5
15
Unit
ms
ms
ms
ms
ms
Powerup Time
t
PU
From VDD
≥
1.67 V to ready for a
conversion, 25 °C
From VDD
≥
1.67 V to ready for a
conversion, full temperature range
After issuing a software reset
command
—
10
—
—
—
1.2
50
2.0
ms
ms
Notes:
1.
In Normal Mode, a temperature conversion is performed first, followed by an RH conversion.
2.
In Fast Mode, both a temperature conversion and an RH conversion are initiated at the same time and occur in parallel.
3.
Current consumption of RH conversion after the temperature conversion has finished. In Fast Mode, the temperature
conversion finishes before the RH conversion.
4.
Additional time for RH conversion after the temperature conversion has finished.
5.
No conversion or I
2
C transaction in progress. Typical values measured at 25 °C.
6.
Occurs once during powerup. Duration is <5 msec.
7.
Occurs during I
2
C commands for Reset, Read/Write User Registers, Read EID, and Read Firmware Version. Duration
is <100
μs
when I
2
C clock speed is >100 kHz (>200 kHz for 2-byte commands).
8.
IDD after a user register write. Initiating any other subsequent I
2
C transaction on the same bus (such as a user register
read, starting an RH measurement, or traffic directed at other I
2
C devices) will transition the device to standby mode.
9.
Additional current consumption when HTRE bit enabled.
Table 3. I
2
C Interface Specifications
1
1.67
V
DD
1.98 V; T
A
= –40 to +125 °C unless otherwise noted.
Parameter
Hysteresis
SCLK Frequency
2
SCL High Time
SCL Low Time
Start Hold Time
Symbol
V
HYS
f
SCL
t
SKH
t
SKL
t
STH
Test Condition
High-to-low versus
low-to-high transition
Min
0.05 x V
DD
—
0.6
1.3
0.6
Typ
—
—
—
—
—
Max
—
400
—
—
—
Unit
V
kHz
µs
µs
µs
Notes:
1.
All values are referenced to V
IL
and/or V
IH
.
2.
Depending on the conversion command, the Si7034 may hold the master during the conversion (clock stretch). At
above 300 kHz SCL, the Si7034 may hold the master briefly for user register and device ID transactions. At the highest
I
2
C speed of 400 kHz the stretching will be <50 µs.
3.
Pulses up to and including 50 ns will be suppressed.
Rev. 1.0
5
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