Si7022-A20-IM1 - Silicon Labs - Datasheet.Directory

Si7022-A20

HUMIDITY/TEMPERATURE SENSOR WITH PWM OUTPUT

Features

Applications

Description

The Si7022 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 a PWM output. The PWM

output may be filtered to produce an analog voltage output. 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 recalibration or software changes required.

The Si7022 is available in a 3x3 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 3x3 mm DFN-6 packages, featuring precision sensing

over a wider range and lower power consumption. The optional factory-installed

cover offers a low profile, convenient means of protecting the sensor during

assembly (e.g., reflow soldering) and throughout the life of the product, excluding

liquids (hydrophobic/oleophobic) and particulates.

The Si7022 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.

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

Wide operating voltage

(1.9 to 3.6 V)

Low Power Consumption

Factory-calibrated

PWM Output

3x3 mm DFN Package

Excellent long term stability

Optional factory-installed cover

Low-profile

Protection during reflow

Excludes liquids and particulates

HVAC/R

Thermostats/humidistats

Respiratory therapy

White goods

Indoor weather stations

Micro-environments/data centers

Automotive climate control and

defogging

Asset and goods tracking

Mobile phones and tablets

Patent Protected. Patents pending

Ordering Information:

See page 18.

Pin Assignments

Top View

PWM2

VDD

SELECTPWM1

GND

DNC

Si7022-A20

2 Rev. 1.3

Functional Block Diagram

ADC

GND

Humidity

Sensor Control Logic

Si7022

Temp

Sensor

1.25V

Ref

PWM Interface PWM1

Vdd

Calibration

Memory

SELECT

PWM2

Si7022-A20

Rev. 1.3 3

TABLE OF CONTENTS

Section Page

1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

2. Typical Application Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

3. Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

4. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

4.1. Relative Humidity Sensor Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

4.2. Hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

4.3. Prolonged Exposure to High Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

4.4. PCB Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

4.5. Protecting the Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

4.6. Bake/Hydrate Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

4.7. Long Term Drift/Aging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

5. PWM Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

6. Pin Descriptions: Si7022 (Top View) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

7. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

8. Package Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

8.1. Package Outline: 3x3 6-pin DFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

8.2. Package Outline: 3x3 6-pin DFN with Protective Cover . . . . . . . . . . . . . . . . . . . . . . 20

9. PCB Land Pattern and Solder Mask Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

10. Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

10.1. Si7022 Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

10.2. Top Marking Explanation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

11. Additional Reference Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Si7022-A20

4 Rev. 1.3

1. Electrical Specifications

Unless otherwise specified, all min/max specifications apply over the recommended operating conditions.

Table 1. Recommended Operating Conditions

Parameter Symbol Test Condition Min Typ Max Unit

Power Supply VDD 1.9 — 3.6 V

Operating Temperature TA–40 — +125 °C

Table 2. General Specifications

1.9 < VDD <3.6 V; TA= –40 to 125 °C unless otherwise noted.

Parameter Symbol Test Condition Min Typ Max Unit

Input Voltage High VIH SELECT pin 0.7xVDD ——V

Input Voltage Low VIL SELECT pin — — 0.3xVDD V

Input Voltage Range VIN SELECT pin with respect to GND 0.0 — VDD V

Input Leakage IIL SELECT pin — — 1 μA

Output Voltage High VOH PWM1, PWM2 pins, IOH = –10 μA VDD – 0.1 — — V

PWM1, PWM2 pins pin,

IOH = –0.5 mA, VDD =2.0V

VDD – 0.2 — —

PWM1, PWM2 pins,

IOH = –1.7 mA, VDD =3.0V

VDD – 0.4 — —

Output Voltage Low VOL PWM1, PWM2 pins; IOL = 2.5 mA;

VDD =3.3V

——0.6V

PWM1, PWM2 pins; IOL = 1.2 mA;

VDD =1.9V

——0.4V

Sample Rate RH and Temperature — 2 — Hz

Current

Consumption

IDD Average Current — 150 300 μA

Powerup Time tPU From VDD ≥1.9 V to PWM output

enabled, 25 °C

—4855

From VDD ≥1.9 V to PWM output

enabled, full temperature range

——110

Si7022-A20

Rev. 1.3 5

Figure 1. PWM Interface Timing Diagram

Table 3. PWM Interface Spe cificati ons

1.9  VDD  3.6 V; TA = –40 to +125 °C unless otherwise noted.

Parameter Symbol Test Condition Min Typ Max Unit

PWM Frequency FPWM 1.00 1.22 1.40 kHz

PWM Duty Cycle DCPWM tH / tPWM 0—1

SELECT Setup Time tSS From SELECT transition to

PWM valid

—500—ms

tPWM

tSS

RH Data Temperature Data

Si7022-A20

6 Rev. 1.3

Figure 2. RH Accuracy at 30 °C

Table 4. Humidity Sensor

1.9 ≤ VDD ≤ 3.6 V; TA = 30 °C

Parameter Symbol Test Condition Min Typ Max Unit

Operating Range1Non-condensing 0 — 100 %RH

Accuracy2, 3 0 – 80% RH — ±3 ±4 %RH

80 – 100% RH See Figure 2.

Repeatability/Noise — 0.025 — %RH RMS

Resolution — 11 — Bits

Response Time4τ63% 1m/s airflow, with or without

cover

—6— S

Drift vs. Temperature — 0.05 — %RH/°C

Hysteresis — ±1 — %RH

Long Term Stability3—<0.25 — %RH/yr

Notes:

1. Recommended humidity operating range is 20% to 80% RH (non-condensing) over –10 °C to 60 °C. Prolonged

operation beyond these ranges may result in a shift of sensor reading, with slow recovery time.

2. Excludes hysteresis, long term drift, and certain other factors and is applicable to non-condensing environments only.

See Section “4.1. Relative Humidity Sensor Accuracy” for more details.

3. Drift due to aging effects at typical room conditions of 30 °C and 30% to 50% RH. May be impacted by dust, vaporized

solvents or other contaminants, e.g., out-gassing tapes, adhesives, packaging materials, etc. See Section “4.7. Long

Term Drift/Aging” .

4. Response time to a step change in RH. Time for the RH output to change by 63% of the total RH change.

Si7022-A20

Rev. 1.3 7

Figure 3. Te mperature Accuracy

Table 5. Temperature Sensor

1.9 ≤ VDD ≤3.6 V; TA= –40 to +125 °C unless otherwise noted.

Parameter Symbol Test Condition Min Typ Max Unit

Operating Range –40 — +125 °C

Accuracy –10 °C< tA<85 °C — ±0.3 ±0.4 °C

–40 < tA<125 °C Figure 3.

Repeatability/Noise — 0.04 — °C RMS

Resolution — 11 — Bits

Response Time* τ63% Unmounted device — 0.7 — s

Si7022-EB board — 5.1 —

Long Term Stability —  0.01 — °C/Yr

*Note: Time to reach 63% of final value in response to a step change in temperature. Actual response time will vary

dependent on system thermal mass and air-flow.

Si7022-A20

8 Rev. 1.3

Table 6. Thermal Characteristics

Parameter Symbol Test Condition DFN-6 Unit

Junction to Air Thermal Resistance JA JEDEC 2-Layer board,

No Airflow

256 °C/W

Junction to Air Thermal Resistance JA JEDEC 2-Layer board,

1m/s Airflow

224 °C/W

Junction to Air Thermal Resistance JA JEDEC 2-Layer board,

2.5 m/s Airflow

205 °C/W

Junction to Case Thermal Resistance JC JEDEC 2-Layer board 22 °C/W

Junction to Board Thermal Resistance JB JEDEC 2-Layer board 134 °C/W

Table 7. Absolute Maximum Ratings1

Parameter Symbol Test Condition Min Typ Max Unit

Ambient temperature

under bias

–55 — 125 °C

Storage Temperature2–65 — 150 °C

Voltage on I/O pins –0.3 — VDD+0.3 V V

Voltage on VDD with

respect to GND

–0.3 — 4.2 V

ESD Tolerance HBM — — 2 kV

CDM — — 1.25 kV

MM — — 250 V

Notes:

1. Absolute maximum ratings are stress ratings only, operation at or beyond these conditions is not implied and may

shorten the life of the device or alter its performance.

2. Special handling considerations apply; see application note, “AN607: Si70xx Humidity Sensor Designer’s Guide”.

Si7022-A20

Rev. 1.3 9

2. Typical Application Circuits

The primary function of the Si7022 is to measure relative humidity and temperature. Figure 4 demonstrates the

typical application circuit to achieve these functions.

Figure 4. Typical Application Circuit for Relative Humidity and Temperature Measurement

GND

PWM1

Si7022

SELECT

1.9 V to 3.6 V

VDD

0.1 µF

PWM2

SELECT

1 µF

100 k

VRH/VTEMP

100 k

1 µF

VTEMP/VRH

Optional



Si7022-A20

10 Rev. 1.3

3. Bill of Materials

Table 8. Typical Application Circuit BOM for Relative Humidity and Temperature Measurement

Reference Description Mfr Part Number Manufacturer

C1 Capacitor, 0.1 μF, 16 V, X7R, 0603 Various Various

R1 Resistor, 100 k, ±5%, 1/16W, 0603 Various Various

C2 Capacitor, 1 μF, 16 V, X7R, 0603 Various Various

R2 Resistor, 100 k, ±5%, 1/16W, 0603 (optional) Various Various

C3 Capacitor, 1 μF, 16 V, X7R, 0603 (optional) Various Various

U1 IC, Digital Temp/Humidity Sensor Si7022-A20 Silicon Labs

Si7022-A20

Rev. 1.3 11

4. Functional Description

Figure 5. Si7022 Block Diagram

The Si7022 is a digital relative humidity and temperature sensor that integrates temperature and humidity sensor

elements, an analog-to-digital converter, signal processing, calibration, polynomial non-linearity correction, and a

PWM output all in a single chip. The Si7022 is individually factory-calibrated for both temperature and humidity,

with the calibration data stored in on-chip, non-volatile memory. This ensures that the sensor is fully

interchangeable, with no recalibration or changes to software required. Patented use of industry-standard CMOS

and low-K dielectrics as a sensor enables the Si7022 to achieve excellent long term stability and immunity to

contaminants with low drift and hysteresis. The Si7022 offers a low-power, high-accuracy, calibrated and stable

solution ideal for a wide range of temperature, humidity, and dew-point applications including medical and

instrumentation, high-reliability automotive and industrial systems, and cost-sensitive consumer electronics.

While the Si7022 is largely a conventional mixed-signal CMOS integrated circuit, relative humidity sensors in

general and those based on capacitive sensing using polymeric dielectrics have unique application and use

requirements that are not common to conventional (non-sensor) ICs. Chief among those are:

The need to protect the sensor during board assembly, i.e., solder reflow, and the need to subsequently

rehydrate the sensor.

The need to protect the senor from damage or contamination during the product life-cycle.

The impact of prolonged exposure to extremes of temperature and/or humidity and their potential effect on

sensor accuracy.

The effects of humidity sensor “memory”.

Each of these items is discussed in more detail in the following sections.

PWM2

PWM1

SELECT

ADC

GND

Humidity

Sensor Control Logic

Si7022

Temp

Sensor

1.25V

Ref

PWM Interface

Vdd

Calibration

Memory

Si7022-A20

12 Rev. 1.3

4.1. Relative Humidity Sensor Accuracy

To determine the accuracy of a relative humidity sensor, it is placed in a temperature and humidity controlled

chamber. The temperature is set to a convenient fixed value (typically 25–30 °C) and the relative humidity is swept

from 20 to 80% and back to 20% in the following steps: 20% – 40% – 60% – 80% – 80% – 60% – 40% – 20%. At

each set-point, the chamber is allowed to settle for a period of 60 minutes before a reading is taken from the

sensor. Prior to the sweep, the device is allowed to stabilize to 50%RH. The solid trace in Figure 6, “Measuring

Sensor Accuracy Including Hysteresis,” shows the result of a typical sweep.

Figure 6. Measuring Sensor Accuracy Including Hysteresis

The RH accuracy is defined as the dotted line shown in Figure 6, which is the average of the two data points at

each relative humidity set-point. In this case, the sensor shows an accuracy of 0.25%RH. The Si7022 accuracy

specification (Table 4) includes:

Unit-to-unit and lot-to-lot variation

Accuracy of factory calibration

Margin for shifts that can occur during solder reflow

The accuracy specification does not include:

Hysteresis (typically ±1%)

Effects from long term exposure to very humid conditions

Contamination of the sensor by particulates, chemicals, etc.

Other aging related shifts ("Long-term stability")

Variations due to temperature (see Drift vs. Temperature in Table 4). RH readings will typically vary with

temperature by less than  0.05%  C.

Si7022-A20

Rev. 1.3 13

4.2. Hysteresis

The moisture absorbent film (polymeric dielectric) of the humidity sensor will carry a memory of its exposure

history, particularly its recent or extreme exposure history. A sensor exposed to relatively low humidity will carry a

negative offset relative to the factory calibration, and a sensor exposed to relatively high humidity will carry a

positive offset relative to the factory calibration. This factor causes a hysteresis effect illustrated by the solid trace

in Figure 6. The hysteresis value is the difference in %RH between the maximum absolute error on the decreasing

humidity ramp and the maximum absolute error on the increasing humidity ramp at a single relative humidity

setpoint and is expressed as a bipolar quantity relative to the average error (dashed trace). In the example of

Figure 6, the measurement uncertainty due to the hysteresis effect is ±1.0%RH.

4.3. Prolonged Exposure to High Humidity

Prolonged exposure to high humidity will result in a gradual upward drift of the RH reading. The shift in sensor

reading resulting from this drift will generally disappear slowly under normal ambient conditions. The amount of

shift is proportional to the magnitude of relative humidity and the length of exposure. In the case of lengthy

exposure to high humidity, some of the resulting shift may persist indefinitely under typical conditions. It is generally

possible to substantially reverse this effect by baking the device (see Section “4.6. Bake/Hydrate Procedure” ).

4.4. PCB Assembly

4.4.1. Soldering

Like most ICs, Si7022 devices are shipped from the factory vacuum-packed with an enclosed desiccant to avoid

any RH accuracy drift during storage and to prevent any moisture-related issues during solder reflow. The following

guidelines should be observed during PCB assembly:

Si7022 devices are compatible with standard board assembly processes. Devices should be soldered

using reflow per the recommended card reflow profile. See Section “9. PCB Land Pattern and Solder Mask

Design” for the recommended card reflow profile.

A "no clean" solder process is recommended to minimize the need for water or solvent rinses after

soldering. Cleaning after soldering is possible, but must be done carefully to avoid impacting the

performance of the sensor. See “AN607: Si70xx Humidity Sensor Designer’s Guide” for more information

on cleaning.

It is essential that the exposed polymer sensing film be kept clean and undamaged. This can be

accomplished by careful handling and a clean, well-controlled assembly process. When in doubt or for

extra protection, a heat-resistant, protective cover such as Kapton™ KPPD-1/8 polyimide tape can be

installed during PCB assembly.

Si7022s may be ordered with a factory-fitted, solder-resistant protective cover. This cover provides protection

during PCB assembly or rework but without the time and effort required to install and remove the Kapton tape. It

can be left in place for the lifetime of the product, preventing liquids, dust or other contaminants from coming into

contact with the polymer sensor film. See Section “7. Ordering Guide” for a list of ordering part numbers that

include the cover.

Si7022-A20

14 Rev. 1.3

4.4.2. Rehydration

The measured humidity value will generally shift slightly after solder reflow. A portion of this shift is permanent and

is accounted for in the accuracy specifications in Table 4. After soldering, an Si7022 should be allowed to

equilibrate under controlled RH conditions (room temperature, 45–55%RH) for at least 48 hours to eliminate the

remainder of the shift and return the device to its specified accuracy performance.

4.4.3. Rework

To maintain the specified sensor performance, care must be taken during rework to minimize the exposure of the

device to excessive heat and to avoid damage/contamination or a shift in the sensor reading due to liquids, solder

flux, etc. Manual touch-up using a soldering iron is permissible under the following guidelines:

The exposed polymer sensing film must be kept clean and undamaged. A protective cover is

recommended during any rework operation (Kapton® tape or the factory installed cover).

Flux must not be allowed to contaminate the sensor; liquid flux is not recommended even with a cover in

place. Conventional lead-free solder with rosin core is acceptable for touch-up as long as a cover is in

place during the rework.

If possible, avoid water or solvent rinses after touch-up. Cleaning after soldering is possible, but must be

done carefully to avoid impacting the performance of the sensor. See “AN607: Si70xx Humidity Sensor

Designer’s Guide” for more information on cleaning.

Minimize the heating of the device. Soldering iron temperatures should not exceed 350 °C and the contact

time per pin should not exceed five seconds.

Hot air rework is not recommended. If a device must be replaced, remove the device by hot air and solder

a new part in its place by reflow following the guidelines above.

*Note: All trademarks are the property of their respective owners.

Figure 7. Si7022 with Factory-Installed Protective Cover

Si7022-A20

Rev. 1.3 15

4.5. Protecting the Sensor

Because the sensor operates on the principal of measuring a change in capacitance, any changes to the dielectric

constant of the polymer film will be detected as a change in relative humidity. Therefore, it is important to minimize

the probability of contaminants coming into contact with the sensor. Dust and other particles as well as liquids can

affect the RH reading. It is recommended that a cover is employed in the end system that blocks contaminants but

allows water vapor to pass through. Depending on the needs of the application, this can be as simple as plastic or

metallic gauze for basic protection against particulates or something more sophisticated such as a hydrophobic

membrane providing up to IP67 compliant protection.

The Si7022 may be ordered with a factory-fitted, solder-resistant cover that can be left in place for the lifetime of

the product. It is very low-profile, hydrophobic and oleophobic. See Section “7. Ordering Guide” for a list of ordering

part numbers that include the cover. A dimensioned drawing of the IC with the cover is included in Section “8.

Package Outline” . Other characteristics of the cover are listed in Table 9.

4.6. Bake/Hydrate Procedure

After exposure to extremes of temperature and/or humidity for prolonged periods, the polymer sensor film can

become either very dry or very wet, in each case the result is either high or low relative humidity readings. Under

normal operating conditions, the induced error will diminish over time. From a very dry condition, such as after

shipment and soldering, the error will diminish over a few days at typical controlled ambient conditions, e.g.,

48 hours of 45 ≤%RH ≤55. However, from a very wet condition, recovery may take significantly longer. To

accelerate recovery from a wet condition, a bake and hydrate cycle can be implemented. This operation consists of

the following steps:

Baking the sensor at 125 °C for ≥ 12 hours

Hydration at 30 °C in 75% RH for ≥ 10 hours

Following this cycle, the sensor will return to normal operation in typical ambient conditions after a few days.

4.7. Long Term Drift/Aging

Over long periods of time, the sensor readings may drift due to aging of the device. Standard accelerated life

testing of the Si7022 has resulted in the specifications for long-term drift shown in Table 4 and Table 5. This

contribution to the overall sensor accuracy accounts only for the long-term aging of the device in an otherwise

benign operating environment and does not include the effects of damage, contamination, or exposure to extreme

environmental conditions.

Table 9. Specifications of Protective Cover

Parameter Value

Material PTFE

Operating Temperature –40 to 125 °C

Maximum Reflow Temperature 260 °C

IP Rating (per IEC 529) IP67

Si7022-A20

16 Rev. 1.3

5. PWM Output

During operation, the Si7022 takes a relative humidity and temperature measurement once per second and

converts the result into a pulse width modulated waveform. Two output pins are available for reading the

measurement results: PWM1 and PWM2. The information output on each pin is determined by the SELECT pin as

follows:

The duty cycle of the waveform on the PWM outputs corresponds to the relative humidity and temperature results

shown in the following equations. The PWM duty cycle varies linearly with the measurement result between the

minimum and maximum values:

Equation 1.

Equation 2.

In the typical application, the PWM output is filtered using an RC network to provide an analog output voltage that

varies linearly with RH and temperature. See Section “2. Typical Application Circuits” for the recommended

application circuit.

Due to normal variations in RH accuracy of the device as described in Table 4, it is possible for the measured value

of %RH to be slightly less than 0 when the actual RH level is close to or equal to 0. Similarly, the measured value

of %RH may be slightly greater than 100 when the actual RH level is close to or equal to 100. This is expected

behavior.

Table 10. PWM Outputs

Voltage on SELECT Pin PWM1 Output PWM2 Output

High RH Temperature

Low Temperature RH

RH (%RH) 6–125 DCPWM

Where DCPWM is the ratio of high time to period (i.e., a number that varies from 0 to 1)

+=

T(°C) 46.85–175.72 DCPWM

+=

Si7022-A20

Rev. 1.3 17

6. Pin Descriptions: Si7022 (Top View)

Pin Name Pin # Pin Description

PWM1 1 Pulse width modulated output #1

GND 2 Ground. This pin is connected to ground on the circuit board through a trace. Do not

connect directly to GND plane.

DNC 3 This pin should be soldered to pads on the PCB for mechanical stability. It can be

electrically floating or tied to VDD (do not tie to GND).

PWM2 4 Pulse width modulated output #2

VDD 5 Power. This pin is connected to power on the circuit board.

SELECT 6 Digital input that toggles between RH and temperature outputs on PWM1 and PWM2.

This pin should be pulled high or low (do not leave floating).

TGND Paddle This pad is connected to GND internally. This pad is the main thermal input to the on-

chip temperature sensor. The paddle should be soldered to a floating pad.

PWM2

VDD

SELECTPWM1

GND

DNC

Si7022-A20

18 Rev. 1.3

7. Ordering Guide

Table 11. Device Ordering Guide

P/N Description Max.

Accuracy Pkg Operating

Range (°C) Protective

Cover Packing

Format

Temp RH

Si7022-A20-IM Digital temperature/ humidity sensor –

industrial temp range

±0.4 °C ± 4% DFN 6 –40 to +125 °C N Cut Tape

Si7022-A20-IMR Digital temperature/ humidity sensor –

industrial temp range

±0.4 °C ± 4% DFN 6 –40 to +125 °C N Tape &

Reel

Si7022-A20-IM1 Digital temperature/ humidity sensor –

industrial temp range

±0.4 °C ± 4% DFN 6 –40 to +125 °C Y Cut Tape

Si7022-A20-IM1R Digital temperature/ humidity sensor –

industrial temp range

±0.4 °C ± 4% DFN 6 –40 to +125 °C Y Tape &

Reel

Si7022-A20-YM0 Digital temperature/ humidity sensor –

automotive

±0.4 °C ± 4% DFN 6 –40 to +125 °C N Cut Tape

Si7022-A20-YM0R Digital temperature/ humidity sensor –

automotive

±0.4 °C ± 4% DFN 6 –40 to +125 °C N Tape &

Reel

Si7022-A20-YM1 Digital temperature/ humidity sensor –

automotive

±0.4 °C ± 4% DFN 6 –40 to +125 °C Y Cut Tape

Si7022-A20-YM1R Digital temperature/ humidity sensor –

automotive

±0.4 °C ± 4% DFN 6 –40 to +125 °C Y Tape &

Reel

Note: The “A” denotes product revision A and “20” denotes firmware version 2.0.

Si7022-A20

Rev. 1.3 19

8. Package Outline

8.1. Package Outline: 3x3 6-pin DFN

Figure 10. 3x3 6-pin DFN

Table 12. 3x3 6-pin DFN Package Diagram Dimensions

Dimension Min Nom Max

A 0.70 0.75 0.80

A1 0.00 0.02 0.05

b 0.35 0.40 0.45

D 3.00 BSC.

D2 1.40 1.50 1.60

e 1.00 BSC.

E 3.00 BSC.

E2 2.30 2.40 2.50

H1 0.85 0.90 0.95

H2 1.39 1.44 1.49

L 0.35 0.40 0.45

aaa 0.10

bbb 0.10

ccc 0.05

ddd 0.10

eee 0.05

fff 0.05

Notes:

1. All dimensions shown are in millimeters (mm).

2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.

Si7022-A20

20 Rev. 1.3

8.2. Package Outline: 3x3 6-pin DFN with Protective Cover

Figure 8 illustrates the package details for the Si7022 with the optional protective cover. Table 13 lists the values

for the dimensions shown in the illustration.

Figure 8. 3x3 6-pin DFN with Protective Cover

Table 13. 3x3 6-pin DFN with Protective Cover Package Diagram Dimensions

Dimension Min Nom Max

A——1.21

A1 0.00 0.02 0.05

A2 0.70 0.75 0.80

b 0.35 0.40 0.45

D 3.00 BSC.

D2 1.40 1.50 1.60

e 1.00 BSC.

E 3.00 BSC.

E2 2.30 2.40 2.50

F1 2.70 2.80 2.90

F2 2.70 2.80 2.90

h 0.76 0.83 0.90

L 0.35 0.40 0.45

R1 0.45 0.50 0.55

aaa 0.10

bbb 0.10

ccc 0.05

ddd 0.10

eee 0.05

Notes:

1. All dimensions are shown in millimeters (mm).

2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.

Si7022-A20

Rev. 1.3 21

9. PCB Land Pattern and Solder Mask Design

Figure 9. Si7022 PCB Land Pattern

Table 14. PCB Land Pattern Dimensions

Symbol mm

C1 2.90

E1.00

P1 1.60

P2 2.50

X1 0.45

Y1 0.85

Notes:

General

1. All dimensions shown are at Maximum Material Condition (MMC). Least Material

Condition (LMC) is calculated based on a Fabrication Allowance of 0.05 mm.

2. This Land Pattern Design is based on the IPC-7351 guidelines.

Solder Mask Design

3. All metal pads are to be non-solder mask defined (NSMD). Clearance between the

solder mask and the metal pad is to be 60 µm minimum, all the way around the

pad.

Stencil Design

4. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls

should be used to assure good solder paste release.

5. The stencil thickness should be 0.125 mm (5 mils).

6. The ratio of stencil aperture to land pad size should be 1:1 for all perimeter pins.

7. A 2x1 array of 1.00 mm square openings on 1.30 mm pitch should be used for the

center ground pad to achieve a target solder coverage of 50%.

Card Assembly

8. A No-Clean, Type-3 solder paste is recommended.

9. The recommended card reflow profile is per the JEDEC/IPC J-STD-020

specification for Small Body Components.



Si7022-A20

22 Rev. 1.3

10. Top Marking

10.1. Si7022 Top Marking

10.2. Top Marking Explanation

Mark Method: Laser

Font Size 0.30 mm

Pin 1 Indicator: Circle = 0.30 mm Diameter

Upper-Left Corner

Line 1 Marking: TTTT = Mfg Code

Si7022-A20

Rev. 1.3 23

11. Additional Reference Resources

AN607: Si70xx Humidity Sensor Designer’s Guide

Si7022-A20

24 Rev. 1.3

DOCUMENT CHANGE LIST

Revision 0.9 to Revision 1.0

Updated Table 2.

Updated Table 3.

Revision 1.0 to Revision 1.1

Updated Section “4.5. Protecting the Sensor”

Updated Table 9

Updated Table 13 dimensions F1 and F2

Revision 1.1 to Revision 1.2

Updated PWM Duty Cycle parameter in Table 3 on

page 5.

Updated Equation 1 and Equation 2 on page 16.

Revision 1.2 to Revision 1.3

Changed packing format from tube to cut tape for all

non-tape & reel part numbers without protective filter

covers.

Disclaimer

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using or intending to use the Silicon Laboratories products. Characterization data, available modules and peripherals, memory sizes and memory addresses refer to each specific

device, and "Typical" parameters provided can and do vary in different applications. Application examples described herein are for illustrative purposes only. Silicon Laboratories

reserves the right to make changes without further notice and limitation to product information, specifications, and descriptions herein, and does not give warranties as to the accuracy

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