HDC3021DEHR [TI]

HDC302x High-Accuracy, Low-Power, Digital Humidity and Temperature Sensor With Ultra-Low Drift;


型号：	HDC3021DEHR
厂家：	TEXAS INSTRUMENTS
描述：	HDC302x High-Accuracy, Low-Power, Digital Humidity and Temperature Sensor With Ultra-Low Drift
文件：	总51页 (文件大小：2002K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

HDC3020

SNAS778 – JUNE 2021

HDC302x High-Accuracy, Low-Power, Digital Humidity and Temperature Sensor With

Ultra-Low Drift

1 Features

3 Description

•

Relative humidity (RH) sensor:

– Operating range: 0% to 100%

– Accuracy: ±1.5% typical

– Drift Correction: reduces offset to return device

to within accuracy specification

– Long-term drift: 0.21%RH/yr

– Condensation protection with integrated heater

Temperature sensor:

– Operating range: -40°C to 125°C

– Accuracy: ±0.1°C typical

NIST traceability: Relative humidity & temperature

Low power: average current 0.7 µA

I²C interface compatibility up to 1-Mhz speeds

– Four selectable I²C addresses

– Command/data protection through CRC

checksum

The HDC302x is an integrated capacitive based

relative humidity (RH) and temperature sensor, which

provides high accuracy measurements over a wide

supply range (1.62 V – 5.5 V), along with ultra-low

power consumption in a compact 2.5-mm × 2.5-mm

package. Both the temperature and humidity sensors

are 100% tested and trimmed on a production setup

that is NIST traceable and verified with equipment that

is calibrated to ISO/IEC 17025 standards.

•

Drift Correction reduces RH sensor offset due to

aging, exposure to extreme operating conditions, and

contaminants to return device to within accuracy

specifications. For battery IoT applications, auto

measurement mode and ALERT feature enable low

system power by maximizing MCU sleep time. There

are four different I²C addresses that support speeds

up to 1 MHz. A heating element is available to

dissipate condensation and moisture.

•

Supply voltage: 1.62 V to 5.50 V

Available auto measurement mode

Programmable interrupts

Programmable measurement calibration

Factory-installed polyimide tape assembly cover

Factory-installed IP67 rated environmental cover

The HDC3020 comes in an open cavity package

without a protective cover. Two device variants have

a cover option to protect the open cavity RH sensor:

HDC3021 and HDC3022. HDC3021 has removable

protective tape to allow conformal coatings and

PCB wash. HDC3022 has a permanent IP67 filter

membrane cover to protect against dust and water.

2 Applications

•

Washer & dryer

Refrigerator & freezer

Industrial transport

Cold Chain asset tracking & data logger

IoT environmental sensors

Air quality and gas detection

Humidifier/dehumidifier

Thermostat

CPAP and ventilator

Water leak detector

IP Camera

Device Information

PART NUMBER

PACKAGE⁽¹⁾

BODY SIZE (NOM)

HDC3020

HDC3021⁽²⁾

HDC3022⁽²⁾

WSON (8)

2.50 mm × 2.50 mm

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

(2) Preview only.

3.30 V

HDC3

VDD

SCL

SDA

I²C

Controller

Calibration

ADC

ALERT

ADDR

ADDR1

I²C

GPIO

RH Sensor

T Sensor

Linearization

µC

RESET

GND

Typical Application

Typical RH Accuracy vs. RH Setpoint (T_A= 25°C)

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. ADVANCE INFORMATION for preproduction products; subject to change

without notice.

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Table of Contents

1 Features............................................................................1

2 Applications.....................................................................1

3 Description.......................................................................1

4 Revision History.............................................................. 2

5 Pin Configuration and Functions...................................3

6 Specifications.................................................................. 4

6.1 Absolute Maximum Ratings ....................................... 4

6.2 ESD Ratings .............................................................. 4

6.3 Recommended Operating Conditions ........................4

6.4 Thermal Information ...................................................4

6.5 Electrical Characteristics ............................................5

6.6 Switching Characteristics ...........................................7

6.7 Timing Diagram...........................................................7

6.8 Typical Characteristics................................................8

7 Detailed Description........................................................9

7.1 Overview.....................................................................9

7.2 Functional Block Diagram...........................................9

7.3 Feature Description.....................................................9

7.4 Device Functional Modes..........................................12

7.5 Programming............................................................ 12

8 Application and Implementation..................................29

8.1 Application Information............................................. 29

8.2 Typical Application.................................................... 29

9 Power Supply Recommendations................................32

10 Layout...........................................................................32

10.1 Layout Guidelines................................................... 32

10.2 Layout Example...................................................... 33

10.3 Storage and PCB Assembly................................... 33

11 Device and Documentation Support..........................35

11.1 Documentation Support.......................................... 35

11.2 Receiving Notification of Documentation Updates..35

11.3 Support Resources................................................. 35

11.4 Trademarks............................................................. 35

11.5 Electrostatic Discharge Caution..............................35

11.6 Glossary..................................................................35

12 Mechanical, Packaging, and Orderable

Information.................................................................... 35

12.1 Package Option Addendum....................................45

12.2 Tape and Reel Information......................................47

4 Revision History

DATE

VERSION

NOTES

June 2021

Initial release.

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

5 Pin Configuration and Functions

SDA

ADDR

ALERT

SCL

GND

ADDR1

RESET

Not to scale

1. DEF package has a transparent top.

2. HDC3021 DEH and HDC3022 DEJ packages are preview only.

Figure 5-1. HDC302x DEF, DEH, or DEJ Package 8-Pin WSON Top View

Table 5-1. Pin Functions

TYPE⁽¹⁾

DESCRIPTION

NAME

V_DD

NO.

Supply Voltage. From 1.62 V to 5.50 V.

Ground

GND

SCL

Serial clock line for I²C, open-drain; requires a pullup resistor to V_DD

SDA

I/O

Serial data line for I²C, open-drain; requires a pullup resistor to V_DD

I²C Device Address Pin.

For device addresses 0x44 and 0x45, ADDR1 voltage must be below maximum V_ILor left floating.

0x44 requires ADDR voltage to be below maximum V_ILor left floating.

0x45 requires ADDR voltage to be above minimum V_IH.

ADDR

I²C Device Address Pin.

For device addresses 0x46 and 0x47, ADDR1 voltage must be above minimum V_IH.

0x46 requires ADDR voltage to be below maximum V_ILor left floating.

0x47 requires ADDR voltage to be above minimum V_IH.

ADDR1

RESET

ALERT

Reset Pin. Active Low. If not used, leave floating or tie to V_DD.

Interrupt Pin to drive high impedance loads. Push-Pull Output.

If not used, must be left floating.

(1) Type:

G = Ground

I = Input

O = Output

P = Power

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)⁽¹⁾

MIN

–0.3

–55

MAX

6.0

UNIT

V_DD

Applied Voltage on VDD pin

Applied Voltage on SCL pin

Applied Voltage on SDA pin

Applied Voltage on ADDR pin

Applied Voltage on ADDR1 pin

Applied Voltage on ALERT pin

Applied Voltage on RESET pin

Junction temperature

SCL

6.0

SDA

6.0

ADDR

ADDR1

ALERT

RESET

T_J

6.0

V_DD+ 0.3

150

°C

T_stg

Storage temperature

–65

150

(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress

ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under

Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device

reliability.

6.2 ESD Ratings

VALUE

UNIT

Human body model (HBM), per ANSI/ESDA/JEDEC

±2000

JS-001⁽¹⁾

Charged device model (CDM), per JEDEC specification

V_(ESD)

Electrostatic discharge

All Pins

±500

±750

JESD22-C101⁽²⁾

Charged device model (CDM), per JEDEC specification

JESD22-C101⁽²⁾

Corner Pins

(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process

(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process

6.3 Recommended Operating Conditions

PARAMETER

MIN

1.62

–40

–20

–40

MAX UNIT

V_DD

Supply voltage

5.5

125

T_TEMP

T_RH

Temperature Sensor - Operating free-air temperature

°C

Relative Humidity Sensor - Operating free-air temperature

Integrated Heater for condensation removal - Operating free-air temperature⁽¹⁾

Relative Humidity Sensor Operating Range (Non-condensing) ⁽¹⁾

T_HEATER

RH_OR

100 %RH

(1) Prolonged operation outside the recommended temperature operating conditions and/or at >80%RH with temperature in the higher

recommended operating range can result in a shift of sensor reading, with slow recovery time. See Exposure to High Temperature and

High Humidity Conditions for more details.

6.4 Thermal Information

HDC3x

THERMAL METRIC⁽¹⁾

DEF, DEH, and DEJ

UNIT

8 PINS

84.9

N/A

R_θJA

Junction-to-ambient thermal resistance

Junction-to-case (top) thermal resistance⁽²⁾

Junction-to-board thermal resistance

°C/W

R_θJC(top)

R_θJB

52.0

N/A

Ψ_JT

Junction-to-top characterization parameter⁽²⁾

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

HDC3x

DEF, DEH, and DEJ

8 PINS

THERMAL METRIC⁽¹⁾

UNIT

Ψ_JB

Junction-to-board characterization parameter

Junction-to-case (bottom) thermal resistance

51.7

°C/W

R_θJC(bot)

30.4

(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application

report.

(2) JEDEC standard JESD51-X specifies this measurement at the center position on the top surface of the package. Due to the location of

the cavity opening at the center position, this measurement is not applicable.

6.5 Electrical Characteristics

T_A= -40°C to 125°C, VDD = 1.62V to 5.50V (unless otherwise noted), Typical Specifications are T_A= 25°C, V_DD

1.8V unless otherwise noted

PARAMETER

Current Consumption

TEST CONDITIONS

MIN

TYP

MAX

UNIT

Low Power Mode 0 (lowest noise)

Low Power Mode 1

125

TBD

100

TBD

I_{DD_ACTIVE}Active Current⁽¹⁾

µA

Low Power Mode 2

Low Power Mode 3

TBD

No Active Measurement

trigger on demand mode

0.4

I_{DD_SLEEP}Sleep Current⁽¹⁾

µA

No Active Measurement,

auto measurement mode

0.55

TBD

I_{DD_AVG_E}

measurement freq = numbers of samples per

second

(9)

Averaged Current Equation

Low Power Mode 0 (lowest noise)

Averaged at 1 sample per second

2.0

1.2

1.0

0.9

0.7

TBD

Low Power Mode 1

Averaged at 1 sample per second

Low Power Mode 2

Averaged at 1 sample per second

I_{DD_AVG}

Averaged Current^{(1) (2)}

µA

Low Power Mode 3 (lowest power)

Averaged at 1 sample per second

Low Power Mode 3 (lowest power)

Averaged at 1 sample every two seconds

Heater Current (Condensation

Removal)

T_HEATER- T_AMBIENT= 20°C. V_DD= 3.3V for

Typical Value

I_HEATER

Sensor Timing

Low Power Mode 0 (lowest noise)

Low Power Mode 1

12.0

7.0

4.5

3.3

TBD

t_meas

Measurement Duration ⁽⁸⁾

Low Power Mode 2

Low Power Mode 3 (lowest power)

Sensor ready once V_DD≥ 1.62V

T_A= 25°C

0.5

Sensor_PU

Power Up Ready

Soft Reset Ready

Sensor ready once V_DD≥ 1.62V

1.5

Sensor ready once Soft Rest Command

received

T_A= 25°C

0.5

Sensor_SR

Sensor ready once Soft Rest Command

received

1.5

Relative Humidity Sensor

RH_ACC

Accuracy^{(3) (4)}

T_A= 25°C, 10% to 90% RH

±1.5

±2

%RH

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

www.ti.com

UNIT

SNAS778 – JUNE 2021

T_A= -40°C to 125°C, VDD = 1.62V to 5.50V (unless otherwise noted), Typical Specifications are T_A= 25°C, V_DD

1.8V unless otherwise noted

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

at ambient room tempT_A= 25°C, 10% to 90%

Low Power Mode 0 (lowest noise)

±0.02

T_A= 25°C, 10% to 90% RH

Low Power Mode 1

TBD

RH_REP

Repeatability

%RH

T_A= 25°C, 10% to 90% RH

Low Power Mode 2

T_A= 25°C, 10% to 90% RH

Low Power Mode 3 (lowest power)

TBD

±1

RH_HYS

RH_RT

Hysteresis ⁽⁵⁾

T_A= 25°C, 10% to 90% RH

%RH

T_A= 25°C, 10% to 90% RH

t_63%step.

Response Time^{(6) (7)}

Long-term Drift ⁽⁴⁾

RH_LTD

0.21

%RH/yr

Temperature Sensor

-20°C ≤ T_A≤ 60°C

±0.1

±0.2

±0.3

±0.4

TEMP_ACCAccuracy

°C

-40°C ≤ T_A< -20°C or 60°C < T_A≤ 125°C

Low Power Mode 0 (lowest noise)

Low Power Mode 1

±0.04

TBD

TEMP_REPRepeatability

Low Power Mode 2

TBD

Low Power Mode 3 (lowest power)

±0.07

25C <T_A<75C

t_63%step

TEMP_RTResponse Time (in air)^{(6) (7)}

TBD

TEMP_LTDLong Term Drift

±0.03

0.3*V_DD

0.4

°C/yr

SCL, SDA Pins

V_IL

LOW-level input voltage

HIGH-level input voltage

LOW-level output voltage

V_IH

V_OL

0.7*V_DD

V_DD–0.2

I_OL= 3 mA

Control Pins

High-level Output Voltage -

V_{OH_ALERT}

I_OH= -100 µA

I_OL= 100 µA

ALERT

Low-level Output Voltage -

ALERT

V_{OL_ALERT}

0.2

V_{IH_ADDR}High Level Input Voltage - ADDR

V_{IL_ADDR}Low Level Input Voltage - ADDR

0.7*V_DD

0.3*V_DD

High Level Input Voltage -

V_{IH_ADDR1}

ADDR1

V_{IL_ADDR1}Low Level Input Voltage - ADDR1

0.3*V_DD

High Level Input Voltage -

V_{IH_RESET}

RESET

0.7*V_DD

V_{IL_RESET}Low Level Input Voltage - RESET

0.3*V_DD

I_{I_ADDR}

Input Leakage Current - ADDR

V_I= V_DDor GND

-1

µA

I_{I_ADDR1}

Input Leakage Current - ADDR1 V_I= V_DDor GND

EEPROM (T, RH offset)

OS_END

OS_RET

Program Endurance

Data Retention Time

1000

50000

100

Cycles

Years

100% Power-On hours

(1) Does not include I²C read/write communication or pullup resistor current through SCL and SDA

(2) Average current consumption while conversion is in progress

(3) Excludes hysteresis and long-term drift

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

(4) Based on THB (temperature humidity bias) testing. Excludes the impact of dust, gas phase solvents and other contaminents such as

vapors from packaging materials, adhesives, or taptes, etc.

(5) The hysteresis value is the difference between the RH measurement in a rising and falling RH environment, at a specific RH point

(6) Actual response times will vary dependent on system thermal mass and air-flow

(7) Time for the RH output to change by 63% of the total RH change after a step change in environmental humidity

(8) Measurement duration includes the time to measure RH plus Temp

(9) I_{DD_AVG_EQN}= measuruement freq x I_{DD_ACTIVE}x t_meas+ I_sleepx (1- (measurement freq x t_meas))

6.6 Switching Characteristics

T_A= -40°C to 125°C and V_DD= 1.62V to 5.50V (unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP MAX UNIT

SCL, SDA PINS

f_SCL

SCL clock frequency⁽¹⁾

0.6

1.3

100

MHz

µs

t_HIGH

High period of the SCL clock⁽¹⁾

LOW period of the SCL clock⁽¹⁾

Setup Time: Data⁽¹⁾

t_LOW

µs

t_SU;DAT

t_HD;DAT

t_SU;STA

t_HD;STA

t_SU;STO

t_R;SCL

Hold Time: Data⁽¹⁾

µs

Set-up time: Repeated START condition⁽¹⁾

Hold time: Repeated START condition^{(1) (2)}

Set-up time: STOP condition⁽¹⁾

Rise Time: SCL⁽¹⁾

0.6

µs

300 ns

µs

t_R;SDA

Rise Time: SDA⁽¹⁾

t_F;SCL

Fall Time: SCL⁽¹⁾

20*(V_DD/5.5V)

1.3

t_F;SDA

Fall Time: SDA⁽¹⁾

t_BUF

Bus free time between a STOP and START condition⁽¹⁾

Data valid time^{(1) (3)}

t_VD;DAT

t_VD;ACK

RESET

t_{RESET_NPW}

0.9 µs

Data valid acknowledge time^{(1) (4)}

Negative pulse width to trigger hard reset

µs

EEPROM (T, RH OFFSET)

t_{OS_PROG}

Offset Programming Time

15 ms

(1) Guaranteed by design/characterization; not production tested

(2) After this period, the first clock pulse is generated

(3) Time for data signal from SCL low to SDA output (high to low, depending on which is worse)

(4) Time for acknowledement signal from SCL low to SDA output (high or low, depending on which is worse)

6.7 Timing Diagram

t_LOW

t_R

t_F

t_HIGH

V_IH

SCL

V_IL

t_SU;STO

t_HD;DAT

t_VD;DAT

t_SU;STA

t_HD;STA

t_BUF

t_SU;DAT

V_IH

V_IL

SDA

Figure 6-1. HDC302x I²C Timing Diagram

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

6.8 Typical Characteristics

Unless otherwise noted. T_A= 25°C, V_DD= 1.80 V.

Graph Placeholder

C00

Figure 6-2. RH Accuracy vs. RH Set Point

Figure 6-3. T Accuracy vs. T Set Point

Graph Placeholder

C00

Figure 6-4. RH Accuracy vs. T Set Point

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

7 Detailed Description

7.1 Overview

The HDC302x is an integrated digital interface sensor that incorporates both humidity-sensing and temperature-

sensing elements, an analog-to-digital converter, calibration memory, and an I²C compatible interface in a

2.50-mm × 2.50-mm, 8-pin WSON package. The HDC302x also provides excellent measurement accuracy.

The HDC302x measures relative humidity through variations in the capacitance of a polymer dielectric. As with

most relative humidity sensors that include this type of technology, care must be taken to ensure optimal device

performance for the sensing element. This includes:

•

Follow the correct storage and handling procedures during board assembly. See HDC3x Silicon User's Guide

(SNAU265) for these guidelines.

•

Protect the sensor from contaminants during board assembly and operation.

Reduce prolonged exposure to both high temperature and humidity extremes that may impact sensor

accuracy.

•

Follow the correct layout guidelines for best performance. See Optimizing Placement and Routing for

Humidity Sensors (SNAA297) for these guidelines.

7.2 Functional Block Diagram

HDC3

VDD

SCL

SDA

Calibration

ADC

ALERT

ADDR

ADDR1

Linearization

I²C

RH Sensor

T Sensor

RESET

GND

7.3 Feature Description

7.3.1 Factory Installed Polyimide Tape

The HDC3021 has a polyimide tape to cover the opening of the humidity sensor element. The tape protects the

humidity sensor element from pollutants that can be produced as part of the manufacturing process, such as

SMT assembly, printed circuit board (PCB) wash, and conformal coating. The tape must be removed after the

final stages of assembly for accurate measurement of relative humidity in the ambient environment. The tape

can withstand at least three standard reflow cycles.

To remove the polyimide tape from the humidity sensor element, TI recommends to use a ESD-safe tweezer to

grip the adhesive-free tab in the top right corner, and slowly peel the adhesive from the top-right corner towards

the bottom-left corner in an upward direction (as opposed to across the surface). This will help to reduce the risk

of scratching the humidity sensor element.

7.3.2 Factory Installed IP67 Protection Cover

HDC3022 has an IP67 rated PTFE permanent filter to cover the opening of the humidity sensor element. The

cover is a hydrophobic micropourous PTFE foil that protects the humidity sensor element against dust and water

according to IP67 specifications. The cover is designed to adhere to the package over lifetime operation while

maintaining the same response time as a sensor without the membrane. The cover has a filtration efficiency of

99.99% down to a particle size of 100 nm.

7.3.3 Measurement of Relative Humidity and Temperature

The HDC302x supports measurements of Relative Humidity and Temperature. The supported Relative Humidity

Range is 0% to 100% and the supported Temperature Range is from –40°C to 125°C. Each measurement is

represented in a 16-bit format, and the conversion formulas are documented below:

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

(1)

(2)

(3)

7.3.4 Drift Correction: Accuracy Restoration

Due to contaminants, the natural aging of the sensor's polymer dielectric, and exposure to extreme operating

conditions resulting in long-term drift, the HDC302x offers drift correction to return the device to factory accuracy

specification. Drift correction is available on the EVM today with more details in the HDC3x EVM user's Guide

(SNAU267) and documentation for how to use this drift correction feature on individual devices without the EVM

will be added to the HDC3x Silicon User's Guide (SNAU265) before the device releases to production.

7.3.5 NIST Traceability of Relative Humidity and Temperature Sensor

The HDC302x units are 100% tested on a production setup that is NIST traceable and verified with equipment

that is calibrated to ISO/IEC 17025 accredited standards. This permits design of the HDC302x into applications

such as cold chain management, where the establishment of an unbroken chain of calibrations to known

references is essential.

7.3.6 Measurement Modes: Trigger-On Demand vs. Auto Measurement

Two types of measurement modes are available on the HDC302x: Trigger-on Demand and Auto Measurement

mode.

Trigger-on Demand is a single measurement reading of temperature and relative humidity that is triggered

through an I²C command on an as-needed basis. After the measurement is converted, the device remains in

sleep mode until another I²C command is received.

Auto Measurement mode is a recurring measurement reading of temperature and relative humidity, eliminating

the need to repeatedly initiate a measurement request through an I²C command. The measurement interval

can be adjusted from 1 measurement every 2 seconds to 1 measurement every second. In Auto Measurement

mode, the HDC302x wakes up from sleep to measurement mode based on the selected sampling rate.

Auto Measurement mode helps to reduce overall system power consumption in two ways. First, by removing

the need to repeatedly initiate a measurement through an I²C command, sink current through the SCL and SDA

pullup resistors is eliminated. Secondly, a microcontroller can be programmed into a deep sleep mode, and only

woken up through an interrupt by the ALERT pin in the event of excessive temperature and relative humidity

measurements.

7.3.7 Heater

The HDC302x includes an integrated heating element that can be switched on to prevent or remove

any condensation that may develop when the ambient environment approaches its dew point temperature.

Additionally, the heater can be used to verify functionally of the integrated temperature sensor.

If the dew point of an application is continuously calculated and tracked, and the application firmware is written

such that it can detect a potential condensing situation (or a period of it), a software subroutine can be run, as

a precautionary measure, to activate the onboard heater as an attempt to remove the condensate. The device

shall continue to measure and track the %RH level after the heater is activated. Once the %RH reading goes

to zero % (or near it), the heater can be subsequently turned off to allow the device to cool down. Cooling of

the device can take several minutes, but the temperature measurement will continue to run to ensure the device

goes back to normal operating condition before restarting the device for normal service.

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Note that when the heater activates, the operating temperature of the device shall be limited based on the

Recommended Operating Conditions T_HEATERlimits.

It is important to recognize that the integrated heater evaporates condensate that forms on top of the humidity

sensor, but does not remove any dissolved contaminants. Any contaminant residue, if present, may impact the

accuracy of the humidity sensor.

7.3.8 ALERT Output With Programmable Interrupts

The ALERT output pin can be used to indicate when the HDC302x records a measurement that indicates either

the temperature and/or relative humidity result is outside of a programmed "comfort zone".

The ALERT output pin serves to drive circuit blocks where software monitoring is not feasible. Examples include

enabling a power switch to start a dehumidifier, or to initiate a thermal shutdown. Additionally, the ALERT pin

can minimize power drain by enabling a microcontroller to remain in deep sleep until environmental conditions

require the microcontroller to wake up and perform debug and corrective actions.

7.3.9 Checksum Calculation

Error checking of data is supported with a Checksum Calculation. The 8-bit CRC checksum transmitted after

each data word is generated by a CRC algorithm. Table 7-1 shows the CRC properties. The CRC covers the

contents of the two previously transmitted data bytes. To calculate the checksum, only these two previously

transmitted data bytes are used.

A CRC byte is sent by the HDC302x to the I²C controller in the following cases:

1. Following the transmission of a relative humidity measurement

2. Following the transmission of a temperature measurement

3. Following the transmission of the contents of the Table 7-12

4. Following the transmission of any of the programmed ALERT limit values (High Alert, Set; High Alert, Clear;

Low Alert, Set; Low Alert, Clear)

A CRC byte must be sent by the I²C controller to the HDC302x in the following cases:

1. Following the configuration of any of the ALERT limit values (High Alert, Set; High Alert, Clear; Low Alert,

Set; Low Alert, Clear).

Table 7-1. HDC302x CRC Properties

PROPERTY

Name

VALUE

CRC-8

Width

8 bit

Read and/or Write Data

0x31 (x⁸+ x⁵+ x⁴+ 1)

0xFF

Protected Data

Polynomial

Initialization

Reflect Input

Reflect Output

Final XOR

Examples

False

0x00

CRC of 0xABCD = 0x6F

Retrieving the CRC byte from the HDC302x is optional. A NACK can be issued by the I²C controller prior to

reception of the CRC byte to cancel, as shown in Figure 7-1 and Figure 7-2.

I²C Controller

HDC

Address

0x24

0x0B

MSB [T]

LSB [T]

CRC [T]

MSB [RH]

LSB [RH]

Address

Figure 7-1. Example I²C NACK to Discard CRC Byte Corresponding to Humidity Measurement Readout

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

I²C Controller

HDC

Address

0x24

0x0B

MSB [T]

LSB [T]

Address

Figure 7-2. Example I²C NACK to Discard CRC Byte Corresponding to Temperature Measurement

Readout

7.3.10 Programmable Offset of Relative Humidity and Temperature Results

HDC302x allows for the user to program offset value after the device acquires its relative humidity and

temperature results. The offset value can only be used to add or subtract from the sensor measurement results.

7.4 Device Functional Modes

The HDC302x has two modes of operation: Sleep Mode and Measurement Mode.

7.4.1 Sleep Mode vs. Measurement Mode

Sleep mode is the default mode of the HDC302x upon Power Up/Cycle, Hard Reset through the RESET pin,

and Soft Reset. The HDC302x will wait for an I²C instruction to trigger a measurement, or to read and write valid

data. A measurement request will trigger the HDC302x to switch to measurement mode, where measurements

from the integrated sensors are passed through an internal ADC, and go through linearization using calibration

data from within the device to produce accurate calculations of temperature and relative humidity. The results

are stored in their respective data registers. After completing the conversion, the HDC302x returns to sleep

mode.

7.5 Programming

7.5.1 I²C Interface

The HDC302x operates only as a target device on the I²C bus. Multiple devices on the same I²C bus with the

same address are not allowed. Connection to the bus is made through the open-drain I/O lines, SCL and SDA.

After power-up, the sensor needs at most 3 ms to be ready to begin acquisition of temperature and relative

humidity measurements. All data bytes are transmitted MSB first.

7.5.2 I²C Serial Bus Address Configuration

An I²C controller will communicate to a desired target device through a target address byte. The target address

byte consists of seven address bits and a direction bit that indicates the intent to execute a read or write

operation. The HDC302x features two address pins, which allow for supporting four addressable HDC302x

devices on a single I²C bus. Table 7-2 describes the pin logic levels used to communicate up to four devices.

HDC302x pins ADDR and ADDR1 must be set before any activity on the interface occurs and remain constant

while the device is powered on.

Table 7-2. HDC302x I²C Target Address

ADDR

ADDR1

Logic Low or Open

Logic High

ADDRESS (Hex Representation)

Logic Low or Open

Logic High

0x44

0x46

0x45

0x47

Logic Low or Open

Logic High

7.5.3 I²C Write - Send Device Command

Communication to the HDC302x is based upon a command list, which is documented in Table 7-3. Commands

other than those documented are undefined and should not be sent to the device. An unsupported command

returns a NACK after the pointer, and a read or write operation with incorrect I²C address returns a NACK after

the I²C address.

An I²C write sequence is performed to send a command to the HDC302x. Some of these commands also

require configuration data from the I²C controller. In those instances, a CRC byte must accompany the

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

configuration data to permit error checking by the HDC302x. Both of these I²C write scenarios are illustrated

in Figure 7-3 and Figure 7-4.

START

WRITE

STOP

I²C Controller

HDC

Command

(MSB)

Command

(LSB)

I²C Address

ACK

Figure 7-3. I²C Write Command, No Configuration Data Required

START

WRITE

STOP

I²C Controller

HDC

Command

(MSB)

Command

(LSB)

Data

(MSB)

Data

(LSB)

I²C Address

CRC

ACK

Figure 7-4. I²C Write Command, Configuration Data and CRC Byte Required

7.5.4 I²C Read - Retrieve Single Data Result

An I²C read sequence is performed to retrieve data from the HDC302x. The I²C read sequence must follow the

I²C write sequence that was used to initiate the data acquisition. A CRC byte always accompanies data that is

transmitted by the HDC302x. If the I²C controller does not use the CRC byte to perform a data integrity check,

then an I²C NACK can be issued to discard CRC transmission and save time. Both of these I²C read scenarios

are illustrated in Figure 7-5 and Figure 7-6.

START

READ

STOP

I²C Controller

HDC

Data

(MSB)

Data

(LSB)

I²C Address

ACK

NACK

Figure 7-5. I²C Read Single Data Result, CRC Discarded

START

READ

STOP

I²C Controller

HDC

Data

(MSB)

Data

(LSB)

I²C Address

CRC

ACK

NACK

Figure 7-6. I²C Read Single Data Result, CRC Retained

The HDC302x will stop transmission of a data byte if the I²C controller fails to ACK after any byte of data.

7.5.5 I²C Read - Retrieve Multi Data Result

When an I²C read sequence is performed to retrieve multiple data results and the I²C controller does not use the

CRC byte to perform a data integrity check, then an I²C NACK can be issued to only discard CRC transmission

from the final transmitted data result. Both of these I²C read scenarios are illustrated in Figure 7-7 and Figure

7-8.

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

START

READ

STOP

I²C Controller

HDC

Data 1

(MSB)

Data 1

(LSB)

Data 2

(MSB)

Data 2

(LSB)

I²C Address

CRC

ACK

NACK

Figure 7-7. I²C Read Multi Data Result, Final CRC Discarded

START

READ

STOP

I²C Controller

HDC

Data 1

(MSB)

Data 1

(LSB)

Data 2

(MSB)

Data 2

(LSB)

I²C Address

CRC

ACK

NACK

Figure 7-8. I²C Read Multi Data Result, Final CRC Retained

7.5.6 I²C Repeated START - Send Command and Retrieve Data Results

HDC302x supports I²C repeated START, which enables the issue of a command and retrieval of data without

releasing the I²C bus. As with all other data retrieval requests, reception of the CRC byte corresponding to the

last data result may be discarded or retained. Both of these examples are illustrated in Figure 7-9 and Figure

7-10 for a single data result retrieval, and in Figure 7-11 and Figure 7-12 for a multi data result retrieval.

START

WRITE

REPEATED START

READ

STOP

I²C Controller

HDC

Command

(MSB)

Command

(LSB)

Data 1

(MSB)

Data 1

(LSB)

I²C Address

Sr I²C Address

ACK

NACK

Figure 7-9. I²C Repeated START Sequence, Single Data Result, CRC Discarded

START

WRITE

REPEATED START

READ

STOP

I²C Controller

HDC

Command

(MSB)

Command

(LSB)

Data 1

(MSB)

Data 1

(LSB)

I²C Address

Sr I²C Address

CRC

ACK

NACK

Figure 7-10. I²C Repeated START Sequence, Single Data Result, CRC Retained

START

WRITE

REPEATED START

READ

STOP

I²C Controller

Command

(MSB)

Command

(LSB)

Data 1

(MSB)

Data 1

(LSB)

Data 2

(MSB)

Data 2

(LSB)

I²C Address

Sr I²C Address

CRC

HDC

ACK

NACK

Figure 7-11. I²C Repeated START Sequence, Multi Data Result, Final CRC Discarded

START

WRITE

REPEATED START

READ

STOP

I²C Controller

HDC

Command

(MSB)

Command

(LSB)

Data 1

(MSB)

Data 1

(LSB)

Data 2

(MSB)

Data 2

(LSB)

I²C Address

Sr I²C Address

CRC

ACK

NACK

Figure 7-12. I²C Repeated START Sequence, Multi Data Result, Final CRC Retained

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

7.5.7 Command Table and Detailed Description

The HDC302x command structure is documented below in Table 7-3. Details about each individual command

are documented in the subsections below.

Table 7-3. HDC302x Command Table

HEX CODE HEX CODE

COMMAND

COMMAND DETAIL

(MSB)

(LSB)

Low Power Mode 0 (lowest noise)

Low Power Mode 1

Trigger-On Demand Mode

Single Temperature (T) Measurement

Single Relative Humidity (RH) Measurement

Low Power Mode 2

Low Power Mode 3 (lowest power)

Low Power Mode 0 (lowest noise)

Low Power Mode 1

Auto Measurement Mode

1 measurement per 2 seconds.

Low Power Mode 2

Low Power Mode 3 (lowest power)

Low Power Mode 0 (lowest noise)

Low Power Mode 1

Auto Measurement Mode

1 measurement per second.

Low Power Mode 2

Low Power Mode 3 (lowest power)

Low Power Mode 0 (lowest noise)

Low Power Mode 1

Auto Measurement Mode

2 measurements per second.

Low Power Mode 2

Low Power Mode 3 (lowest power)

Low Power Mode 0 (lowest noise)

Low Power Mode 1

Auto Measurement Mode

4 measurements per second.

Low Power Mode 2

Low Power Mode 3 (lowest power)

Low Power Mode 0 (lowest noise)

Low Power Mode 1

Auto Measurement Mode

10 measurements per second.

Low Power Mode 2

Low Power Mode 3 (lowest power)

Exit, then return to Trigger-on Demand Mode.

Measurement Readout of T and RH.

Measurement History Readout of Minimum T.

Measurement History Readout of Maximum T.

Measurement History Readout of Minimum RH.

Measurement History Readout of Maximum RH.

Programs Thresholds for "Set Low Alert"

Programs Thresholds for "Set High Alert"

Programs Thresholds for "Clear Low Alert"

Programs Thresholds for "Clear High Alert"

Auto Measurement Mode

Configure ALERT Thresholds of T and RH

Verify ALERT Thresholds of T and RH

Transfer ALERT thresholds into Non-Volatile

Memory (NVM)

Read Thresholds for "Set Low Alert"

Read Thresholds for "Set High Alert"

Read Thresholds for "Clear Low Alert"

Read Thresholds for "Clear High Alert"

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Table 7-3. HDC302x Command Table (continued)

HEX CODE HEX CODE

COMMAND

COMMAND DETAIL

(MSB)

(LSB)

Enable

Integrated Heater

Disable

Read Content

Clear Content

Status Register

Program/Read offset value into/from non-volatile

memory

Soft Reset

Read NIST ID (Serial Number) Bytes 5 and 4

Read NIST ID (Serial Number) Bytes 3 and 2

Read NIST ID (Serial Number) Bytes 1 and 0

Read Manufacturer ID (Texas Instruments) (0x3000)

Override Default Device Power-On/Reset

Measurement State. Table 7-5 lists all valid

configuration values that may be sent as part of this

command.

7.5.7.1 Reset

7.5.7.1.1 Soft Reset

The HDC302x provides a software command, as illustrated in Figure 7-13, to force itself into its default state

while maintaining supply voltage. It is the software equivalent to a hardware reset through the Power Cycle or

toggle of the RESET pin. When executed, the HDC302x will reset its Status Register, reload the calibration data

and programmed humidity/temperature offset error from memory, clear previously stored measurement results,

set Interrupt Thresholds limits back to their defaults, and re-configure the ALERT output to its default condition.

I²C Controller

I²C Address

0x30

0xA2

HDC

Figure 7-13. I²C Command Sequence: HDC302x Software Reset

7.5.7.1.2 I²C General Call Reset

In addition to the device-specific Soft Reset command, the HDC302x supports the general call address of the

I²C specification. This enables the use of a single command to reset an entire I²C system (provided that all

devices on the I²C bus support it). Figure 7-14 shows this command. The general call is recognized when the

sensor is able to process I²C commands and is functionally equivalent to the Software Reset.

I²C Controller

I²C Address

0x00

0x06

HDC

Figure 7-14. I²C Command Sequence: HDC302x Reset Through General Call

7.5.7.2 Trigger-On Demand

This set of commands will trigger a single measurement acquisition of temperature, followed by relative humidity.

The HDC302x will transition from sleep mode into measurement mode, and upon measurement completion,

return to sleep mode. There are four possible Trigger On Demand commands, each one corresponding to

a different low power mode (and therefore, different levels of power consumption). Table 7-3 shows these

commands.

The measurement readout from these commands is obtained through an I²C read sequence, as previously

documented in I²C Read - Retrieve Single Data Result and I²C Read - Retrieve Multi Data Result. The format of

the measurement readout is two bytes of data representing temperature, followed by one byte CRC checksum,

and then another two bytes of data representing relative humidity, followed by one byte CRC checksum as

illustrated in Figure 7-15.

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Trigger On Demand - Default Low Power Mode

Temperature

Relative Humidity

I²C Controller

HDC

(MSB)

(LSB)

(MSB)

(LSB)

I²C Address

0x24

0x00

Sr I²C Address

CRC

Figure 7-15. I²C Command Sequence: Example Measurement Readout in Trigger-On Demand Mode

If the I²C controller attempts to read the measurements results prior to measurement completion, the HDC302x

will respond with a NACK condition, as illustrated in Figure 7-16.

Measurement Not Ready

Temperature

Relative Humidity

Trigger On Demand - Default Low Power Mode

I²C Controller

HDC

(MSB)

(LSB)

(MSB)

(LSB)

I²C Address

0x24

0x00

Sr I²C Address

I²C Address

CRC

Figure 7-16. I²C Command Sequence: Example Measurement Not Ready in Trigger-On Demand Mode

7.5.7.3 Auto Measurement Mode

Auto Measurement mode forces the HDC302x to perform a temperature and relative humidity measurement at a

specific timing interval, removing the need for the I²C controller to repeatedly initiate a measurement acquisition.

This section gives additional details for each command

7.5.7.3.1 Auto Measurement Mode: Enable and Configure Measurement Interval

There are 20 possible timing intervals when Auto Measurement mode is enabled, (and therefore, different levels

of average power consumption). These commands are documented in Table 7-3. To avoid self-heating of the

temperature sensor, TI recommends to limit the sampling interval to no faster than 1 measurement/second, as

illustrated in Figure 7-17.

Auto Mode œ 1 measurement/second œ Default Low Power Mode

I²C Controller

I²C Address

0x21

0x30

HDC

Figure 7-17. I²C Command Sequence: Enable Auto Measurement mode at 1 Measurement per Second

7.5.7.3.2 Auto Measurement Mode: Measurement Readout

The latest measurement acquisition in Auto Measurement Mode can be retrieved using a measurement readout

command, which is documented in Table 7-3, and illustrated in Figure 7-18. Once the measurement readout is

complete, the HDC302x clears the measurement result from memory.

As in Trigger-On Demand, if the I²C controller attempts to read the measurement results prior to measurement

completion, the HDC302x will respond with a NACK condition.

Measurement Readout œ Auto Mode

Temperature

Relative Humidity

I²C Controller

HDC

(MSB)

(LSB)

(MSB)

(LSB)

I²C Address

0xE0

0x00

Sr I²C Address

CRC

Figure 7-18. I²C Command Sequence: Measurement Readout in Auto Measurement Mode

7.5.7.3.3 Auto Measurement Mode: Exit

The command to exit Auto Measurement mode is documented in Table 7-3 and illustrated in Figure 7-19. The

HDC302x will immediately discontinue any measurement in progress and return to sleep mode. This takes

typically 1 ms.

Exit Auto Mode

I²C Controller

HDC

I²C Address

0x30

0x93

Figure 7-19. I²C Command Sequence: Exit Auto Measurement Mode

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

7.5.7.3.4 Auto Measurement Mode: Measurement History Readout

Within Auto Measurement Mode, the HDC302x maintains a history of the maximum and minimum measurement

for temperature and relative humidity (described as variables MIN T, MAX T, MIN RH, and MAX RH). This

feature is useful for scenarios where the user would like to assess if the ambient conditions ever approached,

but did not surpass, the defined environmental thresholds as documented in Section 7.5.7.4.1. Table 7-4

summarizes the status of MIN T, MAX T, MIN RH, and MAX RH based on device configuration.

Table 7-4. Status of Measurement History Variables based on HDC302x Configuration

HDC302x Configuration

Outside of Auto Measurement Mode

Within Auto Measurement Mode

MIN T

MAX T

MIN RH

MAX RH

130°C

-45°C

100%

Monitored and Latched When Appropriate

Whenever the HDC302x exits Auto Measurement Mode (e.g. via Auto Measurement Mode: Exit, Soft Reset,

General Call Reset, or ), all four variables will return to their default values documented in Table 7-4. Therefore,

measurement history readouts outside of Auto Measurement Mode are invalid. Figure 7-20, Figure 7-21, Figure

7-22, and Figure 7-23 illustrate the I²C sequence for measurement readout of MIN T, MAX T, MIN RH, and MAX

RH.

Minimum Temperature Readout œ Auto Mode

I²C Controller

Min T

(MSB)

Min T

(LSB)

I²C Address

0xE0

0x01

Sr I²C Address

CRC

HDC

Figure 7-20. I²C Sequence: Minimum Temperature Measurement Readout (Auto Measurement Mode)

Maximum Temperature Readout œ Auto Mode

I²C Controller

Max T

(MSB)

Max T

(LSB)

I²C Address

0xE0

0x02

Sr I²C Address

CRC

HDC

Figure 7-21. I²C Sequence: Maximum Temperature Measurement Readout (Auto Measurement Mode)

Minimum Humidity Readout œ Auto Mode

I²C Controller

Min RH

(MSB)

Min RH

(LSB)

I²C Address

0xE0

0x03

Sr I²C Address

CRC

HDC

Figure 7-22. I²C Sequence: Minimum Relative Humidity Measurement Readout (Auto Measurement Mode)

Maximum Humidity Readout œ Auto Mode

I²C Controller

Max RH

(MSB)

Max RH

(LSB)

I²C Address

0xE0

0x04

Sr I²C Address

CRC

HDC

Figure 7-23. I²C Sequence: Maximum Relative Humidity Measurement Readout (Auto Measurement

Mode)

7.5.7.3.5 Override Default Device Power-On and Device-Reset State

The HDC302x defaults to entering sleep mode after a device power-on or a device-reset. However, an override

command may be sent to the HDC302x to force entry into Automatic Measurement mode upon every device

power-on and device-reset. The command is illustrated in below in Figure 7-24 and the list of all possible

command configurations is documented in Table 7-5.

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Measurement Default

Configuration

I²C Controller

HDC

CFG

(MSB)

CFG

(LSB)

I²C Address

0x61

0xBB

CRC

Figure 7-24. I²C Sequence: Configure Default Measurement

Table 7-5 lists all valid configuration values that may be sent as part of this command.

Table 7-5. List of Valid Measurement Configuration Values to send to HDC302x

CFG (MSB) CFG (LSB)

CRC

0xB0

0xD2

0x74

0x16

0x09

0xF3

0x91

0x37

0x55

0x4A

0x36

0x54

0xF2

0x90

0x8F

0x75

0x17

0xB1

0xD3

0xCC

Configuration

Low Power Mode

Measurements per Second

0x03

0x05

0x07

0x09

0x0B

0x13

0x15

0x17

0x19

0x1B

Automatic Measurement Mode

0 (lowest noise)

0.5

0 (lowest noise)

0.5

0x23

0x00

0x25

0x27

0x29

0x2B

0x33

0x35

0x37

0x39

0x3B

0.5

3 (lowest power)

Restores Factory Default (Sleep

Mode)

0x00

0x81

N/A

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

7.5.7.4 ALERT Output Configuration

The HDC302x provides hardware notification of events through an interrupt output pin (ALERT). Specifically,

the ALERT output represents the status of bits 15, 11, 10, and 4 from the Status Register Section 7.5.7.6. The

ALERT output asserts to Logic High upon detection of an event and de-asserts to Logic Low when the event has

passed or after the Status Register Section 7.5.7.6 is cleared.

The ALERT output is activated by default upon Power Up, Hardware Reset, and Soft Reset. It is deactivated

when the HDC302x has been disabled via assertion of the RESET pin. When deactivated, the HDC302x will

clear the Status Register Section 7.5.7.6.

If temperature and relative humidity tracking through the ALERT output is not desired, the feature can be

disabled as explained in Section 7.5.7.4.4

7.5.7.4.1 ALERT Output: Environmental Tracking of Temperature and Relative Humidity

The primary use of the ALERT output is to provide a hardware notification of ambient temperature and relative

humidity measurements that violate programmed thresholds. There are a total of four programmable thresholds

for temperature and relative humidity, as documented in Table 7-3 and illustrated in Figure 7-25 below.

Measured RH/T

Set High Alert

Clear High Alert

Clear Low Alert

Set Low Alert

Time

ALERT

V_OH

V_OL

Time

Figure 7-25. Graphical Illustration of ALERT Programmable Environmental Thresholds

The four programmable thresholds are listed below

1. Set High Alert: Asserts ALERT output when HDC302x measures a temperature or relative humidity level

that has risen above this value.

2. Clear High Alert: Deasserts the ALERT output caused by Set High Alert, once HDC302x measures a

temperature or relative humidity level that has fallen below this value.

3. Set Low Alert: Programmed value that asserts ALERT output when HDC302x measures a temperature or

relative humidity level that has fallen below this value.

4. Clear Low Alert: Programmed value that deasserts the ALERT output caused by Set Low Alert, once

HDC302x measures a temperature of relative humidity level that has risen above this value.

If the user application utilizes the ALERT output for environmental tracking, it is best practice to program these

four thresholds prior to any temperature or relative humidity measurement acquisition. Programming enough

separation between the Set versus Clear thresholds will prevent fast oscillations of the ALERT output.

These programmed limits are accessible at any time of operation .

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

7.5.7.4.2 ALERT Output: Representation of Environmental Thresholds and Default Threshold Values

The Set High Alert, Clear High Alert, Set Low Alert, and Clear Low Alert thresholds are each represented

by a truncated 16 bit value, as illustrated Figure 7-26. The 7 MSBs from a relative humidity measurement

are concatenated with the 9 MSBs from a temperature measurement. The actual temperature and relative

humidity measurement result are always stored as a 16-bit value, but when compared against the programmed

threshold values, due to the truncated representation, there is a resolution loss of 0.5°C in temperature and a

1% resolution loss in relative humidity.

16-Bit RH Measurement (MSB to LSB)

15 14 13 12 11 10

16-Bit T Measurement (MSB to LSB)

15 14 13 12 11 10

Combined 16-Bit RH and T Threshold (MSB to LSB)

Figure 7-26. Representation of ALERT Threshold Value Using Combined RH and T

The default values of the relative humidity and temperature thresholds after Power Up/Cycle, Hardware Reset,

and Soft Reset are documented in Table 7-6 below. Refer to Table 7-3 for the appropriate command to re-

program the thresholds.

Table 7-6. Default Value of ALERT Thresholds

ALERT THRESHOLD

Set High Alert

DEFAULT RH THRESHOLD

DEFAULT T THRESHOLD

HEX VALUE

0xCD33

0xC92D

0x3466

CRC

0xFD

0x22

0xAD

0x37

80% RH

79% RH

20% RH

22% RH

60°C

58°C

-10°C

-9°C

Clear High Alert

Set Low Alert

Clear Low Alert

0x3869

7.5.7.4.3 ALERT Output: Steps to Calculate and Program Environmental Thresholds

The steps to calculate the Set High Alert, Clear High Alert, Set Low Alert, and Clear Low Alert thresholds are

listed below:

1. Select the desired relative humidity and temperature threshold to program, and the programmed value.

2. Convert the relative humidity and temperature threshold value to its respective 16-bit binary value

3. Retain the 7 MSBs for relative humidity and the 9 MSBs for temperature

4. Concatenate the 7 MSBs for relative humidity with the 9 MSBs for temperature to complete the 16-bit

threshold representation

5. Calculate the CRC byte from the 16-bit threshold value

An example is provided below.

1. In this case, the Set High Alert threshold will be programmed to 90% RH and 65°C

2. 90% RH converts to 0b1110011001100111 and 65°C T converts to 0b1010000011101011

3. 7 MSBs for 90% RH is 0b1110011 and 9 MSBs for 65°C T is 0b101000001

4. After concatenation of the relative humidity and temperature MSBs, the threshold representation is

0b1110011101000001 = 0xE741

5. For 0xE741, this corresponds to a CRC byte 0x55

a. Figure 7-27 illustrates the appropriate command to send to the HDC302x.

b. The HDC302x will respond to reception of an incorrect CRC byte with a I²C NACK.

Set High Alert

90%RH, 65°C

CRC

I²C Controller

HDC

I²C Address

0x61

0x1D

0xE7

0x41

0x55

Figure 7-27. I²C Command Sequence: Example Programming of Set High Alert to 90% RH, 65°C

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

7.5.7.4.4 ALERT Output: Deactivation of Environmental Tracking

To deactivate the ALERT output from responding to measurement results of temperature and/or relative

humidity, the Set High Alert thresholds must be programmed to be lower than the Set Low Alert thresholds.

Figure 7-28 illustrates an example of threshold programming that disables tracking of temperature as well as

relative humidity. To be more specific:

•

To disable Temperature Alert Tracking: Configure the temperature bits within the Set Low Alert threshold to

be larger than the temperature bits within the Set High Alert threshold.

•

To disable Humidity Alert Tracking: Configure the humidity bits within the Set Low Alert threshold to be larger

than the humidity bits within the Set High Alert threshold.

Set Low Alert

100%RH, 130°C

CRC

Set High Alert

0%RH, -45°C

CRC

I²C Controller

HDC

I²C Address

0x61

0x00

0xFF

0xAC

Sr I²C Address

0x61

0x1D

0x00

0x81

Figure 7-28. I²C Command Sequence: Example to Deactivate ALERT Output Tracking of Temperature and

Relative Humidity

7.5.7.4.5 ALERT Output: Transfer Thresholds into Non-Volatile Memory

This command, illustrated below in Figure 7-29, enables an override of the default ALERT threshold values

after a device reset or power cycle. This permits independent assembly of a sensor board and a remote MCU

board. Normally, the MCU is local to the sensor (that is, they share a common board) and the MCU will program

the threshold values. However, there are applications where the sensor and MCU are on separate boards,

and deployed to various applications, each with unique threshold requirements. This normally adds significant

tracking overhead (that is, each MCU board must be assigned to a specific sensor board). With this feature, the

HDC302x thresholds may be configured using a debugger/programmer during product assembly, and later on,

connected to any MCU board on its own assembly, with the application-specific thresholds already ensured.

NVM Transfer of ALERT Thresholds

I²C Controller

HDC

I²C Address

0x61

0x55

Figure 7-29. I²C Command Sequence: Transfer ALERT Thresholds into NVM

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

7.5.7.5 Programmable Measurement Offset

The HDC302x can be programmed to return a relative humidity measurement and/or a temperature

measurement that accounts for a programmed offset value. An operation bit determines whether to add or

subtract the offset from the actual sensor measurement results. This feature is targeted for designs where

local heat sources can not be isolated from the temperature sensor and said heat sources show variation over

time (due to different components being enabled/disabled). The command is documented in the Table 7-3. The

device should be in shutdown mode when changing the offset because if it is in Auto Measurement mode. it

could give unpredictable results.

Programming either offset value requires programming of a corresponding non-volatile memory location in the

EEPROM. Therefore, I²C writes are not permitted until offset programming is complete. Refer to the electrical

characteristics table t_{OS_PROG}parameters for the time to complete a programming a single location. The

HDC302x will draw approximately 230 µA during offset programming.

7.5.7.5.1 Representation of Offset Value and Factory Shipped Default Value

As illustrated in Figure 7-30, the programmed offset values for relative humidity (RH_OS) and temperature (T_OS

)

are combined into a single 16-bit representation. 7 bits represent RH_OS, 7 bits represent T_OS, 1 operation

bit (RH_+/-) to add or subtract RH_OS, and 1 operation bit (T_+/-) to add or subtract T_OS. From the 16-bit

representation of relative humidity, bits 13 through 7 are used to represent RH_OS. From the 16-bit representation

of temperature, bits 12 through 6 are used to represent T_OS

16-Bit Representation of Relative Humidity (MSB to LSB)

16-Bit Representation of Temperature (MSB to LSB)

15 14 13 12 11 10

RH₁₅RH₁₄RH₁₃RH₁₂RH₁₁RH₁₀RH₉RH₈RH₇RH₆RH₅RH₄RH₃RH₂RH₁RH₀

T₁₅T₁₄T₁₃T₁₂T₁₁T₁₀T₉

T₈

T₇

T₆

T₅

T₄

T₃

T₂

T₁

T₀

15 14 13 12 11 10

RH_+/-RH₁₃RH₁₂RH₁₁RH₁₀RH₉RH₈RH₇T_+/-T₁₂T₁₁T₁₀T₉

T₈

T₇

T₆

RH_OS

T_OS

16-Bit Combined RH and T Offset (MSB to LSB)

Figure 7-30. Data Structure to Represent Programmed Offset Values for RH and T

7.5.7.5.2 Factory Shipped Default Offset Values

The HDC302x is factory-shipped with default values of RH_OSand T_OSas documented in Table 7-7.

Table 7-7. Factory Shipped Default Offset Value

DEFAULT RH_OS[%]

DEFAULT T_OS[°C]

HEX VALUE (0x)

CRC (0x)

00 00

7.5.7.5.3 Calculate Relative Humidity Offset Value

Table 7-8 documents the programmed offset value that is represented by each individual relative humidity offset

bit within RH_OS. The minimum programmable offset is 0.1953125% and the maximum programmable offset is

24.8046875%.

Table 7-8. Relative Humidity Offset Value (RH_OS) Represented by Each Data Bit

RH OFFSET BIT

VALUE WHEN PROGRAMMED TO 0

VALUE WHEN PROGRAMMED TO 1

RH_+/-

Subtract

Add

12.5

RH₁₃

RH₁₂

6.25

RH₁₁

3.125

RH₁₀

1.5625

0.78125

0.390625

RH₉

RH₈

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Table 7-8. Relative Humidity Offset Value (RH_OS) Represented by Each Data Bit (continued)

RH OFFSET BIT

VALUE WHEN PROGRAMMED TO 0

VALUE WHEN PROGRAMMED TO 1

RH₇

0.1953125

Table 7-9 below gives an example of some of the possible calculated relative humidity offset values (including

the operation bit RH_+/-):

Table 7-9. Example Programmed Values of RH_OS

RH_+/-

RH₁₃

RH₁₂

RH₁₁

RH₁₀

RH₉

RH₈

RH₇

RH OFFSET VALUE

+0.1952125% RH

-0.1952125% RH

+12.5% RH

-12.5% RH

+8.203125% RH

-8.203125% RH

+24.8046875% RH

-24.8046875% RH

7.5.7.5.4 Calculate Temperature Offset Value

Table 7-10 documents the programmed offset value that is represented by each individual relative temperature

offset bit within T_OS. The minimum programmable offset is 0.1708984375°C and the maximum programmable

offset is 21.7041015625°C.

Table 7-10. Temperature Offset Value (T_OS) Represented by Each Data Bit

T OFFSET BIT

VALUE WHEN PROGRAMMED TO 0

VALUE WHEN PROGRAMMED TO 1

T_+/-

T₁₂

T₁₁

T₁₀

T₉

Subtract

Add

10.9375

5.46875

2.734375

1.3671875

0.68359375

0.341796875

0.1708984375

T₈

T₇

T₆

Table 7-11 below gives an example of some of the possible calculated temperature offset values (including the

operation bit T_+/-):

Table 7-11. Example Programmed Values of T_OS

T_+/-

T₁₂

T₁₁

T₁₀

T₉

T₈

T₇

T₆

T OFFSET VALUE

+0.1708984375°C

-0.1708984375°C

+10.9375°C

-10.9375°C

+7.177734375°C

-7.177734375°C

21.7041015625°C

-21.7041015625°C

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

7.5.7.5.5 Write an Offset Value

After determining the desired value of RH_+/-, RH_OS, T_+/-, and T_OS, as documented in Calculate Relative Humidity

Offset Value and Calculate Temperature Offset Value, determine the correct CRC checksum and send all three

bytes to the HDC302x as illustrated in Figure 7-31 (along with an example scenario of +8.20% RH and –7.17°C).

Access RH+T Offset

I²C Controller

I²C Address

0xA0

0x04

RH_+/-, RH_OS

T_+/-, T_OS

CRC

HDC

Access RH+T Offset +8.20%RH, -7.17°C

CRC

I²C Controller

HDC

I²C Address

0xA0

0x04

0xAA

0x33

0xAC

Figure 7-31. I²C Command Sequence: RH and T Offset (Example With +8.20% RH and –7.17°C)

7.5.7.5.6 Verify a Programmed Offset Value

The command to verify the programmed offset values is documented in Table 7-3 and the command sequence is

illustrated in Figure 7-32.

Access RH+T offset

I²C Controller

HDC

I²C Address

0xA0

0x04

Sr I²C Address

RH_+/-, RH_OS

T_+/-, T_OS

CRC

Figure 7-32. I²C Command Sequence: Verify Programmed RH and T Offset

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

7.5.7.6 Status Register

The Status Register contains real-time information about the operating state of the HDC302x, as documented in

Table 7-12. There are two commands associated with the Status Register: Read Content and Clear Content, as

documented in Table 7-3 and illustrated in Figure 7-33 and Figure 7-34.

Table 7-12. Customer View: Status Register

BIT

DEFAULT

DESCRIPTION

Overall Alert Status

0 = No active alerts

1 = At least one active alert

Reserved

Heater Status

0 = Heater Disabled

1 = Heater Enabled

Reserved

RH Tracking Alert

0 = No RH alert

1 = RH alert

T Tracking Alert

0 = No T alert

1 = T alert

RH High Tracking Alert

0 = No RH High alert

1 = RH High alert

RH Low Tracking Alert

0 = No RH Low alert

1 = RH Low alert

T High Tracking Alert

0 = No T High alert

1 = T High alert

T Low Tracking Alert

0 = No T Low alert

1 = T Low alert

Reserved

Device Reset Detected

0 = No reset detected since last clearing of Status Register

1 = Device reset detected (via hard reset, soft reset command or supply fail)

Reserved

Checksum verification of last data write

0 = Pass (correct checksum received)

1 = Fail (incorrect checksum received)

Status Register Readout

Bits 15-8

Bits 7-0

I²C Controller

HDC

Status

(MSB)

Status

(LSB)

I²C Address

0xF3

0x2D

Sr I²C Address

CRC

Figure 7-33. I²C Command Sequence: Read Status Register

Clear Status Register

I²C Controller

HDC

I²C Address

0x30

0x41

Figure 7-34. I²C Command Sequence: Clear Status Register

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

7.5.7.7 Heater: Enable and Disable

The HDC302x includes an integrated heater with enough current draw (up to 45 mA) to enable operation in

condensing environments. The heater protects the humidity sensor area by preventing condensation as well as

removing condensate. Enabling and disabling of the heater is documented in Table 7-3 and illustrated in Figure

7-35 and Figure 7-36.

The heater is expected to impact the temperature measurement result and the relative humidity measurement

result. An IC-based humidity sensor uses the die temperature as an estimate for the ambient temperature. Use

of the heater will increase the die temperature up to 60°C above ambient temperature. Therefore, accurate

measurement results of ambient temperature and relative humidity are not possible when the heater is in

operation.

As long as condensate is present on the RH sensor, the measurement reading will continue to be > 99%.

Continue enabling the heater until the RH measurement reading falls to below 80%. In most cases, 2-3 minutes

of heater enable time is sufficient. It is best practice to ensure that the ambient temperature is higher than the

dew point temperature.

It is important to recognize that the integrated heater will evaporate condensate that forms on top of the humidity

sensor, but does not remove any dissolved contaminants. This contaminant residue, if present, may impact the

accuracy of the humidity sensor.

Enable Heater

I²C Controller

HDC

I²C Address

0x30

0x6D

Figure 7-35. I²C Command Sequence: Enable Heater

Disable Heater

I²C Controller

HDC

I²C Address

0x30

0x66

Figure 7-36. I²C Command Sequence: Disable Heater

7.5.7.8 Read NIST ID/Serial Number

Each HDC302x is configured with a unique 48-bit value that is used to support NIST traceability of the

temperature and relative humidity sensor. It can also be used to represent the unique serial number for that

device. Three commands are required to read the full 48-bit value as illustrated in Figure 7-37, Figure 7-38, and

Figure 7-39. Each command will return two bytes of NIST ID followed by a CRC byte. From MSB to LSB, the full

device NIST ID is read as NIST_ID_5, NIST_ID_4, NIST_ID_3, NIST_ID_2, NIST_ID_1, and NIST_ID_0.

Read NIST ID Bytes 5 and 4

I²C Controller

HDC

I²C Address

0x36

0x84

Sr I²C Address

NIST_ID_5

NIST_ID_4

CRC

Figure 7-37. I²C Command Sequence: Read NIST ID (Bytes NIST_ID_5, Then NIST_ID_4)

Read NIST ID Bytes 3 and 2

I²C Controller

HDC

I²C Address

0x36

0x84

Sr I²C Address

NIST_ID_3

NIST_ID_2

CRC

Figure 7-38. I²C Command Sequence: Read NIST ID (Bytes NIST_ID_3, Then NIST_ID_2)

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Read NIST ID Bytes 1 and 0

I²C Controller

HDC

I²C Address

0x36

0x85

Sr I²C Address

NIST_ID_1

NIST_ID_0

CRC

Figure 7-39. I²C Command Sequence: Read NIST ID (Bytes NIST_ID_1, Then NIST_ID_0)

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

8 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

8.1 Application Information

The HDC302x is used to measure the relative humidity and temperature of the board location where the device

is mounted. The programmable I²C address option allow up to four locations be monitored on a single serial bus.

8.2 Typical Application

One common application which requires a relative humidity and temperature sensor is a HVAC system

thermostat control. It is based on environmental sensors and a microcontroller. The microcontroller acquires data

from humidity and temperature sensors and controls the heating and cooling system. The collected data are then

shown on a display that can be easily controlled by the microcontroller. Based on data from the humidity and

temperature sensor, the heating and cooling system then maintains the environment at the customer-defined

preferred conditions.

In a battery-powered HVAC system thermostat, one of the key parameters in the selection of components is

the power consumption. The HDC302x, with 550 nA of current consumption (the average consumption over 1

s for RH and Temperature measurements), in conjunction with a MSP430, represents one way an engineer can

obtain low power consumption and extend battery life. A system block diagram of a battery-powered thermostat

is shown in Figure 8-1.

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

DISPLAY

TEMPERATURE: 25°C/ 77°F

Relative Humidity (RH): 40%

Red

Lithium

Ion Battery

TIME: XX:XX

DATE: XX:XX:XX

1.8V

VDD

1.8V

VDD

HDC3020

MCU

Sensor

Violet

SCL

SDA

INT

ADDR

I2C P^Re^er^dipheral

GPIOs

Registers/

Logic

I²C

Interface

Red

e g a r n O

Red

MUX

Red

ADC

GPIO

T_Ve_iom_letp

Sensor

GND

Calibration

Red

Coefficients

GND

KEYPAD

ButCton1

ButCton2

ButCton3

ButtCon4

Figure 8-1. Typical Application Schematic HVAC

8.2.1 Design Requirements

To improve measurement accuracy, TI recommends to isolate the HDC302x from all heat sources in the form

of active circuitry, batteries, displays and resistive elements. If design space is a constraint, cutouts surrounding

the device or the inclusion of small trenches can help minimize heat transfer from PCB heat sources to the

HDC302x. To avoid self-heating the HDC302x, TI recommends to configure the device to no faster than 1

measurement/second.

The HDC302x operates only as a target device and communicates with the host through the I2C-compatible

serial interface. SCL is an input pin, SDA is a bidirectional pin, and ALERT is an output. The HDC302x requires

a pullup resistor on the SDA. An SCL pullup resistor is required if the system microprocessor SCL pin is

open-drain. The recommended value for the pullup resistors is 5 kΩ. In some applications, the pullup resistor

can be lower or higher than 5 kΩ. A 0.1-µF bypass capacitor is recommended to be connected between V+

and GND. Use a ceramic capacitor type with a temperature rating that matches the operating range of the

application, and place the capacitor as close as possible to the VDD pin of the HDC302x. The ADDR and

ADDR0 pins should be connected directly to GND, VDD, or left open for address selection of four possible

unique target ID addresses per the addressing scheme Table 7-2. The ALERT output pin can be connected to a

microcontroller interrupt that triggers an event that occurred when the relative humidity and/or temperature limit

exceeds the programmed value. The ALERT pin should be left floating when not in use.

8.2.2 Detailed Design Procedure

When a circuit board layout is created from the schematic shown in Figure 8-1, a small circuit board is possible.

The accuracy of a temperature and relative humidity measurement is dependent upon the sensor accuracy

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

and the setup of the sensing system. Since the HDC302x measures relative humidity and temperature in its

immediate environment, it is critical that the local conditions at the sensor match the ambient environment. Use

one or more openings in the physical cover of the thermostat to obtain a good airflow even in static conditions.

Refer to the layout (Figure 10-1) for a PCB layout which minimizes the thermal mass of the PCB in the region of

the HDC302x, which can improve measurement response time and accuracy.

8.2.3 Application Curve

These results were acquired at T_A= 25°C using a humidity chamber that sweeps RH%. The sweep profile used

was 10% > 20% > 30% > 40% > 50% > 60% > 70% > 80% > 70% > 60% > 50% > 40% > 30% > 20% > 10%.

Each RH% set point was held for 20 minutes.

TBD

Figure 8-2. RH% Readings of Chamber and HDC302x vs. Time

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

9 Power Supply Recommendations

The HDC302x supports a voltage supply range from 1.62 V up to 5.50 V. TI recommends a multilayer ceramic

bypass X7R capacitor of 0.1 µF between the V_DDand GND pins.

10 Layout

10.1 Layout Guidelines

Proper PCB layout of the HDC302x is critical to obtaining accurate measurements of temperature and relative

humidity. Therefore, TI recommends to:

1. Isolate all heat sources from the HDC302x. This means positioning the HDC302x away from power intensive

board components such as a battery, display, or micrcocontroller. As illustrated in Figure 10-1, ideally the

only onboard component close to the HDC302x is the supply bypass capacitor.

2. Eliminate copper layers below the device (GND, V_DD

)

3. Use slots or a cutout around the device to reduce the thermal mass and obtain a quicker response time to

sudden environmental changes.

•

The diameter of the cutout around the part in this case is approximately 6 mm. The important details are

to implement a separation of thermal planes while allowing for power, ground and data lines and place

the part on the board, while still meeting mechanical assembly requirements. In addition Figure 10-1

other representations of cutouts for thermal relief can be found in SNAA297 section 2.3.

4. Follow the Example Board Layout and Example Stencil Design that is illustrated in Mechanical, Packaging,

and Orderable Information.

•

The SCL and the SDA lines require pull up resistors and TI recommends to connect a 0.1-uF cap to the

VDD line.

•

TI recommends a multilayer ceramic bypass X7R capacitor of 0.1 μF between the VDD and GND pins.

5. It is generally best practice to solder the package thermal pad to a board pad that is connected to ground,

however to minimize thermal mass for maximum heater efficiency or to measure ambient temperature it may

be left floating. Floating the thermal pad is an option because the thermal pad has a non-conductive epoxy.

See HDC3x Silicon User guide for more information regarding when leaving the thermal pad floating may be

helpful. for your application

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

10.2 Layout Example

Figure 10-1. HDC302x PCB Layout Example

10.3 Storage and PCB Assembly

10.3.1 Storage and Handling

As with all humidity sensors, the HDC302x must follow special guidelines regarding handling and storage that

are not common with standard semiconductor devices. Long exposure to UV and visible light, or exposure to

chemical vapors for prolonged periods, should be avoided as it may affect RH% accuracy. Additionally, the

device should be protected from out-gassed solvent vapors produced during manufacturing, transport, operation,

and package materials (that is, adhesive tapes, stickers, bubble foils). For further detailed information, see

HDC3x Silicon User's Guide (SNAU265)

10.3.2 Soldering Reflow

For PCB assembly, standard reflow soldering ovens may be used. The HDC302x uses the standard soldering

profile IPC/JEDEC J-STD-020 with peak temperatures at 260°C. When soldering the HDC302x, it is mandatory

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

to use no-clean solder paste, and the paste must not be exposed to water or solvent rinses during assembly

because these contaminants may affect sensor accuracy. After reflow, it is expected that the sensor will

generally output a shift in relative humidity, which will reduce over time as the sensor is exposed to typical indoor

ambient conditions. These conditions include 30-40% RH at room temperature during a duration of several

days. Following this rehydration procedure allows the polymer to correctly settle after reflow and return to the

calibrated RH accuracy.

10.3.3 Rework

TI recommends to limit the HDC302x to a single IR reflow with no rework, but a second reflow may be possible if

the following guidelines are met:

•

The exposed polymer (humidity sensor) is kept clean and undamaged.

No-clean solder paste is used and the process is not exposed to any liquids, such as water or solvents.

The peak soldering temperature does not exceed 260°C.

10.3.4 Exposure to High Temperature and High Humidity Conditions

Long exposure outside the recommended operating conditions may temporarily offset the RH output. The

recommended humidity operating range is 10 to 90% RH (non-condensing) over -20°C to 70°C. Prolonged

operation beyond these ranges may shift the sensor reading with a slow recovery time.

10.3.5 Bake/Rehydration Procedure

Prolonged exposure to extreme conditions or harsh contaminants may impact sensor performance. In the case

that permanent offset is observed from contaminants, the following procedure is suggested, which may recover

or reduce the error observed in sensor performance:

1. Baking: 100°C, at less than 5%RH, for 5 to 10 hours

2. Rehydration: Between 20°C to 30°C, 60%RH to 75%RH, for 6 to 12 hours

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

11 Device and Documentation Support

11.1 Documentation Support

11.1.1 Related Documentation

For related documentation, see the following:

•

Texas Instruments, Humidity Sensor: Storage and Handling Guidelines application report (SNIA025)

Texas Instruments, Optimizing Placement and Routing for Humidity Sensors application report (SNAA297)

Texas Instruments, HDC3x Silicon User's Guide (SNAU265)

11.2 Receiving Notification of Documentation Updates

To receive notification of documentation updates, navigate to the device product folder on ti.com. Click on

Subscribe to updates to register and receive a weekly digest of any product information that has changed. For

change details, review the revision history included in any revised document.

11.3 Support Resources

TI E2E^™support forums are an engineer's go-to source for fast, verified answers and design help — straight

from the experts. Search existing answers or ask your own question to get the quick design help you need.

Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do

not necessarily reflect TI's views; see TI's Terms of Use.

11.4 Trademarks

TI E2E^™is a trademark of Texas Instruments.

All trademarks are the property of their respective owners.

11.5 Electrostatic Discharge Caution

This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled

with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.

ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may

be more susceptible to damage because very small parametric changes could cause the device not to meet its published

specifications.

11.6 Glossary

TI Glossary

This glossary lists and explains terms, acronyms, and definitions.

12 Mechanical, Packaging, and Orderable Information

The following pages include mechanical, packaging, and orderable information. This information is the most

current data available for the designated devices. This data is subject to change without notice and revision of

this document. For browser-based versions of this data sheet, refer to the left-hand navigation.

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Figure 12-1. HDC3020 Package Outline Drawing

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Figure 12-2. HDC3020 Example Board Layout

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Figure 12-3. HDC3020 Example Stencil Design

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Figure 12-4. HDC3020 Package Outline Drawing

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Figure 12-5. HDC3021 Example Board Layout

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Figure 12-6. HDC3021 Example Stencil Design

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

HDC3021

Figure 12-7. Package Outline Drawing

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Figure 12-8. HDC3022 Example Board Layout

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

Figure 12-9. HDC3022 Example Stencil Design

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

12.1 Package Option Addendum

Packaging Information

Orderable

Device

Package

Drawing

Lead/Ball

Finish⁽⁶⁾

MSL Peak

Temp⁽³⁾

Device

Status⁽¹⁾

Package Type

Pins

Package Qty

Eco Plan⁽²⁾

Op Temp (°C)

Marking^{(4) (5)}

PHDC3020DEF ACTIVE

WSON

DEF

DEH

DEJ

DEF

DEH

DEJ

250

RoHS & Green NIPDAU

Level-1-260C- -40°C to 125°C

UNLIM

PHDC3021DE PREVIEW

WSON

250

-40°C to 125°C

PHDC3022DEJ PREVIEW

250

Level-1-260C- -40°C to 125°C

UNLIM

HDC3020DEFR PRE_PROD

3000

250

Level-1-260C- -40°C to 125°C

UNLIM

HDC3020DEFT PRE_PROD

Level-1-260C- -40°C to 125°C

UNLIM

HDC3021DEH PRE_PROD

3000

250

Level-1-260C- -40°C to 125°C

UNLIM

HDC3021DEHT PRE_PROD

HDC3022DEJR PRE_PROD

HDC3022DEJT PRE_PROD

Level-1-260C- -40°C to 125°C

UNLIM

3000

250

Level-1-260C- -40°C to 125°C

UNLIM

Level-1-260C-

UNLIM

(1) The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs.

LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.

NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.

PRE_PROD Unannounced device, not in production, not available for mass market, nor on the web, samples not available.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.

OBSOLETE: TI has discontinued the production of the device.

(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check www.ti.com/productcontent for the latest

availability information and additional product content details.

TBD: The Pb-Free/Green conversion plan has not been defined.

Pb-Free (RoHS): TI's 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, TI Pb-Free products are suitable for use in specified

lead-free processes.

Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used

between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.

Green (RoHS & no Sb/Br): TI 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).

(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

(5) Multiple Device markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a

continuation of the previous line and the two combined represent the entire Device Marking for that device.

(6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the

finish value exceeds the maximum column width.

Important Information and Disclaimer: The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI 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.

TI 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. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

12.2 Tape and Reel Information

REEL DIMENSIONS

TAPE DIMENSIONS

Reel

Diameter

Cavity

A0 Dimension designed to accommodate the component width

B0 Dimension designed to accommodate the component length

K0 Dimension designed to accommodate the component thickness

Overall width of the carrier tape

P1 Pitch between successive cavity centers

Reel Width (W1)

QUADRANT ASSIGNMENTS FOR PIN 1 ORIENTATION IN TAPE

Sprocket Holes

Q1 Q2

Q3 Q4

Q1 Q2

Q3 Q4

User Direction of Feed

Pocket Quadrants

Reel

Diameter

(mm)

Reel

Width W1

(mm)

Package

Type

Package

Drawing

(mm)

Pin1

Quadrant

Device

Pins

SPQ

PHDC3020DEFT

PHDC3021DEFT

PHDC3022DEFT

HDC3020DEFR

HDC3020DEFT

HDC3021DEHR

HDC3021DEHT

HDC3022DEJR

HDC3022DEJT

WSON

DEF

DEH

DEJ

DEF

DEH

DEJ

250

178

2.75

2.8

2.75

2.8

1.3

1.1

1.3

250

3000

250

178

3000

250

178

2.8

3000

250

2.75

178

Submit Document Feedback

Product Folder Links: HDC3020

HDC3020

SNAS778 – JUNE 2021

www.ti.com

TAPE AND REEL BOX DIMENSIONS

Width (mm)

Device

Package Type

WSON

Package Drawing Pins

SPQ

250

Length (mm) Width (mm)

Height (mm)

PHDC3020DEFT

DEF

DEH

DEJ

193

PHDC3021DEFT

PHDC3022DEFT

HDC3020DEFR

HDC3020DEFT

HDC3021DEHR

HDC3021DEHT

HDC3022DEJR

HDC3022DEJT

WSON

250

WSON

250

WSON

3000

250

WSON

3000

250

WSON

3000

250

WSON

Submit Document Feedback

Product Folder Links: HDC3020

PACKAGE OPTION ADDENDUM

www.ti.com

18-Jun-2021

PACKAGING INFORMATION

Orderable Device

Status Package Type Package Pins Package

Eco Plan

Lead finish/

Ball material

MSL Peak Temp

Op Temp (°C)

Device Marking

Samples

Drawing

Qty

(1)

(2)

(3)

(4/5)

(6)

PHDC3020DEFT

ACTIVE

WSON

DEF

250

Non-RoHS &

Non-Green

Call TI

-40 to 125

⁽¹⁾The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs.

LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.

NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.

OBSOLETE: TI has discontinued the production of the device.

⁽²⁾RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance

do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may

reference these types of products as "Pb-Free".

RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.

Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based

flame retardants must also meet the <=1000ppm threshold requirement.

⁽³⁾MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

⁽⁴⁾There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.

⁽⁵⁾Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation

of the previous line and the two combined represent the entire Device Marking for that device.

(6)

Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two

lines if the finish value exceeds the maximum column width.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI 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. TI 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.

TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

Addendum-Page 1

PACKAGE OPTION ADDENDUM

www.ti.com

18-Jun-2021

OTHER QUALIFIED VERSIONS OF HDC3020 :

Automotive : HDC3020-Q1

•

NOTE: Qualified Version Definitions:

Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects

•

Addendum-Page 2

IMPORTANT NOTICE AND DISCLAIMER

TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE

DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS”

AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY

IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD

PARTY INTELLECTUAL PROPERTY RIGHTS.

These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate

TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable

standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you

permission to use these resources only for development of an application that uses the TI products described in the resource. Other

reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party

intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages,

costs, losses, and liabilities arising out of your use of these resources.

TI’s products are provided subject to TI’s Terms of Sale (https:www.ti.com/legal/termsofsale.html) or other applicable terms available either

on ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s

applicable warranties or warranty disclaimers for TI products.IMPORTANT NOTICE

Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265

HDC3021DEHR [TI]

相关型号：

HDC3021DEHT

HDC3021QDEHRQ1

HDC3022

HDC3022DEJR

HDC3022DEJT

HDC302X

HDC30CA

HDC30CA-T

HDC334A-75

HDC33A-75

HDC350P

HDC4-K-D