HDC2021 TI1 | Alldatasheet
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ADVANCE□INFORMATION RH (%RH) Accuracy (r%RH) 0 10 20 30 40 50 60 70 80 90 100 Typical RH Sensor Temperature Sensor Registers Logic Calibration I2CADC SCL SDA DRDY/INT ADDR HDC2021 VDD MCU VDD GPIO I2C Master GND GND 1.80 V Product Folder Order Now T echnical Documents Tools & Software Support & Community 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 pre-production products; subject to change without notice. HDC2021 SNAS773 –DECEMBER 2019 HDC2021High-Accuracy,Low-PowerHumidityandTemperatureSensorWithAssembly ProtectionCover
1 Features
1• Factory-installed polyimide tape to protect sensor during assembly
- Backward-compatible with HDC2080
- RH measurement range: 0% to 100%
- Temperature measurement range: –40°C to 125°C
- Supply voltage range: 1.62 V to 3.6 V
- I2C interface compatibility
- ±2% RH sensor accuracy
- ±0.2°C temperature sensor accuracy
- 50-nA sleep mode current
- 550-nA average supply current (11-bit, 1 measurement/second)
- Available auto measurement mode
2 Applications
- Thermostats
- Smart speakers (with voice assistant)
- Washers and dryers
- HVAC sensor transmitters (temperature, pressure, and humidity)
- HVAC system controllers
- Wireless environmental sensors
- Home printers Typical Application
3 Description
The HDC2021 is an integrated relative humidity and temperature sensor with a factory-installed polyimide tape cover over the opening of the relative humidity sensor element. The tape cover provides protection against pollutants that can appear in certain stages of the manufacturing process, such as SMT assembly, PCB board wash, and conformal coating. The tape design allows for a full conformal coating of the PCB, and includes an adhesive free corner tab for quick removal using a pair of tweezers. The HDC2021 device is backward-compatible with the HDC2080, providing high accuracy measurements with very low power consumption in a small DFN package. The capacitive-based sensor includes new integrated digital features and a heating element to dissipate condensation and moisture. The HDC2021 digital features include programmable interrupt thresholds to provide alerts and system wake-ups without requiring a microcontroller to continuously monitor the system. Combined with programmable sampling intervals, low power consumption, and 1.8-V supply voltage support, the HDC2021 is designed for ultra-low power battery- operated systems. Device Information(1) PART NUMBER PACKAGE BODY SIZE (NOM) HDC2021 WSON (6) 3.00 mm × 3.00 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. RH Accuracy (TA = 30°C)
ADVANCE□INFORMATION HDC2021 SNAS773 –DECEMBER 2019 www.ti.com Product Folder Links: HDC2021 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated Table of Contents
12.2 Receiving Notification of Documentation Updates 32
13 Mechanical, Packaging, and Orderable
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version. DATE REVISION NOTES December 2019 * Initial release.
ADVANCE□INFORMATION 3 4 6SDA GND ADDR DRDY/INT VDD SCL HDC2021 www.ti.com SNAS773 –DECEMBER 2019 Product Folder Links: HDC2021 Submit Documentation FeedbackCopyright © 2019, Texas Instruments Incorporated (1) The definitions below define the functionality of the TYPE cells for each pin: (a) I = input (b) O = output (c) I/O = input/output (d) G = ground (e) P = power
5 Description (continued)
The HDC2021 provides high-accuracy measurement capability for a wide range of environmental monitoring and Internet of Things (IoT) applications such as smart thermostats and smart home assistants. For applications with strict power-budget restrictions, Auto Measurement Mode enables the HDC2021 to automatically initiate temperature and humidity measurements. This feature allows users to configure a microcontroller into deep sleep mode because the HDC2021 is no longer dependent upon the microcontroller to initiate a measurement. Programable temperature and humidity thresholds in the HDC2021 allow the device to send a hardware interrupt to wake up the microcontroller when necessary. In addition, the power consumption of the HDC2021 is significantly reduced, which can help minimize self-heating and improve measurement accuracy. The HDC2021 is factory-calibrated to ±0.2°C temperature accuracy and ±2% relative humidity accuracy.
6 Pin Configuration and Functions
TYPE(1) DESCRIPTION NAME NO. ADDR 3 I Address select pin – leave unconnected or hardwired to VDD or GND. Unconnected slave address: 1000000X GND: slave address: 1000000X VDD: slave address: 1000001X where 'X' represents the read-write (R/W) bit. DRDY/INT 4 O Data ready/Interrupt. Push-Pull Output. GND 2 G Ground SCL 6 I Serial clock line for I2C, open-drain. Requires a pullup resistor to VDD. SDA 1 I/O Serial data line for I2C, open-drain. Requires a pullup resistor to VDD. VDD 5 P Positive Supply Voltage
ADVANCE□INFORMATION HDC2021 SNAS773 –DECEMBER 2019 www.ti.com Product Folder Links: HDC2021 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated (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.
7 Specifications
7.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1) MIN MAX UNIT VDD Applied Voltage on VDD pin –0.3 3.9 V GND Applied Voltage on GND pin –0.3 3.9 V ADDR Applied Voltage on ADDR pin –0.3 3.9 V SCL Applied Voltage on SCL pin –0.3 3.9 V SDA Applied Voltage on SDA pin –0.3 3.9 V Tstg Storage temperature –65 150 °C (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.
7.2 ESD Ratings
V(ESD) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V Charged device model (CDM), per JEDEC specification JESD22-C101(2) ±500
7.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted) PARAMETER MIN MAX UNIT VDD Supply voltage 1.62 3.6 V TTEMP Temperature Sensor - Operating free-air temperature –40 125 °C TRH Relative Humidity Sensor - Operating free-air temperature –20 70 °C THEATER Integrated Heater - Operating free-air temperature –40 85 °C (1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report.
7.4 Thermal Information
THERMAL METRIC(1) HDC2021 UNITWSON (DEB)
6 PINS
RθJA Junction-to-ambient thermal resistance 57.9 °C/W RθJC(top) Junction-to-case (top) thermal resistance 58.7 °C/W RθJB Junction-to-board thermal resistance 27.0 °C/W ΨJT Junction-to-top characterization parameter 5.6 °C/W ΨJB Junction-to-board characterization parameter 26.9 °C/W RθJC(bot) Junction-to-case (bottom) thermal resistance 16.5 °C/W
ADVANCE□INFORMATION HDC2021 www.ti.com SNAS773 –DECEMBER 2019 Product Folder Links: HDC2021 Submit Documentation FeedbackCopyright © 2019, Texas Instruments Incorporated (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 (4) Excludes the impact of dust, gas phase solvents and other contaminents such as vapors from packaging materials, adhesives, or tapes, etc. (5) Limits apply over the humidity operating 20% to 80% RH (non-condensing) from 0°C to 60°C (6) This parameter is specified by design and/or characterization and is not tested in production (7) The hysteresis value is the difference between the RH measurement in a rising and falling RH environment, at a specific RH point (8) Actual response times will vary dependent on system thermal mass and air-flow (9) Time for the RH output to change by 63% of the total RH change after a step change in environmental humidity (10) Recommneded humidity operating range is 20% to 80% RH (non-condensing) over 0°C to 60°C. Prolonged operation beyond these ranges may result in a shift of sensor reading, with slow recovery time (11) Drift due to aging effects at typical conditions (30°C and 20% to 50% RH). This value may be impacted by dust, vaporized solvents, outgassing tapes, adhesives, packaging materials, etc.
7.5 Electrical Characteristics
TA = 30°C, VDD = 1.8 V, 20% ≤ RH ≤ 80% (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT POWER CONSUMPTION IDD Supply Current Averaged at 1 sample per second RH & TEMP sensor(1)(2) 0.55 µA IDD Supply Current Averaged at 1 sample every two seconds RH & TEMP sensor(1)(2) 0.3 µA IDD Supply Current No Measurement (Sleep Mode) 0.05 0.1 µA IDD Supply Current During RH measurement(1) 650 890 µA IDD Supply Current During TEMP measurement(1) 550 730 µA IDD Supply Current Startup (average on startup time) 80 µA IHEATER Integrated Heater (enabled) VDD = 3.3V; THEATER - TA = 80°C Steady state measurement 90 mA RELATIVE HUMIDITY SENSOR RHACC Accuracy(3)(4)(5) ±2 ±3 %RH RHREP Repeatability(6) 14 bit resolution ±0.1 %RH RHHYS Hysteresis(7) ±1 %RH RHHYS Response Time(8) t63% step(9) 8 s RHCT Conversion Time(6) 9 bit resolution 275 µs RHCT Conversion Time(6) 11 bit resolution 400 µs RHCT Conversion Time(6) 14 bit resolution 660 µs RHOR Operating Range Non-condensing(10) 0 100 %RH RHLTD Long-term Drift(11) ±0.25 %RH/yr TEMPERATURE SENSOR TEMPACC Accuracy(6) 5°C ≤ TA ≤ 60°C ±0.2 ±0.7 °C TEMPACC Accuracy(6) 10°C ≤ TA ≤ 35°C ±0.2 ±0.4 °C TEMPREP Repeatability(6) 14 bit resolution ±0.1 °C TEMPCT Conversion Time(6) 9 bit resolution 225 µs TEMPCT Conversion Time(6) 11 bit resolution 350 µs TEMPCT Conversion Time(6) 14 bit resolution 610 µs
7.6 Switching Characteristics
7.7 Timing Diagram
Figure 1. I2C Timing
7.8 Typical Characteristics
Unless otherwise noted, TA = 30°C, VDD = 1.8 V. Figure 2. RH Accuracy vs. RH Set Point Figure 3. Temperature Accuracy vs. Temperature Set Point Figure 4. Supply Current vs. Supply Voltage, Average at 1 Figure 5. Supply Current vs. Temperature, Average at 1 Figure 6. Supply Current vs. Supply Voltage, Sleep Mode Figure 7. Supply Current vs. Temperature, Sleep Mode
ADVANCE□INFORMATION RH Sensor Temperature Sensor Registers Logic Calibration I2CADC SCL SDA DRDY/INT ADDR HDC2021 VDD GND HDC2021 SNAS773 –DECEMBER 2019 www.ti.com Product Folder Links: HDC2021 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated
8 Detailed Description
8.1 Overview
The HDC2021 is a highly integrated digital humidity and temperature sensor that incorporates both humidity- sensing and temperature-sensing elements, an analog-to-digital converter, calibration memory, and an I2C interface that are all contained in a 3.00-mm × 3.00-mm, 6-pin WSON package. The HDC2021 provides excellent measurement accuracy with very low power consumption and features programmable resolution for both humidity and temperature:
- Temperature resolution [9, 11, or 14 bits]
- Humidity resolution [9, 11, or 14 bits] The conversion time during measurements is dependent upon the configured resolution for humidity and temperature, which can be configured for optimal power consumption. The HDC2021 device incorporates a state-of-the-art polymer dielectric to provide capacitive-sensing measurements. As with most relative humidity sensors that include this type of technology, the user must meet these application requirements to ensure optimal device performance for the sensing element:
- Follow the correct storage and handling procedures during board assembly. See Humidity Sensor: Storage and Handling Guidelines. (SNIA025) for these guidelines.
- Protect the sensor from contaminants during 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.
8.2 Functional Block Diagram
ADVANCE□INFORMATION HDC2021 www.ti.com SNAS773 –DECEMBER 2019 Product Folder Links: HDC2021 Submit Documentation FeedbackCopyright © 2019, Texas Instruments Incorporated
8.3 Feature Description
8.3.1 Factory Installed Polyimide Tape
A polyimide tape covers 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, PCB board 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 lower right corner, then slowly peel from the bottom right corner towards the top left corner (pin 1 designator) in an upward direction (as opposed to across the surface). This will help to reduce the risk of scratching the humidity sensor element.
8.3.2 Sleep Mode Power Consumption
One key feature of the HDC2021 is the low power consumption designed for battery-powered or energy- harvesting applications. In these applications, the HDC2021 spends most of the time in sleep mode that has a typical current consumption of 50 nA. This minimizes the average power consumption and self-heating. 8.3.3 Measurement Modes: Trigger on Demand vs. Auto Measurement The two types of measurement modes are available on the HDC2021: Trigger on Demand and Auto Mode. Trigger on Demand is when each measurement reading is initiated 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. The HDC2021 can perform measurement readings on a periodic basis in auto measurement mode to eliminate the need to initiate a measurement request through an I2C command and improve power consumption. The user can adjust the Soft Reset and Interrupt Configuration register to select one of 7 different sampling rates (the range spans from 1 sample every 2 minutes to 5 samples every second). In auto measurement mode, the HDC2021 wakes up from sleep to measurement mode based on the selected sampling rate.
8.3.4 Heater
The HDC2021 includes an integrated heating element that can be switched on briefly to prevent or remove any condensation that may build up in high humidity environments. Additionally, the heater can be used to verify functionally of the integrated temperature sensor. The operating range of the heater should be limited to –40°C to 85°C. The heater will have a typical current draw of 90 mA at 3.3-V operation and 55 mA at 1.8-V operation.
8.3.5 Interrupt Description
When multiple bits are enabled, the DRDY/INT pin can only reflect the status of one interrupt bit at a time. The DRDY/INT pin DOES NOT function as the logical ‘OR’ of interrupt bits that have been enabled. The highest priority is given to TH_ENABLE bit, followed by TL_ENABLE, HH_ENABLE, and HL_ENABLE bits in descending order. Therefore, programming recommendations are provided as below:
- The DRDY/INT will track the HL_ENABLE, if enabled, and all other ENABLE bits are disabled.
- The DRDY/INT will track the HH_ENABLE, if enabled, and the TH_ENABLE and TL_ENABLE are disabled.
- The DRDY/INT will track the TL_ENABLE, if enabled, and the TH_ENABLE is disabled.
- The DRDY/INT will track the TH_ENABLE, if enabled, and is independent of other ENABLE bit settings.
8.3.5.1 DRDY
Figure 8. Data Ready Interrupt - Active High (INT_POL = 1) Figure 9. Data Ready Interrupt - Active Low (INT_POL = 0)
8.3.6 INTERRUPT on Threshold
8.3.6.1 Temperature High
The INT_MODE bit sets the threshold to either comparator mode or a level-sensitive alarm. of the DRDY/INT pin is set by INT_POL. Figure 10. INTERRUPT on Threshold - Temperature High
8.3.6.2 Temperature Low
based on the INT_POL and INT_MODE bits. The INT_MODE bit sets the threshold to either comparator mode or a level-sensitive alarm. the DRDY/INT pin is set by INT_POL. Figure 11. INTERRUPT on Threshold - Temperature Low
8.3.6.3 Humidity High
The INT_MODE bit sets the threshold to either comparator mode or a level-sensitive alarm. of the DRDY/INT pin is set by INT_POL. Figure 12. INTERRUPT on Threshold - Humidity High
8.3.6.4 Humidity Low
The INT_MODE bit sets the threshold to either comparator mode or a level-sensitive alarm. of the DRDY/INT pin is set by INT_POL. Figure 13. INTERRUPT on Threshold - Humidity Low
8.4 Device Functional Modes
The HDC2021 has two modes of operation: sleep mode and measurement mode. Configuration registers. After completing the conversion, the HDC2021 returns to sleep mode.
8.5 Programming
8.5.1 I2C Serial Bus Address Configuration
To communicate with the HDC2021, the master must first address slave devices through a slave address byte. Table 1. HDC2021 I2C Slave Address
8.5.2 I2C Interface
measurement is performed. All data bytes are transmitted MSB first.
8.5.3 Serial Bus Address
To communicate with the HDC2021, the master must first address slave devices through a slave address byte.
8.5.4 Read and Write Operations
requires a value for the register address (refer to Table 2).
read or write operation with incorrect I2C address returns a NACK after the I2C address. Table 2. Write Single Byte Table 3. Write Multibyte Table 4. Read Single Byte Table 5. Read Multibyte
8.6 Register Maps
measurement results, and status information. Table 6. Register Map
8.6.1 Address 0x00 Temperature LSB
Table 7. Address 0x00 Temperature LSB Register Table 8. Address 0x00 Temperature LSB Field Descriptions
8.6.2 Address 0x01 Temperature MSB
measurement must be read LSB first, followed by MSB. Table 9. Address 0x01 Temperature MSB Register Table 10. Address 0x01 Temperature MSB Field Descriptions
8.6.3 Address 0x02 Humidity LSB
Table 11. Address 0x02 Humidity LSB Register Table 12. Address 0x02 Humidity LSB Field Descriptions
8.6.4 Address 0x03 Humidity MSB
measurement must be read LSB first, followed by MSB. Table 13. Address 0x03 Humidity MSB Register Table 14. Address 0x03 Humidity MSB Field Descriptions
8.6.5 Address 0x04 Interrupt DRDY
Table 15. Address 0x04 Interrupt DRDY Register Table 16. Address 0x04 Interrupt DRDY Field Descriptions
7 DRDY_STATUS R/W 0 DataReady bit status
6 TH_STATUS R/W 0 Temperature threshold HIGH Interrupt status
5 TL_STATUS R/W 0 Temperature threshold LOW Interrupt status
4 HH_STATUS R/W 0 Humidity threshold HIGH Interrupt status
3 HL_STATUS R/W 0 Humidity threshold LOW Interrupt status
2 RES 0 Reserved
1 RES 0 Reserved
0 RES 0 Reserved
HUMIDITY_HIGH and HUMIDITY_LOW are read. 0x0E Configuration register value. The bit is cleared when the register Interrupt DRDY is read. 0x0E Configuration register value. The bit is cleared when the register Interrupt DRDY is read. 0x0E Configuration register value. The bit is cleared when the register Interrupt DRDY is read. 0x0E Configuration register value. The bit is cleared when the register Interrupt DRDY is read. DRDY/INT pin behaves like the STATUS bits based on the 0x0E Configuration register value.
8.6.6 Address 0x05 Temperature MAX
after the power up. Value is reset at power up and/or with soft reset procedure. Table 17. Address 0x05 Temperature MAX Register Table 18. Address 0x05 Temperature Max Field Descriptions
8.6.7 Address 0x06 Humidity MAX
power up. Value is reset at power up and/or with soft reset procedure. Table 19. Address 0x06 Humidity MAX Register Table 20. Address 0x06 Humidity MAX Field Descriptions
8.6.8 Address 0x07 Interrupt Configuration
Table 21. Address 0x07 Interrupt Configuration Register Table 22. Address 0x07 Interrupt Configuration Field Descriptions
7 DRDY_ENABLE R/W 0 DataReady Interrupt enable
6 TH_ENABLE R/W 0 Temperature threshold HIGH Interrupt enable
5 TL_ENABLE R/W 0 Temperature threshold LOW Interrupt enable
4 HH_ENABLE R/W 0 Humidity threshold HIGH Interrupt enable
3 HL_ENABLE R/W 0 Humidity threshold LOW Interrupt enable
8.6.9 Address 0x08 Temperature Offset Adjustment
Table 23. Address 0x08 Temperature Offset Adjustment Register Table 24. Address 0x08 Temperature Offset Adjustment Field Descriptions The value is added to the converted temperature value for offset adjustment as shown in Figure 14. Figure 14. Temperature Output Calculation
- Programming TEMP_OFFSET_ADJUST to 00000001 adjusts the reported temperature by +0.16°C.
- Programming TEMP_OFFSET_ADJUST to 00000111 adjusts the reported temperature by +1.12°C.
- Programming TEMP_OFFSET_ADJUST to 00001101 adjusts the reported temperature by +2.08°C.
- Programming TEMP_OFFSET_ADJUST to 11111111 adjusts the reported temperature by –0.16°C.
- Programming TEMP_OFFSET_ADJUST to 11111001 adjusts the reported temperature by –1.12°C.
- Programming TEMP_OFFSET_ADJUST to 11110011 adjusts the reported temperature by –2.08°C.
8.6.10 Address 0x09 Humidity Offset Adjustment
Table 25. Address 0x09 Humidity Offset Adjustment Register Table 26. Address 0x09 Humidity Offset Adjustment Field Descriptions Figure 15. Humidity Output Calculation
- Programming HUM_OFFSET_ADJUST to 00000001 adjusts the reported humidity by +0.20%RH.
- Programming HUM_OFFSET_ADJUST to 00000101 adjusts the reported humidity by +1.00%RH.
- Programming HUM_OFFSET_ADJUST to 00001010 adjusts the reported humidity by +2.00%RH.
- Programming HUM_OFFSET_ADJUST to 11111111 adjusts the reported humidity by –0.10%RH.
- Programming HUM_OFFSET_ADJUST to 11111011 adjusts the reported humidity by –0.90%RH.
- Programming HUM_OFFSET_ADJUST to 11110101 adjusts the reported humidity by –2.10%RH.
8.6.11 Address 0x0A Temperature Threshold LOW
Table 27. Address 0x0A Temperature Threshold LOW Register Table 28. Address 0x0A Temperature Threshold LOW Field Descriptions
8.6.12 Address 0x0B Temperature Threshold HIGH
Table 29. Address 0x0B Temperature Threshold HIGH Register Table 30. Address 0x0B Temperature Threshold HIGH Field Descriptions
8.6.13 Address 0x0C Humidity Threshold LOW
Table 31. Address 0x0C Humidity Threshold LOW Register Table 32. Address 0x0C Humidity Threshold LOW Field Descriptions
8.6.14 Address 0x0D Humidity Threshold HIGH
Table 33. Address 0x0D Humidity Threshold HIGH Register Table 34. Address 0x0D Humidity Threshold HIGH Field Descriptions
8.6.15 Address 0x0E Reset and DRDY/INT Configuration Register
Table 35. Address 0x0E Configuration Register Table 36. Address 0x0E Configuration Field Descriptions
7 SOFT_RES R/W 0 0 = Normal Operation mode, this bit is self-clear
3 HEAT_EN R/W 0 0 = Heater off
2 DRDY/INT_EN R/W 0 DRDY/INT_EN pin configuration
1 INT_POL R/W 0 Interrupt polarity
0 INT_MODE R/W 0 Interrupt mode
8.6.16 Address 0x0F Measurement Configuration
Table 37. Address 0x0F Measurement Configuration Register Table 38. Address 0x0F Measurement Configuration Field Descriptions
3 RES R/W 0 Reserved
0 MEAS_TRIG R/W 0 Measurement trigger
8.6.17 Manufacturer ID Low
Table 39. Manufacturer ID Low Register Table 40. Address 0xFC Manufacturer ID Low Field Descriptions
8.6.18 Manufacturer ID High
same I2C bus. The manufacturer ID reads 0x4954. Table 41. Manufacturer ID High Register Table 42. Address 0xFD Manufacturer ID High Field Descriptions
8.6.19 Device ID Low
Table 43. Device ID Low Register Table 44. Address 0xFE Device ID Low Field Descriptions
8.6.20 Device ID High
These registers contain a factory-programmable identification value that identifies this device as a HDC2021. Table 45. Device ID High Register Table 46. Address 0xFF Device ID High Field Descriptions
9 Application and Implementation
validate and test their design implementation to confirm system functionality.
9.1 Application Information
system. The collected data are then shown on a display that can be easily controlled by the microcontroller. environment at the customer-defined preferred conditions.
9.2 Typical Application
Figure 16. Typical Application Schematic HVAC
9.2.1 Design Requirements
9.2.2 Detailed Design Procedure
can improve measurement response time and accuracy.
9.2.3 Application Curve
Figure 17. RH% Readings of Chamber and HDC2021 vs. Time
ADVANCE□INFORMATION HDC2021 SNAS773 –DECEMBER 2019 www.ti.com Product Folder Links: HDC2021 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated
10 Power Supply Recommendations
The HDC2021 requires a voltage supply within 1.62 V and 3.6 V. TI recommends a multilayer ceramic bypass X7R capacitor of 0.1 µF between the VDD and GND pins.
11 Layout
11.1 Layout Guidelines
The HDC2021’s relative humidity-sensing element is located on the top side of the package. TI recommends that the user eliminate the copper layers below the device (GND, VDD) and create slots in the PCB around the device to enhance the thermal isolation of the HDC2021. To ensure the temperature sensor performance, TI highly recommends that the user follow the Land Pattern, Solder Mask, and Solder Paste examples depicted in the Mechanical, Packaging, and Orderable Information.
11.1.1 Guidelines for HDC2021 Storage and PCB Assembly
11.1.1.1 Storage and Handling
As with all humidity sensors, the HDC2021 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 Humidity Sensor: Storage and Handling Guidelines (SNIA025).
11.1.1.2 Soldering Reflow
For PCB assembly, standard reflow soldering ovens may be used. The HDC2021 uses the standard soldering profile IPC/JEDEC J-STD-020 with peak temperatures at 260°C. When soldering the HDC2021, it is mandatory 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, once the polyimide tape is peeled off, 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.
11.1.1.3 Rework
The polyimide tape of the HDC2021 can withstand at least three standard reflow cycles. In the case of tape removal, TI recommends to limit the HDC2021 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.
- The 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.
11.1.1.4 High Temperature and Humidity Exposure
Long exposure outside the recommended operating conditions may temporarily offset the RH output. The recommended humidity operating range is 20% to 80% RH (non-condensing) over 0°C to 60°C. Prolonged operation beyond these ranges may shift the sensor reading with a slow recovery time.
11.1.1.5 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
11.2 Layout Example
Figure 18. HDC2021 PCB Layout Example
ADVANCE□INFORMATION HDC2021 SNAS773 –DECEMBER 2019 www.ti.com Product Folder Links: HDC2021 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated
12 Device and Documentation Support
12.1 Documentation Support
12.1.1 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)
12.2 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me 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.
12.3 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.
12.4 Trademarks
E2E is a trademark of Texas Instruments. All other trademarks are the property of their respective owners.
12.5 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.
12.6 Glossary
SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions.
13 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.
ADVANCE□INFORMATION HDC2021 www.ti.com SNAS773 –DECEMBER 2019 Product Folder Links: HDC2021 Submit Documentation FeedbackCopyright © 2019, Texas Instruments Incorporated
ADVANCE□INFORMATION HDC2021 SNAS773 –DECEMBER 2019 www.ti.com Product Folder Links: HDC2021 Submit Documentation Feedback Copyright © 2019, Texas Instruments Incorporated
ADVANCE□INFORMATION HDC2021 www.ti.com SNAS773 –DECEMBER 2019 Product Folder Links: HDC2021 Submit Documentation FeedbackCopyright © 2019, Texas Instruments Incorporated
www.ti.com 24-Dec-2019 Addendum-Page 1 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/Ball Finish (6) MSL Peak Temp (3) Op Temp (°C) Device Marking (4/5) Samples PHDC2021DEBT ACTIVE WSON DEB 6 250 TBD Call TI 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/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.
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