SNAS817C June   2021  – March 2023 HDC3020-Q1 , HDC3021-Q1 , HDC3022-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 I2C Interface Timing
    7. 7.7 Timing Diagram
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Factory Installed Polyimide Tape
      2. 8.3.2  Factory Installed IP67 Protection Cover
      3. 8.3.3  Wettable Flanks
      4. 8.3.4  Measurement of Relative Humidity and Temperature
      5. 8.3.5  Offset Error Correction: Accuracy Restoration
      6. 8.3.6  NIST Traceability of Relative Humidity and Temperature Sensor
      7. 8.3.7  Measurement Modes: Trigger-On Demand vs Auto Measurement
      8. 8.3.8  Heater
      9. 8.3.9  ALERT Output With Programmable Interrupts
      10. 8.3.10 Checksum Calculation
      11. 8.3.11 Programmable Offset of Relative Humidity and Temperature Results
    4. 8.4 Device Functional Modes
      1. 8.4.1 Sleep Mode vs Measurement Mode
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
      2. 8.5.2 I2C Serial Bus Address Configuration
      3. 8.5.3 I2C Write - Send Device Command
      4. 8.5.4 I2C Read - Retrieve Single Data Result
      5. 8.5.5 I2C Read - Retrieve Multi Data Result
      6. 8.5.6 I2C Repeated START - Send Command and Retrieve Data Results
      7. 8.5.7 Command Table and Detailed Description
        1. 8.5.7.1 Reset
          1. 8.5.7.1.1 Soft Reset
          2. 8.5.7.1.2 I2C General Call Reset
        2. 8.5.7.2 Trigger-On Demand
        3. 8.5.7.3 Auto Measurement Mode
          1. 8.5.7.3.1 Auto Measurement Mode: Enable and Configure Measurement Interval
          2. 8.5.7.3.2 Auto Measurement Mode: Measurement Readout
          3. 8.5.7.3.3 Auto Measurement Mode: Exit
          4. 8.5.7.3.4 Auto Measurement Mode: Measurement History Readout
          5. 8.5.7.3.5 Override Default Device Power-On and Device-Reset State
        4. 8.5.7.4 ALERT Output Configuration
          1. 8.5.7.4.1 ALERT Output: Environmental Tracking of Temperature and Relative Humidity
          2. 8.5.7.4.2 ALERT Output: Representation of Environmental Thresholds and Default Threshold Values
          3. 8.5.7.4.3 ALERT Output: Steps to Calculate and Program Environmental Thresholds
          4. 8.5.7.4.4 ALERT Output: Deactivation of Environmental Tracking
          5. 8.5.7.4.5 ALERT Output: Transfer Thresholds into Non-Volatile Memory
        5. 8.5.7.5 Programmable Measurement Offset
          1. 8.5.7.5.1 Representation of Offset Value and Factory Shipped Default Value
          2. 8.5.7.5.2 Factory Shipped Default Offset Values
          3. 8.5.7.5.3 Calculate Relative Humidity Offset Value
          4. 8.5.7.5.4 Calculate Temperature Offset Value
          5. 8.5.7.5.5 Write an Offset Value
          6. 8.5.7.5.6 Verify a Programmed Offset Value
        6. 8.5.7.6 Status Register
        7. 8.5.7.7 Heater: Enable and Disable
        8. 8.5.7.8 Heater: Configure Level of Heater Current
        9. 8.5.7.9 Read NIST ID/Serial Number
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
      3. 9.4.3 Storage and PCB Assembly
        1. 9.4.3.1 Storage and Handling
        2. 9.4.3.2 Soldering Reflow
        3. 9.4.3.3 Rework
        4. 9.4.3.4 Exposure to High Temperature and High Humidity Conditions
        5. 9.4.3.5 Bake/Rehydration Procedure
  10. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DEJ|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information
8.5.7.4.3 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
    1. Figure 8-27 illustrates the appropriate command to send to the HDC302x-Q1.
    2. The HDC302x-Q1 will respond to reception of an incorrect CRC byte with a I2C NACK.
GUID-3349B4D8-B00D-4D2A-A35C-BBD72B94C6F7-low.gifFigure 8-27 I2C Command Sequence: Example Programming of Set High Alert to 90% RH, 65°C