SNAS890A February   2025  – June 2025 HDC3120-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Device Power-Up
      2. 7.3.2 Device Disable and Enable
      3. 7.3.3 Conversion of the Signal Output
        1. 7.3.3.1 Relative Humidity (RH%) Measurement
        2. 7.3.3.2 Temperature Measurement
      4. 7.3.4 NIST Traceability and Unique ID
      5. 7.3.5 Output Short Circuit Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 On-Chip Heater
        1. 7.4.1.1 Operating Principle
          1. 7.4.1.1.1 Heater Configuration Example
        2. 7.4.1.2 Heater Electrical Behavior
        3. 7.4.1.3 Heater Temperature Increase
        4. 7.4.1.4 Heater Usage Guidelines
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
    5. 8.5 Storage and PCB Assembly
      1. 8.5.1 Storage and Handling
      2. 8.5.2 Product Storage
      3. 8.5.3 PCB Assembly Flow
      4. 8.5.4 Rework Consideration
      5. 8.5.5 Sensitivity to Chemicals and Vapors
      6. 8.5.6 Exposure to High Temperature and High Humidity Conditions
      7. 8.5.7 Recovering Sensor Performance: Bake and Rehydration Procedure
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DEF|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.3 Conversion of the Signal Output

The HDC3120-Q1 has two analog ratiometric output voltages—one for temperature and one for relative humidity—that are ratiometric to the supply voltage (VDD). In a ratiometric design, the output voltage scales proportionally with changes in VDD. Any variation in supply voltage directly adjusts the sensor output. This architecture keeps the sensor readings accurate, even with supply fluctuations.

HDC3120-Q1 ratiometric architecture provides the benefit in applications that use the same reference or supply voltage for both the HDC3120-Q1 and the sampling ADC. When VDD changes, the sensor offset and span shift together, verifying that the measured ratio remains constant. For instance, at 5.0V VDD, the VRH reads 0.5V at 0% RH and 4.5V at 100% RH. If the supply drops 10% to 4.5V, those outputs become 0.45V and 4.05V, respectively, hence maintaining the same ratio.

A ratiometric design can help mitigate supply voltage errors as long as the measurement reference tracks the same supply. The outputs are linearly proportional to temperature and humidity and can be converted to physical units using transfer functions described in the following sections.