SNAS758A February   2025  – June 2025 HDC3120

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 Rehydration Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
    6. 8.6 Storage and PCB Assembly
      1. 8.6.1 Storage and Handling
      2. 8.6.2 Product Storage
      3. 8.6.3 PCB Assembly Flow
      4. 8.6.4 Rework Consideration
      5. 8.6.5 Sensitivity to Chemicals and Vapors
      6. 8.6.6 Exposure to High Temperature and High Humidity Conditions
      7. 8.6.7 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

7.3.1 Device Power-Up

The HDC3120 includes a power-on reset (POR) function that controls the output voltage at power up. After the VDD supply has been established (VDD> VPOR), a POR event is issued. The POR causes the device to load the default settings from the memory and subsequently performs temperature and humidity measurements.

During the first humidity and temperature measurement, the DAC outputs are driven to a default level of 0.1* VDD. Each DAC channel remains at the default voltage level until the measurement is completed, which takes approximately RHPUR for the humidity measurement and TPUR for the temperature measurement. After the measurement is completed, the DAC outputs are driven to the voltage level corresponding to the measured humidity and temperature values. Figure 7-3 shows an example of the HDC3120 power-up behavior.

HDC3120 HDC3120 Power-Up BehaviorFigure 7-3 HDC3120 Power-Up Behavior

Note the POR circuit requires specific supply levels to discharge the internal capacitors and to reset the device on power up, as indicated in Figure 7-4. To initiate a POR event, VDD must be below the corresponding low thresholds (VBOR) for a duration of at least tRESET_NPW. If VDD remains above the specified high threshold (VPOR), a POR event does not occur. When the VDD drops below the high threshold VPOR but remain over the lower one (VBOR), the device is situated in an undefined state, and does not necessarily reset under all specified temperature and power supply conditions.

HDC3120 HDC3120 POR Circuit ThresholdsFigure 7-4 HDC3120 POR Circuit Thresholds