SLUSDS3A March   2020  – January 2024 UCC21739-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Power Ratings
    6. 5.6  Insulation Specifications
    7. 5.7  Safety-Related Certifications
    8. 5.8  Safety Limiting Values
    9. 5.9  Electrical Characteristics
    10. 5.10 Switching Characteristics
    11. 5.11 Insulation Characteristics Curves
    12. 5.12 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Propagation Delay
      1. 6.1.1 Regular Turn-OFF
    2. 6.2 Input Deglitch Filter
    3. 6.3 Active Miller Clamp
      1. 6.3.1 External Active Miller Clamp
    4. 6.4 Under Voltage Lockout (UVLO)
      1. 6.4.1 VCC UVLO
      2. 6.4.2 VDD UVLO
    5. 6.5 OC (Over Current) Protection
      1. 6.5.1 OC Protection with 2-Level Turn-OFF
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Power Supply
      2. 7.3.2  Driver Stage
      3. 7.3.3  VCC and VDD Undervoltage Lockout (UVLO)
      4. 7.3.4  Active Pulldown
      5. 7.3.5  Short Circuit Clamping
      6. 7.3.6  External Active Miller Clamp
      7. 7.3.7  Overcurrent and Short Circuit Protection
      8. 7.3.8  2-Level Turn-off
      9. 7.3.9  Fault ( FLT, Reset and Enable ( RST/EN)
      10. 7.3.10 Isolated Analog to PWM Signal Function
    4. 7.4 Device Functional Modes
  9. 8 Applications 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
        1. 8.2.2.1 Input filters for IN+, IN- and RST/EN
        2. 8.2.2.2 PWM Interlock of IN+ and IN-
        3. 8.2.2.3 FLT, RDY and RST/EN Pin Circuitry
        4. 8.2.2.4 RST/EN Pin Control
        5. 8.2.2.5 Turn-On and Turn-Off Gate Resistors
        6. 8.2.2.6 External Active Miller Clamp
        7. 8.2.2.7 Overcurrent and Short Circuit Protection
          1. 8.2.2.7.1 Protection Based on Power Modules with Integrated SenseFET
          2. 8.2.2.7.2 Protection Based on Desaturation Circuit
          3. 8.2.2.7.3 Protection Based on Shunt Resistor in Power Loop
        8. 8.2.2.8 Isolated Analog Signal Sensing
          1. 8.2.2.8.1 Isolated Temperature Sensing
          2. 8.2.2.8.2 Isolated DC Bus Voltage Sensing
        9. 8.2.2.9 Higher Output Current Using an External Current Buffer
      3. 8.2.3 Application Curves
  10. 9 Power Supply Recommendations
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.10 Isolated Analog to PWM Signal Function

The UCC21739-Q1 features an isolated analog to PWM signal function from AIN to APWM pin, which allows the isolated temperature sensing, high voltage dc bus voltage sensing, etc. An internal current source IAIN in AIN pin is implemented in the device to bias an external thermal diode or temperature sensing resistor. The UCC21739-Q1 encodes the voltage signal VAIN to a PWM signal, passing through the isolation barrier, and output to APWM pin on the input side. The PWM signal can either be transferred directly to DSP/MCU to calculate the duty cycle, or filtered by a simple RC filter as an analog signal. The AIN voltage input range is from 0.6V to 4.5V, and the corresponding duty cycle of the APWM output ranges from 88% to 10%. The duty cycle increases linearly from 10% to 88% while the AIN voltage decreases from 4.5V to 0.6V. This corresponds to the temperature coefficient of the negative temperature coefficient (NTC) resistor and thermal diode. When AIN is floating, the AIN voltage is 5V and the APWM operates at 400kHz with approximately 10% duty cycle. The accuracy of the duty cycle is ±5% across temperature without one time calibration. The accuracy can be improved to ±2% with calibration. The accuracy of the internal current source IAIN is 3% across temperature.

The isolated analog to PWM signal feature can also support other analog signal sensing, such as the high voltage dc bus voltage, etc. The internal current source IAIN should be taken into account when designing the potential divider if sensing a high voltage.

GUID-05F7CC11-4269-4F03-97B0-EE0BDAAEA95C-low.gifFigure 7-7 Isolated Analog to PWM Signal