SLUSET9E December   2022  – January 2024 UCC21551-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 (Automotive)
    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 Limiting Values
    8. 5.8  Electrical Characteristics
    9. 5.9  Switching Characteristics
    10. 5.10 Insulation Characteristics Curves
    11. 5.11 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Propagation Delay and Pulse Width Distortion
    2. 6.2 Rising and Falling Time
    3. 6.3 Input and Disable Response Time
    4. 6.4 Programmable Dead Time
    5. 6.5 Power-up UVLO Delay to OUTPUT
    6. 6.6 CMTI Testing
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 VDD, VCCI, and Undervoltage Lock Out (UVLO)
      2. 7.3.2 Input and Output Logic Table
      3. 7.3.3 Input Stage
      4. 7.3.4 Output Stage
      5. 7.3.5 Diode Structure in the UCC21551x-Q1
    4. 7.4 Device Functional Modes
      1. 7.4.1 Enable Pin
      2. 7.4.2 Programmable Dead-Time (DT) Pin
        1. 7.4.2.1 Tying the DT Pin to VCC
        2. 7.4.2.2 DT Pin Connected to a Programming Resistor Between DT and GND Pins
  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
        1. 8.2.2.1 Designing INA/INB Input Filter
        2. 8.2.2.2 Select External Bootstrap Diode and its Series Resistor
        3. 8.2.2.3 Gate Driver Output Resistor
        4. 8.2.2.4 Gate to Source Resistor Selection
        5. 8.2.2.5 Estimate Gate Driver Power Loss
        6. 8.2.2.6 Estimating Junction Temperature
        7. 8.2.2.7 Selecting VCCI, VDDA/B Capacitor
          1. 8.2.2.7.1 Selecting a VCCI Capacitor
          2. 8.2.2.7.2 Selecting a VDDA (Bootstrap) Capacitor
          3. 8.2.2.7.3 Select a VDDB Capacitor
        8. 8.2.2.8 Dead Time Setting Guidelines
        9. 8.2.2.9 Application Circuits with Output Stage Negative Bias
      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 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Certifications
    4. 11.4 Receiving Notification of Documentation Updates
    5. 11.5 Support Resources
    6. 11.6 Trademarks
    7. 11.7 Electrostatic Discharge Caution
    8. 11.8 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.3 Input Stage

The input pins (INA, INB, and EN) of the UCC21551x-Q1 are based on a TTL and CMOS compatible input-threshold logic that is totally isolated from the VDD supply voltage. The input pins are easy to drive with logic-level control signals (such as those from 3.3-V micro-controllers), since the UCC21551x-Q1 has typical high threshold (VINAH) of 2 V and a typical low threshold of 1 V, which vary little with temperature . A wide hysterisis (VINA_HYS) of 1 V makes for good noise immunity and stable operation. If any of the inputs are ever left open, internal pulldown resistors force the pin low. These resistors are typically 90 kΩ (see Section 7.2). However, it is still recommended to ground an input if it is not being used.

Since the input side of the UCC21551x-Q1 is isolated from the output drivers, this allows the user to choose the most efficient VDD for their chosen gate. The amplitude of any signal applied to INA or INB should never be at a voltage higher than VCCI.