SLUSDX3C november   2020  – august 2023 UCC25800-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
  8. 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 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Power Management
      2. 8.3.2 Oscillator
      3. 8.3.3 External Synchronization
      4. 8.3.4 Dead-Time
        1. 8.3.4.1 Adaptive Dead-time
        2. 8.3.4.2 Maximum Programmable Dead-time
      5. 8.3.5 Protections
        1. 8.3.5.1 Overcurrent Protection
          1. 8.3.5.1.1 OCP Threshold Setting
          2. 8.3.5.1.2 Output Power Capability
        2. 8.3.5.2 Input Overvoltage Protection (OVP)
        3. 8.3.5.3 Over-Temperature Protection (TSD)
        4. 8.3.5.4 Pin-Fault Protections
        5. 8.3.5.5 VREG Pin Protection
      6. 8.3.6 DIS/FLT Pin operation
        1. 8.3.6.1 FAULT Codes
    4. 8.4 Device Functional Modes
      1. 8.4.1 UVLO Mode
      2. 8.4.2 Soft-start Mode
      3. 8.4.3 Normal Operation Mode
      4. 8.4.4 Disabled Mode
      5. 8.4.5 Fault Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 LLC Converter Operation Principle
      2. 9.2.2 Design Requirements
      3. 9.2.3 Detailed Design Procedure
      4. 9.2.4 Application Curves
    3. 9.3 What to Do and What Not to Do
  11. 10Power Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  13. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.5.4 Pin-Fault Protections

Table 8-2 below shows the UCC25800-Q1 transformer driver response to open and short circuits on the pins. For example, the SYNC function operates on the rising edge of the SYNC pin. Hence if the pin is open or short the only impact is the loss of synchronization functionality. The transformer driver continues to operate as normal at the switching frequency programmed by the RT pin. .

Table 8-2 Pin Open and Short Response
PIN OPEN SHORT TO GND
SYNC Normal operation with the programmed frequency Normal operation with the programmed frequency
DIS/FLT Normal operation OFF
VREG OFF (VREG open protection) OFF
OC/DT Fault (OC/DT open protection) Fault (OC/DT short protection)
RT fSW = 1.2 MHz Fault (RT short protection)
GND Unknown -
SW VOUT = 0 Fault (OCP) / ✖
VCC OFF OFF
Table 8-3 Pin-to-Pin Shorts Responses
123 SYNC DIS/FLT VREG OC/DT VCC SW GND RT
SYNC –
DIS/FLT – / OFF –
VREG No SYNC Always enabled –
OC/DT – / OC/DT Fault Indeterminate Fault (OC/DT_OPEN) -
VCC ✖ ✖ ✖ ✖ –
SW ✖ OCP Fault / ✖ ✖ Fault / ✖ Fault / ✖ -
GND No SYNC OFF OFF Fault (OC/DT_SHORT) IC not biased Fault (OCP)/ ✖ -
RT Indeterminate Indeterminate Fault (RT_OPEN) Indeterminate ✖ ✖ Fault (RT_SHORT) –
  1. ✖ indicates that the transformer driver will or may become damaged.
  2. – indicates no effect on the circuit operation.
  3. Indeterminate indicates the IC behavior is unpredictable