SLUAAB9A March   2021  – December 2021 UCC25800-Q1

 

  1.   Trademarks
  2. 1 Introduction
  3. 2 Open-Loop LLC Converter Operation Principle
  4. 3 Primary-side and Secondary-side Resonant Configurations
  5. 4 Rectification Methods
    1. 4.1 One Resonant Capacitor, Voltage Doubler
    2. 4.2 Two Resonant Capacitors, Voltage Doubler
    3. 4.3 One Resonant Capacitor, Full-wave Rectifier
  6. 5  LLC Transformer Design Steps
    1. 5.1 Transformer Turns Ratio Selection
    2. 5.2 Transformer Volt-second Rating Calculation
    3. 5.3 Transformer Construction
    4. 5.4 Transformer Winding Selection
    5. 5.5 Transformer Inductance
      1. 5.5.1 Leakage inductance
      2. 5.5.2 Magnetizing inductance
    6. 5.6 Transformer Selections
  7. 6 Negative Voltage Generation
    1. 6.1 Using a Zener Diode
    2. 6.2 Using a Shunt Regulator
    3. 6.3 Using a Shunt Regulator and Linear Regulator
  8. 7 Multiple-output Design
    1. 7.1 One UCC25800-Q1 Drives Each Output
    2. 7.2 Transformer With Multiple Secondary-side Windings
    3. 7.3 Multiple Transformers
  9. 8 EMI Performance
    1. 8.1 EMI Performance With Standalone Converter
    2. 8.2 EMI performance with an inverter power stage
  10. 9 Common-Mode Transient Immunity (CMTI)
  11. 10Summary
  12. 11Revision History

7 Multiple-output Design

In electrical vehicle designs, different gate driver architectures are used based on the cost, the reliability, and the safety requirement. Normally, we see three different architectures, as shown in Figure 7-1. In the pictures, GDx block represents the gate driver circuit. GD1, GD3, and GD5 are the three high-side gate drivers that is biased from its individual ground. GD2, GD4, and GD6 are the three low side gate drivers that share the same common ground. The transformer block represents the isolated bias supply.

(a) Centralized Architecture (1 transformer)
(b) Semi-distributed Architecture (4 transformers)
(c) Distributed Architecture (6 transformers)

Figure 7-1 Gate Driver Bias Supply Architectures

The centralized architecture uses a single bias supply to bias all the gate driver circuits. The semi-distributed architecture biases all the three low side drivers using one bias supply, and uses three bias supplies to bias each of the high side switches. The distributed architecture biases each gate driver with an individual bias supply.

For UCC25800-Q1, multiple outputs can be easily achieved through different circuit configurations.