SLUP413A May   2024  – April 2026 TPS53689T

 

  1.   1
  2.   Abstract
  3. 1 Introduction
  4. 2 Converter Transient Response
  5. 3 Magnetics
  6. 4 TLVR Topology Operating Principles
    1. 4.1 Steady-State Operation
    2. 4.2 Load Transient Step-Up
    3. 4.3 Load Transient Step-Down
    4. 4.4 LC Inductor Selection
    5. 4.5 Steady-State Ripple
  7. 5 Power Loss and Efficiency
  8. 6 Phase Multiplication
  9. 7 PCB Layout
  10. 8 TLVR-Optimized Components
  11. 9 Example Side-by-Side Design
  12. 10Summary
  13. 11Additional Resources

6 Phase Multiplication

As power requirements continue to increase rapidly, it is often necessary to design very high phase-count (more than 16 phase) designs using controller devices that do not have enough independent pulse-width modulation (PWM) outputs to control each phase individually. It has become common to phase double or phase multiply – that is, to drive more than one power stage with the same controller PWM output. This practice enables easy scalability of multiphase designs – buck converter or TLVR – to high power levels.

Figure 27 shows the connections of the LC loops in an interleaved, phase-doubled TLVR design. Such a design could, for example, extend a 12-phase design to 24 or 36 phases, without requiring a different controller device. For all phases (doubled or not) in the same LC loop, the secondary sides are connected in series. The current feedback lines from each phase (not shown in Figure 27) can be resistor-averaged for power stages with voltage-source-output current sensing, or simply added for power stages with current-source-output current sensing. It is possible to connect temperature sense outputs from each power stage (also not shown in Figure 27) together, regardless of which LC loop the power stages are in.

Interleaved phase-doubling TLVR topology. Figure 27 Interleaved phase-doubling TLVR topology.