Overcoming High Frequency Limitations of Current-Mode Control Using a Control Conditioning Approach -- Part II: Implementation and Hardware

TL;DR

This paper presents three innovative control conditioning methods to mitigate interference in high-frequency current-mode control, validated through hardware implementation at multi-MHz switching frequencies.

Contribution

It introduces new control conditioning techniques using slope compensation, low-pass filtering, and comparator-overdrive-delay for interference mitigation in high-frequency power converters.

Findings

All three methods effectively reduce interference effects.

Hardware validation confirms improved stability and transient performance.

Design tradeoffs are thoroughly analyzed and discussed.

Abstract

This article is the second part of a paper series about interference in extremum (i.e., peak or valley) current-mode control, which applies to both fixed and variable switching frequency power converters. Specifically, this part presents three control conditioning methods that mitigate the adverse effect of interference. These methods are new ways to use: (i) slope compensation; (ii) low-pass filtering; and (iii) the phenomenon of comparator-overdrive-delay, for control conditioning. The stability criterion, closed-loop dynamics, and transient performance are derived with mathematical rigor for each method. The design tradeoffs are illustrated, discussed, and compared. The effectiveness of all three methods are demonstrated and validated in hardware using a power converter operating at multi-MHz switching frequencies.