High-Bandwidth Envelope Tracking in Boost Converters Using State-Feedback-Based Mixed-Signal Hysteresis Current Control

The presence of right-half-plane (RHP) zero and sampling delay in a digital current-mode controlled (DCMC) boost converter restricts the achievable closed-loop bandwidth (BW) to ω<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> = ω<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rhp</inf>/3, making it impractical for high BW and efficient envelope tracking applications. State-feedback-based mixed-signal hysteresis current control (SFMSHCC) enhances the converter’s dynamic performance and damping at higher BW without exhibiting any overshoot/undershoot. The resistive characteristics of fixed-gain power amplifiers offer the potential to further improve performance by incorporating reference feed-forward. Steady-state frequency regulation is realized through real-time band adaptation. The performance improvements, supported by analytical predictions, are validated using simulation and experimental results.