Paper Info
Title
10.7 A 25MHz 4-phase SAW hysteretic DC-DC converter with 1-cycle APC achieving 190ns t<inf>settle</inf> to 4A load transient and above 80% efficiency in 96.7% of the power range
Abstract
Switching power converters with fast load transients are crucial for application processors (APs) to facilitate system-level power adaptability with high current slew rate. While current-mode hysteretic control has been popularly employed in switching converters for simple structure, robust operation and fast transient response [1], it still does not suffice for the unprecedented 1A/ns current slew rate required by modern APs [2]. Meanwhile, current slew rate can be improved by extending single-phase to multiphase operation. However, when a converter powers light load, power loss caused by added phases adversely affects the efficiency. Active phase count (APC) was thus proposed to manage the number of active phases judiciously to load by sensing average inductor current [3,4]. However, the inherent sensing delay drastically slows down the phase adding/dropping actions and degrades load transient response. On the other hand, phase current imbalance among phase sub-converters could cause hot spots, jeopardizing system reliability. Upgrading from conventional current-mode hysteretic control, we propose a simple synchronized adaptive window (SAW) hysteretic control which automatically adjusts the hysteretic window to speed up the transient response. Inherent clock synchronization makes it a natural fit to multiphase operation, where APC can be accomplished within one switching cycle through an internal current sensing mechanism in the control.
Year
DOI
Venue
2017
10.1109/ISSCC.2017.7870325
2017 IEEE International Solid-State Circuits Conference (ISSCC)
Keywords
Field
DocType
4-phase SAW hysteretic DC-DC converter,1-cycle APC,load transient,switching power converters,system-level power adaptability,current slew rate,current-mode hysteretic control,robust operation,fast transient response,power loss,active phase count,average inductor current sensing,inherent sensing delay,phase adding-dropping action,load transient response,phase current imbalance,phase sub-converters,system reliability,synchronized adaptive window hysteretic control,SAW hysteretic control,hysteretic window,inherent clock synchronization,switching cycle,internal current sensing mechanism,frequency 25 MHz,time 190 ns,current 4 A
Transient response,Synchronization,Computer science,Control theory,Inductor,Hysteresis,Electronic engineering,Converters,Clock synchronization,Slew rate,Electrical engineering,Speedup
Conference
ISBN
Citations 
PageRank 
978-1-5090-3759-9
0
0.34
References 
Authors
4
4
Name
Order
Citations
PageRank
Bumkil Lee101.35
Minkyu Song2214.61
Ashis Maity3174.46
D. Brian Ma412.85