As smartphones become thinner and faster, and AI drives more power-hungry processors and higher battery capacity, power management engineers face an increasingly difficult challenge: deliver more charging power and higher efficiency without consuming valuable space inside the device.
pSemi, a Murata company and leader in advanced power management solutions, unveiled the PE26100, a breakthrough multi-level buck regulator architecture designed for next–generation mobile platforms. Combining high-efficiency power conversion, support for wired and wireless charging standards, and an ultra-low-profile design under 1 mm, this innovation addresses some of the industry’s most pressing power delivery challenges.
More importantly, it represents a fundamental shift in how power conversion can be implemented in mobile electronics.
As shown in Figure 1, a typical smartphone architecture uses a main interface PMIC with some level of charging capability – usually relatively low current. To increase charging speed and reduce charging time, the PE26100 multi-level converter is added as a parallel or auxiliary charger.
Figure 1: Typical smartphone charging systems with PE26100 as the auxiliary charger providing fast charge to complement the main charger.
The Challenge: More Power in Less Space
Modern smartphones have become extraordinarily complex systems. Engineers must fit processors, batteries, antennas, cameras, sensors, memory, RF subsystems, and charging electronics into increasingly compact form factors. Every cubic millimeter matters.
At the same time, user expectations continue to rise. Consumers expect faster battery charging, longer battery life, and higher performance from AI-enabled processors and advanced mobile applications. These trends place significant demands on power delivery systems.
Traditional buck converters have served the industry well for decades. They efficiently step–down voltage from a power source to the lower voltages needed by batteries and processors. However, conventional buck architectures require large inductors with high z-height.
For ultra-thin smartphones and tablets, these larger magnetic components can become a major design constraint.
Why Multi-level Conversion Matters
Multi-level buck conversion addresses this challenge by increasing the number of switching voltage levels available within the converter.
In a traditional buck converter (Figure 2(i)), the switching node alternates between just two levels: input voltage and ground. In contrast, a 3-level converter (Figure 2(ii)), introduces an additional voltage state, while a 4-level converter (Figure 2(iii)), introduces four levels.
This architectural change delivers significant benefits.
By reducing the voltage excursion seen at the switching node, multi-level converters dramatically lower inductor ripple current. Additionally, the inductor sees twice the switching frequency of the FETs. As a result, designers can use smaller, lower-profile inductors while maintaining high power capability.
The architecture also reduces voltage stress on switching MOSFETs. In a 3-level converter, MOSFETs experience only half the input voltage. In a 4-level converter, they experience just one-third.
Lower voltage stress allows the use of lower-voltage MOSFETs with significantly lower on-resistance (RDS(on)), reducing conduction losses, and improving efficiency.
The result is a power converter that delivers high current while reducing component size and improving overall system performance
A Flexible Architecture for Modern Charging Standards
One of the most significant challenges facing smartphone manufacturers today is supporting multiple charging ecosystems.
Devices must accommodate USB Power Delivery (USB-PD), Programmable Power Supply (PPS), and wireless charging standards such as Qi, and numerous regional charging implementations. Input voltages can vary dramatically depending on the charging source.
pSemi’s PE26100 hybrid multi-level architecture was designed specifically to address this challenge.
The converter operates across an exceptionally wide 4.5 V to 18 V input range, enabling compatibility across modern charging technologies. Depending on operating conditions, the architecture intelligently adapts its topology – switching between regulated, multi-level, buck modes and switching-capacitor, charge–pump modes, as follows:
- 4-level buck mode for higher input voltages.
- 3-level buck mode for mid-range voltages.
- Divide-by-2 capacitor-divider mode for low-voltage PPS operation.
- Divide-by-3 capacitor-divider mode for higher-voltage PPS operation.
This creates what can best be described as an intelligent hybrid converter. This adaptability allows a single power conversion platform to support a diverse charging ecosystem while maintaining high efficiency.
For smartphone manufacturers, this can simplify system design and improve charging performance regardless of whether power arrives from a wired USB-PD adapter, a PPS charger, or a wireless charging pad.
Built for Fast Charging and AI Processing
Beyond battery charging, modern mobile systems increasingly require high-current power delivery for advanced AI processing.
As semiconductor technologies continue moving toward smaller process nodes, operating voltages decrease while current requirements rise. Advanced mobile processors often demand substantial electrical current delivered with tight regulation and minimal losses.
The pSemi architecture is designed with these requirements in mind.
Each device can deliver up to 6 A of current while using a low-profile 1–mm inductor. Multiple devices can also be paralleled to support even higher power levels and faster charging applications.
This capability makes the technology well suited for battery charging future generations of AI power–hungry smartphones.
From Research to Real-world Product Innovation
While multi-level conversion concepts have existed in higher-voltage industrial and power applications for years, bringing them into the highly constrained mobile environment required significant innovation.
Challenges such as fly capacitor balancing, control complexity, and switching-state management had to be overcome before a practical mobile solution could emerge.
Drawing on more than a decade of research and intellectual property development, including foundational work originating from MIT patents, pSemi has successfully translated these concepts into a commercial platform optimized for mobile electronics.
The result is what pSemi describes as the industry’s first multi-level converter capable of operating in both 4-level buck mode and high-current capacitor-divider charge pump configurations. In short, pSemi is not simply improving battery charging. It is redefining how power is converted, managed, and delivered in the mobile devices of tomorrow.