Nexperia Residential EV Wall Boxes

System Architecture Overview

A typical wall box integrates multiple smart subsystems. It begins with a single-phase or three-phase AC input, followed by fuse protection and EMI filtering to ensure safety and compliance.
Sensors, power management, and signal processing regulate and monitor the charging process. A communication interface and MCU manage control logic, while the HMI and LCD provide user interaction and feedback. Protection circuitry safeguards against overvoltage, overcurrent, and other fault conditions.

Block diagram

Efficient Power Conversion with Flyback Architecture

In smart or feature-rich wall boxes, a flyback converter is a preferred design for the auxiliary power supply, providing isolated low-voltage DC power (e.g., 5V, 12V, or 24V) from the AC mains. This powers the MCU, communication modules, sensors, and HMI.
To maximize efficiency, a MOSFET on the secondary side replaces the traditional diode, significantly reducing conduction losses. Integrating the Multi-Mode Flyback Controller NEX8080x on the primary side and the Adaptive Synchronous Rectifier Controller NEX8180x on the secondary side optimizes switching performance.

Isolation and Signal Integrity

Isolation between voltage domains is achieved using transformer drivers and digital isolators.
The NXF605 or NXF6501 transformer drivers ensure efficient power transfer across the isolation barrier while maintaining safety and signal integrity. Digital isolators manage communication between the high-voltage and low-voltage domains.
 
Explore Nexperia’s product portfolio and design recommendations for EV wall box applications in our webinar: “Boost System Efficiency in Energy Management and Storage.”

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