The Lenovo 45W USB PD fast charger features a single USB-C port, offering multiple voltage levels and supporting up to 45W PD fast charging. 

Designed for tablets, laptops, smartphones, and other devices, this charger combines robust performance with advanced safety features. In this teardown analysis, we explore its internal architecture, key components like the CX7545ES and CX7539 chips, and why it’s a top choice for tech enthusiasts.

The input casing of the charger displays the following parameters:

Model: MC-458

Input: 100-240V~50/60Hz 2A

Output: 5V3A / 9V3A / 12V3A

Manufacturer: Jiangsu Chenyang Electronics Co., Ltd.

Certifications: 3C Certification, Level VI Energy Efficiency Certification

Supported Charging Protocols

Using the ChargerLAB POWER-Z KT002 to analyze the USB-C port output protocols, the charger supports PD3.0, PPS, QC4, and DCP charging protocols.

Additionally, its PDO report confirms the following voltage levels:

Fixed Voltage Levels: 5V3A / 9V3A / 12V3A

PPS Voltage Range: 5-11V/4.5A

Internal Structure & Component Analysis

The Lenovo 45W USB PD charger adopts a wide-range switch-mode power supply design. Below is an in-depth teardown analysis of its internal components.

The front side of the PCB consists of the following key components:

Fuse / NTC thermistor / Common-mode inductor / VCC capacitor / Toroidal inductor / Two high-voltage filter capacitors / Transformer / Y capacitor

Solid-state electrolytic capacitor / NMOS transistor / Protocol chip

PCBA Back Side

Primary Controller Chip: CX7545ES

Synchronous Rectifier Chip: CX7539

Rectifier bridge and other supporting components

CX7545ES PWM Primary Controller

The CX7545ES is a high-performance AC/DC power controller designed for power applications up to 45W. It operates as a current-mode PWM control chip with a built-in high-voltage MOSFET, ensuring stable and efficient power conversion.

Key Features of CX7545ES:

Fixed switching frequency with internal precision control.

Adaptive frequency regulation in light-load conditions to reduce power loss.

Green mode operation to enhance energy efficiency.

Low startup and operating current to minimize standby power consumption.

Built-in slope compensation circuit for improved system stability at high duty cycles.

Leading-edge blanking (LEB) to eliminate reverse recovery current effects.

Frequency jittering technology to optimize EMI performance.

Jump frequency setting above 22kHz, preventing audible noise.

Comprehensive protection mechanisms:

Overcurrent Protection (OCP)

Overvoltage Protection (OVP)

Undervoltage Lockout (UVLO)

Overtemperature Protection (OTP)

Soft drive structure to enhance EMI performance

CX7539 Synchronous Rectifier Controller

The CX7539 is a high-performance secondary-side synchronous rectifier controller, designed to replace Schottky diodes, significantly reducing power loss and improving efficiency.

Key Features of CX7539:

Supports switching frequencies up to 150kHz.

Compatible with CCM, QR, and DCM operating modes.

Ultra-low conduction loss, reducing heat dissipation.

Enhances power efficiency and thermal management.

Conclusion: High Performance and Broad Compatibility

The Lenovo 45W USB PD fast charger employs a wide-range switch-mode power design featuring the CX7545ES primary controller and CX7539 synchronous rectifier, ensuring high efficiency and excellent compatibility. The USB-C port supports PD4.0 and PPS protocols with the following voltage levels:

Fixed Voltage Outputs: 5V3A / 9V3A / 12V3A

Adjustable PPS Voltage Ranges: 3.3-5.9V/4A and 5-11V/4.5A

Although this charger is primarily designed for Lenovo tablets, it is also compatible with most smartphones, laptops, TWS earbuds, and other digital devices that support fast charging.

This high-efficiency fast charger delivers a powerful and reliable charging experience, making it an excellent choice for modern power users.