Automotive High-Current Step-Down Converter with USB-C Dedicated Charging Port

The MAX20459 combines a 3A high-efficiency, automoive-grade, step-down converter, a USB Type-C DFP controller, and automatic BC1.2 DCP, Apple®, and Samsung® dedicated charger-detection circuitry. The device also includes a USB load current-sense amplifier and configurable feedback-adjustment circuit designed to provide automatic USB voltage compensation. The device limits the USB load current using both a fixed internal peak-current threshold and a user-configurable external current- sense USB load threshold.

The MAX20459 is optimized for high-frequency operation and includes programmable frequency selection from 310kHz to 2.2MHz, allowing optimization of efficiency, noise, and board space based on application requirements. The fully synchronous DC-DC converter integrates high-side and low-side MOSFETs along with an external SYNC input/output, and can be configured for spread-spectrum operation. Additionally, thermal foldback is implemented to avoid excessive heating of the module while charging at high ambient temperature.

The MAX20459 allows flexible configuration and advanced diagnostic options for both standalone and supervised applications. The device can operate as a true one- chip solution that offers advanced fault autorecovery and can be programmed using external programming resistors and/or internal I2C registers.

The MAX20459 is available in a small 5mm x 5mm 32-pin TQFN package and is designed to minimize required external components and layout area.

Applications

* Dedicated Charging Modules * Dedicated USB Charging Port (DCP) * Host and Hub Module Dedicated Charging Ports

* One-Chip Type-C Solution Directly from Car Battery to Portable Device

* USB Type-C-Compliant DFP Controller * Integrated iPhone®/iPad®, Samsung® and BC1.2 DCP Charger Detection * 4.5V to 28V Input (40V Load Dump), Synchronous Buck Converter * 5V to 7V, 3A Output Capability * Standalone Device or I2C Configuration Options and Fault Autorecovery

* Optimal USB Charging and Communication for Portable Devices

* User-Programmable Voltage Gain Adjusts Output for up to 474mΩ Cable Resistance * User-Programmable USB Current Limit

* Low-Noise Features Prevent Interference with AM Band and Portable Devices

* Fixed-Frequency 310kHz to 2.2MHz Operation * Fixed-PWM Option at No Load * Spread Spectrum for EMI Reduction * SYNC Input/Output for Frequency Parking

* Robust Design Keeps Vehicle System and Portable Device Safe in an Automotive Environment

* Short-to-Battery Protection on VBUS, HVD± Pins * ±15kV Air/±8kV Contact ISO 10605 (330pF, 330Ω)* * ±15kV Air/±8kV Contact ISO 10605 (330pF, 2kΩ)* * ±15kV Air/±8kV Contact IEC 61000-4-2 (150pF, 330Ω)* * Overtemperature Protection, Warning, and Intelligent Current Foldback * AEC-Q100 Qualified * -40°C to +125°C Operating Temperature Range