Automotive High-Current Step-Down Converter with USB Protection/Host Charger Adapter Emulator

The MAX16984A combines a 5V automotive-grade step-down converter capable of driving up to 3.0A, a USB host charger adapter emulator, and 1 GHz USB protection switches for automotive USB host applications. The USB protection switches provide high-ESD, short-circuit protection and feature integrated host-charger port-detection circuitry adhering to the USB 2.0 Battery Charging Specification BC1.2 battery charging specification and Chinese Telecommunication Industry Standard YD/T 1591-2009. They also include circuitry for iPod® /iPhone® 1.0A and iPad® 2.4A dedicated charging modes. The HVD+ and HVD- ESD protection features include protection to ±15kV Air/±8kV Contact on the HVD+ and HVD- outputs to the IEC 61000-4-2 model and 330Ω, 330pF ESD model.

The high-efficiency step-down DC-DC converter operates from a voltage up to 28V and is protected from load dump transients up to 40V. The device is optimized for high-frequency operation and includes I2C or resistor-programmable frequency selection from 310kHz to 2.2MHz to allow optimization of efficiency, noise, and board space based on application requirements. The fully synchronous DC-DC converter integrates high-side and low-side MOSFETs with an external SYNC input/output, and can be configured for spread-spectrum operation. Skip mode is available in light/no-load conditions to minimize quiescent current. The converter can deliver up to 3A of continuous current at +105°C. The MAX16984A has an integrated spread-spectrum oscillator to improve EMI performance

The MAX16984A also includes a USB load current-sense amplifier and configurable feedback adjustment circuit designed to provide automatic USB voltage adjustment to compensate for voltage drops in captive cables associated with automotive applications. The MAX16984A limits the USB load current using both a fixed internal peak current threshold of the DC-DC converter and a user-configurable external USB load current-sense amplifier threshold.

Applications

* Automotive Connectivity

* Automotive Radio and Navigation

* Dedicated USB Power Charger

* Telematics

* USB Port for Host and Hub Applications

* Integrated DC-DC and USB Host Charge Emulator Enables 1-Chip Solution Directly from Car Battery to Portable Device

* 4.5V to 28V (42V Load Dump) Operating Voltage* 5V, 3.0A Output Current Capability* Low-Q Current Skip and Shutdown Modes * Soft-Start Reduces Inrush Current * Low-Noise Features Prevent Interference with AM Band and Portable Devices

* Fixed-Frequency 220kHz to 2.2MHz Operation * Forced-PWM Option at No Load* Spread Spectrum for EMI Reduction * SYNC Input for Frequency Parking * Optimal USB Power and Communication for Portable Devices

* User-Adjustable Voltage Gain Adjusts Output Between 5V and 7V for Cable Compensation* ±5% Accuracy User-Adjustable USB Current Limit* 4Ω USB 2.0 1GHz Data Switches* Integrated Samsung/iPod/iPhone/iPad Charge Detection Termination Resistors* Supports USB BC1.2 Charging Downstream Port(CDP) and Dedicated Charging Port (DCP) Modes* Supports Chinese Telecommunication Industry Standard YD/T 1591-2009* Compatible with USB On-the-Go Specification* High-Speed Pass-Through Mode * Robust Design Keeps Vehicle System and Portable Devices Safe in Automotive Environment

* Short-to-Battery Protection on DC-DC Converter

* Short-to-Battery Protection on USB Pins* ±15kV Air/±8kV Contact ISO 10605* ±15kV Air/±8kV Contact IEC 61000-4-2* ±15kV Air/±8kV Contact (330Ω, 330pF)* Advanced Diagnostics Through I2C Bus* Reduced Inrush Current with Soft-Start* Over-temperature Protection* -40°C to +125°C Operating Temperature Range * 32-Pin, 5mm x 5mm, TQFN Package