EVALUATION KIT AVAILABLE MAX16984 Automotive High-Current Step-Down Converter with USB Protection/Host Charger Adapter Emulator General Description Benefits and Features The MAX16984 combines a 5V automotive-grade step- Integrated DC-DC and USB Host Charge Emulator down converter capable of driving up to 2.5A, a USB host Enables 1-Chip Solution Directly from Car Battery to charger adapter emulator, and USB protection switches Portable Device for automotive USB host applications. The USB protection 4.5V to 28V (42V Load Dump) Operating Voltage switches provide high-ESD, short-circuit protection and 5V, 2.5A Output Current Capability feature integrated host-charger port-detection circuitry Low-Q Current Skip and Shutdown Modes adhering to the USB 2.0 Battery Charging Specifica- Soft-Start Reduces Inrush Current tion BC1.2 battery charging specification and Chinese Low-Noise Features Prevent Interference with AM Telecommunication Industry Standard YD/T 1591-2009. Band and Portable Devices They also include circuitry for iPod/iPhone 1.0A and Fixed-Frequency 220kHz to 2.2MHz Operation iPad 2.1A dedicated charging modes. The HVD+ and Forced-PWM Option at No Load HVD- ESD protection features include protection to 15kV Spread Spectrum for EMI Reduction Air/8kV Contact on the HVD+ and HVD- outputs to the SYNC Input for Frequency Parking IEC 61000-4-2 model and 330, 330pF ESD model. Optimal USB Power and Communication for The high-efficiency step-down DC-DC converter Portable Devices operates from a voltage up to 28V and is protected User-Adjustable Voltage Gain Adjusts Output from load dump transients up to 42V. The device is opti- Between 5V and 6.15V for Cable Compensation mized for high-frequency operation and includes resistor- 3% Accuracy User-Adjustable USB Current Limit programmable frequency selection from 220kHz to 2.2MHz 4 USB 2.0 480Mbps/12Mbps Data Switches to allow optimization of efficiency, noise, and board space Integrated iPod/iPhone/iPad Charge-Detection based on application requirements. The converter has Termination Resistors an internal high-side n-channel switch and uses a low Supports USB BC1.2 Charging Downstream Port forward-drop freewheeling Schottky diode for rectification. (CDP) and Dedicated Charging Port (DCP) Modes There is a small low-side n-channel switch to maintain fixed Supports Chinese Telecommunication Industry frequency under light loads. For lower quiescent current Standard YD/T 1591-2009 operation requirements, the low side n-channel switch can Compatible with USB On-the-Go Specification be disabled to allow skip mode operation under light loads. High-Speed Pass-Through Mode The converter can deliver up to 2.1A of continuous current Robust Design Keeps Vehicle System and at 105C. The MAX16984S has an integrated spread- Portable Devices Safe in Automotive Environment spectrum oscillator to improve EMI performance. Short-to-Battery Protection on DC-DC Converter The MAX16984 also includes a USB load current-sense Short-to-Battery Protection on USB Pins amplifier and configurable feedback adjustment circuit 25kV Air/8kV Contact ISO 10605 designed to provide automatic USB voltage adjustment to 15kV Air/8kV Contact IEC 61000-4-2 compensate for voltage drops in captive cables associat- 15kV Air/8kV Contact (330, 330pF) ed with automotive applications. The MAX16984 limits the Fault-Indication Active-Low, Open-Drain Output USB load current using both a fixed internal peak current Reduced Inrush Current with Soft-Start threshold of the DC-DC converter and a user-configurable Overtemperature Protection external USB load current-sense amplifier threshold. -40C to +125C Operating Temperature Range 28-Pin, 5mm x 5mm, TQFN and Side-Wettable Applications QFND Packages Automotive Radio and Navigation USB Port for Host and Hub Applications Ordering Information and Typical Operating Circuit appear at end of data sheet. Automotive Connectivity Telematics iPod, iPhone, and iPad are registered trademarks of Apple, Inc. Dedicated USB Power Charger 19-6627 Rev 3 4/15MAX16984 Automotive High-Current Step-Down Converter with USB Protection/Host Charger Adapter Emulator Pin Configuration TOP VIEW 21 20 19 18 17 16 15 BST 22 14 GND LX 23 13 HVD+ 12 HVD- LX 24 MAX16984 N.C. SUPSW 25 11 SUPSW 26 10 D- PGND 27 9 D+ EP + 28 8 IN ENBUCK 12 3 45 67 TQFN/QFND Pin Description PIN NAME FUNCTION 1 Active-Low Open-Drain Fault Indicator Output. Connect a 100kI pullup resistor to IN. FAULT Synchronization Input. The device synchronizes to an external signal applied to SYNC. When 2 SYNC connected to GND or unconnected, skip mode is allowed under light loads. See Table 1. When connected to a clock source or IN, forced-PWM (FPWM) mode is enabled. Resistor-Programmable Switching-Frequency Setting Control Input. Connect a resistor from FOSC to 3 FOSC GND to set the switching frequency. 4 CD0 Charger Detection Configuration Bit 0 5 CD1 Charger Detection Configuration Bit 1 6 I.C. Internal Connection. Must be connected to external GND. 7 FBPER Digital Input. Used to select voltage feedback adjustment percentage. Logic Enable Input. Connect to I/O voltage of USB transceiver. IN is also used for clamping during 8 IN overvoltage events on HVD+ or HVD-. Connect a 1FF ceramic capacitor from IN to GND. 9 D+ USB Differential Data D+ Input. Connect D+ to low-voltage USB transceiver D+ pin. 10 D- USB Differential Data D- Input. Connect D- to low-voltage USB transceiver D- pin. 11 N.C. No Connection High-Voltage-Protected USB Differential Data D- Output. Connect HVD- directly to the USB 12 HVD- connector D- pin. Maxim Integrated 15 www.maximintegrated.com FAULT SUP SYNC BIAS FOSC SENSP CD0 SENSN CD1 SENSO I.C. FBCAP FBMAX FBPER