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

Industry's First Synchronous USB Buck Converter with I2C, Short to VBAT and Protection/Host Charge Emulator

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The MAX20037/MAX20038 ICs combine a 3.5A automotive- grade step-down converter, USB host charger adapter emulator, and USB protection switches for automotive USB host applications. The device family also includes a USB load current-sense amplifier and configurable feedback-adjustment circuit, designed to provide automatic USB voltage compensation for voltage drops in captive cables often found in automotive applications. The ICs limit 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.

The ICs allow flexible configuration options for both stand-alone and supervised applications, and can be programmed for desired operation using both external programming resistors and/or internal I2C registers through the I2C bus.

The ICs are optimized for high-frequency operation and include 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 converters feature integrated high-side and low-side MOSFETs, an external SYNC input/output, and can be configured for spread-spectrum operation.

The MAX20037/MAX20038 are available in a small (5mm x 5mm) 28-pin TQFN package (side-wettable available) designed to minimize required components and layout area.

Design Solution: Add Even More USB Ports to Your Car—In Less Space ›

Key Features

  • One-Chip Solution Directly from Car Battery to Portable Device
    • 4.5V to 28V (40V Load Dump) Input Voltage
    • 5V, 3.5A Output Current Capability
    • Device-Attach Detection Output
    • Low-Q Current Skip and Shutdown Modes
  • Low-Noise Features Prevent Interference with AM Band and Portable Devices
    • Fixed-Frequency 275kHz to 2.2MHz Operation
    • Fixed-PWM Option at No Load
    • Spread Spectrum for EMI Reduction
    • SYNC Input/Output for Frequency Parking
  • Optimal USB Power and Communication for Portable Devices
    • User-Programmable Voltage Gain Adjusts Output for Up to 600mΩ Cable Resistance
    • User-Programmable USB Current Limit
    • USB 480Mbps/12Mbps/1.5Mbps Data Switches
    • Integrated iPod®/iPhone®/iPad® and Samsung® Charge-Detection Termination Resistors
    • Supports USB BC1.2 CDP and DCP Modes
    • Supports China YD/T 1591-2009
    • Compatible with USB On-the-Go Specification
  • Robust Design Keeps Vehicle System and Portable Devices Safe in Automotive Environment
    • Short-to-Battery Protection on DC-DC Converter Pins
    • Short-to-VBUS Protection on USB Pins (MAX20037)
    • Short-to-Battery Protection on USB Pins (MAX20038)
    • ± 15kV Air/±8kV Contact ISO 10605*
    • ± 15kV Air/±8kV Contact IEC 61000-4-2*
    • Reduced Inrush Current with Soft-Start
    • Overtemperature Protection
    • -40°C to +125°C Operating Temperature Range


  • Automotive Connectivity/Telematics
  • Automotive Radio and Navigation
  • Dedicated USB Charging Port (DCP)
  • USB Port for Host and Hub Applications

See parametric specs for Step-Down Switching Regulators (404)

Part NumberVIN
Synchronous SwitchingOper. Freq.
MAX20038 4.5285.16.683.5Yes2200
Adjustable Freq.
Current Limit
D+D- Protection
External Sync.
Fixed Freq./PWM
I2C Interface
Output OVP
Output UVP
Reset Output
USB ESD Protection Diodes
USB Host Adapter Emulator
USB Overvoltage Protection Controller
See Data Sheet

See parametric specs for USB Host Adapter Emulator (23)

Part NumberSupported Charging ConfigurationsSupported USB Battery Charging SpecificationCharging ModesCurrent Limit Switch ControlCDP EmulationRemote Wake-Up SupportVBUS Reset Time
Package/PinsOper. Temp.
typSee Notes
Apple 1.0A
Apple 2.1A
Apple 2.4A
China YD/T 1591-2009
Integrated High-Voltage Buck (see Power->Switching Regulators->Step-Down (Buck) Parametric Table)
Samsung Galaxy Tablet 2A
Auto-CDP (Automatic Charging Downstream facing Port)
Auto-DCP (Automatic Dedicated Charging Port)
Default Firmware Update Mode
First-Boot Factory Programming Mode
High-Speed Pass-through
Config Resistor or I2CYesYes0.016
-40�C to +125�C$3.95 @1k

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX20038EVKIT: Evaluation Kit for the MAX20038
Request Reliability Report for: MAX20038 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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

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