4.5V to 60V Input, Ultra-Small, High-Efficiency, Iso-Buck DC-DC Converter

Reduce External Components, Solution Size and Cost for DC-DC Isolation

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The Rainier series of isolated DC-DC products enable small, efficient solutions with a lower BOM. The MAX17687 is a high-voltage, high-efficiency, iso-buck DC-DC converter designed to provide isolated power up to 10W. The device operates over a wide 4.5V to 60V input voltage range and uses primary-side feedback to regulate the output voltage. It delivers primary peak current up to 3.2A and regulates primary output voltage to within ±1.2%.

The device features peak-current-mode control with pulse-width modulation (PWM) scheme. The low-resistance, on-chip MOSFETs ensure high efficiency at full load and simplify the layout.

A programmable soft-start feature allows users to reduce input inrush current. The device also incorporates an output enable/undervoltage lockout pin (EN/UVLO) that allows the user to turn on the part at the desired input-voltage level. An open-drain active-low RESET pin provides a delayed power-good signal to the system upon achieving successful regulation of the primary output voltage.

The device operates from -40°C to +125°C and is available in a compact 20-pin (4mm x 4mm) TQFN package. Simulation models are available.

MAX17687: Typical Application Circuit MAX17687: Typical Application Circuit Enlarge+

Key Features

  • Eliminates External Components and Reduces Total Cost
    • Synchronous Primary Operation for High Efficiency and Reduced Cost
    • All-Ceramic Capacitors, Ultra-Compact Layout
  • Supports Numerous Isolated DC-DC Applications
    • Wide 4.5V to 60V Input Voltage Range
    • Delivers up to 3.2A Peak Current
    • 100kHz to 500kHz Adjustable Frequency with External Synchronization
    • Available in a 20-Pin, 4mm x 4mm TQFN Package
  • Reduces Power Dissipation
    • Peak Efficiency > 90%
    • Shutdown Current = 2.8μA (typ)
  • Operates Reliably in Adverse Industrial Environments
    • Hiccup-Mode Current Limit, Sink Current Limit, and Auto-Retry Startup
    • Programmable EN/UVLO Threshold
    • Adjustable Soft-Start
    • -40°C to +125°C Ambient Operating Temperature Range
    • -40°C to +150°C Junction Temperature Range


  • Communication Hub in Smart Meters
  • Floating Power Supply Generation
  • Industrial Process Control
  • Isolated Power Supplies in Medical Equipment
Part NumberVIN
VOUT1 Tolerance
Output Adjust. MethodSwitch TypeSynchronous SwitchingPower Good SignalICC
DC-DC OutputsAlternate TopologyOper. Freq.
Design ToolsPackage/PinsOper. Temp.
minmaxmaxSee Notes
MAX17687 4.5601ResistorInternalYesYes1.161
-40 to +125$2.50 @1k
See All Step-Down/Up Switching Regulators (30)
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.

MAX17687EVKITA: Evaluation Kit for the MAX17687 for Isolated +12V Output Configuration

Quality and Environmental Data

Request Reliability Report for: MAX17687 
Lead-Free Package Tin (Sn) Whisker Reports

Tools & Models

  • EE-Sim: Design & Simulate MAX17687
  • Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

    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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    Related Resources

    Type ID Title
    Evaluation Board10198MAX17687EVKITA Evaluation Kit for the MAX17687 for Isolated +12V Output Configuration