Ultra-Tiny Nanopower, 1A Ideal Diodes with Ultra-Low-Voltage Drop

Current Switch/Ideal Diode Saves Space and Offers 10x Lower Voltage Drop Than Schottkys

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The MAX40203 is an ideal diode current-switch with forward voltage drop that is approximately an order of magnitude smaller than that of Schottky diodes. When forward biased and enabled, the MAX40203 conducts with 90mV of voltage drop while carrying currents as high as 1A. During a short-circuit or a fast power-up, the device limits its output current to 2A. The MAX40203 thermally protects itself and any downstream circuitry from overcurrent conditions.

This ideal diode operates from a supply voltage of 1.2V to 5.5V. The supply current is relatively constant with load current, and is typically 300nA. When disabled (EN = low), the ideal diode blocks voltages up to 6V in either direction, makes it suitable for use in most low-voltage, portable electronic devices.

The MAX40203 is available in a tiny, 0.77mm x 0.77mm, 4-bump wafer-level package (WLP), with a 0.35mm bump pitch and a 5-pin SOT-23 package. It is specified over the automotive -40°C to +125°C temperature range.

Also see: nanoPower Technology ›

MAX40203: Simplified Block Diagram MAX40203: Simplified Block Diagram Enlarge+

Key Features

  • Lower Voltage Drop in Portable Applications
    • 14mV Forward Drop at 1mA (WLP)
    • 16mV Forward Drop at 100mA (WLP)
    • 43mV Forward Drop at 500mA (WLP)
    • 90mV Forward Drop at 1A (WLP)
  • Longer Battery Life
    • Low Leakage When Reverse-Biased from VDD:
      • 10nA (Typ)
    • Low Supply Quiescent Current
      • 300nA (Typ), 500nA (Max)
  • Smaller Footprint Than Larger Schottky Diodes
    • Tiny 0.77mm x 0.77mm 4-Bump WLP
    • SOT23-5 Package
  • Wide Supply Voltage Range: 1.2V to 5.5V
  • Thermally Self-Protecting
  • -40°C to +125°C Operating Temperature Range


  • Battery Backup Systems
  • Cellular Phones
  • Electronic Toys
  • Notebook and Tablet Computers
  • Portable Medical Devices
  • Powerline Fault Recorders
  • USB-Powered Peripherals
Part NumberOutput FormatCMVR
Bi-Dir. Curr. SenseVSENSE_FS
ReferenceOper. Temp.
minmaxminmaxtyprecomm.See Notes
MAX40203 Voltage1. to +85
$0.27 @1k
See All Current Sense Amplifiers (51)
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.

MAX40203EVKIT: Evaluation Kit for the MAX40203

Quality and Environmental Data

Request Reliability Report for: MAX40203 
Lead-Free Package Tin (Sn) Whisker Reports

Additional Resources

nanoPower Technology

Tools & Models

  • MAX40203 Orcad Library
  • CAD Symbols and Footprints

  • MAX40203ANS+T
  • MAX40203AUK+T
  • 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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