Features and Benefits

  • Buck/Boost Charge Pump Generates 1.8V, 3V or 5V
  • Input Voltage Range: 2.6V to 6V
  • Controller VCC Range: 1.425V to 4.4V
  • >10kV ESD on All SIM Contact Pins
  • Short-Circuit and Overtemperature Protected
  • Meets all ETSI and IMT-2000 SIM Interface Requirements
  • 1.8V to 5V Signal Level Translators
  • Very Low Operating Current: 32µA
  • Very Low Shutdown Current: <1µA
  • Soft-Start Limits Inrush Current at Turn-On
  • 1MHz Switching Frequency
  • Available in 16-Pin Narrow SSOP Package

Product Details

The LTC1555L-1.8 provides power conversion and level shifting needed for low voltage GSM and WCDMA cellular telephones to interface with either 1.8V, 3V or 5V subscriber identity modules (SIMs). The part contains a patented buck/boost charge pump DC/DC converter* that delivers a regulated VCC supply voltage to the SIM card. Input voltage may range from 2.6V to 6V allowing direct connection to the battery. The output voltage may be programmed to 1.8V, 3V, 5V or direct connection to the VIN pin.


Internal level translators allow controllers operating with supplies as low as 1.425V to interface with 1.8V, 3V and 5V SIMs. A soft-start feature limits inrush current at turn-on, mitigating start-up problems that may result when the input is supplied by another low-power DC/DC converter. Battery life is maximized by 32µA operating current, and 1µA shutdown current. Board area is minimized by the miniature 16-pin narrow SSOP packages and the need for only three small external capacitors.


  • SIM Interface in GSM Cellular Telephones
  • WCDMA SIM Interface
  • Smart Card Readers

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.

Support & Discussions

LTC1555L-1.8 Discussions

RE: LTC2984 TC CJ Diode Overrange
2 week(s) ago in Temperature Sensors
6 week(s) ago in Precision ADCs

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The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

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