LTC4557 - Dual SIM/Smart Card Power Supply and Interface

The LTC®4557 provides power conversion and signal level translation needed for 2.5G and 3G cellular telephones to interface with 1.8V or 3V subscriber identity modules (SIMs). The part meets all requirements for 1.8V and 3V SIMs. The part contains LDO regulators to power 1.8V or 3V SIM cards from a 2.7V to 5.5V input. The output voltages can be set using the two voltage selection pins and up to 50mA of load current can be supplied.

Internal level translators allow controllers operating with supplies as low as 1.2V to interface with 1.8V or 3V smart cards. Battery life is maximized by a low operating current of less than 100µA and a shutdown current of less than 1µA. Board area is minimized by the low profile 3mm x 3mm x 0.75mm leadless QFN package.

*U.S. Patent No. 6,356,140

  • Power Management and Signal Level Translators for Two SIM Cards or Smart Cards
  • Independent 1.8V/3V VCC Control for Both Cards
  • Automatic Level Translation
  • ISO7816, ETSI and EMV Compatible
  • Dynamic Pull-Ups Deliver Fast Signal Rise Times*
  • Built-In Fault Protection Circuitry
  • Automatic Activation/Deactivation Sequencing Circuitry
  • Low Operating/Shutdown Current
  • >10kV ESD on SIM Card Pins
  • Compatible with EMV Fault Tolerance Requirements
  • Available in 16-Lead (3mm ´ 3mm) QFN Package
Typical Application
LTC4557 Typical Application
LTC4557 Typical Application
  • GSM and 3G Cellular Phones
  • Wireless P.O.S. Terminals
  • Multiple SAM Card Interface
LTC4557 Package Drawing
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC4557EUD#PBF3x3 QFN-16E$2.14$1.50
LTC4557EUD#TRPBF3x3 QFN-16E$1.56
Demo Boards
Part NumberDescriptionPrice
DC709ALTC4557EUD | Dual SIM Card Power Supply and Interface$100.00
Reliability Data
CAD Symbol
Related Products
LTC4557 - Dual SIM/Smart Card Power Supply and Interface
R527 Reliability Data
LTC4557 Footprints and Symbols