LTC4555 - SIM Power Supply and Level Translator

The LTC4555 provides power conversion and signal level shifting needed for low voltage 2.5G and 3G cellular telephones to interface with 1.8V or 3V subscriber identity modules (SIMs). The part meets all type approval requirements for 1.8V and 3V SIMs and smart cards. The part contains an LDO linear regulator to supply SIM power at either 1.8V or 3V from a 3V to 6V input. The output voltage is selected with a single pin 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 20µA operating current and <1µA shutdown current. Board area is minimized by the 3mm x 3mm leadless QFN package.

  • SIM Power Supply: 1.8V/3V at 50mA
  • Input Voltage Range: 3V to 6V
  • Controller Voltage Range: 1.2V to 4.4V
  • 14kV ESD on all SIM Contact Pins
  • Meets all ETSI, IMT-2000 and ISO7816 SIM/Smart Card Interface Requirements
  • Level Translators to 1.8V or 3V
  • 20µA Operating Current
  • Logic Controlled Shutdown (ISD < 1µA)
  • Available in 0.75mm Profile, 3mm x 3mm QFN Package
Typical Application
LTC4555 Typical Application
  • SIM Interface in 3G Cellular Telephones
  • Smart Card Readers
LTC4555 Package Drawing
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC4555EUD#PBF3x3 QFN-16E$1.71$1.20
LTC4555EUD#TRPBF3x3 QFN-16E$1.26
Reliability Data
CAD Symbol
Related Products
LTC4555 - SIM Power Supply and Level Translator
R421 Reliability Data
LTC4555 Footprints and Symbols