LTC4555
SIM Power Supply
and Level Translator
Features n n n n n n n Description 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
20ВµA Operating Current
Logic-Controlled Shutdown (ISD < 1ВµA)
Available in a Low Profile, 16-Pin (3mm Г— 3mm)
QFN Package The LTCВ®4555 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 20ВµA operating current …