LTC4555

· 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
· 20mA Operating Current
· Logic Controlled Shutdown (ISD < 1mA)
· Available in 0.8mm Tall, 3mm ´ 3mm QFN Package

·SIM Interface in 3G Cellular Telephones
· Smart Card Readers

V_BAT, DV_CC, V_CC to GND ............................... 0.3V to 6.5V
Digital Inputs to GND .................................... 0.3V to 6.5V
CLK, RST, I/O to GND .......................... 0.3V to V_CC + 0.3V
V_CC Short-Circuit Duration ....................................... Infinite
Operating Temperature Range (Note 2) .. 40°C to 85°C
Storage Temperature Range ................. 65°C to 125°C
Lead Temperature (Soldering, 10 sec)..................... 300°C

The LTC^®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 of LTC4555 allow controllers operating with supplies as low as 1.2V to interface with 1.8V or 3V smart cards. Battery life is maximized by 20mA operating current and <1mA shutdown current. Board area is minimized by the 3mm ´ 3mm leadless QFN package.