Press Release Summary:
Offered in 16-Lead, 3 mmÂ² QFN package, LTC4557 dual SIM (subscriber identity module)/Smart card power supply and level translator provides 1.8 and 3 V SIM power and digital signal level shifting. Unit withstands more than 10 kV ESD on all SIM contact pins and has 0.75 mm profile. It contains internal level translators and LDO regulator. Voltage is selected by baseband controller via one pin per channel, enabling device to deliver up to 50 mA load current.
Original Press Release:
Dual SIM/Smart Card Power Supply & Interface Meets ISO7816, ETSI & EMV Standards
MILPITAS, CA - April 12, 2004 - Linear Technology announces the LTC4557, a dual SIM/Smart card power supply and level translator, which provides both 1.8V and 3V SIM power and digital signal level shifting from a 3 x 3mm QFN package. It provides power and level shifting for 2.5G/3G wireless applications which are required to interface with either a 1.8V or 3V subscriber identity module (SIM) or Smart Card. The LTC4557 can withstand >10kV ESD on all of the SIM contact pins and meets all ETSI, EMV and ISO7816 SIM/Smart card approval requirements. Its tiny 16 lead QFN package has only a 0.75mm profile, making it ideal for space-constrained applications.
The LTC4557 contains an LDO regulator to supply SIM power at either 1.8V or 3V from a 3V to 6V input. The SIM/Smart card voltage is selected by the baseband controller via a single pin (each channel), enabling the device to deliver up to 50mA of load current. Internal level translators allow controllers operating with supply voltages from 1.2V to 4.4V to interface with 1.8V or 3V SIM cards. Finally, a very low operating current of 100uA (<1uA in shut down) ensures optimal battery life. The combination of a very small solution footprint and low supply current make it ideal for battery-powered wireless applications.
LTC4557EUD is available from stock in a 16-Lead QFN package, 1,000-piece pricing starts at $2.50 each.
Summary of Features: LTC4557
Power Management & Signal Level Translators for Two SIM Cards or Smart Cards
Independent 1.8V/3V VCC Control for Each Card
Automatic Level Translation
ISO7816, ETSI & EMV Compliant
Built-In Fault Protection Circuitry
Automatic Activation/Deactivation Sequencing Circuitry
Quiescent Current: 100uA, ISD, 1uA
>10kV ESD on SIM Card Pins
Available in 16-Lead (3mm x 3mm) QFN Package
Linear Technology Corporation was founded in 1981 as a manufacturer of high performance linear integrated circuits. Linear Technology products include operational, instrumentation and audio amplifiers; voltage regulators,power management devices, DC-DC converters and voltage references; comparators; monolithic filters; communications interface circuits; one-chip data acquisition sub-systems; pulse-width modulators and sample-and-hold devices; and high frequencydevices. Applications for Linear Technology's high performance circuits include wireless and broadband telecommunications infrastructure, cellular telephones, networking products and satellite systems, notebook and desk top computers, computer peripherals, video/multimedia, industrial and medical instrumentation, automotive electronics, factory automation, process control, military and space systems, and high-end consumer products including digital cameras, MP3 players and other electronic products.
Note: LT, AND LTC are registered trademarks of Linear Technology Corp.