Analog Devices Inc./Maxim Integrated

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.ApplicationsSIM Interface in 3G Cellular TelephonesSmart Card Readers

The LTC4556 provides all necessary power control, level translation and supervisory functions for a smart card or S.A.M. card interface. The part contains a low noise charge pump plus LDO for generating VCC power, as well as all necessary level shifting circuitry.The card voltage can be set to either 1.8V, 3V or 5V. The LTC4556 includes a card detection channel with automatic debounce circuitry. To reduce wiring costs, the LTC4556 interfaces to a microcontroller via a simple 4‑wire serial interface. Multiple devices may be connected in daisy-chain fashion so that the number of wires to the card socket board is independent of the number of sockets. Status data is returned over the same interface.Extensive security features ensure proper deactivation sequencing in the event of a supply fault or a smart card electrical fault. The smart card pins can withstand greater than 10kV ESD in-situ with no additional components. The LTC4556 is available in a small, low profile (0.75mm), 4mm × 4mm QFN package.ApplicationsHandheld Payment TerminalsPay TelephonesATM MachinesPOS TerminalsComputer KeyboardsMultiple S.A.M. Sockets

The LTC485 is a low power differential bus/line transceiver designed for multipoint data transmission standard RS485 applications with extended common mode range (12V to –7V). It also meets the requirements of RS422.The CMOS design offers significant power savings over its bipolar counterpart without sacrificing ruggedness against overload or ESD damage.The driver and receiver feature three-state outputs, with the driver outputs maintaining high impedance over the entire common mode range. Excessive power dissipation caused by bus contention or faults is prevented by a thermal shutdown circuit which forces the driver outputs into a high impedance state.The receiver has a fail-safe feature which guarantees a high output state when the inputs are left open.The LTC485 is fully specified over the commercial and extended industrial temperature range.ApplicationsLow Power RS485/RS422 TransceiverLevel Translator

The LTC488 and LTC489 are low power differential bus/line receivers designed for multipoint data transmission standard RS485 applications with extended common mode range (12V to –7V). They also meet the requirements of RS422.The CMOS design offers significant power savings over its bipolar counterpart without sacrificing ruggedness against overload or ESD damage.The receiver features three-state outputs, with the receiver output maintaining high impedance over the entire common mode range.The receiver has a fail-safe feature which guarantees a high output state when the inputs are left open.Both AC and DC specifications are guaranteed 4.75V to 5.25V supply voltage range.ApplicationsLow Power RS485/RS422 ReceiversLevel Translator

The LTC488 and LTC489 are low power differential bus/line receivers designed for multipoint data transmission standard RS485 applications with extended common mode range (12V to –7V). They also meet the requirements of RS422.The CMOS design offers significant power savings over its bipolar counterpart without sacrificing ruggedness against overload or ESD damage.The receiver features three-state outputs, with the receiver output maintaining high impedance over the entire common mode range.The receiver has a fail-safe feature which guarantees a high output state when the inputs are left open.Both AC and DC specifications are guaranteed 4.75V to 5.25V supply voltage range.ApplicationsLow Power RS485/RS422 ReceiversLevel Translator