Smart card peripherals require lots of small electronic functions to meet their internal needs. The LTC1955 Dual Smart Card Interface from Linear Technology provides all of the needed supervisory, level-shifting, and power-control functions. It can also interface with two Security Access Module (SAM) cards or one SAM card and one smart card. The IC, in a 5×5 mm QFN package, contains a buck-boost charge pump so it can generate 1.8, 3, or 5V from an input voltage of 2.7 to 5.5V, allowing its use with single-cell Li-ion or multicell NiMH/Alkaline batteries. Level translation is automatic for optimum data transfer, while the supervisory functions assess smart card faults and instigate shutdown when it detects an electrical fault.
The LTC1955 Dual Smart Card Interface provides critical smart card reader functions in a tiny, low-power IC.
The LTC1955 interfaces with your µC via a simple four-wire serial interface. If needed, you can daisy-chain the control/status serial port for applications that require multiple cards. Operating current is 250 µA and shutdown current is under 1 µA for this US$2.45 (1000 piece) IC, which meets all ISO7816-3 EMI specifications.
Smart card peripherals require lots of small electronic functions to meet their internal needs. The LTC1955 Dual Smart Card Interface from Linear Technology provides all of the needed supervisory, level-shifting, and power-control functions. It can also interface with two Security Access Module (SAM) cards or one SAM card and one smart card. The IC, in a 5×5 mm QFN package, contains a buck-boost charge pump so it can generate 1.8, 3, or 5V from an input voltage of 2.7 to 5.5V, allowing its use with single-cell Li-ion or multicell NiMH/Alkaline batteries. Level translation is automatic for optimum data transfer, while the supervisory functions assess smart card faults and instigate shutdown when it detects an electrical fault.
