The NVT4556 device is built for interfacing a SIM card with a single low-voltage host-sideinterface. The NVT4556 contains an LDO that can deliver two different voltages, 1.8 V or3 V, from a typical mobile phone battery voltage, and three level translators to convert thedata, RSTn and CLKn signals between a SIM card and a host microcontroller.

The NVT4556 VCC pin provides power to the host side I/Os and doubles as an enable pin,for this reason it can be connected to a GPIO that matches the host side voltage. The totalcurrent draw from the VCC pin is only 100 μA maximum. The NVT4556 also uses theI2C-bus interface to enable normal operation and to select either 1.8 V or 3 V for the SIMcard power supply. The NVT4556 can also disable the LDO functionality while maintainingthe level translator paths so that the user can use a system-controlled regulator to powerthe SIM card power supply. The NVT4556 can enable users to provide second and thirdSIM card functionality with a low-voltage one host SIM port, at the same time reducing thenumber of GPIOs used in the system. The NVT4556 is compliant with all ETSI, IMT-2000and ISO-7816 SIM/Smart card interface requirements.

The NVT4556 is available in a 12-pin WLCSP package and has three factoryprogrammed slave address options.

• Support SIM card supply voltages 1.8 V and 3 V
• Input voltage range to LDO: 2.5 V to 5.25 V
• Host microcontroller operating voltage range: 1.55 V to 3.6 V
• VCC input pin provides both host supply voltage and logic level hardwareenable/disable pin: source through Host GPIO (ICC<100 μA)
• RST_HOST/EN pin can be programmed as a reset pin or as a device enable/disablepin
• Level translation of I/O, RSTn and CLKn between SIM card and host-side interfacewith capacitive isolation
• I2C-bus interface for device enable and LDO voltage selection
• Low current shutdown mode < 3 μA
• Supports clock speed beyond 5 MHz clock
• Supports CLK stop mode
• Integrated EMI filters
• Incorporates ISO-7816-3 shutdown feature for the SIM card signals
• ETSI, IMT2000 and ISO-7816 compliant
• ±8 kV IEC61000-4-2 ESD protected on all SIM card contact pins
• Pb-free, Restriction of Hazardous Substances (RoHS) compliant and free of halogenand antimony (Dark Green compliant)
• Available in 12-pin WLCSP package (1.205 mm × 1.605 mm × 0.412 mm,0.4 mm pitch)

• NVT4556 can be used with a range of SIM card attached devices including:
  • Mobile and personal phones
  • Wireless modems
  • SIM card terminals