General description
The NVT4556 device is built for interfacing a SIM card with a single low-voltage host-side
interface. The NVT4556 contains an LDO that can deliver two different voltages, 1.8 V or
3 V, from a typical mobile phone battery voltage, and three level translators to convert the
data, 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 total
current draw from the VCC pin is only 100 A maximum. The NVT4556 also uses the
I2C-bus interface to enable normal operation and to select either 1.8 V or 3 V for the SIM
card power supply. The NVT4556 can also disable the LDO functionality while maintaining
the level translator paths so that the user can use a system-controlled regulator to power
the SIM card power supply. The NVT4556 can enable users to provide second and third
SIM card functionality with a low-voltage one host SIM port, at the same time reducing the
number of GPIOs used in the system. The NVT4556 is compliant with all ETSI, IMT-2000
and ISO-7816 SIM/Smart card interface requirements.
The NVT4556 is available in a 12-pin WLCSP package and has three factory
programmed slave address options.

Features and benefits
 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 hardware
enable/disable pin: source through Host GPIO (ICC <100 A)
 RST_HOST/EN pin can be programmed as a reset pin or as a device enable/disable
pin
 Level translation of I/O, RSTn and CLKn between SIM card and host-side interface
with capacitive isolation
 I2C-bus interface for device enable and LDO voltage selection
 Low current shutdown mode < 3 A
 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 halogen
and antimony (Dark Green compliant)
 Available in 12-pin WLCSP package (1.205 mm  1.605 mm  0.412 mm,
0.4 mm pitch)

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