1. General description

The NXT4557 device is built for interfacing a SIM card with a single low-voltage host side interface.

The NXT4557 has three level translators to convert the data, RST and CLK signals between a

SIM card and a host microcontroller. A high speed level translation capable of supporting class-B,

class-C SIM cards. An active HIGH EN pin enables normal operation of the translator. A HIGH

to LOW transition on pin EN initiates a shutdown sequence on SIM card pins in accordance with

ISO-7816-3.

The NXT4557 is compliant with all ETSI, IMT-2000 and ISO-7816 SIM/Smart card interface

requirements.

2. Features and benefits

• Support SIM cards and eSIM with supply voltages 1.62 V to 3.3 V

• Host micro-controller operating voltage range: 1.08 V to 1.98 V

• Automatic level translation of I/O, RST and CLK between SIM card and host side interface with

capacitance isolation

• Incorporates shutdown feature for the SIM card signals according to ISO-7816-3

• High Vdis(UVLO_AC) switching level, arranging quick shut down when VCC_SIM powers down

• Integrated pull-up resistors; no external resistor required

• Integrated EMI Filters suppresses higher harmonics of digital I/O's

• A HIGH EN signal enables the translation of the signals

• Low current shutdown mode < 1 μA

• Supports clock speed beyond 5 MHz clock

• Pb-free, Restriction of Hazardous Substances (RoHS) compliant and free of halogen and

antimony (Dark Green compliant)

• ESD protection:

• HBM ANSI/ESDA/JEDEC JS-001 exceeds 2 kV

• CDM ANSI/ESDA/JEDEC JS-002 exceeds 1 kV

• IEC61000-4-2 level 4, contact and air discharge on all SIM card-side pins are 8kV and

15 kV

• Available in 10-pin XQFN package

3. Applications

• NXT4557 can be used with a range of SIM card attached devices including:

• Mobile and personal phones

• Wireless modems

• SIM card terminals