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