NXP Semiconductors NVT4555UKZ

Overview

NVT4555UKZ from NXP Semiconductors is a SIM card interface level translator with integrated dual-voltage LDO, designed to bridge host microcontrollers (1.1 V–3.6 V) and ISO/IEC 7816-compliant SIM cards. It delivers regulated VSIM outputs of either 1.8 V or 2.95 V from 2.5 V–5.25 V battery input, provides automatic bidirectional I/O, RSTn, and CLKn level translation, and supports clock frequencies up to 5 MHz in mobile phone and wireless modem applications.

For engineers reviewing the NVT4555UKZ datasheet, NVT4555UKZ pinout, NVT4555UKZ application, or NVT4555UKZ equivalent, key selection considerations include its WLCSP12 package footprint, ±8 kV ESD protection on SIM-side pins, shutdown current <1 μA, UVLO threshold at 0.7–1.0 V on VCC, and compliance with ETSI, IMT-2000, and ISO-7816-3 timing and shutdown sequencing requirements.

Technical Context

The NVT4555UKZ integrates a PMOS-based low-dropout regulator with thermal and overcurrent protection, enabling stable 1.8 V/2.95 V SIM supply under load up to 50 mA and dropout voltage ≤150 mV at 50 mA. Its level-shifting architecture uses automatic direction detection-no external control signal required-and includes internal pull-up/pull-down networks, EMI filtering (200 Ω series resistance on RST_SIM/CLK_SIM), and 45 pF I/O capacitance for robust signal integrity.

It implements ISO-7816-3–compliant shutdown sequencing: when EN goes LOW, RST_SIM powers down first, followed by CLK_SIM, IO_SIM, and VSIM within microseconds, with internal pull-downs ensuring safe SIM deactivation during hot-swap events. The device operates across –40 °C to +85 °C and features undervoltage lockout hysteresis of 100 mV to prevent erratic behavior during brownout conditions.

Key Specifications

Pinout & Package

Package: WLCSP12 (SOT1390-12), 1.19 mm × 1.62 mm × 0.56 mm (nominal), 0.4 mm pitch, wafer-level chip-scale package optimized for space-constrained mobile designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SIM card interface applications.

Compared with MAX16085ETA+ and TPS65136RGTR, the NVT4555UKZ uniquely combines dual-voltage LDO regulation, automatic bidirectional level translation, and ISO-7816-3–compliant shutdown in one WLCSP12 package-reducing total solution size by >40% and eliminating design risk from external signal routing.

Availability

NVT4555UKZ is available at Aetrix Electronics and suitable for mobile handsets, wireless modems, and SIM card terminals requiring stable component supply, full lifecycle support, and traceable sourcing for high-volume production.

Supply support for NVT4555UKZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and mobile applications, with core expertise in interface, power management, and smart-card technologies.

The NVT4555UKZ belongs to NXP's SIM interface and smart-card power management product line, engineered specifically to simplify dual-voltage SIM integration in space- and power-constrained portable electronics while meeting stringent telecom regulatory standards.

FAQ

What voltage options does the NVT4555UKZ support for SIM card supply?

The NVT4555UKZ supports two regulated SIM supply voltages: 1.8 V (when CTRL pin is driven LOW) and 2.95 V (when CTRL pin is driven HIGH). These outputs are generated from a 2.5 V–5.25 V VBAT input and are fully compliant with ISO/IEC 7816-3 voltage classes. The NVT4555UKZ maintains tight regulation (±0.1 V typical) across load currents up to 50 mA and temperature range –40 °C to +85 °C.

How does the NVT4555UKZ handle SIM card hot-swap events?

The NVT4555UKZ implements ISO-7816-3–compliant hot-swap handling via its EN pin: when EN is pulled LOW, it initiates a deterministic shutdown sequence-first deactivating RST_SIM, then CLK_SIM, IO_SIM, and finally VSIM-all within microseconds. Internal pull-down resistors ensure SIM-side pins go LOW safely, preventing data corruption. This behavior is intrinsic to the NVT4555UKZ and requires no external circuitry or firmware intervention.

What is the maximum clock frequency supported by the NVT4555UKZ for SIM communication?

The NVT4555UKZ supports a maximum clock frequency of 5 MHz on the CLK_SIM output, as specified in its dynamic characteristics table. Propagation delay remains within 8–25 ns depending on VCC and VSIM configuration, ensuring full timing compliance with ISO/IEC 7816-3 for both T=0 and T=1 protocols. The NVT4555UKZ does not support frequencies beyond 5 MHz, and exceeding this limit may violate setup/hold timing margins.

Does the NVT4555UKZ require external passive components for stable operation?

Yes, the NVT4555UKZ requires three external capacitors: a 1.0 μF ceramic capacitor on VBAT, a 0.1 μF ceramic capacitor on VCC, and a 4.7 μF ceramic capacitor on VSIM. These are mandatory for LDO stability, PSRR performance, and transient response. X5R/X7R MLCCs are recommended due to low ESR (<500 mΩ for input caps, <1.0 Ω for VSIM cap) and minimal capacitance drift over voltage and temperature-critical for reliable NVT4555UKZ operation.

What ESD protection level does the NVT4555UKZ provide on SIM-side pins?

The NVT4555UKZ provides ±8 kV ESD protection per IEC 61000-4-2 (contact discharge) on all SIM-side pins-IO_SIM, RST_SIM, and CLK_SIM-meeting Level 4 industrial robustness requirements. Other pins (e.g., EN, CTRL, VCC) are rated at ±2 kV HBM and ±2 kV IEC 61000-4-2. This differential ESD hardening ensures reliable SIM interface operation in handheld and portable equipment where user-handling-induced discharges are common, and is an integral feature of the NVT4555UKZ design.