NXP Semiconductors NX2A4WPZ

Overview

NX2A4WPZ from NXP Semiconductors is an A4WP-compliant high-frequency wireless power receiver front end IC for 6.78 MHz resonant charging systems. It integrates a 20 V-tolerant active rectifier, 5 V/1.2 A DC-DC buck regulator, dual LDOs (1.8 V/3.3 V @ 100 mA), 12-bit 7-channel ADC, four GPIOs, and Fast-Mode I²C interface - enabling full system control in compact portable devices.

For engineers reviewing the NX2A4WPZ datasheet, NX2A4WPZ pinout, NX2A4WPZ application, or NX2A4WPZ equivalent, key selection criteria include A4WP compliance, integrated rectifier protection (OVP/OCP/OTP), programmable rectifier modes (active/half-active/passive), and support for external NTC temperature monitoring with interrupt-driven host MCU coordination.

Technical Context

The NX2A4WPZ implements a digital controller that reads real-time analog inputs (V_RECT, I_RECT, V_DCOUT, I_DCOUT, chip junction temp, NTC voltage) via its 12-bit SAR ADC and autonomously manages rectifier mode, DC-DC output, and GPIO states using interrupt-driven firmware logic. Its I²C slave address is fixed at 0x40 (7-bit).

Protection architecture includes dual independent over-voltage mechanisms: automatic AC-clamp (shorting AC1/AC2 to GND above 18 V) and over-power detection (GPIO1/GPIO2 activation above 18 V), both triggering open-drain INT assertion and flag registration in STATU/STATL registers for host MCU response.

Key Specifications

Pinout & Package

Package: Wafer-level chip-scale package (WLCSP42) with 42 bumps, 3.56 × 3.41 mm body, 0.5 mm pitch, back-side coating included.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar wireless power receiver applications.

Compared with MP-A21 and BQ51222, the NX2A4WPZ uniquely combines A4WP protocol alignment, dual thermal sensing (on-die + external NTC), four configurable GPIOs for CTUNE control, and interrupt-driven host coordination - making it the only option for thermally constrained, high-integrity A4WP receiver designs.

Availability

NX2A4WPZ is available at Aetrix Electronics and suitable for smartphones, wearables, true wireless stereo earbuds, and portable medical sensors requiring stable component supply and A4WP-compliant wireless charging capability.

Supply support for NX2A4WPZ 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 specializing in secure connectivity solutions for automotive, industrial, and consumer applications, with core expertise in RF, power management, and embedded security.

The NX2A4WPZ belongs to NXP's A4WP wireless power receiver product line, designed specifically to accelerate development of compact, standards-compliant 6.78 MHz wireless charging receivers for portable electronics with integrated thermal and electrical protection.

FAQ

What wireless standard does the NX2A4WPZ support?

The NX2A4WPZ is explicitly designed for A4WP (Alliance for Wireless Power) compliance and operates at the 6.78 MHz ISM band. It implements the full A4WP receiver protocol stack including automatic rectifier mode selection, resonant tuning via GPIO-controlled CTUNE, and coordinated communication with A4WP transmitters. It is not compatible with Qi or PMA standards.

How does the NX2A4WPZ handle over-voltage protection on its antenna inputs?

The NX2A4WPZ provides dual over-voltage protection: automatic AC-clamp shorts AC1 and AC2 to ground when LDRECT exceeds 18 V, and over-power detection activates GPIO1/GPIO2 to reduce energy transfer. Both mechanisms assert the open-drain INT pin and set corresponding flags (OVP/OVD) in STATU register, enabling host MCU intervention without external components.

Can the NX2A4WPZ monitor external temperature sensors?

Yes, the NX2A4WPZ supports one external NTC thermistor via the TEMP pin, referenced to its internal 3.3 V VREF33 supply. It compares the NTC voltage against thresholds corresponding to 10 °C and 60 °C, setting NTCL or NTCU flags and asserting INT when limits are exceeded - enabling host MCU-triggered thermal mitigation in medical or wearable applications.

What are the key power supply configurations supported by the NX2A4WPZ?

The NX2A4WPZ supports three supply domains: (1) LDRECT (rectifier output, up to 20 V) powers LDOs initially; (2) LDDC (5 V DC-DC output) becomes secondary LDO input via LDODCPL control; (3) DCIN serves as backup supply. LDOs auto-enable above VUVLO (~3.8 V) and include discharge paths for controlled shutdown.

Does the NX2A4WPZ include built-in temperature monitoring beyond external NTC support?

Yes, the NX2A4WPZ integrates two on-die p-n junction temperature sensors - OTP1 monitors the DC-DC converter and OTP2 monitors the active rectifier. Each triggers dedicated flags (OTP1/OTP2) and interrupts at 125 °C, with recovery flags (OTR1/OTR2) asserted at ~100 °C. These are fully independent of the external NTC path and require no calibration.