NXP Semiconductors QN9021/EY

Overview

QN9021/EY from NXP Semiconductors is an ultra-low-power Bluetooth LE System-on-Chip integrating a 32-bit ARM Cortex-M0 MCU, 128 kB on-chip flash, 64 kB system memory, and a Bluetooth LE v4.2-compliant radio with integrated protocol stack and profiles. It operates from 2.4 V to 3.6 V, delivers −95 dBm RX sensitivity (non-DC-to-DC mode), and supports master/slave dual-mode operation for wearable fitness sensors and smart accessories.

For engineers reviewing the QN9021/EY datasheet, QN9021/EY pinout, QN9021/EY application, or QN9021/EY equivalent, this page provides verified technical context, validated pin functions, confirmed low-power operating modes (2 µA deep sleep), real-world interface capabilities (dual UART/SPI/I²C), and two rigorously cross-referenced alternative SoCs for Bluetooth LE design continuity.

Technical Context

QN9021/EY implements a tightly coupled Bluetooth LE subsystem with integrated link controller, host stack, and qualified profiles (e.g., Heart Rate, Battery Service, HID over GATT), enabling standalone BLE operation without external host processing. Its ARM Cortex-M0 executes user applications directly from 128 kB flash while managing RF timing via dual oscillators: 16/32 MHz HFXO for radio accuracy and 32.768 kHz LFXO for protocol timing.

The SoC integrates a 4-channel 10-bit SAR ADC with battery monitoring, AES-128 coprocessor for secure connections, and power management unit supporting three sleep states - including 2 µA deep sleep with RAM retention - all coordinated by a 32-bit sleep timer and NVIC-driven interrupt wake-up on GPIOs P0_0–P0_7 and P1_0–P1_7 only.

Key Specifications

Pinout & Package

QN9021/EY uses a 5 mm × 5 mm HVQFN32 package (SOT617-13) with 32 terminals and exposed thermal pad grounded to PCB. Pin functions are validated per NXP datasheet Rev. 2.7 (2018), Table 3.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Bluetooth LE SoC applications.

Compared with QN9021/EY, nRF52832-QFAA offers higher MCU performance but requires external LDO and lacks battery monitoring, while DA14585-01FXQ adds BLE v5.0 support and improved power regulation but has lower RX sensitivity - making QN9021/EY optimal for cost-sensitive, long-life coin-cell wearable designs requiring BLE v4.2 compliance and integrated analog sensing.

Availability

QN9021/EY is available at Aetrix Electronics and suitable for wearable electronics, medical sensors, and wireless remote controls requiring stable component supply, long-term lifecycle assurance, and qualified Bluetooth LE functionality.

Supply support for QN9021/EY 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 company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT markets.

QN9021/EY belongs to NXP's QN902x ultra-low-power Bluetooth LE SoC family, designed specifically for battery-constrained wearable and medical devices requiring integrated RF, MCU, memory, and analog peripherals in compact HVQFN packages.

FAQ

What is the maximum TX output power of QN9021/EY?

QN9021/EY supports TX output power from −20 dBm to +4 dBm in 1 dB steps. The +4 dBm maximum is achievable in DC-to-DC mode with proper RF layout and matching network tuning. This output level enables reliable 10–15 m line-of-sight communication in typical wearable use cases while maintaining regulatory compliance under FCC/ETSI limits.

Does QN9021/EY support Bluetooth LE Secure Connections?

Yes, QN9021/EY supports Bluetooth LE Secure Connections using FIPS-compliant ECC key generation and AES-128 encryption handled by its dedicated coprocessor. The QN9021/EY implements the Secure Connections Pairing protocol defined in Bluetooth Core Specification v4.2, enabling strong encryption without burdening the ARM Cortex-M0 core.

How many GPIOs does QN9021/EY provide, and which support wake-up from sleep?

QN9021/EY provides 15 GPIO pins (P0_0–P0_7 and P1_0–P1_7). Only these 15 pins can generate interrupts to wake the device from sleep or deep sleep modes. All other pins lack wake-up capability - a critical constraint for low-power system design that must be accounted for in PCB layout and firmware initialization.

What crystal frequencies are supported by QN9021/EY for RF operation?

QN9021/EY supports 16 MHz and 32 MHz external crystals for its high-frequency oscillator (HFXO), both with ±50 ppm tolerance. These crystals provide the precise reference frequency required for BLE v4.2-compliant RF operation. Internal load capacitance is integrated, eliminating the need for external capacitors in most designs.

Can QN9021/EY operate as a network processor connected to an external host MCU?

Yes, QN9021/EY can operate as a network processor via UART or SPI interface to an external application processor. In this configuration, it handles all BLE radio, link layer, and host stack operations while the host MCU manages application logic - enabling rapid BLE integration into existing non-BLE platforms without modifying core firmware.