STMicroelectronics SN250Q

Overview

SN250Q from STMicroelectronics is a single-chip ZigBee®/IEEE 802.15.4 SoC integrating a 2.4GHz transceiver, 16-bit XAP2b microprocessor, 128KB Flash, 5KB SRAM, and hardware-accelerated AES encryption. It delivers −97 dBm RX sensitivity (1% PER), +3 dBm nominal TX power, and deep-sleep current of 1.0 µA - enabling battery-powered wireless sensor nodes for home automation and asset tracking.

For engineers reviewing the SN250Q datasheet, SN250Q pinout, SN250Q application, or SN250Q equivalent, this page provides verified technical context on its integrated MAC, low-power sleep modes, dual serial controllers (I²C/SPI/UART), sigma-delta ADC, and non-intrusive SIF debug interface - all critical for ZigBee stack integration and RF coexistence design.

Technical Context

The SN250Q implements a low-IF super-heterodyne receiver with differential RF paths, integrated VCO/loop filter, and hardware-based IEEE 802.15.4 MAC that handles ACK generation, CCA, automatic backoff, and packet filtering. Its digital baseband includes coherent demodulation and on-chip radio calibration logic.

It features two DMA-capable serial controllers (SC1 and SC2), each supporting I²C master, SPI master/slave, and UART modes; a 12-bit sigma-delta ADC with four analog inputs; and dual 16-bit general-purpose timers with capture/compare/PWM capability - all synchronized to a shared 24MHz crystal or internal RC oscillator.

Key Specifications

Pinout & Package

SN250Q is housed in a 7 mm × 7 mm, 48-pin QFN package with exposed thermal pad (Pin 49). The package supports reflow soldering and requires controlled impedance RF routing per ST's reference design guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ZigBee/802.15.4 SoC applications.

Compared with EM357-RTR and CC2530F256, the SN250Q uniquely combines XAP2b deterministic timing, hardware AES, PTI trace, and ultra-low deep-sleep current - making it optimal for long-life, security-critical, and debug-intensive ZigBee sensor designs.

Availability

SN250Q is available at Aetrix Electronics and suitable for building automation, home security systems, and industrial asset tracking requiring stable component supply across extended product lifecycles.

Supply support for SN250Q 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, specializing in microcontrollers, power management, and wireless connectivity solutions for industrial and consumer markets.

The SN250Q belongs to ST's ZigBee System-on-Chip product line, designed specifically to deliver certified, low-power, single-chip wireless sensor and control solutions compliant with IEEE 802.15.4 and ZigBee PRO stacks.

FAQ

Does SN250Q require an external 24 MHz crystal?

Yes - the SN250Q relies on a 24 MHz crystal connected to OSCA/OSCB pins for primary system clock generation and PLL reference. The internal RC oscillator serves only for low-power idle states and cannot replace the crystal for full-rate operation or RF synthesis accuracy.

How is the Packet Trace Interface (PTI) used in development?

The PTI uses dedicated PTI_EN and PTI_DATA pins to stream real-time MAC-layer packet metadata (frame type, timestamp, RSSI, status) to ST's InSight Development Environment. This enables protocol-level debugging without modifying application code or inserting software breakpoints.

What GPIO pins support analog ADC input?

ADC0–ADC3 are mapped to GPIO4, GPIO5, GPIO6, and GPIO7 respectively. Each must be enabled via specific bits in the GPIO_CFG register (e.g., GPIO4 enabled by GPIO_CFG[12] and GPIO_CFG[8]) before analog sampling. VREF_OUT is available on GPIO8 when configured accordingly.

Can SN250Q operate without the optional 32.768 kHz crystal?

Yes - the 32.768 kHz crystal on OSC32A/OSCB is optional. When omitted, the internal RC oscillator provides sleep timer clocking, though with ±50% accuracy versus ±20 ppm with the crystal. Deep-sleep current increases to 1.5 µA only if the XO is physically installed and enabled.