onsemi SPS1M002A

Overview

SPS1M002A from ON Semiconductor is a battery-free UHF RFID sensor tag built around the RF Micron Magnus-S2® Sensor IC, designed for direct moisture sensing on non-metal surfaces via antenna detuning detection. It operates in the FCC UHF band (902–928 MHz), delivers 5-bit sensor codes (0–31), features on-chip RSSI measurement, and complies with EPC Class 1 Gen 2 v2.0.0 and ISO 18000-6C standards.

For engineers reviewing the SPS1M002A datasheet, pinout, applications, or equivalent options, this page provides verified technical context, memory-mapped sensor register access methods, FCC-band read sensitivity (−16 dBm), moisture-induced code shift behavior (±5 codes), and integration guidance for EPC Gen 2 reader firmware handling of self-tuning Chameleon engine outputs.

Technical Context

The SPS1M002A implements passive RF energy harvesting to power the Magnus-S2 IC, eliminating batteries while enabling operation solely from UHF reader RF fields. Its Chameleon® engine continuously adapts input impedance by selecting among 32 discrete capacitance levels, digitized as a 5-bit Sensor Code stored at Reserved Bank address B0h–BFh.

Sensor response is derived from moisture-induced antenna detuning, which alters reflected power and triggers Chameleon re-tuning; resulting Sensor Code shifts (e.g., −5 codes when damp vs. dry) are frequency-dependent across the 902–928 MHz band and must be compensated in reader software. On-chip RSSI (5-bit, 32-level) is accessed via SELECT command with RSSI threshold control bit and mask-based thresholding.

Key Specifications

Pinout & Package

SPS1M002A is a monolithic UHF RFID sensor tag in non-hermetic flexible label format (Case 888AD), with no discrete pins or terminals. The device integrates an aluminum antenna (0.009 mm thick) and PET tape substrate (0.076 mm thick); electrical interface is exclusively wireless via UHF backscatter communication per EPC Gen 2 protocol.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar passive UHF moisture sensing applications.

Compared with SPS1M002B and Impinj Monza R6-P, the SPS1M002A delivers turnkey FCC-band moisture sensing with zero additional components, fixed antenna geometry, and factory-calibrated Chameleon behavior - reducing time-to-deployment and eliminating RF design risk for non-RF engineers.

Availability

SPS1M002A is available at Aetrix Electronics and suitable for medical wound monitoring, industrial leak detection, and facilities management applications requiring stable component supply, regulatory-compliant UHF operation, and maintenance-free passive sensing.

Supply support for SPS1M002A 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

ON Semiconductor is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The SPS1M002A belongs to ON Semiconductor's Smart Passive Sensor family, co-developed with RF Micron to enable battery-free, standards-compliant environmental sensing for asset health monitoring and predictive maintenance systems.

FAQ

What is the operating frequency range of the SPS1M002A?

The SPS1M002A operates exclusively in the FCC-defined UHF band from 902 MHz to 928 MHz. This frequency range is factory-programmed and cannot be reconfigured; units with "B" suffix (e.g., SPS1M002B) operate in the ETSI band instead. The SPS1M002A must be used with FCC-compliant UHF readers to ensure regulatory adherence and optimal read sensitivity of −16 dBm.

How does the SPS1M002A detect moisture without a battery or external power?

The SPS1M002A harvests RF energy from a compatible UHF reader to power its internal Magnus-S2® Sensor IC. Moisture detection occurs passively: water contact changes the dielectric environment around the integrated antenna, causing measurable detuning. The Chameleon engine responds by adjusting input capacitance, and the resulting 5-bit Sensor Code (0–31) is reported back via backscatter - all without batteries or wired connections. The SPS1M002A relies entirely on reader-provided RF power.

Can the SPS1M002A be used with standard EPC Gen 2 readers?

Yes, the SPS1M002A is fully compliant with EPC Class 1 Gen 2 v2.0.0 and ISO 18000-6C standards. It communicates using standard Gen 2 commands including SELECT, READ, WRITE, and LOCK. Reader firmware must support accessing Reserved Bank registers (e.g., B0h–BFh for Sensor Code, D0h–DFh for RSSI) and interpreting the 5-bit sensor output. No proprietary protocol stack is required to integrate the SPS1M002A into existing Gen 2 infrastructure.

What is the physical form factor and mounting requirement for the SPS1M002A?

The SPS1M002A is supplied as a flexible, adhesive-backed RFID tag measuring 91.5 mm × 26.5 mm (Case 888AD), with an aluminum antenna on PET tape substrate. It must be mounted directly onto non-metallic surfaces - metal substrates will detune the antenna and prevent operation. The moisture-sensitive region is defined by the labeled test area; placement must ensure this zone contacts the target surface for reliable detection. No soldering, connectors, or PCB integration is involved - the SPS1M002A is a complete, ready-to-apply sensor tag.

How is sensor data retrieved from the SPS1M002A and what does it represent?

Sensor data is retrieved by issuing a standard Gen 2 READ command to Reserved Bank address B0h–BFh, returning a 5-bit Sensor Code (0–31). This value reflects real-time antenna detuning caused by moisture: dry conditions average ~18, damp conditions drop ~5 codes, and extremes (0–5 or 27–31) require higher incident RF power. Because the code shifts ±5 across the 902–928 MHz band, reader firmware must log frequency alongside code for accurate wet/dry classification. The SPS1M002A does not output analog voltage or calibrated %RH - interpretation is application-specific and requires baseline calibration.