Microchip Technology U3280M-NFBG3Y

Overview

U3280M-NFBG3Y from Microchip Technology (formerly Atmel) is a contactless transponder interface IC designed for passive and battery-assisted RFID sensor and ID systems. It provides contactless power harvesting (100–150 kHz LC field), bi-directional data communication up to 10 kbaud, integrated 32 × 16-bit EEPROM, two-wire serial interface, and automatic dual-source power management switching between magnetic field and VBatt. It enables wireless position sensing, access control tags, and telemetry nodes where microcontroller wake-up and non-volatile configuration storage are required.

For engineers reviewing the U3280M-NFBG3Y datasheet, U3280M-NFBG3Y pinout, U3280M-NFBG3Y application, or U3280M-NFBG3Y equivalent, this page delivers verified functional role, validated pin functions, confirmed RF timing parameters (tBFS = 1 ms, TFGAP1 ≤ 50 µs), real-world EEPROM endurance (500k cycles), and precise coil interface requirements (f_COIL = 100–150 kHz, Q = 30–80).

Technical Context

The U3280M-NFBG3Y implements a fully integrated transponder front-end with analog rectifier, field clock extractor (FC), gap/field detector (NGAP), and programmable damping modulator (MOD). Its power management autonomously switches between VBatt (2.0–6.5 V) and coil-derived VDDC (2.6–3.2 V) based on VFDon (2.3–2.9 V) and VFDoff (0.8 V) thresholds, with tBFS = 1 ms delay to suppress noise-induced toggling.

It supports two-wire serial communication (SCL/SDA) at ≤100 kHz with bi-phase or Manchester encoding via dedicated control bytes (e.g., 1100x111b), and embeds a 512-bit EEPROM organized as 32 × 16-bit rows with auto-increment read, 9–12 ms write cycle, and 10-year data retention - all powered exclusively from VDD.

Key Specifications

Pinout & Package

U3280M-NFBG3Y is housed in a Pb-free 16-pin SSO (Shrink Small Outline) package with 0.65 mm pitch, optimized for compact RFID tag PCB layouts and automated tape-and-reel assembly (as indicated by "-NFBG3Y" suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SLI52120T and TDA8035, the U3280M-NFBG3Y uniquely combines 125 kHz field harvesting, battery backup, on-chip EEPROM, and programmable modulation - making it irreplaceable for cost-sensitive, maintenance-free LF telemetry and access control where infrastructure operates below 150 kHz.

Availability

U3280M-NFBG3Y is available at Aetrix Electronics and suitable for wireless sensor nodes, contactless access control tags, and industrial telemetry systems requiring stable component supply across long production lifecycles.

Supply support for U3280M-NFBG3Y 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

Microchip Technology acquired Atmel in 2016 and maintains full support for legacy Atmel RFID products including the U3280M series.

The U3280M product line was engineered specifically for low-frequency (100–150 kHz) contactless identification and sensor tagging, targeting applications where passive operation, battery backup, and embedded EEPROM are essential.

FAQ

What is the primary function of the U3280M-NFBG3Y in an RFID system?

The U3280M-NFBG3Y serves as a transponder interface IC that enables microcontrollers to operate wirelessly via magnetic field energy harvesting (100–150 kHz), manage dual power sources (coil field and battery), store configuration in on-chip EEPROM, and communicate bidirectionally using NGAP wake-up and MOD-based backscatter. Its core role is bridging passive RF fields to active digital subsystems in U3280M-NFBG3Y-based tags and sensors.

How does the U3280M-NFBG3Y handle power source switching between field and battery?

The U3280M-NFBG3Y implements automatic power management that switches from VBatt to coil-derived VDDC when the rectified coil voltage exceeds VFDon (2.3–2.9 V), and reverts to VBatt when voltage drops below VFDoff (0.8 V). This transition includes tBFS = 1000 µs delay to prevent noise-induced toggling, and the NRST pin can assert reset to the MCU during field-to-battery switchover to ensure deterministic recovery in U3280M-NFBG3Y designs.

Can the U3280M-NFBG3Y operate without a battery, and what are the limitations?

Yes, the U3280M-NFBG3Y supports fully passive operation using only magnetic field energy - provided the coil antenna delivers sufficient voltage (>VFDon) to power the IC and attached MCU. Limitations include reduced operating range (dependent on coupling factor and Q-factor), inability to retain state during field absence, and no background sensing capability. Battery backup (VBatt) in U3280M-NFBG3Y restores continuous monitoring and EEPROM persistence when the field is inactive.

What EEPROM features does the U3280M-NFBG3Y provide, and how is it accessed?

The U3280M-NFBG3Y integrates a 32 × 16-bit (512-bit) EEPROM with 500,000 erase/write cycles and 10-year data retention at 25°C. It is accessed exclusively via the two-wire SCL/SDA interface using control bytes that specify row address, byte order (high/low first), and read/write direction. Special control bytes (e.g., 1100x111b) also enable bi-phase modulation - all operations occur under VDD supply in U3280M-NFBG3Y implementations.

What are the critical timing parameters for reliable U3280M-NFBG3Y communication with a base station?

Reliable U3280M-NFBG3Y communication depends on TFGAP1 ≤ 50 µs (field-on detection), TFGAP0 ≤ 50 µs (gap detection), and tBFS = 1000 µs (battery-to-field switch delay) to avoid false wake-ups. The serial interface requires SCL ≤ 100 kHz with tLOW ≥ 4.7 µs and tHIGH ≥ 4.0 µs. These values ensure robust synchronization with base-station carrier and accurate decoding of Manchester/bi-phase encoded commands in U3280M-NFBG3Y systems.