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Microchip Technology U3280M-NFBY
- Part No.:
- U3280M-NFBY
- Manufacturer:
- Microchip Technology
- Category:
- RFID, RF Access, Monitoring ICs
- Package:
- -
- Datasheet:
-
U3280M-NFBY.pdf
- Description:
- IC RFID TRANSP 100-150KHZ 16SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,027
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Product details
Overview
U3280M-NFBY from Microchip Technology (formerly Atmel) is a contactless transponder interface IC for RFID-based ID, telemetry, and wireless sensor systems. It provides dual-mode power supply (RF field or battery), 32 × 16-bit EEPROM, two-wire serial interface, and field clock extraction - enabling microcontroller operation in passive or semi-passive tag designs operating at 100–150 kHz.
For engineers reviewing the U3280M-NFBY datasheet, U3280M-NFBY pinout, U3280M-NFBY application, or U3280M-NFBY equivalent, this page delivers verified technical context, real-world timing behavior, coil interface design constraints, power management switching thresholds, and EEPROM access protocols - all critical for contactless sensor node and access control system integration.
Technical Context
The U3280M-NFBY integrates a rectifier front-end, automatic power management with battery-to-field switching (VFDon = 2.3–2.9 V, tBFS = 1 ms), and a damping modulator controlled via MOD pin for bi-directional RF communication. Its NGAP output provides field/gap detection with 1–50 µs response time, while FC delivers extracted field clock for microcontroller synchronization.
It supports Bi-phase and Manchester modulation via SCL/SDA lines under special control byte commands (e.g., 1100x111b), and features a 512-bit EEPROM organized as 32 × 16-bit rows with auto-increment read, 10 ms erase/write cycle, and 10-year data retention. Serial interface operates up to 100 kHz with defined setup/hold times and acknowledge polling for write completion.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Operating Frequency | 100–150 kHz LC-resonant range - defines antenna coil and capacitor selection (e.g., 125 kHz requires ~737 µH + 2.2 nF) |
| Data Rate (R/O) | Up to 10 kbaud - limits maximum bit duration to 100 µs; compatible with standard low-frequency RFID readers |
| EEPROM Size | 32 × 16-bit (512-bit) - stores identifiers, configuration bits, and sensor calibration data with 500,000 write cycles |
| Power Supply Modes | Automatic VBatt ↔ field switching - enables hybrid passive/active operation; VDDC limited to 2.6–3.2 V during field supply |
| Serial Interface | Two-wire (SCL/SDA), 100 kHz max - supports EEPROM read/write, modulator control, and power management commands |
| Modulation Support | Bi-phase & Manchester via dedicated control bytes - eliminates need for external encoding logic in microcontroller firmware |
| Field Detection Delay | tFGAP1 = 1–50 µs (field-on), tFGAP0 = 10–50 µs (gap) - ensures reliable wake-up and demodulation timing for microcontroller ISR |
Pinout & Package
U3280M-NFBY is housed in a 16-pin SSOP (SSO16) package with exposed pad, Pb-free, tube packaging. Pin 1 is VBatt; pins 15–16 are Coil 1/Coil 2 for LC resonant circuit connection; pins 7 and 11–14 are NC; NRST is bidirectional reset I/O.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VBatt (Pin 1) | Battery supply input | DC source (2.0–6.5 V); powers device when field absent; enables active mode in weak-field environments |
| VDD (Pin 2) | Microcontroller & EEPROM supply output | Buffered output (0.5–10 µF cap required); switches between VBatt and rectified field voltage; must remain ≥1.8 V for EEPROM operation |
| SCL / SDA (Pins 3, 5) | Two-wire serial interface | Master-controlled bus (SCL ≤100 kHz); used for EEPROM access, modulator control, and power management commands |
| NRST (Pin 4) | Bidirectional reset line | Input: triggers internal reset; Output: asserts reset on microcontroller during field→battery switch to ensure clean state transition |
| VSS (Pin 6) | Ground reference | Common return for all analog/digital circuits; must be low-impedance path to minimize noise coupling into coil inputs |
| FC (Pin 8) | Field clock output | Extracted carrier frequency (100–150 kHz); used to synchronize microcontroller timer for precise gap detection and modulation timing |
| MOD (Pin 9) | Modulation control input | Digital input controlling damping stage: MOD = 1 damps coil (lowers Vcoil), MOD = 0 releases damping (raises Vcoil) |
| NGAP (Pin 10) | Field/gap detection output | Active-high signal: NGAP = 1 = field present, NGAP = 0 = gap detected; used for wake-up interrupt and data demodulation |
| Coil 1 / Coil 2 (Pins 15–16) | LC resonant circuit interface | Connects to parallel-tuned antenna coil + capacitor; Q-factor 30–80 recommended; determines operating distance and coupling efficiency |
Key Features
| Feature | Design Value |
|---|---|
| Auto-switching dual power supply | Enables seamless transition between battery and RF field power without microcontroller intervention - critical for long-life sensor nodes |
| On-chip field clock extractor (FC) | Provides synchronous timing reference directly from carrier - eliminates need for external crystal or PLL in reader-synchronized applications |
| Integrated gap detection (NGAP) | Delivers digital wake-up and demodulation trigger with sub-50 µs latency - allows microcontroller to enter ultra-low-power sleep until field activation |
| Bi-phase/Manchester modulator control | Configurable via serial interface using documented control bytes - reduces firmware overhead and avoids external encoding hardware |
| 512-bit EEPROM with serial interface | Stores persistent ID, calibration, and configuration data; supports 10 ms writes and 10-year retention - suitable for unattended industrial deployments |
Applications
| Access Control Systems | Wireless Telemetry Nodes |
|---|---|
|
Use Scenario: Contactless passive access tags for secure entry points, vault doors, or equipment cabinets where battery replacement is impractical. IC Role / Device Role / Timing Role: Transponder interface supplying power and bidirectional data to MCU; NGAP triggers wake-up on field presence; FC synchronizes modulation to reader clock. Use Value: Eliminates batteries in high-security zones while maintaining tamper-resistant, maintenance-free operation over 10+ years. |
Use Scenario: Battery-assisted environmental sensors (temperature/humidity) deployed in remote infrastructure, reporting via intermittent RFID interrogation. IC Role / Device Role / Timing Role: Manages hybrid power (VBatt + field bursts); uses EEPROM to store last reading; NGAP initiates measurement on field detection. Use Value: Extends battery life by >95% through field-triggered wake-up and zero-idle-current sleep - typical 5+ year deployment without service. |
| Contactless Position Sensors | Industrial Status Verification |
|
Use Scenario: Non-contact alignment verification in CNC machines or robotic arms, where physical connectors would wear or interfere with motion. IC Role / Device Role / Timing Role: Provides coil interface and damping modulation; FC enables precise phase-aligned position encoding; MOD pin controls data transmission timing. Use Value: Enables micron-level repeatability without mechanical wear, EMI immunity, and immunity to oil/dust contamination in factory environments. |
Use Scenario: Verifying valve position, door latch status, or safety interlock states in hazardous or sealed enclosures using passive RFID interrogation. IC Role / Device Role / Timing Role: Stores status bits in EEPROM; NGAP detects reader field; SDA/SCL reads status on demand; MOD transmits encoded state via damping. Use Value: Provides intrinsically safe, spark-free verification without wiring penetrations - certified for Zone 1/21 hazardous area use with appropriate enclosure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transponder interface applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SLI52130A (NXP) | Higher 134.2 kHz fixed frequency; integrated 128-bit EEPROM; no VBatt support - field-only operation | Limited to pure passive tags; lacks battery backup for continuous sensing or wake-on-event logic | Choose for cost-sensitive, single-frequency access cards where battery independence is mandatory |
| TRF7960ARHBT (TI) | Multi-standard (125/134/13.56 MHz); integrated analog front-end; SPI interface; no on-chip EEPROM | Requires external MCU + memory; supports ISO/IEC 14443/15693 but adds complexity and BOM cost | Choose when multi-frequency interoperability or higher data rates (>106 kbps) are required - not a drop-in replacement |
Compared with SLI52130A and TRF7960ARHBT, U3280M-NFBY uniquely balances passive field operation with battery backup, on-chip EEPROM, and 100–150 kHz tunability - making it optimal for hybrid sensor nodes and maintenance-free access systems where reliability and long-term autonomy outweigh protocol flexibility.
Availability
U3280M-NFBY is available at Aetrix Electronics and suitable for access control systems, wireless telemetry nodes, contactless position sensors, and industrial status verification requiring stable component supply across extended product lifecycles.
Supply support for U3280M-NFBY 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 interface products including the U3280M series.
The U3280M-NFBY belongs to Microchip's contactless transponder interface product line, designed specifically for low-frequency (100–150 kHz) RFID tag and sensor applications requiring dual-mode power, embedded memory, and minimal external components.
FAQ
What is the primary function of the U3280M-NFBY in an RFID system?
The U3280M-NFBY serves as a transponder interface IC that supplies power to a microcontroller from an RF magnetic field (via coil resonance) or a battery, and enables bidirectional data communication through field damping and gap detection. It integrates EEPROM, serial interface, field clock extraction, and power management - allowing compact, low-power tag designs without external regulators or encoding logic. The U3280M-NFBY is essential for building semi-passive RFID sensors and access devices.
How does the U3280M-NFBY handle power source switching between battery and RF field?
The U3280M-NFBY automatically switches between VBatt and field supply using internal power management: it transitions to field supply when rectified coil voltage exceeds VFDon (2.3–2.9 V) for >1 ms, and reverts to battery when voltage drops below VFDoff (0.8 V). During field supply, VDD is clamped to VDDC (2.6–3.2 V), and a 0.5–10 µF capacitor at VDD buffers transient loads. The U3280M-NFBY also supports software disable of auto-switching via serial command for battery-only operation.
What are the key timing parameters for reliable U3280M-NFBY serial communication?
The U3280M-NFBY supports I²C-compatible two-wire serial interface with maximum SCL frequency of 100 kHz, tLOW ≥ 4.7 µs, tHIGH ≥ 4.0 µs, and data hold time tHDDAT = 0 ns. START/STOP setup/hold times are ≥4.7 µs, and input filter time is 100 ns. For EEPROM writes, acknowledge polling is required - the master must issue repeated START + control byte until ACK is received, as internal programming takes ~10 ms. These values are validated across –40°C to +85°C and define robust firmware timing margins for the U3280M-NFBY.
Can the U3280M-NFBY operate without a battery in purely passive mode?
Yes, the U3280M-NFBY can operate in purely passive mode using only RF field power - the rectifier stage converts coil AC to DC for VDD, and the internal power management disables VBatt when field is present. However, passive operation depends on sufficient field strength and coupling: with 150 µA consumption, a minimum coupling factor <0.5% is achievable. The U3280M-NFBY's 40–80 µA field supply current and 0.4 µA sleep current make it viable for passive tags, but battery backup extends functionality to wake-on-event and continuous sensing.
What modulation schemes does the U3280M-NFBY support, and how are they configured?
The U3280M-NFBY supports Bi-phase and Manchester modulation via its internal modulator stage, controlled through dedicated serial interface control bytes: 1100x111b enables Bi-phase, 1101x111b enables Manchester. In this mode, SCL acts as modulator clock and SDA as data input - bypassing EEPROM access. The U3280M-NFBY does not require external encoding logic; modulation is synchronized to FC output, and damping is driven directly by the MOD pin. This capability is confirmed in the official datasheet section 5.2.4.
U3280M-NFBY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- U3280M
- Package/Case:
- -
- Packaging:
- Tube
- Product Status:
- Obsolete
- Type:
- RFID Transponder
- Frequency:
- 100kHz ~ 150kHz
- Standards:
- -
- Interface:
- -
- Voltage - Supply:
- 2V ~ 6.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- -
U3280M-NFBY FAQ
1.How can I place an order for U3280M-NFBY through Aetrix?
Please submit a Request for Quotation (RFQ) for U3280M-NFBY on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for U3280M-NFBY reliable?
The price and inventory of U3280M-NFBY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for U3280M-NFBY is usually 5 days.
3.What payment methods are accepted for U3280M-NFBY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for U3280M-NFBY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for U3280M-NFBY?
U3280M-NFBY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your U3280M-NFBY order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for U3280M-NFBY?
For technical support, including U3280M-NFBY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your U3280M-NFBY requirements.
6.How does Aetrix verify that U3280M-NFBY is sourced from the original manufacturer or authorized distributors?
All U3280M-NFBY products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that U3280M-NFBY meets industry standards.
7.What is the process for return or replacement of U3280M-NFBY?
All U3280M-NFBY units undergo pre-shipment inspection (PSI). If there is an issue with U3280M-NFBY, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The U3280M-NFBY part is unused and in its original packaging.
Return procedure for U3280M-NFBY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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