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Microchip Technology U3280M-NFBG3
- Part No.:
- U3280M-NFBG3
- Manufacturer:
- Microchip Technology
- Category:
- RFID, RF Access, Monitoring ICs
- Package:
- 16-LSSOP (0.154", 3.90mm Width)
- Datasheet:
-
U3280M-NFBG3.pdf
- Description:
- IC RFID TRANSP 100-150KHZ 16SSO
- Quantity:
- Payment:
- Shipping:
Inventory:1,665
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Product details
Overview
U3280M-NFBG3 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), 512-bit EEPROM, two-wire serial interface, and field clock extraction. It enables microcontroller operation in passive or semi-passive tags used in access control and industrial position sensing.
For engineers reviewing the U3280M-NFBG3 datasheet, U3280M-NFBG3 pinout, U3280M-NFBG3 application, or U3280M-NFBG3 equivalent, key selection criteria include its 100–150 kHz operating frequency, bi-phase/Manchester modulation support, automatic field/battery power management, NGAP wake-up capability, and SSO16 package compatibility with coil-resonant antenna design.
Technical Context
The U3280M-NFBG3 integrates a rectifier stage for LC-resonant coil inputs (Coil 1/Coil 2), a field clock extractor (FC), gap detection (NGAP), and a damping modulator controlled via MOD pin. Its power management automatically switches between VBatt (2.0–6.5 V) and field-derived VDDC (2.6–3.2 V) based on VFDon/VFDoff thresholds.
It implements a two-wire serial interface (SCL/SDA) supporting EEPROM read/write, Bi-phase/Manchester modulation control, and power management enable/disable commands via defined control bytes. The internal 32 × 16-bit EEPROM supports auto-increment reads and 10 ms erase/write cycles with 500 k-cycle endurance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Operating Frequency | 100–150 kHz - matches standard LF RFID base station frequencies; requires parallel LC antenna tuned to this band. |
| EEPROM Size | 512-bit (32 × 16-bit) - stores identifiers, configuration, and sensor data; accessible via two-wire serial interface. |
| Data Rate (R/O) | Up to 10 kbaud - defines maximum reliable bit rate for passive backscatter communication using gap/damping modulation. |
| Power Supply Modes | Battery (VBatt: 2.0–6.5 V) + RF field (VDDC: 2.6–3.2 V) - automatic switching enables hybrid passive/active tag operation. |
| Modulation Support | Bi-phase and Manchester - selectable via serial control byte; enables standardized encoding for robust demodulation by readers. |
| Wake-up Signal | NGAP output - logic-high indicates field presence; used to trigger microcontroller interrupt and exit low-power sleep mode. |
| Serial Interface Speed | DC to 100 kHz SCL - compatible with standard I²C timing; supports acknowledge polling during EEPROM write cycles. |
Pinout & Package
U3280M-NFBG3 is housed in a 16-pin SSOP (SSO16) package with exposed pad, Pb-free, tape-and-reel format (NFBG3 suffix). Pin 1 is marked with a dot; pin numbering follows standard counter-clockwise layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VBatt (Pin 1) | Battery voltage input | Connects external 2.0–6.5 V battery; supplies device when field is absent; enables semi-passive operation. |
| VDD (Pin 2) | Microcontroller/EEPROM supply output | Delivers regulated power to MCU and EEPROM; requires 0.5–10 µF buffer capacitor to sustain operation during field gaps. |
| SCL (Pin 3) | Serial clock input/output | Master-generated clock for two-wire interface; also serves as modulator clock in Bi-phase/Manchester mode. |
| NRST (Pin 4) | Bi-directional reset line | Accepts active-low reset; outputs reset pulse during field-to-battery switch to synchronize MCU state. |
| SDA (Pin 5) | Serial data bidirectional line | Transfers EEPROM data and control bytes; doubles as modulator data input in encoded modulation modes. |
| VSS (Pin 6) | Ground reference | Primary circuit ground; all voltage measurements referenced here; must be low-impedance connection. |
| FC (Pin 8) | Field clock output | Provides extracted 100–150 kHz clock signal to MCU timer for synchronous modulation/demodulation. |
| MOD (Pin 9) | Modulation control input | Digital input controlling damping stage: high = coil damped (transmit '1'), low = undamped (transmit '0'). |
| NGAP (Pin 10) | Field/gap detection output | Open-drain output: high = field present (wake-up), low = gap detected (incoming data bit '0'). |
| Coil 1 / Coil 2 (Pins 15–16) | LC resonant antenna interface | Connects parallel LC tank (e.g., 737 µH + 2.2 nF @ 125 kHz); forms primary energy harvesting and communication path. |
Key Features
| Feature | Design Value |
|---|---|
| Contactless Power & Data | Enables battery-free or hybrid operation via 100–150 kHz magnetic coupling; eliminates wiring in sealed or rotating sensors. |
| Automatic Power Management | Seamlessly transitions between VBatt and field supply without MCU intervention; includes low-pass filtering to suppress noise-induced switching. |
| On-chip Field Clock Extraction | Delivers synchronized 100–150 kHz clock (FC) to MCU-critical for precise timing of Manchester/Bi-phase encoding and gap detection. |
| Integrated Gap Detection (NGAP) | Generates clean digital wake-up and data-reception signal from field interruptions-enables reliable reader-to-tag command decoding. |
| Configurable Modulation Control | Supports both direct MOD pin control and serial-driven Bi-phase/Manchester encoding-flexible for custom or standards-compliant protocols. |
| 512-bit EEPROM with Serial Interface | Persists unique IDs and calibration data; accessible via standard two-wire protocol with auto-increment reads and 10 ms write cycles. |
Applications
| Access Control Systems | Wireless Position Sensors |
|---|---|
|
Use Scenario: Contactless passive badge reading in secure entry points, where tamper resistance and no battery maintenance are required. IC Role / Device Role / Timing Role: Transponder interface supplying power and bidirectional data to MCU; extracts field clock (FC) for precise timing of modulation and gap detection. Use Value: Enables fully passive, maintenance-free tags with 512-bit EEPROM storing encrypted credentials-no local power source needed during reader interrogation. |
Use Scenario: Non-contact alignment verification of machine components (e.g., robotic arms, CNC fixtures) in harsh industrial environments. IC Role / Device Role / Timing Role: Front-end interface powering MCU and sensors via coil; uses NGAP for wake-up and FC for synchronization during field-on intervals. Use Value: Eliminates slip rings and connectors; supports operation in oil, dust, or vacuum via hermetic sealing-field-powered only during measurement cycles. |
| Telemetry Sensor Nodes | Valuables Protection Alarms |
|
Use Scenario: Battery-backed wireless sensor nodes monitoring temperature, humidity, or vibration in remote infrastructure (e.g., pipelines, transformers). IC Role / Device Role / Timing Role: Hybrid power manager-uses battery for continuous sensing, switches to field for high-bandwidth data upload; modulates via MOD/NGAP. Use Value: Extends battery life years by offloading transmission energy to reader field; 10 kbaud R/O supports burst telemetry without local RF transceiver. |
Use Scenario: Tamper-evident alarm tags attached to artwork, safes, or server racks that trigger alerts upon unauthorized movement or removal. IC Role / Device Role / Timing Role: Passive transponder detecting field presence (NGAP) and transmitting status via damping modulation; stores tamper flags in EEPROM. Use Value: Zero-power standby until interrogated; EEPROM retains last-known state (e.g., "door opened") even after battery depletion or field removal. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transponder interface applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SLI1300ATP | 13.56 MHz HF RFID interface; integrated analog front-end; no battery input; 64-byte EEPROM | Designed for proximity card readers (ISO 14443), not LF 125 kHz systems; lacks VBatt support and NGAP wake-up | Select for ISO-compliant HF access systems; avoid for LF telemetry or battery-assisted sensors. |
| TDA8035 | Smart card controller with contactless interface; supports 106–848 kbps; requires external LDO; no built-in EEPROM | Targets secure payment cards; needs external memory and power regulation; no field clock extraction or gap detection | Choose for secure financial transactions; unsuitable for low-power industrial sensor tagging due to higher current draw and complexity. |
Compared with SLI1300ATP and TDA8035, U3280M-NFBG3 uniquely combines LF 100–150 kHz operation, dual VBatt/field power management, on-chip EEPROM, and dedicated NGAP/FC signals-making it the only viable option for battery-assisted passive telemetry and alignment sensing at 125 kHz.
Availability
U3280M-NFBG3 is available at Aetrix Electronics and suitable for access control systems, wireless position sensors, and telemetry sensor nodes requiring stable component supply across long-lifecycle industrial deployments.
Supply support for U3280M-NFBG3 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 company specializes in microcontrollers, analog, and connectivity solutions for industrial and automotive markets.
The U3280M product line was designed specifically for low-frequency (125 kHz) contactless identification and sensor tagging-targeting applications needing passive power harvesting, EEPROM storage, and robust field-based wake-up and communication.
FAQ
What is the function of the NGAP pin on the U3280M-NFBG3?
The NGAP pin on the U3280M-NFBG3 is a field/gap detection output that signals magnetic field presence (logic high) or absence/gap (logic low). It serves dual roles: as a wake-up interrupt for the connected microcontroller when a field is applied, and as a data-reception indicator during reader-to-tag communication. Its Schmitt-trigger input ensures noise immunity, and it operates without external amplification-directly interfacing with MCU GPIO pins configured for edge-triggered interrupts.
How does the U3280M-NFBG3 handle power supply switching between battery and RF field?
The U3280M-NFBG3 implements automatic power management that switches between VBatt and field-derived VDDC based on comparator thresholds: VFDon (2.3–2.9 V) triggers battery-to-field transition, while VFDoff (0.8 V) initiates field-to-battery fallback. A built-in low-pass filter prevents false switching from coil noise. The NRST pin can also assert a reset pulse during supply transitions to ensure MCU synchronization. Software control via serial command allows disabling auto-switching for pure battery-only operation.
Can the U3280M-NFBG3 operate without a battery in fully passive mode?
Yes, the U3280M-NFBG3 can operate fully passively using only RF field energy harvested through its Coil 1 and Coil 2 pins. The internal rectifier converts AC from the LC-resonant antenna into DC to power the IC and connected microcontroller via VDD. A 0.5–10 µF buffer capacitor at VDD sustains operation during field gaps and modulation events. However, EEPROM writes and high-current MCU activity may require stronger field coupling or supplemental battery assist for reliability.
What modulation schemes does the U3280M-NFBG3 support, and how are they configured?
The U3280M-NFBG3 supports direct digital MOD pin control and serial-configured Bi-phase or Manchester encoding. Bi-phase modulation is enabled by sending control byte 1100x111b; Manchester by 1101x111b over the SCL/SDA interface. These modes repurpose SCL as clock and SDA as data for continuous bitstream transmission-bypassing standard I²C ACK cycles. The damping stage generates ~2 Vpp modulation at the coil, enabling compliant communication with ISO/IEC 11784/11785 LF readers.
What is the purpose of the FC (Field Clock) output on the U3280M-NFBG3?
The FC pin on the U3280M-NFBG3 outputs a clean, extracted 100–150 kHz clock signal derived directly from the incoming RF field. This signal provides precise timing reference for the connected microcontroller-enabling synchronous modulation (e.g., phase-aligned damping) and accurate gap detection for demodulating reader commands. Unlike free-running oscillators, FC guarantees lock-step operation with the reader's carrier, eliminating timing drift and improving communication robustness in noisy industrial settings.
U3280M-NFBG3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- U3280M
- Package/Case:
- 16-LSSOP (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- 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:
- 16-SSO
U3280M-NFBG3 FAQ
1.How can I place an order for U3280M-NFBG3 through Aetrix?
Please submit a Request for Quotation (RFQ) for U3280M-NFBG3 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-NFBG3 reliable?
The price and inventory of U3280M-NFBG3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for U3280M-NFBG3 is usually 5 days.
3.What payment methods are accepted for U3280M-NFBG3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for U3280M-NFBG3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for U3280M-NFBG3?
U3280M-NFBG3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your U3280M-NFBG3 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-NFBG3?
For technical support, including U3280M-NFBG3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your U3280M-NFBG3 requirements.
6.How does Aetrix verify that U3280M-NFBG3 is sourced from the original manufacturer or authorized distributors?
All U3280M-NFBG3 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-NFBG3 meets industry standards.
7.What is the process for return or replacement of U3280M-NFBG3?
All U3280M-NFBG3 units undergo pre-shipment inspection (PSI). If there is an issue with U3280M-NFBG3, 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-NFBG3 part is unused and in its original packaging.
Return procedure for U3280M-NFBG3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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