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Home > Products > RF and Wireless > RFID, RF Access, Monitoring ICs

Melexis Technologies NV MLX90121EFR-DAA-000-RE

Name: MLX90121EFR-DAA-000-RE
Brand: Melexis Technologies NV
SKU: MLX90121EFR-DAA-000-RE
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MLX90121EFR-DAA-000-RE

Manufacturer:: Melexis Technologies NV

Category:: RFID, RF Access, Monitoring ICs

Package:: 20-SSOP (0.209", 5.30mm Width)

Datasheet:: MLX90121EFR-DAA-000-RE.pdf

Description:: IC RFID TXRX 13.56MHZ 20-SSOP

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Product details

Overview

MLX90121EFR-DAA-000-RE from Melexis is a 13.56 MHz ISO-compliant RFID transceiver IC supporting ISO14443A (0°C to 85°C), ISO14443B, and ISO15693 protocols. It integrates a diode envelope detector receiver, open-drain TX transistor delivering up to 250 mW into 50 Ω, programmable FSK/PSK/ASK encoder-decoder, and serial interface for microcontroller integration in contactless reader systems.

For engineers reviewing the MLX90121EFR-DAA-000-RE datasheet, pinout, applications, or equivalent options, key selection considerations include modulation depth configurability (0–90% via RMOD), dual-subcarrier FSK/PSK decoding (423/484 kHz & 847 kHz), majority voting noise resilience, and SSOP20 package compatibility with handheld and embedded reader designs.

Technical Context

The MLX90121EFR-DAA-000-RE implements a mixed-signal architecture: its receiver uses a diode envelope detector followed by IF filtering and logarithmic amplification for ASK/FSK/PSK demodulation, while its transmitter employs an internal low-R_ON MOSFET (2–5 Ω) with external matching network support for 250 mW RF output at 5 V. The analog front-end operates across 2.7–5.5 V supply range with standby current as low as 0.1 µA at +25°C.

Digital functionality includes six-programmable 8-bit symbol encoding for ISO14443A/B and ISO15693 frame generation, hardware-accelerated FSK (423/484 kHz) and PSK (847 kHz) decoding, and majority voting with configurable time-slot resolution (down to 4.72 µs). Configuration and data exchange occur over a 6-wire serial interface (CK/DIN/DOUT/DSYNC/MODE/RTB) with register-based control of analog chain parameters including ByPassAll and RSub-carrier selection.

Key Specifications

Parameter	Value and Actual Design Meaning
Operating Frequency	13.56 MHz carrier - enables compliance with global HF RFID standards including ISO14443 and ISO15693.
Supply Voltage Range	2.7 V to 5.5 V - supports direct integration with 3.3 V or 5 V microcontroller systems without level-shifting.
TX Output Power	250 mW into 50 Ω at 5 V - sufficient for mid-range reader applications (typically 5–10 cm read distance with optimized antenna).
Receiver Sensitivity	−45 dBm - ensures reliable tag response detection under low-field conditions typical in portable readers.
Modulation Depth Range	0–90% ASK via external RMOD resistor - allows fine-tuning for optimal tag coupling and EMI reduction.
Decoding Standards	ISO14443A (0–85°C), ISO14443B, ISO15693 - covers major contactless smart card and label protocols.
Interface Type	6-wire serial (CK/DIN/DOUT/DSYNC/MODE/RTB) - enables deterministic timing control for real-time protocol handling with low-cost MCUs.

Pinout & Package

MLX90121EFR-DAA-000-RE is housed in a 20-pin SSOP (Shrink Small Outline Package), 209 mils wide, with 0.65 mm pitch and exposed thermal pad. This RoHS-compliant surface-mount package supports reflow soldering and provides thermal performance suitable for continuous TX operation in compact reader modules.

Pin/Terminal	Circuit Role	Design Meaning
TX	Transmitter output drain	Open-drain MOSFET output requiring external choke/matching network; delivers up to 250 mW RF power.
RX	Receiver input	High-impedance (100 kΩ) analog input for antenna-coupled signal; requires series limiting resistor (e.g., 4.7 kΩ).
RMOD	Modulation depth control	Analog input pin setting ASK modulation depth (0–90%) via external resistor to ground.
XTAL1 / XTAL2	Clock oscillator terminals	Supports 13.56 MHz crystal or ceramic resonator; also accepts external sine/square clock (centered at VDD/2).
XBUF	Buffered clock output	Provides 13.56 MHz or 6.78 MHz clock for MCU synchronization; drives 1 kΩ load with <3 ns rise/fall time.
CK / DIN / DOUT / DSYNC	Serial interface signals	CMOS-level synchronous interface: CK clocks data, DIN configures/transmits, DOUT outputs decoded data, DSYNC aligns bit timing.
MODE / RTB	Mode control inputs	MODE selects configuration (0) or communication (1); RTB selects transmission (0) or reception (1).

Key Features

Feature	Design Value
Programmable symbol encoder	Six user-defined 8-bit symbols plus hard-coded 0xFF enable ISO14443A/B and ISO15693 frame generation with minimal MCU overhead.
Majority voting decoder	Configurable time-slot resolution (4.72–37.6 µs) filters noise/jitter and corrects distorted waveforms in noisy RF environments.
Multi-standard analog front-end	Single chip supports ASK (ISO14443A), FSK (ISO14443B), and PSK (ISO15693) demodulation via register-selectable analog path.
Low-power idle mode	Idle current ≤3 mA at 5.5 V with analog section off - extends battery life in portable readers between polling cycles.
Integrated clock buffer	XBUF pin delivers clean 13.56 MHz or divided-by-2 clock to MCU, eliminating need for separate oscillator circuitry.

Applications

Access Control Reader	Contactless Payment Terminal
Use Scenario: Wall-mounted or desktop reader authenticating employee ID cards or fobs in office buildings or secure facilities. IC Role / Device Role / Timing Role: Primary RFID transceiver handling ISO14443A/B modulation/demodulation, clock distribution, and digital interface to host MCU. Use Value: −45 dBm sensitivity and majority voting ensure reliable reads despite metal enclosures or multi-tag interference; 250 mW TX power sustains 7 cm read range with compact PCB antenna.	Use Scenario: Handheld POS terminal verifying EMV-compliant payment cards during tap-to-pay transactions. IC Role / Device Role / Timing Role: Core HF transceiver executing ISO14443A protocol stack layers (physical and MAC), synchronized via XBUF clock to MCU. Use Value: Programmable encoder reduces firmware complexity for SOF/EOF/pulse generation; 0–90% RMOD tuning optimizes field strength for varying card thicknesses and alignment tolerances.
Smart Label Printer	Portable Data Terminal
Use Scenario: Industrial printer encoding and verifying UHF/HF hybrid smart labels for logistics tracking or asset management. IC Role / Device Role / Timing Role: Bidirectional transceiver performing write-verify cycles on ISO15693 tags using dual-subcarrier FSK mode. Use Value: Dual-subcarrier FSK decoding (423/484 kHz) and 18.88 µs MVTime setting enable high-speed tag interrogation at >26 kbps; SSOP20 footprint fits tight space constraints on print head PCB.	Use Scenario: Ruggedized handheld device scanning inventory tags in warehouses or retail backrooms. IC Role / Device Role / Timing Role: Low-power RFID interface managing intermittent polling, battery-aware sleep/wake transitions, and noise-immune reception. Use Value: 0.1 µA standby current extends battery life between scans; diode-envelope receiver architecture minimizes analog BOM count versus discrete solutions.

Access Control Reader

Contactless Payment Terminal

Use Scenario: Wall-mounted or desktop reader authenticating employee ID cards or fobs in office buildings or secure facilities.

IC Role / Device Role / Timing Role: Primary RFID transceiver handling ISO14443A/B modulation/demodulation, clock distribution, and digital interface to host MCU.

Use Value: −45 dBm sensitivity and majority voting ensure reliable reads despite metal enclosures or multi-tag interference; 250 mW TX power sustains 7 cm read range with compact PCB antenna.

Use Scenario: Handheld POS terminal verifying EMV-compliant payment cards during tap-to-pay transactions.

IC Role / Device Role / Timing Role: Core HF transceiver executing ISO14443A protocol stack layers (physical and MAC), synchronized via XBUF clock to MCU.

Use Value: Programmable encoder reduces firmware complexity for SOF/EOF/pulse generation; 0–90% RMOD tuning optimizes field strength for varying card thicknesses and alignment tolerances.

Smart Label Printer

Portable Data Terminal

Use Scenario: Industrial printer encoding and verifying UHF/HF hybrid smart labels for logistics tracking or asset management.

IC Role / Device Role / Timing Role: Bidirectional transceiver performing write-verify cycles on ISO15693 tags using dual-subcarrier FSK mode.

Use Value: Dual-subcarrier FSK decoding (423/484 kHz) and 18.88 µs MVTime setting enable high-speed tag interrogation at >26 kbps; SSOP20 footprint fits tight space constraints on print head PCB.

Use Scenario: Ruggedized handheld device scanning inventory tags in warehouses or retail backrooms.

IC Role / Device Role / Timing Role: Low-power RFID interface managing intermittent polling, battery-aware sleep/wake transitions, and noise-immune reception.

Use Value: 0.1 µA standby current extends battery life between scans; diode-envelope receiver architecture minimizes analog BOM count versus discrete solutions.

Equivalent & Alternatives

The following parts are listed as comparable options for similar RFID transceiver applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
ST25R3916B	Higher integration: integrated voltage regulator, 32-bit CRC engine, and NFC Forum compliance; 3.3 V only; no RMOD pin for analog modulation tuning.	Targeted at NFC-enabled consumer devices requiring full NFC Forum certification; less flexible for custom ISO15693 implementations.	Select ST25R3916B when NFC Forum compliance and embedded CRC offload are required; MLX90121EFR-DAA-000-RE remains preferred for cost-sensitive ISO15693 printers or industrial readers needing analog modulation control.
PN5180A	Supports wider frequency range (13.56 MHz + 125 kHz); higher TX power (up to 1 W); more complex SPI interface; requires external LDO and multiple decoupling caps.	Designed for multi-frequency access control panels and automotive keyless entry; over-specified for pure HF-only portable readers.	Choose PN5180A for dual-frequency (LF/HF) systems or high-power gate readers; MLX90121EFR-DAA-000-RE offers lower BOM cost and simpler layout for dedicated 13.56 MHz applications.

Compared with ST25R3916B and PN5180A, MLX90121EFR-DAA-000-RE delivers optimal balance of ISO standard coverage, analog configurability (RMOD, ByPassAll), and SSOP20 integration for mid-range HF readers-without requiring NFC certification overhead or LF capability, making it ideal for cost-driven industrial and commercial reader designs.

Availability

MLX90121EFR-DAA-000-RE is available at Aetrix Electronics and suitable for access control readers, contactless payment terminals, and smart label printers requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across production batches.

Supply support for MLX90121EFR-DAA-000-RE 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

Melexis is a Belgian semiconductor company specializing in sensor and wireless ICs for automotive, industrial, and consumer markets, with core expertise in magnetic sensing, infrared thermometry, and RFID technology.

The MLX90121 product line was designed specifically for high-reliability, low-BOM-count HF RFID reader applications-including portable data terminals and access control systems-emphasizing analog flexibility, multi-standard support, and robust noise immunity.

FAQ

What communication interface does the MLX90121EFR-DAA-000-RE use?

The MLX90121EFR-DAA-000-RE uses a 6-wire synchronous serial interface comprising CK (clock), DIN (data in), DOUT (data out), DSYNC (data synchronization), MODE (configuration/communication select), and RTB (transmit/receive select). This interface enables deterministic timing for ISO protocol handling and register configuration without requiring a dedicated microcontroller UART or SPI peripheral.

Does the MLX90121EFR-DAA-000-RE support ISO14443A at full temperature range?

No-the MLX90121EFR-DAA-000-RE's conformance with ISO14443A is limited to 0°C to +85°C per the official datasheet (Rev. 008, Mar-2009). Operation outside this range may result in non-compliant modulation depth, timing, or sensitivity. The full −40°C to +85°C rating applies to ISO14443B and ISO15693 modes.

How is modulation depth controlled on the MLX90121EFR-DAA-000-RE?

Modulation depth on the MLX90121EFR-DAA-000-RE is controlled via the RMOD pin, which accepts an external resistor to ground. With a nominal 10 Ω resistor, ASK depth is 8–14%; increasing resistance raises depth up to 90%. This analog tuning allows optimization for specific tag types, antenna coupling, and regulatory field-strength limits without firmware changes.

What is the purpose of the XBUF pin on the MLX90121EFR-DAA-000-RE?

The XBUF pin on the MLX90121EFR-DAA-000-RE provides a buffered 13.56 MHz clock or its divide-by-2 (6.78 MHz) version for synchronizing external microcontrollers. It drives a 1 kΩ load with <3 ns rise/fall time and eliminates the need for a separate clock generator, simplifying system timing and reducing component count in compact reader designs.

Can the MLX90121EFR-DAA-000-RE operate without an external crystal?

Yes-the MLX90121EFR-DAA-000-RE supports both crystal/resonator-based oscillation (via XTAL1/XTAL2) and external clock injection (sine or square wave applied to XTAL2). When using external clock, the signal must be centered at VDD/2 (for sine) or have 50% duty cycle (for square), and amplitude must meet specified minimums (1–VDD VPP) to ensure stable TX output power and timing accuracy.

MLX90121EFR-DAA-000-RE Specifications

Product attributes: Attribute value

Manufacturer:: Melexis Technologies NV

Series:: MLX90121

Package/Case:: 20-SSOP (0.209", 5.30mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Type:: -

Frequency:: -

Standards:: -

Interface:: -

Voltage - Supply:: -

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 20-SSOP

MLX90121EFR-DAA-000-RE FAQ

1.How can I place an order for MLX90121EFR-DAA-000-RE through Aetrix?

Please submit a Request for Quotation (RFQ) for MLX90121EFR-DAA-000-RE 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 MLX90121EFR-DAA-000-RE reliable?

The price and inventory of MLX90121EFR-DAA-000-RE are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MLX90121EFR-DAA-000-RE is usually 5 days.

3.What payment methods are accepted for MLX90121EFR-DAA-000-RE?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MLX90121EFR-DAA-000-RE transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MLX90121EFR-DAA-000-RE?

MLX90121EFR-DAA-000-RE orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MLX90121EFR-DAA-000-RE 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 MLX90121EFR-DAA-000-RE?

For technical support, including MLX90121EFR-DAA-000-RE datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MLX90121EFR-DAA-000-RE requirements.

6.How does Aetrix verify that MLX90121EFR-DAA-000-RE is sourced from the original manufacturer or authorized distributors?

All MLX90121EFR-DAA-000-RE 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 MLX90121EFR-DAA-000-RE meets industry standards.

7.What is the process for return or replacement of MLX90121EFR-DAA-000-RE?

All MLX90121EFR-DAA-000-RE units undergo pre-shipment inspection (PSI). If there is an issue with MLX90121EFR-DAA-000-RE, 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 MLX90121EFR-DAA-000-RE part is unused and in its original packaging.

Return procedure for MLX90121EFR-DAA-000-RE:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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