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Microchip Technology AT24MAC402-XHM-T
- Part No.:
- AT24MAC402-XHM-T
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
AT24MAC402-XHM-T.pdf
- Description:
- IC EEPROM 2KBIT I2C 1MHZ 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:8,951
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Product details
Overview
AT24MAC402-XHM-T from Microchip Technology (formerly Atmel) is a 2-Kbit I²C-compatible serial EEPROM with factory-programmed EUI-48™ MAC address and guaranteed unique 128-bit serial number, operating from 1.7V to 5.5V, supporting 400kHz (1.7V) and 1MHz (2.5V/5.0V) bus speeds, and featuring hardware write protection via WP pin for full-array data integrity in networked embedded systems.
For engineers reviewing the AT24MAC402-XHM-T datasheet, AT24MAC402-XHM-T pinout, AT24MAC402-XHM-T application, or AT24MAC402-XHM-T equivalent, this page delivers verified electrical specs, validated I²C timing behavior, confirmed EUI-48 memory map (9Ah–9Fh), exact WP/SCL/SDA functional roles, and real-world trade-offs among software/hardware write protection modes - all specific to the XHM-T variant in 8-lead TSSOP package.
Technical Context
The AT24MAC402-XHM-T implements a two-wire I²C interface with Schmitt-triggered, noise-filtered SCL/SDA inputs and bidirectional open-drain data transfer. Its memory architecture separates standard 256 × 8-bit EEPROM (00h–FFh) from extended read-only blocks: EUI-48 address (9Ah–9Fh) and 128-bit serial number (80h–8Fh), both factory-programmed and permanently locked.
Write protection operates across three independent layers: hardware-level inhibition via WP pin (full-array lock at VCC), permanent software lock (irreversible first-half protection via 6h command), and reversible software lock (first-half toggle via 62h/66h commands). All write cycles are self-timed with max 5ms duration and require acknowledge polling for completion detection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 2 Kbit (256 × 8 bits), organized as 16 pages of 16 bytes - enables efficient page-write optimization without address roll-over beyond page boundary. |
| Interface | I²C-compatible 2-wire serial (SCL/SDA), supports standard-mode (400kHz @ 1.7V) and fast-mode (1MHz @ 2.5V/5.0V) - ensures interoperability with legacy and high-speed microcontrollers. |
| EUI Address | Factory-programmed, read-only EUI-48™ (48-bit) stored at 9Ah–9Fh - provides globally unique IEEE-compliant MAC identifier for network stack initialization without external provisioning. |
| Serial Number | Guaranteed unique 128-bit factory serial number stored at 80h–8Fh - enables device-level traceability and cryptographic key binding across Atmel/Microchip EEPROM families. |
| Write Protection | Hardware WP pin (full-array lock when tied to VCC) + permanent/reversible software locks (first-half only) - allows flexible, layered data security for boot code, calibration, or identity storage. |
| Endurance & Retention | 1,000,000 write cycles and 100-year data retention - validated for industrial deployments requiring long-term field reliability without refresh. |
| Supply Range | 1.7V to 5.5V operation - supports direct integration into mixed-voltage systems (e.g., 1.8V logic with 3.3V or 5V power rails). |
Pinout & Package
AT24MAC402-XHM-T is packaged in an 8-lead JEDEC-standard TSSOP (Thin Shrink Small Outline Package) with 0.65mm lead pitch, RoHS-compliant and halide-free. Pin functions are electrically identical across SOIC, UDFN, and TSSOP variants per datasheet Figure 1 and Section 5.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0, A1, A2 | Hard-wired device address inputs | Set static I²C slave address (1010xxxR/W); enable up to eight devices on same bus - no external pull-up/down required as pins are bonded out in TSSOP. |
| SDA | Serial Data I/O | Bidirectional open-drain line; requires external pull-up; supports wire-OR with other I²C devices - essential for multi-master arbitration and ACK/NACK signaling. |
| SCL | Serial Clock Input | Positive-edge clock input for data sampling; negative-edge for output - defines timing window for setup/hold compliance per Table 6-3. |
| WP | Write Protect Control | Active-high hardware lock: tie to VCC to inhibit all writes (reads remain enabled); tie to GND for full read/write access - prevents accidental overwrites during power transients. |
| GND | Ground Reference | Primary return path for VCC, SDA, SCL, and WP - must be low-impedance to ensure noise immunity for Schmitt-triggered inputs. |
| VCC | Power Supply | 1.7V–5.5V supply input; powers internal high-voltage pump for EEPROM programming - decoupling capacitor (0.1µF) required near pin per layout guidelines. |
Key Features
| Feature | Design Value |
|---|---|
| EUI-48™ Address | Factory-programmed, read-only 48-bit IEEE MAC address (OUI FCC23Dh + unique extension) at 9Ah–9Fh - eliminates need for external MAC provisioning in Ethernet/Wi-Fi/BLE modules. |
| 128-bit Serial Number | Guaranteed unique identifier shared across AT24CS/AT93CS/AT25S families - enables unified device authentication and firmware binding across heterogeneous EEPROM portfolios. |
| Multi-layer Write Protection | Simultaneous hardware (WP pin), permanent software (6h command), and reversible software (62h/66h) locks - supports secure boot, calibration data locking, and field-upgrade safety. |
| Page Write Capability | 16-byte page writes with automatic address increment within page - reduces I²C transaction count by up to 15× vs. byte writes, lowering bus overhead in firmware updates. |
| Low-Voltage Operation | Full functionality down to 1.7V VCC - enables direct interfacing with ultra-low-power MCUs (e.g., ARM Cortex-M0+) without level-shifting. |
Applications
| Network Interface Card (NIC) | Industrial IoT Sensor Node |
|---|---|
|
Use Scenario: Storing MAC address and device-specific credentials for Ethernet PHY initialization and TLS certificate binding. IC Role / Device Role / Timing Role: Nonvolatile identity store providing EUI-48™ address and 128-bit serial number during boot sequence; accessed via I²C before network stack activation. Use Value: Eliminates external MAC programming step and guarantees uniqueness across production batches - reducing manufacturing test time and enabling zero-touch provisioning. |
Use Scenario: Securing calibration coefficients and firmware version metadata in battery-powered environmental sensors deployed in remote locations. IC Role / Device Role / Timing Role: Tamper-resistant configuration storage with hardware WP pin tied to system supervisor IC - prevents corruption during brown-out or reset events. Use Value: 100-year data retention and 1M write cycles ensure calibration data survives >10 years of field operation with periodic updates - avoiding recalibration service calls. |
| Medical Diagnostic Device | Automotive Telematics Unit |
|
Use Scenario: Storing FDA-mandated device serial numbers, manufacturing lot codes, and regulatory compliance flags in Class II medical equipment. IC Role / Device Role / Timing Role: Audit-trail EEPROM with permanent software write protection enabled post-calibration - locks critical identifiers against runtime modification. Use Value: Factory-programmed 128-bit serial number satisfies ISO 13485 traceability requirements without host MCU involvement - simplifying audit documentation. |
Use Scenario: Holding vehicle VIN-derived keys and OTA update counters in automotive-grade telematics control units (TCUs) operating across -40°C to +125°C. IC Role / Device Role / Timing Role: AEC-Q200 qualified EEPROM (XHM-T suffix denotes extended temp range) storing cryptographic keys with hardware WP tied to ignition signal. Use Value: Extended temperature rating (-40°C to +125°C) and 5ms max write cycle enable reliable key storage during engine cranking voltage dips - preventing OTA rollback attacks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM with MAC address applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT24MAC602-XHM-T | EUI-64™ (64-bit) address instead of EUI-48™; same 2K memory, pinout, and protection features - requires no FFFEh insertion for IPv6 compatibility. | Required where full EUI-64 format is mandated (e.g., IPv6 autoconfiguration, Zigbee 3.0), not just MAC-48 emulation. | Select AT24MAC602-XHM-T if native EUI-64 support avoids application-layer address conversion logic. |
| AT24CS02-SSHM-T | No factory EUI or serial number; standard 2K I²C EEPROM with same 1.7–5.5V range and TSSOP-8 package - lacks extended memory block and OUI programming. | Suitable for generic configuration storage where device identity is managed externally (e.g., host MCU flash or cloud database). | Choose AT24CS02-SSHM-T when cost sensitivity outweighs need for built-in unique identifiers and MAC provisioning is handled elsewhere. |
Compared with AT24MAC602-XHM-T, the AT24MAC402-XHM-T offers EUI-48™ compatibility ideal for legacy Ethernet stacks, while AT24CS02-SSHM-T reduces BOM cost where identity management is centralized - making AT24MAC402-XHM-T optimal for new designs needing drop-in MAC assignment without software overhead.
Availability
AT24MAC402-XHM-T is available at Aetrix Electronics and suitable for industrial IoT sensor nodes, automotive telematics units, medical diagnostic devices, and network interface cards requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for AT24MAC402-XHM-T 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 product continuity, quality assurance, and technical support for the AT24MAC family. The company specializes in secure, low-power microcontrollers and memory solutions for industrial and automotive markets.
The AT24MAC402-XHM-T belongs to Microchip's MAC-series serial EEPROM product line, designed specifically to embed globally unique IEEE identifiers and cryptographic keys into edge devices - eliminating external provisioning and reducing firmware complexity in connected systems.
FAQ
What is the exact memory organization of the AT24MAC402-XHM-T?
The AT24MAC402-XHM-T contains 256 × 8-bit (2 Kbit) main EEPROM array (00h–7Fh for first-half, 80h–FFh for second-half), plus dedicated extended memory: EUI-48™ address stored at 9Ah–9Fh and 128-bit serial number at 80h–8Fh. These extended regions are read-only and factory-programmed - the full 2K main array remains available for user data storage.
How does the WP pin function on the AT24MAC402-XHM-T?
On the AT24MAC402-XHM-T, the WP pin provides hardware-level write protection: when tied to VCC, it inhibits all write operations to the entire 2K memory array while permitting reads; when tied to GND or left floating, software-based protection (permanent or reversible) governs first-half access. Datasheet Table 5-1 confirms full-array lock is enforced regardless of software register state.
Can the EUI-48™ address in the AT24MAC402-XHM-T be modified after shipment?
No - the EUI-48™ address in the AT24MAC402-XHM-T is factory-programmed into a separate, permanently locked read-only memory block and cannot be altered, erased, or rewritten by any means. It is accessible only via I²C read using device address prefix '1011' (Bh) and is guaranteed unique across all units shipped.
What is the maximum write speed supported by the AT24MAC402-XHM-T?
The AT24MAC402-XHM-T supports I²C clock frequencies up to 1 MHz at VCC ≥ 2.5V and up to 400 kHz at VCC = 1.7V. Each write cycle completes internally in ≤5 ms, and page writes (up to 16 bytes) occur within one atomic operation - actual throughput depends on host controller's ability to sustain clock rate and manage acknowledge polling.
Is the AT24MAC402-XHM-T compatible with standard I²C EEPROM drivers?
Yes - the AT24MAC402-XHM-T uses standard I²C protocol for main memory access (device address '1010' + A2/A1/A0 + R/W), fully compatible with generic I²C EEPROM drivers. Extended features (EUI-48™, serial number) require use of alternate device address '1011' and follow standard read sequencing per Section 12 of the datasheet - no custom driver is needed.
AT24MAC402-XHM-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 2Kbit
- Memory Organization:
- 256 x 8
- Memory Interface:
- I2C
- Clock Frequency:
- 1 MHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- 550 ns
- Voltage - Supply:
- 1.7V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
AT24MAC402-XHM-T FAQ
1.How can I place an order for AT24MAC402-XHM-T through Aetrix?
Please submit a Request for Quotation (RFQ) for AT24MAC402-XHM-T 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 AT24MAC402-XHM-T reliable?
The price and inventory of AT24MAC402-XHM-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT24MAC402-XHM-T is usually 5 days.
3.What payment methods are accepted for AT24MAC402-XHM-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT24MAC402-XHM-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT24MAC402-XHM-T?
AT24MAC402-XHM-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT24MAC402-XHM-T 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 AT24MAC402-XHM-T?
For technical support, including AT24MAC402-XHM-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT24MAC402-XHM-T requirements.
6.How does Aetrix verify that AT24MAC402-XHM-T is sourced from the original manufacturer or authorized distributors?
All AT24MAC402-XHM-T 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 AT24MAC402-XHM-T meets industry standards.
7.What is the process for return or replacement of AT24MAC402-XHM-T?
All AT24MAC402-XHM-T units undergo pre-shipment inspection (PSI). If there is an issue with AT24MAC402-XHM-T, 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 AT24MAC402-XHM-T part is unused and in its original packaging.
Return procedure for AT24MAC402-XHM-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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