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Microchip Technology AT24MAC402-SSHM-B
- Part No.:
- AT24MAC402-SSHM-B
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
AT24MAC402-SSHM-B.pdf
- Description:
- IC EEPROM 2KBIT I2C 1MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,396
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Product details
Overview
AT24MAC402-SSHM-B 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 and dual software write protection modes. It is used in networked embedded systems requiring globally unique device identity and secure, low-voltage nonvolatile storage.
For engineers reviewing the AT24MAC402-SSHM-B datasheet, AT24MAC402-SSHM-B pinout, AT24MAC402-SSHM-B application, or AT24MAC402-SSHM-B equivalent, key selection considerations include EUI-48 address accessibility, 128-bit serial number read protocol, WP pin behavior under VCC/GND/floating conditions, partial page write capability, and compatibility with I²C master timing constraints at 1.7V supply.
Technical Context
The AT24MAC402-SSHM-B implements a standard I²C two-wire interface with Schmitt-triggered, noise-filtered SDA/SCL inputs and supports both byte and 16-byte page writes with self-timed 5ms max write cycles. Its memory is organized as 256 × 8 bits (2K), split into standard user array (00h–FFh) and extended read-only block containing EUI-48 (9Ah–9Fh) and 128-bit serial number (80h–8Fh).
Write protection is implemented through three independent mechanisms: hardware-level inhibition via WP pin (full-array lock when tied to VCC), permanent software lock of first-half array (00h–7Fh) via irreversible PSWP command, and reversible software lock of same region via RSWP command - all validated by ACK/NACK response behavior per Table 11-3 and Table 11-4.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 2 Kbit (256 × 8), fully usable user array plus dedicated extended memory block |
| Interface | I²C-compatible 2-wire serial; supports 400 kHz @ 1.7V, 1 MHz @ 2.5V/5.0V |
| EUI Address | Factory-programmed, read-only EUI-48 (48-bit) stored at 9Ah–9Fh; globally unique |
| Serial Number | Factory-programmed, read-only 128-bit serial number stored at 80h–8Fh; unique across AT24CS/AT93CS/AT25S families |
| Write Protection | Hardware: WP pin → full-array lock when high; Software: PSWP (irreversible) and RSWP (reversible) for first-half array (00h–7Fh) |
| Endurance & Retention | 1,000,000 write cycles; 100 years data retention at 25°C |
| Supply Voltage | 1.7V to 5.5V - enables direct interfacing with 1.8V, 2.5V, 3.3V, and 5V logic domains |
Pinout & Package
AT24MAC402-SSHM-B is packaged in an 8-lead JEDEC SOIC (SOIC-8) with standard pin mapping. Pin functions are electrically validated per Atmel-8807E datasheet Figures 1 and 5-1, and Table 5-1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0, A1, A2 | Device address inputs | Hard-wired inputs enabling up to eight devices on one I²C bus; required for standard EEPROM access (1010xxxx) and extended feature access (1011xxxx) |
| SDA | Serial data bidirectional I/O | Open-drain, wire-OR capable; requires external pull-up; carries address, data, and control words |
| SCL | Serial clock input | Positive-edge sampled clock; defines timing for data setup/hold and ACK generation |
| WP | Hardware write protect control | Active-high lock: tied to VCC → full-array write inhibit; GND/floating → enables software protection modes |
| GND | Ground reference | Return path for VCC, SDA, SCL, and WP; must be low-impedance for noise immunity |
| VCC | Power supply | 1.7V–5.5V operation; powers internal HV pump, timing circuitry, and I/O buffers |
Key Features
| Feature | Design Value |
|---|---|
| EUI-48 address storage | Factory-programmed, permanently locked 48-bit IEEE MAC address in dedicated read-only memory block (9Ah–9Fh), eliminating need for external MAC provisioning |
| 128-bit unique serial number | Guaranteed unique across Atmel's AT24CS/AT93CS/AT25S families; stored at 80h–8Fh; enables secure device authentication and traceability |
| Dual software write protection | Supports both irreversible (PSWP) and reversible (RSWP) locking of first-half memory (00h–7Fh), enabling flexible firmware update partitioning |
| Hardware write protect pin | WP pin provides system-level, always-active full-array lock when pulled high - independent of software state and immune to firmware corruption |
| Low-voltage I²C operation | Validated 400 kHz operation down to 1.7V VCC, enabling direct integration with ultra-low-power microcontrollers and battery-backed systems |
Applications
| Network Interface Card Identity | Industrial IoT Edge Node Authentication |
|---|---|
|
Use Scenario: Assigning globally unique MAC addresses to Ethernet/Wi-Fi modules during manufacturing without host CPU involvement. IC Role / Device Role / Timing Role: Provides factory-locked EUI-48 address accessible via I²C using '1011' device prefix; eliminates post-silicon MAC programming steps. Use Value: Reduces production test time and firmware complexity; ensures IEEE compliance and avoids MAC collision in deployed networks. |
Use Scenario: Enabling cryptographic key binding and firmware attestation in battery-powered sensor nodes. IC Role / Device Role / Timing Role: Supplies immutable 128-bit serial number used as hardware root-of-trust seed; accessed via same I²C interface as main memory. Use Value: Enables deterministic device identity for TLS certificate enrollment and secure boot verification without external secure element. |
| Medical Device Calibration Data Lock | Automotive Body Control Module Configuration |
|
Use Scenario: Storing and protecting factory-calibrated sensor offsets and coefficients in Class II medical equipment. IC Role / Device Role / Timing Role: Uses WP pin hardwired to VCC during final test to permanently lock calibration data; user memory remains writable for runtime logs. Use Value: Meets IEC 62304 traceability requirements; prevents accidental or malicious overwrite of safety-critical calibration values. |
Use Scenario: Managing variant-specific configuration (e.g., mirror fold, seat memory) across vehicle trim levels. IC Role / Device Role / Timing Role: Stores configuration bitmaps in user array; uses reversible software write protection (RSWP) to lock settings after dealer programming. Use Value: Supports field-upgradable configurations while preventing end-user tampering; leverages same I²C bus as main MCU. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM with embedded identity applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT24MAC602-SSHM-B | Provides EUI-64 (64-bit) instead of EUI-48; identical pinout, timing, and protection features; extended memory layout differs (EUI at 98h–9Fh) | Required where IEEE 802.15.4, IPv6 autoconfiguration, or true EUI-64 compliance is mandated - no FFFEh insertion needed | Select AT24MAC602-SSHM-B only if EUI-64 native support is required; otherwise AT24MAC402-SSHM-B offers lower cost and smaller memory footprint for EUI-48 use cases |
| AT24C02D-SSHM-T | Standard 2-Kbit I²C EEPROM without EUI or serial number; same SOIC-8 package, voltage range, and timing; lacks extended memory block and WP-driven full-array lock | Used where device identity is managed externally (e.g., MCU flash or secure element); no factory-provisioned uniqueness | Choose AT24C02D-SSHM-T only when EUI/serial number functionality is unnecessary and BOM cost optimization is critical |
Compared with AT24MAC602-SSHM-B, AT24MAC402-SSHM-B delivers EUI-48 natively with identical reliability and protection - avoiding post-read address expansion. Against AT24C02D-SSHM-T, it adds certified uniqueness and hardware-enforced identity integrity at minimal bill-of-materials impact.
Availability
AT24MAC402-SSHM-B is available at Aetrix Electronics and suitable for industrial IoT edge node authentication, medical device calibration data lock, and automotive body control module configuration requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant green packaging.
Supply support for AT24MAC402-SSHM-B 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 technical and manufacturing continuity for the AT24MAC family. The company specializes in secure microcontrollers, analog, and memory solutions for industrial, automotive, and communications markets.
The AT24MAC402-SSHM-B belongs to Microchip's MAC-series serial EEPROM product line, designed specifically to embed IEEE-compliant device identity and cryptographic roots-of-trust directly into cost-sensitive, space-constrained endpoints without requiring external secure elements or host-based provisioning.
FAQ
What is the exact memory organization of the AT24MAC402-SSHM-B?
The AT24MAC402-SSHM-B contains 2 Kbit (256 × 8) of user-accessible EEPROM organized as 16 pages of 16 bytes each (00h–FFh). In addition, it includes an extended memory block outside the main array: EUI-48 occupies addresses 9Ah–9Fh (6 bytes), and the 128-bit serial number resides at 80h–8Fh (16 bytes). Both extended regions are read-only and factory-programmed.
How is the EUI-48 address accessed on the AT24MAC402-SSHM-B?
The EUI-48 address in AT24MAC402-SSHM-B is accessed by issuing an I²C device address word starting with '1011' (Bh), followed by A2/A1/A0 bits and R/W = 1. This triggers read access to the extended memory block where EUI-48 is stored at 9Ah–9Fh. No write operation is possible - the address is permanently locked and read-only.
Can the AT24MAC402-SSHM-B be used at 1.7V supply while maintaining full I²C speed?
Yes. The AT24MAC402-SSHM-B is fully specified for 400 kHz I²C operation at VCC = 1.7V, with tLOW/tHIGH minima of 1.2 μs and 0.6 μs respectively. This allows direct integration with 1.8V I/O domains and ultra-low-power microcontrollers without level-shifting or speed derating.
What happens when the WP pin of the AT24MAC402-SSHM-B is left floating?
When WP is floating, the AT24MAC402-SSHM-B behaves identically to WP = GND: full-array write operations are permitted unless software write protection (PSWP or RSWP) is enabled. However, Atmel recommends tying WP to a defined state (GND or VCC via ≤10kΩ resistor) to prevent noise-induced erratic behavior due to capacitive coupling.
Is the 128-bit serial number in AT24MAC402-SSHM-B unique across all units ever manufactured?
Yes. The 128-bit serial number in AT24MAC402-SSHM-B is factory-programmed and guaranteed unique across all Atmel/Microchip AT24CS, AT93CS, and AT25S series serial EEPROMs. It is stored in a separate, permanently locked memory area (80h–8Fh) and cannot be altered or duplicated.
AT24MAC402-SSHM-B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- 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-SOIC
AT24MAC402-SSHM-B FAQ
1.How can I place an order for AT24MAC402-SSHM-B through Aetrix?
Please submit a Request for Quotation (RFQ) for AT24MAC402-SSHM-B 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-SSHM-B reliable?
The price and inventory of AT24MAC402-SSHM-B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT24MAC402-SSHM-B is usually 5 days.
3.What payment methods are accepted for AT24MAC402-SSHM-B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT24MAC402-SSHM-B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT24MAC402-SSHM-B?
AT24MAC402-SSHM-B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT24MAC402-SSHM-B 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-SSHM-B?
For technical support, including AT24MAC402-SSHM-B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT24MAC402-SSHM-B requirements.
6.How does Aetrix verify that AT24MAC402-SSHM-B is sourced from the original manufacturer or authorized distributors?
All AT24MAC402-SSHM-B 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-SSHM-B meets industry standards.
7.What is the process for return or replacement of AT24MAC402-SSHM-B?
All AT24MAC402-SSHM-B units undergo pre-shipment inspection (PSI). If there is an issue with AT24MAC402-SSHM-B, 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-SSHM-B part is unused and in its original packaging.
Return procedure for AT24MAC402-SSHM-B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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