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Home > Products > Integrated Circuits (ICs) > Memory > Memory

Microchip Technology AT34C02D-SSHMHL-T

Name: AT34C02D-SSHMHL-T
Brand: Microchip Technology
SKU: AT34C02D-SSHMHL-T
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AT34C02D-SSHMHL-T

Manufacturer:: Microchip Technology

Category:: Memory

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: AT34C02D-SSHMHL-T.pdf

Description:: IC EEPROM 2KBIT I2C 1MHZ 8SOIC

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Product details

Overview

AT34C02D-SSHMHL-T from Microchip Technology (formerly Atmel) is a JEDEC EE1002/EE1002A-compliant Serial Presence Detect (SPD) EEPROM for DDR/DDR2/DDR3 DIMM modules, delivering 2 Kbit (256 × 8) nonvolatile memory with I²C-compatible 2-wire interface, 1.7–5.5 V operation, and hardware/software write protection. It supports SPD data storage in memory subsystems requiring robust configuration persistence and industrial-grade reliability.

For engineers reviewing the AT34C02D-SSHMHL-T datasheet, AT34C02D-SSHMHL-T pinout, AT34C02D-SSHMHL-T application, or AT34C02D-SSHMHL-T equivalent, key selection considerations include SPD compliance, dual software write protection modes (permanent and reversible), WP-pin-controlled full-array hardware protection, 16-byte page write capability, and industrial temperature range (−40°C to +85°C) in JEDEC SOIC package.

Technical Context

The AT34C02D-SSHMHL-T implements a dedicated SPD EEPROM architecture with hardwired A0–A2 address inputs enabling up to eight devices on one I²C bus, and a dedicated WP pin that disables all writes when pulled high. Its internal memory is organized as 16 pages of 16 bytes each, supporting both byte and 16-byte page writes with automatic address incrementing within pages.

It features Schmitt-triggered SCL/SDA inputs for noise immunity, self-timed 5 ms max write cycles, and dual-layer write protection: permanent/reversible software protection for lower 128 bytes (0x00–0x7F) and hardware-level full-array protection via WP. The device responds to standard I²C device address 0xA0–0xA7 (R/W bit dependent) and supports 400 kHz (1.7–3.6 V) or 1 MHz (5.0 V) clock rates.

Key Specifications

Parameter	Value and Actual Design Meaning
Memory Size	2 Kbit (256 × 8 bits), organized as 16 pages × 16 bytes - enables compact SPD data storage for DDR/DDR2/DDR3 module identification and timing parameters.
Supply Voltage Range	1.7 V to 5.5 V - supports interoperability across legacy and modern DIMM power rails including 1.8 V, 2.5 V, 3.3 V, and 5.0 V systems.
I²C Clock Frequency	Up to 400 kHz (1.7–3.6 V) or 1 MHz (5.0 V) - ensures fast SPD read access during system boot while maintaining compatibility with standard SMBus/I²C controllers.
Write Protection	Hardware (WP pin) + permanent/reversible software (lower 128 bytes) - allows flexible, layered security: full-array lockout for field updates, selective lower-half protection for critical SPD fields.
Endurance & Retention	1,000,000 write cycles / 100 years data retention - guarantees long-term reliability in memory module lifecycle management and field reprogramming scenarios.
Operating Temperature	−40°C to +85°C - qualified for industrial-grade DIMM applications including servers, telecom infrastructure, and embedded computing.
Package	8-lead JEDEC SOIC (8S1), 150-mil body - industry-standard footprint compatible with automated PCB assembly and legacy DIMM layout practices.

Pinout & Package

AT34C02D-SSHMHL-T is packaged in an 8-lead JEDEC SOIC (8S1) with 150-mil body width, 1.27 mm pitch, and RoHS-compliant NiPdAu finish. Pin 1 is marked by a beveled corner or laser dot per JEDEC MS-012.

Pin/Terminal	Circuit Role	Design Meaning
A0–A2	Hardwired device address inputs	Set 3-bit hardware address (0–7) for multi-device I²C bus; must be tied to VCC/GND - floating pins default to GND but risk coupling-induced misaddressing.
GND	Ground reference	Return path for VCC and signal logic; requires low-impedance connection to minimize noise in SPD read/write timing margins.
SDA	Bidirectional serial data line	Open-drain I²C bus line requiring external pull-up; supports wire-OR with other open-drain devices on same bus segment.
SCL	Serial clock input	Positive-edge sampled clock for data input, negative-edge sampled for data output - defines timing window for SPD data transfer compliance.
WP	Hardware write protect control	Pulled high → full-array write inhibit; pulled low/floating → enables software protection modes - critical for preventing accidental SPD corruption during system runtime.
VCC	Power supply input	Accepts 1.7–5.5 V; decoupling capacitor (0.1 µF ceramic) required near pin to suppress I²C switching transients and ensure stable SPD reads during power-on initialization.

Key Features

Feature	Design Value
JEDEC EE1002/EE1002A SPD Compliance	Fully implements mandatory SPD register map and timing for DDR, DDR2, and DDR3 DIMMs - eliminates need for custom firmware translation layers in memory controller BIOS.
16-byte Page Write Mode	Reduces SPD programming time by up to 15× vs. byte writes; partial page writes allowed - accelerates factory programming and field updates without full-memory erase.
Permanent + Reversible Software Write Protection	Enables irreversible lockdown of critical SPD fields (e.g., manufacturer ID, module type) while allowing field-serviceable updates to timing parameters - supports secure yet maintainable DIMM lifecycle management.
Self-timed Write Cycle (≤5 ms)	Removes external timing dependency; microcontroller can poll ACK instead of fixed delays - simplifies host driver implementation and improves boot-time predictability.
Schmitt Trigger Inputs	Filters >100 ns noise spikes on SCL/SDA - ensures reliable SPD communication in electrically noisy server backplanes and high-density DIMM slots.

Applications

DDR3 Server DIMM SPD	DDR2 Industrial Memory Module
Use Scenario: Storing JEDEC-defined SPD data (module capacity, speed, timings, manufacturer info) on registered DDR3 RDIMMs used in enterprise servers. IC Role / Device Role / Timing Role: Dedicated SPD EEPROM providing boot-critical configuration data to memory controller during Power-On Self-Test (POST). Use Value: Ensures memory initialization compliance with JEDEC standards, prevents boot failure due to invalid timing parameters, and supports hot-swap module identification via I²C read at 400 kHz.	Use Scenario: Configuring DDR2 UDIMMs deployed in industrial PLCs and ruggedized edge computing systems operating across −40°C to +85°C. IC Role / Device Role / Timing Role: Nonvolatile SPD storage with hardware write protection enabled during field deployment to prevent accidental overwrite of vendor-specific timing tables. Use Value: Guarantees consistent memory behavior after thermal cycling and vibration exposure; WP pin tied to VCC provides tamper-resistant configuration locking.
DDR Legacy Desktop Memory	Embedded System Memory Subsystem
Use Scenario: Supporting DDR SDRAM modules in cost-sensitive desktop PCs where SPD data must persist across 10+ years of consumer use. IC Role / Device Role / Timing Role: Low-voltage (1.8 V) SPD EEPROM interfacing with legacy SMBus controllers in northbridge chipsets. Use Value: 100-year data retention and 1M write cycles enable reliable SPD updates during BIOS upgrades and memory reconfiguration without replacement.	Use Scenario: Providing SPD-like configuration storage for proprietary memory subsystems in medical imaging equipment requiring traceable, field-updatable calibration data. IC Role / Device Role / Timing Role: Secure configuration store using reversible software write protection to allow authorized firmware updates while blocking unauthorized writes to safety-critical registers. Use Value: Combines permanent protection for immutable identifiers with field-programmable timing offsets - meets IEC 62304 software lifecycle requirements.

DDR3 Server DIMM SPD

DDR2 Industrial Memory Module

Use Scenario: Storing JEDEC-defined SPD data (module capacity, speed, timings, manufacturer info) on registered DDR3 RDIMMs used in enterprise servers.

IC Role / Device Role / Timing Role: Dedicated SPD EEPROM providing boot-critical configuration data to memory controller during Power-On Self-Test (POST).

Use Value: Ensures memory initialization compliance with JEDEC standards, prevents boot failure due to invalid timing parameters, and supports hot-swap module identification via I²C read at 400 kHz.

Use Scenario: Configuring DDR2 UDIMMs deployed in industrial PLCs and ruggedized edge computing systems operating across −40°C to +85°C.

IC Role / Device Role / Timing Role: Nonvolatile SPD storage with hardware write protection enabled during field deployment to prevent accidental overwrite of vendor-specific timing tables.

Use Value: Guarantees consistent memory behavior after thermal cycling and vibration exposure; WP pin tied to VCC provides tamper-resistant configuration locking.

DDR Legacy Desktop Memory

Embedded System Memory Subsystem

Use Scenario: Supporting DDR SDRAM modules in cost-sensitive desktop PCs where SPD data must persist across 10+ years of consumer use.

IC Role / Device Role / Timing Role: Low-voltage (1.8 V) SPD EEPROM interfacing with legacy SMBus controllers in northbridge chipsets.

Use Value: 100-year data retention and 1M write cycles enable reliable SPD updates during BIOS upgrades and memory reconfiguration without replacement.

Use Scenario: Providing SPD-like configuration storage for proprietary memory subsystems in medical imaging equipment requiring traceable, field-updatable calibration data.

IC Role / Device Role / Timing Role: Secure configuration store using reversible software write protection to allow authorized firmware updates while blocking unauthorized writes to safety-critical registers.

Use Value: Combines permanent protection for immutable identifiers with field-programmable timing offsets - meets IEC 62304 software lifecycle requirements.

Equivalent & Alternatives

The following parts are listed as comparable options for similar SPD EEPROM applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
AT24C02D-SSHM-T	Same 2 Kbit density and SOIC package, but lacks JEDEC EE1002/EE1002A SPD compliance and permanent software write protection - only offers basic I²C EEPROM functionality.	Not suitable for DDR/DDR2/DDR3 DIMMs requiring SPD register mapping; limited to generic configuration storage where JEDEC compliance is unnecessary.	Select only if SPD functionality is unused and cost reduction outweighs SPD feature loss; verify host firmware does not expect EE1002 register layout.
STMicroelectronics M24C02-RMN6TP	2 Kbit I²C EEPROM in SOIC-8 with 1.7–5.5 V operation and hardware WP, but no permanent/reversible software write protection or SPD-specific addressing modes.	Requires custom firmware adaptation for SPD use; lacks native support for SPD register access patterns and write-protection granularity needed in memory modules.	Use only in non-SPD applications or where full SPD compliance is handled externally; not drop-in for AT34C02D-SSHMHL-T in JEDEC-conformant DIMMs.

Compared with AT24C02D-SSHM-T and M24C02-RMN6TP, the AT34C02D-SSHMHL-T uniquely delivers JEDEC EE1002/EE1002A compliance, dual-mode software write protection, and guaranteed SPD timing - making it the only qualified choice for production DDR/DDR2/DDR3 memory modules requiring certified SPD functionality.

Availability

AT34C02D-SSHMHL-T is available at Aetrix Electronics and suitable for DDR3 server DIMMs, DDR2 industrial memory modules, legacy DDR desktop memory, and embedded system memory subsystems requiring stable component supply, long-lifecycle support, and JEDEC SPD compliance.

Supply support for AT34C02D-SSHMHL-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, qualification, and support for the AT34C02D family. Microchip is a global leader in microcontrollers, analog, and memory solutions with ISO 9001-certified manufacturing.

The AT34C02D belongs to Microchip's Serial EEPROM portfolio designed specifically for JEDEC-compliant Serial Presence Detect applications in DDR/DDR2/DDR3 memory modules - emphasizing SPD register fidelity, industrial temperature resilience, and multi-layer write security.

FAQ

What is the primary function of the AT34C02D-SSHMHL-T in memory modules?

The AT34C02D-SSHMHL-T serves as a JEDEC EE1002/EE1002A-compliant Serial Presence Detect (SPD) EEPROM, storing critical configuration data - including module capacity, speed, timing parameters, and manufacturer information - for DDR, DDR2, and DDR3 DIMMs. During system boot, the memory controller reads this data via I²C to initialize the DRAM correctly. The AT34C02D-SSHMHL-T ensures strict adherence to SPD register maps and timing requirements defined by JEDEC standards.

Does the AT34C02D-SSHMHL-T support both permanent and reversible software write protection?

Yes, the AT34C02D-SSHMHL-T implements two independent software write protection mechanisms: a permanent mode that irreversibly locks the lower 128 bytes (0x00–0x7F) once enabled, and a reversible mode that can be toggled on/off using specific command sequences with controlled A0–A2 pin states. Both operate alongside hardware write protection via the WP pin. This layered approach allows precise control over SPD field integrity - for example, permanently securing vendor ID while permitting field updates to timing parameters - and is a defining feature of the AT34C02D-SSHMHL-T.

What package type and markings identify the AT34C02D-SSHMHL-T?

The AT34C02D-SSHMHL-T uses an 8-lead JEDEC SOIC package (8S1), 150-mil body width, with NiPdAu lead finish and green molding compound. Its top-side marking is "34D" followed by date code and trace identifier (e.g., "34D HM@ YXX"), where "HM" denotes industrial grade (−40°C to +85°C) and NiPdAu finish. The "SS" in the part number explicitly indicates SOIC packaging, and "HL" confirms halogen-free compliance per IEC 61249-2-21.

Can the AT34C02D-SSHMHL-T operate at 1.8 V and interface with standard SMBus controllers?

Yes, the AT34C02D-SSHMHL-T operates across 1.7 V to 5.5 V, fully supporting 1.8 V VCC operation typical in DDR3L and DDR4 memory subsystems. It is I²C-compatible and adheres to SMBus electrical specifications, including open-drain SDA/SCL with Schmitt-trigger inputs for noise immunity. At 1.8 V, it supports up to 400 kHz clock frequency - sufficient for SPD reads during POST - and maintains full write functionality, including page writes and software protection programming, without voltage derating.

How does hardware write protection via the WP pin interact with software protection modes in the AT34C02D-SSHMHL-T?

In the AT34C02D-SSHMHL-T, the WP pin provides unconditional hardware-level write inhibition: when tied to VCC, all write operations (including software protection register programming) are blocked regardless of software protection state. When WP is low or floating, software protection modes govern access - permanent protection locks the lower 128 bytes forever, while reversible protection allows dynamic enable/disable. This hierarchy ensures that WP acts as a master override, enabling system-level lockdown (e.g., during field deployment), while software modes provide granular, firmware-controllable protection - a key safety feature implemented in the AT34C02D-SSHMHL-T.

AT34C02D-SSHMHL-T Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm 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:: -

Voltage - Supply:: 1.7V ~ 5.5V

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

AT34C02D-SSHMHL-T FAQ

1.How can I place an order for AT34C02D-SSHMHL-T through Aetrix?

Please submit a Request for Quotation (RFQ) for AT34C02D-SSHMHL-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 AT34C02D-SSHMHL-T reliable?

The price and inventory of AT34C02D-SSHMHL-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT34C02D-SSHMHL-T is usually 5 days.

3.What payment methods are accepted for AT34C02D-SSHMHL-T?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT34C02D-SSHMHL-T transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AT34C02D-SSHMHL-T?

AT34C02D-SSHMHL-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AT34C02D-SSHMHL-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 AT34C02D-SSHMHL-T?

For technical support, including AT34C02D-SSHMHL-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT34C02D-SSHMHL-T requirements.

6.How does Aetrix verify that AT34C02D-SSHMHL-T is sourced from the original manufacturer or authorized distributors?

All AT34C02D-SSHMHL-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 AT34C02D-SSHMHL-T meets industry standards.

7.What is the process for return or replacement of AT34C02D-SSHMHL-T?

All AT34C02D-SSHMHL-T units undergo pre-shipment inspection (PSI). If there is an issue with AT34C02D-SSHMHL-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 AT34C02D-SSHMHL-T part is unused and in its original packaging.

Return procedure for AT34C02D-SSHMHL-T:

1.Submit a request within 90 days.

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

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