Microchip Technology 24AA02E64T-E/OT

Overview

24AA02E64T-E/OT from Microchip Technology Inc. is a 2 Kbit I²C-compatible serial EEPROM with factory-programmed, globally unique EUI-64™ node address stored in write-protected memory (0xF8–0xFF). It operates from 1.7V to 5.5V, supports 400 kHz I²C clock (100 kHz at VCC <2.5V), and delivers ≤1 µA standby current (I-temp) for low-power embedded identity storage in networked devices.

For engineers reviewing the 24AA02E64T-E/OT datasheet, 24AA02E64T-E/OT pinout, 24AA02E64T-E/OT application, or 24AA02E64T-E/OT equivalent, key selection criteria include guaranteed EUI-64™ uniqueness, 8-byte page write capability, Schmitt-trigger I²C inputs for noise immunity, industrial temperature range (−40°C to +85°C), and SOIC-8/SOT-23-5 package compatibility.

Technical Context

The 24AA02E64T-E/OT implements a two-block 128 × 8-bit EEPROM array with hardware write protection on upper half (0x80–0xFF), where the EUI-64™ address resides. Its I²C slave interface uses fixed 7-bit address 0xA0 (R/W=0) with A0–A2 pins unconnected and functionally "don't care" - eliminating external address configuration.

Internal architecture includes HV generator for EEPROM programming, X/Y decoders, sense amplifiers, and write-protect circuitry. All I/O features Schmitt-trigger inputs and slope-controlled outputs to suppress ground bounce and tolerate bus noise - critical for reliable node ID retrieval in electrically noisy industrial control or IoT edge nodes.

Key Specifications

Pinout & Package

Available in 8-lead SOIC (3.90 mm body) and 5-lead SOT-23 packages. The 24AA02E64T-E/OT uses the 5-lead SOT-23 variant (pin count confirmed per DS20002124H, Table 2-1), with A0, A1, A2 pins unconnected and unused.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar EEPROM-based node identity applications.

Compared with 24AA02E48T-E/OT, the 24AA02E64T-E/OT provides native EUI-64™ compliance for modern IP-based protocols, while AT24C02C-SSHM-T offers greater flexibility at the cost of added firmware complexity and no guaranteed uniqueness.

Availability

24AA02E64T-E/OT is available at Aetrix Electronics and suitable for industrial Ethernet node identity, IoT edge device serialization, medical equipment asset tracking, and automotive telematics module ID requiring stable component supply and guaranteed long-term availability.

Supply support for 24AA02E64T-E/OT 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 Inc. is a leading provider of microcontroller, analog, FPGA, and memory solutions, serving industrial, automotive, communications, and consumer markets with high-reliability silicon and development tools.

The 24AA02E64T-E/OT belongs to Microchip's 24AA02XEXX family of preprogrammed serial EEPROMs, designed specifically to simplify secure, standards-compliant device identity management in networked embedded systems.

FAQ

What is the exact memory organization and address map of the 24AA02E64T-E/OT?

The 24AA02E64T-E/OT contains 256 bytes (2 Kbit) organized as two 128-byte blocks. The EUI-64™ node address occupies addresses 0xF8–0xFF (8 bytes), permanently write-protected. User-accessible memory spans 0x00–0x7F (128 bytes), while 0x80–0xF7 (120 bytes) is reserved and not usable. This layout ensures identity integrity while providing dedicated space for application-specific data in the lower block.

Does the 24AA02E64T-E/OT require external pull-up resistors on SDA and SCL lines?

Yes, the 24AA02E64T-E/OT requires external pull-up resistors on both SDA and SCL lines because it uses open-drain I²C outputs. For 400 kHz operation, a 2 kΩ pull-up to VCC is recommended; for 100 kHz, 10 kΩ is typical. These values ensure proper rise times per I²C specification and prevent bus contention in multi-slave systems.

Can the factory-programmed EUI-64™ address in the 24AA02E64T-E/OT be modified or erased?

No, the EUI-64™ address in the 24AA02E64T-E/OT is factory-programmed into the upper memory block (0xF8–0xFF) and permanently write-protected. Attempts to write to this region are ignored. Only the lower 128-byte block (0x00–0x7F) is user-writable. This ensures cryptographic-grade uniqueness and prevents accidental or malicious tampering with device identity.

What is the maximum I²C clock frequency supported by the 24AA02E64T-E/OT, and does it depend on supply voltage?

The 24AA02E64T-E/OT supports up to 400 kHz I²C clock frequency when VCC ≥2.5V. When VCC is between 1.7V and 2.5V, maximum clock frequency is reduced to 100 kHz. This voltage-dependent limitation is specified in DS20002124H Table 1-2 and ensures reliable timing margin across the full operating range of the 24AA02E64T-E/OT.

Is the 24AA02E64T-E/OT pin-compatible with other variants like the 24AA025E64T-E/OT?

No, the 24AA02E64T-E/OT is not pin-compatible with the 24AA025E64T-E/OT. The former uses 5-lead SOT-23 or 8-lead SOIC packages with A0–A2 pins unconnected, while the latter uses 6-lead SOT-23 or 8-lead SOIC with functional A0–A2 address inputs. Physical pin count and chip-select functionality differ - direct substitution would require PCB redesign and firmware changes to handle address mapping.