Microchip Technology 34AA02-E/SN

Overview

34AA02-E/SN from Microchip Technology is a 2 Kbit I²C-compatible serial EEPROM with permanent and resettable software write-protection for the lower 128 bytes (00h–7Fh), hardware write-protection via WP pin, 1.7V to 5.5V single-supply operation, and 400 kHz max clock frequency. It supports page writes of up to 16 bytes and delivers 100 nA standby current at -40°C to +125°C, enabling use in automotive body control modules requiring nonvolatile configuration storage.

For engineers reviewing the 34AA02-E/SN datasheet, 34AA02-E/SN pinout, 34AA02-E/SN application, or 34AA02-E/SN equivalent, key selection criteria include its automotive-grade temperature range (-40°C to +125°C), dual-layer write protection (SWP/PSWP + hardware WP), low-voltage 1.7V operation, and compatibility with standard I²C bus timing including Schmitt-trigger inputs and slope-controlled outputs.

Technical Context

The 34AA02-E/SN implements a 256 × 8-bit memory array organized as a single block, accessed via a bidirectional 2-wire I²C interface where it operates exclusively as a slave device. Its internal address pointer auto-increments during sequential reads and wraps within 16-byte page boundaries during page writes.

Write protection is enforced through three independent mechanisms: hardware-level protection via the WP pin (VCC = full-array lock), resettable software write-protect (SWP/CSWP), and permanent software write-protect (PSWP) - each validated by distinct high-voltage command sequences applied to A0 and verified against A1/A2 states.

Key Specifications

Pinout & Package

34AA02-E/SN is supplied in an 8-lead SOIC package (3.90 mm width), RoHS-compliant and Pb-free. Pin functions are electrically identical across PDIP, SOIC, TSSOP, MSOP, and TDFN variants; SOT-23 variant omits A2 and WP pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 34AA02-E/SN, AT24C02C-SSHM-T offers faster clocking but lacks PSWP, while BR24G02-3SER adds ECC at the cost of software write-protection granularity - making 34AA02-E/SN uniquely suited for applications requiring layered, irreversible configuration locking.

Availability

34AA02-E/SN is available at Aetrix Electronics and suitable for automotive body control units, industrial sensor nodes, medical handheld diagnostics, and smart energy metering requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 34AA02-E/SN 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, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 34AA02-E/SN belongs to Microchip's serial EEPROM product line, designed specifically for automotive and industrial applications demanding extended temperature operation, robust write protection, and ultra-low power consumption in I²C-based systems.

FAQ

What is the maximum I²C clock frequency supported by the 34AA02-E/SN?

The 34AA02-E/SN supports up to 400 kHz I²C clock frequency when VCC is 1.8V or higher. At VCC < 1.8V, the maximum clock rate drops to 100 kHz to ensure reliable timing margins. This dual-speed capability allows seamless integration across 1.8V, 3.3V, and 5V system domains while maintaining noise immunity via Schmitt-trigger inputs and controlled output slopes.

How does hardware write-protection work on the 34AA02-E/SN?

Hardware write-protection on the 34AA02-E/SN is controlled by the WP pin: tying WP to VCC disables all write operations to the full 256-byte memory array, regardless of software write-protect status; tying WP to VSS enables writes subject to SWP/PSWP settings. This provides fail-safe protection during power-up or system reset sequences where software control may be unavailable.

Can the 34AA02-E/SN be used in place of the 34LC02?

No - the 34AA02-E/SN and 34LC02 are not interchangeable. While both are 2 Kbit I²C EEPROMs, the 34LC02 supports 1 MHz clocking and requires VCC ≥ 2.2V, whereas the 34AA02-E/SN operates down to 1.7V but is limited to 400 kHz. Substituting them risks timing violations or undervoltage lockout in the 34AA02-E/SN or insufficient speed in the 34LC02.

What is the purpose of the A0 pin beyond chip addressing in the 34AA02-E/SN?

In addition to serving as bit 0 of the 3-bit slave address, the A0 pin on the 34AA02-E/SN detects high-voltage (VHV) during software write-protect commands: SWP and CSWP require ≥7V applied to A0 (with specific A1/A2 states) to activate. This prevents accidental activation of permanent or resettable protection under normal logic-level conditions, enhancing system security.

Does the 34AA02-E/SN support page writes across memory boundaries?

No - page writes on the 34AA02-E/SN are strictly confined within 16-byte physical pages (00h–0Fh, 10h–1Fh, etc.). Attempting to write across a boundary causes wraparound to the start of the same page, overwriting prior data. Application firmware must validate write addresses and split multi-page operations manually to avoid unintended data loss during bulk programming.