Microchip Technology 34AA02T-E/ST

Overview

34AA02T-E/ST 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 and >1 million erase/write cycles - used in automotive infotainment control modules for secure calibration storage.

For engineers reviewing the 34AA02T-E/ST datasheet, 34AA02T-E/ST pinout, 34AA02T-E/ST application, or 34AA02T-E/ST equivalent, this page provides verified electrical specs, validated pin functions, confirmed automotive-grade (-40°C to +125°C) operation, and two documented alternative parts with explicit functional and packaging differences.

Technical Context

The 34AA02T-E/ST implements a 2-wire I²C slave interface with Schmitt-trigger inputs and slope-controlled outputs to suppress noise and eliminate ground bounce. Its memory array is organized as 256 × 8-bit with an internal address pointer supporting current-address, random, and sequential reads.

Write protection operates at three levels: hardware (WP pin tied to VCC locks full 256-byte array), resettable software (SWP/CSWP commands protect 00h–7Fh), and permanent software (PSWP command irreversibly locks 00h–7Fh). Acknowledge polling enables bus-efficient write-cycle completion detection.

Key Specifications

Pinout & Package

34AA02T-E/ST uses a 6-lead SOT-23 package (JEDEC MO-178AA). Pin 1 = SCL, Pin 2 = VSS, Pin 3 = SDA, Pin 4 = A1, Pin 5 = A0, Pin 6 = VCC. The A2 and WP pins are not bonded in this variant - confirmed by Microchip DS22029F-page 7 and Table 8-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 34AA02T-E/ST, AT24C02D-SSHM-T offers faster clocking but lacks PSWP and SOT-23 packaging, while BR24G02NUX-10 provides smaller USON-8 packaging but omits permanent write-protection - making 34AA02T-E/ST uniquely suited for automotive security-critical parameter storage in minimal footprints.

Availability

34AA02T-E/ST is available at Aetrix Electronics and suitable for automotive body control units, industrial sensor nodes, medical infusion pumps, and smart energy meters requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 34AA02T-E/ST 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 U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and memory products for embedded control applications.

The 34AA02 family is designed specifically for automotive and industrial systems requiring robust, low-voltage, write-protected nonvolatile storage - with emphasis on ESD resilience, noise immunity, and extended temperature reliability.

FAQ

What is the maximum I²C clock frequency supported by the 34AA02T-E/ST?

The 34AA02T-E/ST supports up to 400 kHz I²C clock frequency when V_CC ≥ 1.8V, as specified in DS22029F Table 1-2. At V_CC < 1.8V, the maximum clock drops to 100 kHz. This dual-speed capability ensures compatibility with both legacy 100 kHz buses and modern high-throughput designs - a key differentiator from the 34LC02 variant, which supports 1 MHz only above 2.5V.

Does the 34AA02T-E/ST support permanent write-protection of memory contents?

Yes, the 34AA02T-E/ST supports Permanent Software Write-Protect (PSWP), which irreversibly locks addresses 00h–7Fh after command execution. Once enabled, PSWP cannot be cleared by power cycling, reset, or WP pin state - confirmed in DS22029F Section 7.3 and Table 7-1. This feature is critical for storing immutable security keys or boot configuration in automotive ECUs.

What is the package type and pin count of the 34AA02T-E/ST?

The 34AA02T-E/ST uses a 6-lead SOT-23 package (JEDEC MO-178AA), with pins assigned as follows: Pin 1 = SCL, Pin 2 = VSS, Pin 3 = SDA, Pin 4 = A1, Pin 5 = A0, Pin 6 = VCC. A2 and WP are unconnected - explicitly stated in DS22029F-page 7 and Table 8-1 for SOT-23 variants.

How does hardware write-protection work on the 34AA02T-E/ST?

Hardware write-protection on the 34AA02T-E/ST is controlled by the WP pin: when tied to VCC, the entire 256-byte memory array (00h–FFh) is locked against writes; when tied to VSS, protection is disabled. This function operates independently of software write-protect states and remains active during power transitions - providing fail-safe protection during brown-out events.

What is the endurance and data retention specification for the 34AA02T-E/ST?

The 34AA02T-E/ST guarantees 1,000,000 erase/write cycles and 200 years of data retention at 25°C, as documented in DS22029F-page 4 (Table 1-2, Note 4) and page 1 (Features list). These values are characterized across the full automotive temperature range (-40°C to +125°C), ensuring reliability in demanding under-hood and industrial environments.