Microchip Technology 34LC02-E/SN

Overview

34LC02-E/SN from Microchip Technology Inc. is a 2 Kbit I²C-compatible serial EEPROM with hardware and dual software write-protection, operating from 2.2V to 5.5V, supporting up to 1 MHz clock frequency, 16-byte page write buffer, and rated for automotive temperature range (–40°C to +125°C). It serves as nonvolatile configuration storage in automotive body control modules, industrial sensor nodes, and embedded system boot loaders.

For engineers reviewing the 34LC02-E/SN datasheet, 34LC02-E/SN pinout, 34LC02-E/SN application, or 34LC02-E/SN equivalent, key selection criteria include its 1 MHz I²C speed at V_CC ≥ 2.5V, permanent and resettable lower-half array protection (00h–7Fh), 8-lead SOIC package with A0/A1/A2 address pins, and automotive-grade reliability with >1 million erase/write cycles and >200 years data retention.

Technical Context

The 34LC02-E/SN implements a 2-wire I²C slave interface with Schmitt-trigger inputs and slope-controlled outputs to suppress noise and eliminate ground bounce. Its internal architecture includes a 256 × 8-bit memory array, HV generator for EEPROM programming, and dedicated write-protect logic that evaluates both WP pin state and software register bits before permitting writes.

It supports three write-protection modes: hardware-based full-array lock via WP pin tied to V_CC, resettable software protection of addresses 00h–7Fh (SWP/CSWP), and permanent software lock of the same region (PSWP). Acknowledge polling is used to detect write cycle completion, and page writes are constrained to 16-byte boundaries without automatic wrap-around across physical pages.

Key Specifications

Pinout & Package

34LC02-E/SN is supplied in an 8-lead SOIC (Small Outline Integrated Circuit) package, 3.90 mm wide, with gull-wing leads and RoHS-compliant matte tin plating. Pin 1 is marked by a beveled corner or dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C02C-SSHM-T and BR24G02FJ-3GE2, the 34LC02-E/SN uniquely delivers permanent software write-protection (PSWP) for critical boot data, automotive temperature qualification, and dual-mode software protection - making it the only option for safety-critical or regulatory-compliant firmware storage where irreversible data integrity is mandatory.

Availability

34LC02-E/SN is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor calibration, and embedded boot loader applications requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for 34LC02-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 microcontrollers, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global manufacturing and support infrastructure.

The 34LC02 belongs to Microchip's serial EEPROM product line, designed specifically for automotive and industrial applications demanding high reliability, extended temperature operation, and robust write-protection mechanisms.

FAQ

What is the maximum I²C clock frequency supported by the 34LC02-E/SN?

The 34LC02-E/SN supports up to 1 MHz I²C clock frequency when V_CC is 2.5V or higher. At lower voltages (e.g., 1.7–2.4V), the maximum clock drops to 400 kHz. This dual-speed capability allows system designers to optimize bus throughput without compromising low-voltage operation in brown-out conditions. The 34LC02-E/SN datasheet specifies exact timing parameters for each voltage band.

How does hardware write-protection work on the 34LC02-E/SN?

Hardware write-protection on the 34LC02-E/SN is controlled by the WP pin: when tied to V_CC, it disables all write operations to the entire 256-byte memory array, regardless of software write-protect status. When tied to V_SS, hardware protection is disabled and software-based protection (SWP/PSWP) governs access. This pin-level lock provides deterministic, glitch-immune protection during firmware updates or power transitions.

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

The 34LC02-E/SN is not a drop-in replacement for the 34AA02 due to differing V_CC minima and clock speed profiles: the 34AA02 operates down to 1.7V and supports only 400 kHz, while the 34LC02-E/SN requires ≥2.2V and supports 1 MHz. Interchangeability depends on whether the host system supplies ≥2.2V and can tolerate the higher clock rate. Electrical pinout and command set are identical.

What is the purpose of the PSWP command in the 34LC02-E/SN?

The PSWP (Permanent Software Write-Protect) command in the 34LC02-E/SN irreversibly locks addresses 00h–7Fh (lower 128 bytes) against all future writes, including power cycles, WP pin state changes, or CSWP commands. Once executed, the device no longer acknowledges the '0110' device identifier used for SWP/CSWP, ensuring cryptographic keys or boot code remain tamper-proof throughout the product's service life.

Does the 34LC02-E/SN support page write operations across memory boundaries?

No, the 34LC02-E/SN does not support page writes across physical page boundaries. Its 16-byte page buffer wraps within the current page (e.g., writing 16 bytes starting at address 0x70 will overwrite 0x70–0x7F and then 0x70–0x7F again, not advance to 0x80). Application firmware must enforce alignment to 16-byte boundaries to avoid unintended data loss - a constraint explicitly documented in the 34LC02-E/SN datasheet.