Microchip Technology 34LC02-I/ST

Overview

34LC02-I/ST 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 1 MHz clock speed, 16-byte page write buffer, and rated for industrial temperature (–40°C to +85°C). It serves as nonvolatile configuration storage in embedded controllers, sensor nodes, and power management ICs.

For engineers reviewing the 34LC02-I/ST datasheet, 34LC02-I/ST pinout, 34LC02-I/ST application, or 34LC02-I/ST equivalent, key selection criteria include its 1 MHz I²C timing compliance, WP pin-based full-array hardware protection, permanent/resetttable lower-half software write-protect, 100 nA standby current, and SOT-23-6 package compatibility with space-constrained PCB layouts.

Technical Context

The 34LC02-I/ST implements a 256 × 8-bit memory array organized as a single block, accessed via a bidirectional 2-wire I²C bus where it operates exclusively as a slave device. Its internal address pointer auto-increments during sequential reads and page writes, enabling contiguous access within the 16-byte page boundary.

Write protection is enforced at three levels: hardware (WP pin tied to VCC), resettable software (SWP/CSWP commands), and permanent software (PSWP command), all targeting addresses 00h–7Fh. Schmitt-trigger inputs on SCL/SDA and input filtering suppress noise, while VCC threshold detection disables write operations below 1.35V to prevent corruption during brown-out.

Key Specifications

Pinout & Package

34LC02-I/ST is packaged in a Pb-free, RoHS-compliant 6-lead SOT-23 surface-mount package (body dimensions: 2.9 mm × 1.6 mm × 1.1 mm). Pin 1 is SCL; pin 2 is VSS; pin 3 is SDA; pin 4 is A1; pin 5 is A0; pin 6 is VCC. A2 and WP pins are not connected (NC) in this variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C02D-SSHM-T and BR24G02NUX-5TR, the 34LC02-I/ST uniquely delivers permanent software write-protection for critical calibration data, making it optimal for applications where irreversible parameter locking is mandated by safety or regulatory standards.

Availability

34LC02-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, smart meter configuration storage, IoT edge node identity, and motor drive parameter storage requiring stable component supply across extended product lifecycles.

Supply support for 34LC02-I/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 leading provider of microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 34LC02 belongs to Microchip's serial EEPROM product line, engineered for robust, low-power nonvolatile storage in industrial, automotive, and consumer applications where data integrity and long-term reliability are essential.

FAQ

What is the maximum I²C clock frequency supported by the 34LC02-I/ST?

The 34LC02-I/ST supports up to 1 MHz I²C clock frequency when VCC is 2.5V or higher. At lower voltages (2.2V ≤ VCC < 2.5V), timing specifications align with 400 kHz operation. This 1 MHz capability enables faster configuration loading than legacy 400 kHz EEPROMs, directly reducing system initialization time in the 34LC02-I/ST implementation.

Does the 34LC02-I/ST have permanent write protection, and how is it enabled?

Yes, the 34LC02-I/ST supports Permanent Software Write-Protect (PSWP) for addresses 00h–7Fh. It is enabled by issuing a specific command sequence with high-voltage detection on the A0 pin and correct A1/A2 levels. Once executed, PSWP cannot be cleared by power cycling, software commands, or WP pin state - ensuring irreversible protection of critical calibration data stored in the 34LC02-I/ST.

What package type is used for the 34LC02-I/ST, and which pins are NC?

The 34LC02-I/ST uses a 6-lead SOT-23 package. Pins A2 and WP are not connected (NC) in this variant - confirmed by the device marking "34LC02I" and Microchip's DS22029F-page 14 pin function table. The functional pins are SCL (1), VSS (2), SDA (3), A1 (4), A0 (5), and VCC (6), enabling compact placement in space-constrained designs using the 34LC02-I/ST.

How does hardware write protection work on the 34LC02-I/ST?

Hardware write protection on the 34LC02-I/ST is controlled by the WP pin: when tied to VCC, the entire 256-byte memory array (00h–FFh) is write-protected regardless of software protection status; when tied to VSS, hardware protection is disabled. This feature provides a physical, always-active safeguard against unintended writes during programming or field operation - a key reliability mechanism built into the 34LC02-I/ST.

What is the endurance and data retention specification for the 34LC02-I/ST?

The 34LC02-I/ST guarantees 1 million erase/write cycles and 200 years of data retention at 25°C. These figures are characterized per Microchip DS22029F-page 4 (Table 1-2, Note 4) and page 1 (Features list). This endurance supports frequent runtime updates in industrial controllers, while the 200-year retention ensures calibration data integrity across decades - a defining reliability attribute of the 34LC02-I/ST.