Microchip Technology 34LC02T-I/ST

Overview

34LC02T-I/ST from Microchip Technology is a 2 Kbit I²C-compatible serial EEPROM with hardware and dual software write-protection, 1 MHz clock support (V_CC ≥ 2.5 V), 16-byte page write buffer, and operation down to 1.7 V. It features Schmitt-trigger inputs, slope-controlled outputs, and >1 million erase/write cycles - used for secure parameter storage in industrial sensor nodes and embedded control modules.

For engineers reviewing the 34LC02T-I/ST datasheet, 34LC02T-I/ST pinout, 34LC02T-I/ST application, or 34LC02T-I/ST equivalent, key selection criteria include write-protection flexibility (hardware WP pin + resettable/permanent SWP), extended temperature range (–40°C to +85°C), TSSOP-8 package compatibility, and I²C bus timing compliance at 1 MHz under 2.5–5.5 V.

Technical Context

The 34LC02T-I/ST implements a slave-only I²C interface with fixed 4-bit device code (1010b) and 3-bit chip-select addressing (A2–A0), enabling up to eight devices on one bus. Its internal address pointer supports current-address, random, and sequential reads across the 256 × 8-bit memory array.

Write protection operates at three levels: hardware (WP pin tied to V_CC locks full 256-byte array), resettable software (SWP/CSWP commands protect addresses 00h–7Fh), and permanent software (PSWP command irreversibly locks lower 128 bytes). All write cycles are self-timed with 5 ms typical duration.

Key Specifications

Pinout & Package

34LC02T-I/ST is packaged in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch, optimized for automated SMT assembly and space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C02D-SSHM-T and FM24CL04B-G, the 34LC02T-I/ST uniquely delivers triple-layer write protection (hardware + resettable + permanent) in a TSSOP-8 package with guaranteed 1 MHz I²C performance above 2.5 V - making it optimal for safety-critical calibration storage where data immutability and bus speed are jointly required.

Availability

34LC02T-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive body control modules, and smart meter firmware settings requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 34LC02T-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 components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 34LC02T-I/ST belongs to Microchip's serial EEPROM product line, engineered specifically for robust, low-power, and secure nonvolatile data storage in industrial, automotive, and consumer applications demanding extended temperature operation and flexible write protection.

FAQ

What voltage range does the 34LC02T-I/ST support, and how does it differ from the 34AA02?

The 34LC02T-I/ST operates from 2.2 V to 5.5 V, with 1 MHz I²C clock capability above 2.5 V. In contrast, the 34AA02 supports 1.7 V minimum and maxes out at 400 kHz - making the 34LC02T-I/ST better suited for 3.3 V systems needing faster configuration writes, while the 34AA02 targets ultra-low-voltage battery applications. Both share identical pinout and software features.

How does the permanent software write-protect (PSWP) function work on the 34LC02T-I/ST?

The PSWP command on the 34LC02T-I/ST irreversibly locks addresses 00h–7Fh against all future writes, regardless of WP pin state or power cycling. It requires applying high voltage (7–10 V) to the A0 pin during command execution. Once activated, the 34LC02T-I/ST no longer acknowledges the 0110b device identifier used for SWP/CSWP - ensuring factory calibration data remains tamper-proof for the device's lifetime.

Can multiple 34LC02T-I/ST devices share the same I²C bus, and what limits the count?

Yes, up to eight 34LC02T-I/ST devices can share one I²C bus using unique combinations of A2/A1/A0 pins. Each device responds only when its 3-bit chip-select matches the corresponding bits in the master's control byte. The 34LC02T-I/ST's TSSOP-8 package includes all three address pins, unlike SOT-23 variants where A2 is NC - confirming full 8-device scalability for this specific variant.

What is the maximum write speed and page buffer size of the 34LC02T-I/ST?

At V_CC ≥ 2.5 V, the 34LC02T-I/ST supports 1 MHz I²C clocking and features a 16-byte page write buffer. This allows up to 16 bytes to be written in a single I²C transaction with a typical self-timed write cycle of 5 ms - delivering 3.2× higher effective throughput than byte-write mode and reducing bus arbitration overhead in configuration-intensive systems.

Does the 34LC02T-I/ST require external pull-up resistors on SDA and SCL, and what values are recommended?

Yes, the 34LC02T-I/ST has open-drain SDA and SCL pins requiring external pull-up resistors to V_CC. For 1 MHz operation, a 2 kΩ pull-up is recommended; for 400 kHz, 10 kΩ is typical. Values must balance rise time (per I²C spec: ≤ 1000 ns at 1 MHz) against bus capacitance and drive strength - undersized resistors increase power consumption, oversized ones risk timing violations.