Microchip Technology AT34C02C-TH-B

Overview

AT34C02C-TH-B from Microchip Technology (formerly Atmel) is a 2 Kbit (256 × 8) two-wire serial EEPROM with permanent and reversible software write protection, hardware write protection via WP pin, and 1.7V to 5.5V operation. It supports 100 kHz (at 1.7V) and 400 kHz (at 2.7V/5.0V) I²C-compatible communication, 16-byte page writes, and operates across –40°C to +85°C. It is used in industrial control systems for storing calibration data, configuration parameters, and firmware revision flags.

For engineers reviewing the AT34C02C-TH-B datasheet, AT34C02C-TH-B pinout, AT34C02C-TH-B application, or AT34C02C-TH-B equivalent, this page delivers verified electrical specs, package mapping to 8-lead TSSOP, validated write protection behavior, endurance (1 million cycles), and real-world use cases in programmable logic controllers and sensor node firmware storage.

Technical Context

The AT34C02C-TH-B implements a two-wire (I²C) interface with open-drain SDA and Schmitt-triggered SCL inputs for noise immunity. Its internal architecture includes an 8-bit address counter, page-based write logic supporting partial-page writes, and dual-layer write protection: hardware-level array-wide lock via WP pin and software-level first-half (00H–7FH) protection via programmable registers.

It features self-timed 5 ms max write cycles, acknowledge polling support, and three read modes (current address, random, sequential). The device uses internal high-voltage charge pump circuitry for EEPROM programming and includes input capacitance limits (6 pF on A0–A2/SCL, 8 pF on SDA) and strict DC timing thresholds (e.g., VIL ≤ 0.3×VCC, VIH ≥ 0.7×VCC).

Key Specifications

Pinout & Package

AT34C02C-TH-B is packaged in an 8-lead TSSOP (JEDEC MO-153, variation AA), 4.4 mm body width, with gull-wing leads. Pin 1 is marked by a beveled corner or dot; the package is lead-free and halogen-free (NiPdAu finish).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT34C02C-TH-B, AT34C02D-TH-B offers enhanced ESD immunity without layout or firmware changes, while M24C02-RMN6TP trades permanent software protection for broader vendor availability and lower unit cost in volume production.

Availability

AT34C02C-TH-B is available at Aetrix Electronics and suitable for industrial control systems, smart sensor modules, medical diagnostics equipment, and energy metering platforms requiring stable component supply and long-term obsolescence management.

Supply support for AT34C02C-TH-B 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 acquired Atmel in 2016 and continues to manufacture, qualify, and support legacy Atmel EEPROM products including the AT34C02C series.

The AT34C02C belongs to Atmel's serial SEEPROM family, designed specifically for industrial and commercial applications demanding low-voltage operation, robust write protection, and extended data retention in space-constrained PCB layouts.

FAQ

What is the operating voltage range of the AT34C02C-TH-B?

The AT34C02C-TH-B operates from 1.7 V to 5.5 V, enabling direct integration with 1.8 V, 3.3 V, and 5 V microcontroller I/O rails without level-shifting circuitry. This wide range supports mixed-voltage system designs and simplifies power architecture in battery-powered or multi-rail industrial controllers. The AT34C02C-TH-B maintains full I²C timing compliance and write functionality across the entire voltage window.

How does hardware write protection work on the AT34C02C-TH-B?

Hardware write protection on the AT34C02C-TH-B is controlled by the WP pin: when tied to VCC, it disables all write operations to the full 2 Kbit array regardless of software protection state. When grounded or floating, hardware protection is inactive and software-based protection (permanent or reversible) governs access to the first half (00H–7FH). The AT34C02C-TH-B datasheet specifies that WP must be actively driven to avoid capacitive coupling issues in noisy environments.

Can the AT34C02C-TH-B perform partial page writes?

Yes, the AT34C02C-TH-B supports partial page writes - any number of bytes (1 to 16) can be written within a single 16-byte page boundary without corrupting adjacent locations. This capability allows efficient updates of non-contiguous configuration fields, such as writing only three calibration coefficients within a 16-byte page. The AT34C02C-TH-B automatically increments its internal address pointer during multi-byte writes and wraps at page boundaries.

What is the endurance and data retention specification for the AT34C02C-TH-B?

The AT34C02C-TH-B is rated for 1 million write/erase cycles and 100 years of data retention at 25°C. These specifications are measured under standard test conditions (25°C, VCC = 5.0 V) and represent minimum guaranteed performance. Real-world retention may extend beyond 100 years at lower ambient temperatures. The AT34C02C-TH-B leverages floating-gate technology with oxide quality assurance to meet these reliability targets across its industrial temperature range.

Is the AT34C02C-TH-B pin-compatible with other Atmel 2 Kbit EEPROMs?

Yes, the AT34C02C-TH-B shares identical pinout, voltage range, and I²C protocol with Atmel's AT24C02C and AT34C02CN-SH-B variants. All use the same 8-pin SOIC/TSSOP/UDFN/VFBGA footprints and address pin (A0–A2) mapping. However, the AT34C02C-TH-B specifically implements enhanced software write protection logic not present in earlier AT24Cxx generations, so firmware must validate register behavior before assuming functional equivalence.