Microchip Technology 24LC1026T-E/ST

Overview

24LC1026T-E/ST from Microchip Technology is a 128K × 8 (1024 Kbit) I²C-compatible serial EEPROM with 2.5V–5.5V supply range, 400 kHz max clock (100 kHz at VCC < 4.5V in automotive temp), and industrial/automotive temperature rating (–40°C to +125°C). It features 128-byte page write buffer, hardware write-protect (WP pin), Schmitt-trigger inputs, and >1 million erase/write cycles - deployed in automotive body control modules for configuration storage and calibration data retention.

For engineers reviewing the 24LC1026T-E/ST datasheet, 24LC1026T-E/ST pinout, 24LC1026T-E/ST application, or 24LC1026T-E/ST equivalent, key selection criteria include its automotive-grade temperature support, I²C bus noise immunity via hysteresis, page write timing (3 ms typical), WP-enabled hardware lockout, and dual 512K-bit address blocks accessed via B0 bit - critical for fault-tolerant memory partitioning in safety-relevant ECUs.

Technical Context

The 24LC1026T-E/ST implements a two-wire I²C slave interface with fixed 1010 control code and user-configurable A1/A2 address bits enabling up to four devices on one bus. Its internal architecture includes dual 512K-bit memory segments selected by the B0 block bit, with automatic address pointer roll-over within each segment (00000h–0FFFFh and 10000h–1FFFFh).

Write operations use self-timed erase/write cycles with 3 ms typical page write time and hardware-based write protection activated when WP = VCC. The device employs Schmitt-trigger inputs on SDA/SCL and slope-controlled outputs to suppress ground bounce and tolerate >4 kV ESD - essential for noisy automotive environments.

Key Specifications

Pinout & Package

24LC1026T-E/ST uses an 8-lead SOIC package (3.90 mm width), RoHS-compliant, with standard 1.27 mm pitch and gull-wing leads. Pin 1 is marked with a notch or dot; package meets JEDEC MS-012AA.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C1024-SSHL-T and BR24G1ME-3SPI, the 24LC1026T-E/ST uniquely combines automotive temperature operation, hardware write-protection, and dual-block addressing - making it the only option among the three qualified for safety-critical ECU configuration storage requiring physical write disable and memory segmentation.

Availability

24LC1026T-E/ST is available at Aetrix Electronics and suitable for automotive electronics, industrial control systems, and medical device manufacturing requiring stable component supply with long-term lifecycle assurance.

Supply support for 24LC1026T-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 is a leading provider of microcontrollers, analog components, and memory solutions, serving automotive, industrial, and consumer markets with high-reliability silicon and design support.

The 24LC1026T-E/ST belongs to Microchip's 24XX1026 family of automotive-qualified serial EEPROMs, engineered specifically for robust nonvolatile data storage in harsh electrical and thermal environments.

FAQ

What is the maximum I²C clock frequency supported by the 24LC1026T-E/ST?

The 24LC1026T-E/ST supports up to 400 kHz I²C clock frequency when VCC ≥ 4.5V and operating in automotive temperature range. At VCC < 4.5V under E-temp conditions, the maximum clock rate drops to 100 kHz to ensure timing margin compliance - a specification explicitly defined in Microchip's DS20002270E datasheet Section 1-2.

Does the 24LC1026T-E/ST require external pull-up resistors on SDA and SCL lines?

Yes, the 24LC1026T-E/ST requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. For 400 kHz operation, a 2 kΩ pull-up to VCC is recommended; for 100 kHz, 10 kΩ is typical. These values ensure rise time compliance per I²C specification and prevent bus contention.

How does the hardware write-protect (WP) pin function on the 24LC1026T-E/ST?

When the WP pin of the 24LC1026T-E/ST is tied to VCC, all write and erase operations are inhibited - including byte, page, and control register writes - while read operations remain fully functional. The pin state is sampled at the Stop condition of each write command, and toggling WP mid-cycle has no effect. This provides fail-safe protection against unintended memory modification.

What memory organization does the 24LC1026T-E/ST use, and how is it accessed?

The 24LC1026T-E/ST organizes its 1024 Kbit array into two 512K-bit blocks (00000h–0FFFFh and 10000h–1FFFFh), selected by the B0 bit in the I²C control byte. Sequential reads wrap within each block but do not cross boundaries. This segmentation enables isolated storage of critical vs. user data and supports redundancy schemes in safety-critical applications.

Is the 24LC1026T-E/ST qualified for automotive applications?

Yes, the 24LC1026T-E/ST carries the 'E' temperature grade suffix and is specified for operation from –40°C to +125°C ambient. It is designed and tested to meet automotive reliability requirements, including AEC-Q100 stress testing - confirmed in Microchip's official documentation and part marking ('E' in T-E/ST).