Microchip Technology 24FC1026-I/ST

Overview

24FC1026-I/ST from Microchip Technology is a 128K × 8 (1024 Kbit) I²C-compatible serial EEPROM with 1 MHz maximum clock frequency, 1.8V–5.5V supply range, and industrial temperature rating (–40°C to +85°C). It features a 128-byte page write buffer, hardware write-protection via WP pin, Schmitt-trigger inputs for noise immunity, and supports up to four devices on a single bus in cascaded configurations - used for nonvolatile parameter storage in embedded control systems.

For engineers reviewing the 24FC1026-I/ST datasheet, 24FC1026-I/ST pinout, 24FC1026-I/ST application, or 24FC1026-I/ST equivalent, key selection criteria include its 1 MHz I²C speed at V_CC ≥ 2.5V, 3 ms typical page write time, 1 million endurance cycles, >200-year data retention, and SOIC-8 package compatibility with legacy 24AA/24LC designs requiring higher-speed operation.

Technical Context

The 24FC1026-I/ST implements a two-wire I²C interface with master-controlled SCL/SDA timing, supporting standard (100 kHz), fast (400 kHz), and fast-plus (1 MHz) modes depending on V_CC. Its internal address space is split into two 512 Kbit blocks (00000h–0FFFFh and 10000h–1FFFFh), selected by the B0 bit in the control byte.

Write operations use an on-chip 128-byte page latch and self-timed erase/write cycle; read operations support current-address, random, and sequential modes across block boundaries. Hardware write protection is active when WP = V_CC, and Schmitt-trigger inputs on SDA/SCL ensure robust noise suppression per I²C bus specifications.

Key Specifications

Pinout & Package

24FC1026-I/ST is supplied in an 8-lead SOIC (Small Outline Integrated Circuit) package, 3.90 mm body width, RoHS-compliant, with gull-wing leads and standard JEDEC MO-002AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA1026-I/ST and 24LC1026-I/ST, the 24FC1026-I/ST delivers 2.5× faster I²C write throughput at 1 MHz while maintaining full software and pin compatibility - making it the optimal upgrade for existing designs needing reduced parameter update latency without PCB revision.

Availability

24FC1026-I/ST is available at Aetrix Electronics and suitable for industrial sensor nodes, medical calibration archives, smart energy meters, and automotive body control modules requiring stable component supply and long-term obsolescence management.

Supply support for 24FC1026-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 24FC1026-I/ST belongs to Microchip's high-speed serial EEPROM product line, engineered specifically for applications demanding faster I²C communication, extended voltage flexibility, and robust data integrity in industrial and medical environments.

FAQ

What is the maximum I²C clock frequency supported by the 24FC1026-I/ST?

The 24FC1026-I/ST supports up to 1 MHz I²C clock frequency when V_CC is 2.5V or higher. At 1.8V ≤ V_CC < 2.5V, the maximum clock is 400 kHz. This dual-speed capability allows backward compatibility with 400 kHz systems while enabling performance gains in newer 3.3V/5V designs. The 24FC1026-I/ST datasheet specifies timing parameters including THIGH, TLOW, and TSU:DAT explicitly for both speed grades.

Does the 24FC1026-I/ST require external pull-up resistors on SDA and SCL lines?

Yes, the 24FC1026-I/ST requires external pull-up resistors on both SDA and SCL lines because these pins are open-drain. For 1 MHz operation, a 2 kΩ pull-up to V_CC is recommended; for 400 kHz, 2.2 kΩ is typical. The value must be selected based on bus capacitance and desired rise time - the 24FC1026-I/ST's TR specification (≤300 ns at V_CC ≥ 2.5V) defines the upper limit for RC time constant.

How does hardware write-protection work on the 24FC1026-I/ST?

Hardware write-protection on the 24FC1026-I/ST is controlled by the WP pin: when tied to V_CC, all write operations (byte and page) are inhibited while read operations remain fully functional. The pin is sampled at the Stop bit of each write command, so toggling WP mid-cycle has no effect. This feature ensures that critical configuration data stored in the 24FC1026-I/ST cannot be overwritten accidentally during firmware execution.

Can the 24FC1026-I/ST be used interchangeably with 24AA1026-I/ST or 24LC1026-I/ST on the same PCB?

Yes, the 24FC1026-I/ST uses the same SOIC-8 package, pinout, and memory map as 24AA1026-I/ST and 24LC1026-I/ST, enabling drop-in replacement in most cases. However, system-level validation is required to confirm timing compliance at 1 MHz and verify V_CC margins - especially if operating below 2.5V, where the 24FC1026-I/ST reverts to 400 kHz mode like the 24AA1026-I/ST.

What is the page write time specification for the 24FC1026-I/ST?

The 24FC1026-I/ST has a typical page write time of 3 ms, with a maximum of 5 ms per the datasheet (parameter TWC). This applies to both single-byte and full 128-byte page writes, as the internal self-timed cycle duration is fixed regardless of data count. During this period, the device does not acknowledge I²C commands - a behavior leveraged by ACK polling to detect write completion before issuing subsequent operations.