Microchip Technology 24FC128-I/MNY

Overview

24FC128-I/MNY from Microchip Technology Inc. is a 128 Kbit (16K × 8) I²C-compatible serial EEPROM with 1 MHz maximum clock frequency at V_CC ≥ 2.5V, 1.7V–5.5V supply range, and industrial temperature rating (–40°C to +85°C). It features 64-byte page write buffer, hardware write-protection via WP pin, and Schmitt-trigger inputs for noise immunity. Used in embedded systems for parameter storage, calibration data retention, and firmware configuration in low-power IoT sensors and industrial controllers.

For engineers reviewing the 24FC128-I/MNY datasheet, 24FC128-I/MNY pinout, 24FC128-I/MNY application, or 24FC128-I/MNY equivalent, key selection criteria include its 1 MHz I²C speed at 2.5–5.5V, 1 µA standby current, 5 ms max page write time, and MNY package (8-lead TSSOP) compatibility with space-constrained PCB layouts.

Technical Context

The 24FC128-I/MNY implements a two-wire I²C slave interface with fixed 4-bit control code '1010' and user-configurable A2/A1/A0 address bits enabling up to eight devices on one bus. Its internal architecture includes a 64-byte page latch, HV generator for EEPROM programming, and memory control logic supporting byte and page writes with self-timed erase/write cycles.

It supports three read modes-current address, random, and sequential-with automatic address pointer increment and wraparound at 0x3FFF. Write protection is hardware-enforced via the WP pin, sampled at the Stop bit; no software lock or register configuration is required.

Key Specifications

Pinout & Package

24FC128-I/MNY is packaged in an 8-lead TSSOP (MNY), 3.0 mm × 4.4 mm body, 0.65 mm pitch, with exposed pad optional for thermal relief. Pin 1 is A0 (chip select), pin 4 is VSS (ground), pin 5 is SDA (open-drain bidirectional data), pin 6 is SCL (clock input), pin 7 is WP (write-protect), and pin 8 is VCC (power).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA128-I/MNY, the 24FC128-I/MNY delivers 2.5× higher I²C bandwidth for time-critical parameter loads; versus AT24C128C-SSHM-T, it offers identical speed but trades extended temperature for TSSOP space savings and industrial-grade qualification.

Availability

24FC128-I/MNY is available at Aetrix Electronics and suitable for smart metering, industrial PLCs, medical infusion pumps, and automotive BCMs requiring stable component supply across multi-year production cycles.

Supply support for 24FC128-I/MNY 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 microcontroller, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24FC128 belongs to Microchip's 24XX128 family of serial EEPROMs, designed specifically for robust, low-power, I²C-based nonvolatile data storage in cost-sensitive, space-constrained embedded systems.

FAQ

What is the maximum I²C clock frequency supported by the 24FC128-I/MNY?

The 24FC128-I/MNY supports up to 1 MHz I²C clock frequency when V_CC is 2.5V or higher. At V_CC between 1.7V and 2.5V, the maximum clock frequency drops to 400 kHz. This dual-speed capability ensures compatibility with both legacy and high-performance I²C masters while maintaining reliable operation across the full 1.7–5.5V supply range. The 24FC128-I/MNY datasheet specifies AC timing parameters for both conditions.

Does the 24FC128-I/MNY require external pull-up resistors on SDA and SCL lines?

Yes, the 24FC128-I/MNY requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. For 1 MHz operation, a 2 kΩ pull-up to V_CC is recommended; for 400 kHz, 2.2 kΩ is typical. These values ensure proper rise times (<300 ns) and noise margin. The 24FC128-I/MNY does not integrate internal pull-ups, so omission will result in bus failure.

How does hardware write-protection work on the 24FC128-I/MNY?

The 24FC128-I/MNY uses a dedicated WP (Write-Protect) pin: when tied to V_CC, all write operations (byte and page) are inhibited, though reads remain fully functional. The WP state is sampled only at the Stop condition of each write command - toggling WP mid-cycle has no effect. This hardware lock prevents accidental or malicious overwrites without firmware involvement, making the 24FC128-I/MNY ideal for immutable calibration storage.

What is the page write buffer size of the 24FC128-I/MNY, and how does it affect write efficiency?

The 24FC128-I/MNY features a 64-byte page write buffer, allowing up to 64 bytes to be loaded into the internal latch and written to memory in a single Stop-initiated cycle. This eliminates the need for 64 separate byte-write commands and their associated I²C overhead (start/stop/address/acknowledge per byte), reducing total write time by ~90% compared to sequential byte writes. The 24FC128-I/MNY enforces strict page boundaries - crossing them causes wraparound within the same page.

Is the 24FC128-I/MNY pin-compatible with other 24XX128 family members in the MNY package?

Yes, the 24FC128-I/MNY is pin-compatible with 24AA128-I/MNY and 24LC128-I/MNY in the 8-lead TSSOP (MNY) package - all share identical pinout (A0–A2, VSS, SDA, SCL, WP, VCC). However, functional differences exist: 24FC128-I/MNY supports 1 MHz I²C, while 24AA128-I/MNY is limited to 400 kHz and 24LC128-I/MNY requires ≥2.5V supply. System-level validation is required before substitution.