Microchip Technology 24FC128T-I/MNY

Overview

24FC128T-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 - deployed in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 24FC128T-I/MNY datasheet, 24FC128T-I/MNY pinout, 24FC128T-I/MNY application, or 24FC128T-I/MNY equivalent, key selection criteria include its 1 MHz I²C speed advantage over 24AA128/24LC128 variants, guaranteed 1 µA standby current at I-temp, and MNY package (8-lead TSSOP) compatibility with high-density PCB layouts requiring low profile and thermal reliability.

Technical Context

The 24FC128T-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/page writes and random/sequential reads across full 128 Kbit address space (0000h–3FFFh).

Write operations are self-timed with ≤5 ms page write cycle; acknowledge polling is supported to detect completion. The WP pin provides hardware-level write protection of the entire array when tied to V_CC, and Schmitt-trigger inputs on SDA/SCL ensure robust operation in electrically noisy environments with fast rise/fall time specs (≤300 ns rise, ≤100 ns fall at V_CC ≥ 2.5V).

Key Specifications

Pinout & Package

24FC128T-I/MNY is packaged in an 8-lead TSSOP (MNY), 4.4 mm × 3.0 mm body, 0.65 mm pitch, with exposed pad optional for thermal relief. Pin functions are identical across SOIC/TSSOP/DFN packages per Microchip DS20001191T.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA128T-I/MNY and 24LC128T-I/MNY, the 24FC128T-I/MNY delivers measurable throughput gain in high-frequency I²C systems while maintaining full backward compatibility in layout, power, and command structure - making it the optimal upgrade path for performance-critical embedded storage.

Availability

24FC128T-I/MNY is available at Aetrix Electronics and suitable for smart metering, industrial sensor calibration, medical device configuration, and automotive body control module applications requiring stable component supply, long-term data integrity, and industrial-grade temperature resilience.

Supply support for 24FC128T-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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global manufacturing and support infrastructure.

The 24FC128 belongs to Microchip's 24XX128 family of I²C EEPROMs, engineered specifically for reliable, low-power nonvolatile data storage in space-constrained, noise-prone embedded systems across industrial, automotive, and medical markets.

FAQ

What is the maximum I²C clock frequency supported by the 24FC128T-I/MNY?

The 24FC128T-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 allows the 24FC128T-I/MNY to maintain high throughput in 3.3V/5V systems while remaining functional in ultra-low-voltage applications - a key differentiator from the 24AA128T-I/MNY and 24LC128T-I/MNY, both limited to 400 kHz across their full voltage ranges.

Does the 24FC128T-I/MNY require external pull-up resistors on SDA and SCL lines?

Yes, the 24FC128T-I/MNY 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 24FC128T-I/MNY's Schmitt-trigger inputs tolerate slower rise times, but proper pull-up sizing ensures timing compliance per Table 1-2 AC characteristics - especially critical for THD:STA, TSU:STA, and TBUF parameters.

How does hardware write-protection work on the 24FC128T-I/MNY?

Hardware write-protection on the 24FC128T-I/MNY 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 WP state is sampled at the Stop condition of each write command, so toggling WP mid-cycle has no effect. This behavior is implemented in silicon and requires no firmware intervention - making the 24FC128T-I/MNY ideal for safety-critical storage where accidental writes must be physically blocked.

What is the page write buffer size of the 24FC128T-I/MNY, and how does it affect write efficiency?

The 24FC128T-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 self-timed cycle (≤5 ms). This eliminates the need for 64 separate I²C transactions required by byte-write mode, reducing bus occupation by >98% and host MCU overhead significantly. Because page boundaries align to 64-byte intervals (addresses 0000h–003Fh, 0040h–007Fh, etc.), software must ensure page write commands do not cross boundaries - a constraint explicitly documented in the 24FC128T-I/MNY datasheet.

Is the 24FC128T-I/MNY compatible with standard I²C protocol stacks and drivers?

Yes, the 24FC128T-I/MNY is fully compliant with the standard Philips I²C-bus specification, using a fixed 7-bit slave address format (1010xxx) where xxx is determined by A2/A1/A0 pins. It supports standard Start/Stop conditions, ACK/NACK handshaking, and repeated Start sequences. All timing parameters - including TAA, THD:STA, and TSU:DAT - meet I²C Fast-mode Plus requirements at 1 MHz, ensuring drop-in compatibility with existing Linux i2c-dev, Arduino Wire, and RTOS-based I²C drivers without modification.