Microchip Technology 25LC128T-E/MF

Overview

25LC128T-E/MF from Microchip Technology is a 128 Kbit SPI Serial EEPROM with 16,384 × 8-bit organization, 64-byte page size, and extended temperature operation from –40°C to +125°C. It supports up to 10 MHz clock frequency at 4.5–5.5 V, features hardware write protection via WP pin and STATUS register, and delivers 1,000,000 erase/write cycles with >200-year data retention - used in automotive infotainment boot code storage and industrial sensor calibration data logging.

For engineers reviewing the 25LC128T-E/MF datasheet, 25LC128T-E/MF pinout, 25LC128T-E/MF application, or 25LC128T-E/MF equivalent, key selection criteria include VCC range (2.5–5.5 V), extended-temp qualification (AEC-Q100), SPI interface timing compliance, HOLD/CS control behavior during interrupt servicing, and block-level write protection granularity (none/¼/½/all array).

Technical Context

The 25LC128T-E/MF implements a standard SPI Mode 0,0 (CPOL=0, CPHA=0) interface with separate SI/SO lines and dedicated CS, SCK, WP, HOLD, and VSS/VCC terminals. Its internal architecture includes a 64-byte page latch, HV generator for EEPROM programming, and status register with WIP, WEL, BP0/BP1, and WPEN bits controlling write enable state and hardware protection logic.

Write operations require explicit WREN instruction followed by CS high-to-low transition to initiate self-timed internal write cycle (≤5 ms). During active write, the WIP bit remains set and memory reads return undefined data; SO enters high-impedance when CS is high or HOLD is asserted low, enabling multi-device bus sharing and host interrupt handling without sequence loss.

Key Specifications

Pinout & Package

25LC128T-E/MF is packaged in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm pitch, body dimensions 3.0 × 4.4 mm, and exposed pad optionally connected to VSS for thermal enhancement.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA128T-I/MF, the 25LC128T-E/MF provides automotive-grade reliability and higher minimum VCC, while AT25DF041A-MAU-T trades parameter security and simplicity for higher density and faster sequential reads - making 25LC128T-E/MF optimal for safety-critical, small-data, high-reliability embedded storage.

Availability

25LC128T-E/MF is available at Aetrix Electronics and suitable for automotive ECU design, industrial PLC commissioning, and medical device calibration requiring stable component supply across extended temperature and long product lifecycles.

Supply support for 25LC128T-E/MF 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 25LC128T-E/MF belongs to Microchip's serial EEPROM product line, engineered specifically for reliable, low-power, SPI-based nonvolatile data storage in automotive, industrial, and medical applications demanding AEC-Q100 compliance and extended temperature operation.

FAQ

What is the maximum clock frequency supported by the 25LC128T-E/MF across its full voltage range?

The 25LC128T-E/MF supports up to 10 MHz at VCC = 4.5–5.5 V, 5 MHz at VCC = 2.5–4.5 V, and is not rated below 2.5 V. This de-rating ensures setup/hold timing margins are maintained across process, voltage, and temperature variations - critical for deterministic SPI communication in automotive systems where 25LC128T-E/MF is deployed.

How does the HOLD pin function during an active SPI transaction in the 25LC128T-E/MF?

The HOLD pin in the 25LC128T-E/MF suspends SPI communication mid-sequence when pulled low while SCK is low; SO, SI, and SCK enter high-impedance, and the internal address pointer retains position. Resuming requires HOLD high while SCK is low - allowing the host MCU to service interrupts without reinitializing the entire transfer, a key feature for real-time systems using 25LC128T-E/MF.

Can the 25LC128T-E/MF be used in a 1.8 V system?

No - the 25LC128T-E/MF has a minimum VCC specification of 2.5 V and is not characterized or guaranteed for operation at 1.8 V. For 1.8 V systems, Microchip's 25AA128T-I/MF (1.8–5.5 V) is the functionally equivalent alternative, though it lacks the extended temperature range and AEC-Q100 qualification of the 25LC128T-E/MF.

What happens if a page write crosses a 64-byte boundary in the 25LC128T-E/MF?

If a page write command attempts to cross a 64-byte boundary in the 25LC128T-E/MF, data wraps around to the start of the current page instead of advancing to the next page - overwriting previously written bytes in that page. This behavior is documented in the datasheet and requires firmware to validate address alignment before issuing page write commands to prevent unintended data corruption in 25LC128T-E/MF deployments.

Is the 25LC128T-E/MF pin-compatible with other members of the 25XX128 family?

Yes - the 25LC128T-E/MF shares identical pinout, package footprint, and SPI instruction set with all 25XX128 variants (e.g., 25AA128, 25LC128, 25AA128T), including the 8-lead TSSOP (MF) package. This allows drop-in substitution where voltage and temperature requirements align, though functional equivalence must be verified per application - especially for 25LC128T-E/MF's extended-temp and AEC-Q100 attributes.