Microchip Technology 25LC128T-E/SN

Overview

25LC128T-E/SN from Microchip Technology Inc. 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, delivers 5 mA read/write current, and features hardware write protection via WP pin and STATUS register control. It is used in automotive infotainment systems for storing calibration data and firmware configuration parameters.

For engineers reviewing the 25LC128T-E/SN datasheet, 25LC128T-E/SN pinout, 25LC128T-E/SN application, or 25LC128T-E/SN equivalent, key selection criteria include extended-temperature SPI EEPROM compatibility, block-level write protection granularity (none/¼/½/all), HOLD pin support for interrupt-safe bus arbitration, and AEC-Q100 qualification for automotive deployment.

Technical Context

The 25LC128T-E/SN implements a standard SPI Mode 0,0 or Mode 1,1 interface with separate SI (data-in) and SO (data-out) lines, requiring CS, SCK, and optional HOLD/WP signals. Its internal architecture includes a 64-byte page latch, high-voltage generator for EEPROM programming, and status register with WIP, WEL, BP0/BP1, and WPEN bits.

It operates across 2.5V–5.5V supply range and supports three voltage-dependent AC timing tiers: 10 MHz max at ≥4.5V, 5 MHz at 2.5–4.5V, and 3 MHz below 2.5V. Write cycles are self-timed with ≤5 ms completion, and endurance is rated at 1,000,000 erase/write cycles with >200-year data retention.

Key Specifications

Pinout & Package

25LC128T-E/SN is packaged in an 8-lead narrow SOIC (SN) with 150-mil body width, 1.27 mm pitch, and JEDEC MS-012AC compliant footprint. The exposed pad is not present in SN package.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC128-I/SN, the 25LC128T-E/SN adds AEC-Q100 qualification and extended temperature operation without changing pinout or software interface; versus AT25DF128A-SHN-T, it trades density and speed for deterministic timing, HOLD support, and automotive-grade reliability in resource-constrained embedded nodes.

Availability

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

Supply support for 25LC128T-E/SN 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 manufacturing and support infrastructure.

The 25LC128T-E/SN belongs to Microchip's serial EEPROM product line, designed specifically for robust, low-power, SPI-based nonvolatile storage in automotive, industrial, and medical applications where data integrity and long-term reliability are critical.

FAQ

What is the operating voltage range for the 25LC128T-E/SN?

The 25LC128T-E/SN operates from 2.5V to 5.5V. At 4.5–5.5V, it supports up to 10 MHz SPI clock frequency; at 2.5–4.5V, maximum clock is 5 MHz. This dual-voltage capability allows seamless integration into both 3.3V and 5V system designs without level shifters. The 25LC128T-E/SN maintains full functionality-including HOLD, WP, and STATUS register access-across its entire specified VCC range.

Does the 25LC128T-E/SN support page write operations, and what is the page size?

Yes, the 25LC128T-E/SN supports page write operations with a fixed 64-byte page size. Up to 64 bytes can be written in a single command, provided all addresses reside within the same physical page boundary (e.g., 0000h–003Fh, 0040h–007Fh). Crossing a page boundary causes automatic wraparound to the start of the current page-not the next-so application firmware must enforce alignment. The 25LC128T-E/SN uses this page buffer to reduce total write cycles and improve throughput versus byte-write-only devices.

How does hardware write protection work on the 25LC128T-E/SN?

Hardware write protection on the 25LC128T-E/SN requires both the WP pin low and the WPEN bit (bit 7 of STATUS register) set to '1'. When active, this combination disables writes to nonvolatile STATUS register bits (BP0, BP1, WPEN), while permitting normal memory reads and writes. If WP is high or WPEN is '0', full STATUS register access is restored. The 25LC128T-E/SN implements this dual-condition lock to prevent accidental corruption of protection settings during board-level debug or rework.

Is the 25LC128T-E/SN pin-compatible with the 25AA128 series?

No, the 25LC128T-E/SN is not pin-compatible with the 25AA128 series due to differing VCC ranges: 25LC128 requires minimum 2.5V, whereas 25AA128 operates down to 1.8V. Though both share identical 8-lead SOIC (SN) packaging and pin functions (CS, SO, WP, VSS, SI, SCK, HOLD, VCC), their DC and AC timing specifications diverge below 2.5V. Using 25LC128T-E/SN in a 1.8V design risks functional failure. The 25LC128T-E/SN is fully compatible with other 25LC128 variants (e.g., 25LC128-I/SN) sharing the same VCC range.

What is the significance of the "T-E/SN" suffix in 25LC128T-E/SN?

The "T-E/SN" suffix in 25LC128T-E/SN decodes as: T = temperature grade indicator, E = extended temperature range (–40°C to +125°C), and SN = 8-lead narrow SOIC package per JEDEC MS-012AC. This marking confirms AEC-Q100 qualification, distinguishes it from industrial-grade (I) variants like 25LC128-I/SN, and specifies the exact package variant for PCB land pattern and assembly. The 25LC128T-E/SN is traceable to Microchip's automotive production flow and undergoes additional reliability screening beyond standard industrial parts.