Microchip Technology 25LC128-E/P

Overview

25LC128-E/P 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, features hardware write protection via WP pin and STATUS register, and delivers 1,000,000 erase/write cycles with >200 years data retention - used in automotive control modules for storing calibration data and fault logs.

For engineers reviewing the 25LC128-E/P datasheet, 25LC128-E/P pinout, 25LC128-E/P application, or 25LC128-E/P equivalent, this page provides verified electrical specs, SPI timing constraints, HOLD/CS/WP functional behavior, package-specific pin mapping (PDIP-8), and real-world use cases in AEC-Q100-compliant systems where nonvolatile parameter storage must survive thermal cycling and power interruption.

Technical Context

The 25LC128-E/P implements a standard SPI Mode 0,0 interface (CPOL = 0, CPHA = 0) with separate SI and SO lines, requiring CS low and HOLD high for normal operation. Its internal architecture includes a 64-byte page latch, status register with WIP/WEL/BP0/BP1 bits, and HV generator for EEPROM cell programming.

Write operations require explicit WREN instruction before WRITE or WRSR commands; CS rising edge after final data byte triggers self-timed internal write cycle (≤5 ms). The HOLD pin suspends ongoing SPI transfers without resetting address pointers, enabling interrupt servicing while preserving transaction state.

Key Specifications

Pinout & Package

25LC128-E/P is packaged in 8-Lead PDIP (Plastic Dual In-Line Package), 300 mil body width, through-hole mountable. Pin 1 is marked by notch or dot; leads are gull-wing shaped with 0.100" pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC128-I/P, the 25LC128-E/P adds extended temperature support and AEC-Q100 qualification for automotive use; compared with AT25DF041A-SSH-T, it offers simpler SPI-3-wire compatibility, deterministic HOLD behavior, and finer-grained write protection - critical for safety-critical parameter storage.

Availability

25LC128-E/P is available at Aetrix Electronics and suitable for automotive control units, industrial PLCs, medical infusion pumps, and smart metering systems requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for 25LC128-E/P 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 25LC128-E/P belongs to Microchip's serial EEPROM product line, designed specifically for reliable, low-power nonvolatile data storage in automotive, industrial, and medical applications where AEC-Q100 qualification and robust write protection are mandatory.

FAQ

What is the maximum clock frequency supported by the 25LC128-E/P across its full voltage range?

The 25LC128-E/P 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. These limits are defined in Table 1-2 AC Characteristics and ensure setup/hold timing margins are met across temperature. The 25LC128-E/P must not be operated above 10 MHz even at 5.5 V unless validated per application-specific timing analysis.

How does the HOLD pin function during an active SPI read sequence in the 25LC128-E/P?

When HOLD is asserted low during an active 25LC128-E/P read sequence (with CS low and SCK low), the device pauses transmission, tri-states SO, and freezes the internal address pointer. SI, SCK, and SO become high-impedance; only CS remains active. Resuming requires bringing HOLD high while SCK is low - then reading continues from the exact byte where it paused, without retransmission.

Can the 25LC128-E/P be used as a direct replacement for the 25AA128 in an existing design?

The 25LC128-E/P is not a direct replacement for the 25AA128 due to differing VCC ranges: 25AA128 operates from 1.8 V, while 25LC128-E/P requires minimum 2.5 V. At 3.3 V or 5 V systems, pinout and instruction set are identical, but firmware must verify VCC tolerance and adjust timing if operating near 2.5 V. The 25LC128-E/P also lacks 1.8 V support present in 25AA128.

What happens if a page write command crosses a 64-byte boundary in the 25LC128-E/P?

If a page write command to the 25LC128-E/P attempts to write across a 64-byte boundary (e.g., starting at address 0x003F with 4 bytes), the device wraps the excess data to the start of the same page (0x0000), overwriting prior content. This behavior is documented in Section 3.3 and requires application-level boundary checking - the 25LC128-E/P does not auto-align or reject invalid page writes.

Is the 25LC128-E/P RoHS compliant and lead-free?

Yes, the 25LC128-E/P is RoHS compliant and manufactured with lead-free terminations per Microchip's packaging specifications. The PDIP package uses matte tin (Sn) plating per JEDEC J-STD-609, and all homogeneous materials meet EU Directive 2011/65/EU Annex II substance restrictions. Compliance documentation is available in Microchip's PPAP package for this part number.