Microchip Technology AT25128N1-10SI

Overview

AT25128N1-10SI from Atmel (now Microchip) is a 128 Kbit SPI serial EEPROM organized as 16,384 × 8-bit memory array, operating from 2.7V to 5.5V, supporting 3 MHz clock rate, 64-byte page write, and hardware/software write protection via WP and HOLD pins. It is used in industrial control systems for parameter storage, firmware configuration, and calibration data retention.

For engineers reviewing the AT25128N1-10SI datasheet, AT25128N1-10SI pinout, AT25128N1-10SI application, or AT25128N1-10SI equivalent, key selection criteria include industrial temperature range (−40°C to +85°C), SOIC-8 package compatibility, SPI Mode 0/3 support, block write protection granularity (1/4, 1/2, full array), and 100,000 write cycle endurance.

Technical Context

The AT25128N1-10SI implements a synchronous SPI slave interface with separate SI (input) and SO (output) lines, requiring CS assertion and MSB-first 8-bit op-code transmission. It supports dual-voltage operation (2.7–5.5 V) and integrates nonvolatile status register bits (BP0/BP1/WPEN) for configurable block protection and hardware write disable.

Its internal architecture enables self-timed 5 ms typical write cycles without external erase commands, automatic address increment during sequential reads/writes, and HOLD pin functionality to suspend ongoing transfers while preserving internal state - critical for real-time system interrupt handling.

Key Specifications

Pinout & Package

AT25128N1-10SI is housed in an 8-pin EIAJ SOIC (8S2) package measuring 4.90 mm × 3.90 mm × 1.75 mm (max height), with gull-wing leads and 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95128-DRMN6TP/K and BR24G128FJ-WE2, AT25128N1-10SI provides guaranteed industrial temperature operation, dedicated HOLD/WP pins for deterministic control, and proven 3 MHz stability in noisy factory environments - making it optimal for safety-critical embedded systems where interface flexibility and environmental robustness outweigh raw speed or pin count savings.

Availability

AT25128N1-10SI is available at Aetrix Electronics and suitable for industrial control, medical instrumentation, automotive body electronics, and smart metering applications requiring stable component supply, long-term obsolescence management, and traceable sourcing.

Supply support for AT25128N1-10SI 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

Atmel Corporation, now part of Microchip Technology, is a semiconductor manufacturer specializing in microcontrollers, nonvolatile memory, and secure authentication ICs.

The AT25128N1-10SI belongs to Atmel's SPI serial EEPROM product line, designed specifically for industrial and automotive applications demanding high reliability, flexible voltage operation, and robust data integrity features.

FAQ

What is the maximum clock frequency supported by the AT25128N1-10SI?

The AT25128N1-10SI supports a maximum SCK clock frequency of 3 MHz across its full 2.7 V to 5.5 V supply range and −40°C to +85°C operating temperature. This value is characterized and tested per AC specifications in the official datasheet, ensuring reliable timing margin for SPI master implementations using common microcontrollers such as STM32 or PIC series.

Does the AT25128N1-10SI require an external erase command before writing?

No, the AT25128N1-10SI does not require a separate erase command. All write operations - whether byte or page - are self-timed and internally manage cell erasure prior to programming. The device automatically handles erase-and-program sequencing, reducing host MCU firmware complexity and eliminating risk of partial writes due to premature CS deassertion.

How does the HOLD pin function during an active SPI transaction on the AT25128N1-10SI?

The HOLD pin on the AT25128N1-10SI suspends serial communication without resetting the internal command or address counter. When asserted low while SCK is low, it places SO in high-impedance and ignores SI inputs until HOLD returns high (also while SCK is low). This allows deterministic pause/resume of multi-byte transfers - essential for RTOS-based systems managing concurrent SPI peripherals.

What memory protection mechanisms are implemented in the AT25128N1-10SI?

The AT25128N1-10SI implements dual-layer protection: (1) Hardware write protection via the WP pin (when WPEN=1), blocking status register writes; and (2) Software-configurable block protection (BP0/BP1 bits) enabling 1/4, 1/2, or full-array lockdown. Both mechanisms prevent unintended modification of critical configuration or calibration data during power transitions or firmware faults.

Is the AT25128N1-10SI pin-compatible with other members of the AT25xxx family?

Yes, the AT25128N1-10SI shares identical 8-pin SOIC (8S2) pinout and SPI interface signaling with AT25080, AT25160, and AT25256 variants in the same package option. However, memory size, status register bit definitions, and timing parameters differ - so firmware must be validated per device density and datasheet revision to ensure correct addressing and protection behavior.