Microchip Technology AT25128N-10SI-2.7

Overview

AT25128N-10SI-2.7 from Microchip Technology (formerly Atmel) is a 128 Kbit SPI serial EEPROM organized as 16,384 × 8 bits, operating from 2.7 V to 5.5 V with 3 MHz max clock rate, 64-byte page write capability, and hardware/software write protection via WP and HOLD pins. It serves as nonvolatile configuration storage in industrial controllers, automotive body modules, and embedded sensor nodes requiring low-power, reliable data retention.

For engineers reviewing the AT25128N-10SI-2.7 datasheet, AT25128N-10SI-2.7 pinout, AT25128N-10SI-2.7 application, or AT25128N-10SI-2.7 equivalent, key selection criteria include its JEDEC SOIC-8 package, 5 ms typical write cycle time, 100,000 write endurance, >200-year data retention, and support for SPI Modes 0 and 3 in extended temperature (–40°C to +85°C).

Technical Context

The AT25128N-10SI-2.7 implements a synchronous SPI slave interface with separate SI (input) and SO (output) lines, MSB-first data framing, and chip-select–driven command sequencing. Its status register controls block write protection (1/4, 1/2, or full array), WPEN bit enablement, and Ready/Busy flag reporting.

It supports self-timed internal write cycles without erase pre-conditioning, uses HOLD to suspend ongoing transfers without resetting sequence state, and enforces write protection through both hardware (WP pin) and software (WRSR instruction) mechanisms - all compliant with standard SPI timing requirements across 1.8 V, 2.7 V, and 5 V supply ranges.

Key Specifications

Pinout & Package

AT25128N-10SI-2.7 is housed in an 8-lead JEDEC SOIC package (8S1), 0.150" wide, with gull-wing leads and standard 1.27 mm pitch. Pin 1 is marked by a beveled corner or dot.

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-3GE2, AT25128N-10SI-2.7 uniquely combines HOLD pin support, dual-mode hardware/software write protection, and guaranteed 3 MHz operation across its full 2.7–5.5 V range - making it optimal for deterministic real-time systems requiring robust communication control and data integrity.

Availability

AT25128N-10SI-2.7 is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive body control units, medical device configuration, and smart energy meter firmware storage requiring stable component supply and long-term lifecycle support.

Supply support for AT25128N-10SI-2.7 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 is a global semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with a focus on reliability, longevity, and embedded system integration.

The AT25128N-10SI-2.7 belongs to Microchip's legacy serial EEPROM product line, designed specifically for cost-sensitive, low-power embedded applications demanding proven data integrity, extended temperature operation, and seamless SPI compatibility with mainstream MCUs.

FAQ

What is the maximum clock frequency supported by the AT25128N-10SI-2.7?

The AT25128N-10SI-2.7 supports a maximum SCK clock frequency of 3 MHz when operating within its specified 2.7 V to 5.5 V supply range. This value is characterized across the full industrial temperature range (–40°C to +85°C) and applies to both read and write operations. The device remains functional at lower frequencies, enabling compatibility with resource-constrained microcontrollers or noise-sensitive environments where reduced clock rates improve signal integrity.

Does the AT25128N-10SI-2.7 require an external erase cycle before writing?

No, the AT25128N-10SI-2.7 does not require a separate erase cycle before writing. All write operations - whether byte or page - are self-timed and internally managed. Once the WRITE instruction is issued and CS is de-asserted, the device automatically performs any necessary erase-and-program sequences. This simplifies firmware design and eliminates timing-critical erase delays, making AT25128N-10SI-2.7 suitable for applications requiring rapid, deterministic configuration updates.

How does the HOLD pin function during an active SPI transaction on the AT25128N-10SI-2.7?

The HOLD pin on the AT25128N-10SI-2.7 suspends ongoing SPI communication without resetting the internal address counter or command state. To activate HOLD, the pin must be driven low while SCK is low; the SO pin enters high-impedance, and SI inputs are ignored. When HOLD is returned high (with SCK still low), transmission resumes from the exact bit position where it paused. This allows external arbitration or priority interrupts without losing transaction context - a key advantage in multi-peripheral MCU systems.

Can the AT25128N-10SI-2.7 be used in 1.8 V systems?

No, the AT25128N-10SI-2.7 is specifically rated for 2.7 V to 5.5 V operation. For 1.8 V systems, Microchip offers the pin-compatible AT25128N-10SI-1.8 variant, which shares the same JEDEC SOIC-8 package and feature set but is characterized down to 1.8 V. Using AT25128N-10SI-2.7 below 2.7 V may result in unreliable read/write behavior or failure to meet AC timing specifications, so voltage compliance must be verified per the ordering code suffix.

What protection mechanisms prevent unintended writes to the AT25128N-10SI-2.7?

The AT25128N-10SI-2.7 employs three layered protections: (1) a Write Enable Latch (WEN bit) that must be set via WREN instruction before any write; (2) software-configurable block protection (BP0/BP1 bits) locking top 1/4, 1/2, or full memory; and (3) hardware write protection via the WP pin when WPEN = 1. These operate independently - e.g., WP low blocks status register writes even if WEN = 1 - ensuring robust defense against firmware bugs, ESD events, or power glitches.