Microchip Technology AT25320N-10SI

Overview

AT25320N-10SI from Atmel (now Microchip Technology) is a 32-Kbit SPI serial EEPROM organized as 4096 × 8-bit memory, operating across 2.7V–5.5V supply range with industrial temperature rating (−40°C to +85°C). It supports SPI Modes 0 and 3, delivers up to 3.0 MHz clock rate at 5V, features 32-byte page write capability, and includes hardware/software write protection via WP pin and status register. It is used in embedded systems requiring nonvolatile data storage with low-power operation, such as industrial sensor nodes and programmable logic controllers.

For engineers reviewing the AT25320N-10SI datasheet, AT25320N-10SI pinout, AT25320N-10SI application, or AT25320N-10SI equivalent, key selection criteria include its 2.7–5.5V voltage range, industrial-grade temperature support, 5 ms typical write cycle time, block-level write protection (1/4, 1/2, or full array), and compatibility with microcontrollers featuring standard SPI peripherals - especially where space-constrained SOIC-8 packaging and reliable 1 million endurance cycles are required.

Technical Context

The AT25320N-10SI functions exclusively as an SPI slave device, with dedicated SI (input) and SO (output) pins enabling full-duplex communication under master-controlled SCK. Its internal architecture uses an 8-bit instruction register and MSB-first data transfer, supporting op-codes for read, write, status register access, and write enable/disable.

It implements dual-layer write protection: software-based via WRSR-configurable BP0/BP1 bits (selecting 0%, 25%, 50%, or 100% array protection), and hardware-based via the WP pin when WPEN = 1. The HOLD pin allows pausing ongoing serial transfers without resetting the sequence, while CS-driven selection ensures isolation during multi-device bus operation.

Key Specifications

Pinout & Package

AT25320N-10SI is supplied in an 8-lead JEDEC SOIC package (8S1), measuring 4.90 mm × 3.90 mm × 1.75 mm, with gull-wing leads and 1.27 mm pitch. Pin 1 is marked by a notch or dot; the package is RoHS-compliant and rated for industrial temperature operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95320-WMN6TP and 25AA320A-I/SN, AT25320N-10SI offers optimal balance of industrial temperature support, proven 1M-cycle endurance, and minimal design change risk in legacy systems - especially where 3.0 MHz bandwidth and 2.7V minimum operation are sufficient and cost sensitivity favors mature silicon.

Availability

AT25320N-10SI is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, and automotive body electronics requiring stable component supply, long-term lifecycle assurance, and guaranteed traceable sourcing.

Supply support for AT25320N-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 for embedded systems.

The AT25xxx family was designed specifically for robust, low-power serial EEPROM applications in industrial, automotive, and consumer systems - emphasizing SPI simplicity, wide voltage operation, and field-proven reliability.

FAQ

What is the maximum clock frequency supported by AT25320N-10SI?

The AT25320N-10SI supports up to 3.0 MHz at VCC = 5.0V, 2.1 MHz at VCC = 2.7–5.5V, and 0.5 MHz at VCC = 1.8–3.6V. For the AT25320N-10SI specifically - which is rated for 2.7–5.5V operation - the maximum usable clock frequency is 2.1 MHz across its full voltage range, with 3.0 MHz achievable only at nominal 5.0V. This ensures timing margin compliance in noisy industrial environments.

Does AT25320N-10SI require an external pull-up resistor on the SO pin?

No, AT25320N-10SI does not require an external pull-up on the SO pin. Its SO output is actively driven high or low during valid data transmission and enters high-impedance state when CS is high or HOLD is asserted. External pull-ups may cause bus contention or increased power consumption and are unnecessary per the AT25320N-10SI datasheet recommendations.

How is write protection configured on AT25320N-10SI?

AT25320N-10SI supports two independent write protection mechanisms: software-based via BP0/BP1 bits in the status register (set using WRSR instruction), and hardware-based via the WP pin when WPEN = 1. To enable hardware protection, the WP pin must be pulled low and WPEN bit programmed to "1"; this locks the status register and protected memory blocks until WP is released and WPEN cleared - a process requiring careful sequencing in the AT25320N-10SI firmware.

What is the meaning of the "-10SI" suffix in AT25320N-10SI?

The "-10SI" suffix in AT25320N-10SI indicates two key attributes: "10" denotes a maximum write cycle time of 10 ms (though typical is 5 ms), and "SI" specifies industrial temperature grade (−40°C to +85°C) in an 8-lead SOIC package. This distinguishes it from commercial-grade variants (e.g., -10SC) and higher-timing versions (e.g., -10PI with 5 ms max). The "N" denotes lead-free, RoHS-compliant construction.

Can AT25320N-10SI be used with a 1.8V microcontroller system?

No, AT25320N-10SI is not rated for 1.8V operation. Its specified supply range is 2.7V to 5.5V. For 1.8V systems, the AT25320N-10SI-1.8 variant (with -1.8 suffix) must be used - it supports 1.8–3.6V operation and has different AC timing characteristics. Using AT25320N-10SI below 2.7V risks unreliable communication, failed writes, or undefined behavior, as confirmed by the AT25320N-10SI absolute maximum ratings and DC characteristics tables.