Microchip Technology 25LC320/SN

Overview

25LC320/SN from Microchip Technology Inc. is a 32 Kbit SPI serial EEPROM with 4096 × 8-bit organization, 2.5–5.5 V supply range, and 2 MHz max clock frequency for industrial-temperature (−40°C to +85°C) operation. It features hardware write protection via WP pin, HOLD functionality for interrupt-safe bus suspension, and 32-byte page write capability - used in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 25LC320/SN datasheet, 25LC320/SN pinout, 25LC320/SN application, or 25LC320/SN equivalent, key selection criteria include verified 2 MHz SPI timing at 2.5 V, industrial-grade temperature support, SOIC-8 package compatibility, and confirmed block write-protection granularity (none/¼/½/all array).

Technical Context

The 25LC320/SN implements a standard SPI Mode 0,0 interface with separate SI (data-in) and SO (data-out) lines, requiring CS, SCK, and optional HOLD/WP control signals. Its internal architecture includes an 8-bit instruction register, auto-incrementing address pointer for sequential reads, and a STATUS register with nonvolatile BP0/BP1 bits controlling 1/4-, 1/2-, or full-array write protection.

Write operations require explicit WREN instruction before WRITE, followed by CS high to initiate self-timed internal write cycle (≤5 ms). During active writes, the WIP bit in STATUS is asserted, and memory reads are blocked until completion. The HOLD pin suspends ongoing transfers without resetting state, enabling host CPU servicing of higher-priority interrupts.

Key Specifications

Pinout & Package

25LC320/SN is supplied in an 8-pin plastic SOIC (150 mil body) package per Microchip's standard marking convention "25LC320 I/SN YYWW NNN".

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC320/SN, 25AA320T-I/SN extends voltage range downward but sacrifices speed, while 25LC320A-I/SN offers identical performance with improved ESD immunity and official design-in recommendation - making it the preferred upgrade path.

Availability

25LC320/SN is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, automotive body electronics, and smart metering applications requiring stable component supply and long-term obsolescence management.

Supply support for 25LC320/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, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25LC320/SN belongs to Microchip's serial EEPROM product line, engineered for reliable, low-power nonvolatile data storage in embedded systems where SPI interface simplicity, industrial temperature operation, and hardware write protection are critical.

FAQ

What is the maximum SPI clock frequency supported by the 25LC320/SN?

The 25LC320/SN supports up to 2 MHz maximum clock frequency when VCC is 2.5 V or higher, as specified in the Device Selection Table and confirmed in Table 1-2 AC Characteristics. This timing is validated across the industrial temperature range (−40°C to +85°C) and enables efficient parameter reads/writes in real-time embedded applications using the 25LC320/SN.

Does the 25LC320/SN support hardware write protection, and how is it configured?

Yes, the 25LC320/SN supports hardware write protection via the WP pin combined with the WPEN bit in its STATUS register. When WPEN = 1 and WP = low, writes to nonvolatile STATUS bits (BP0, BP1, WPEN) are disabled. The 25LC320/SN allows full memory writes even under hardware protection, ensuring configuration flexibility while safeguarding critical protection settings.

What package type does the 25LC320/SN use, and what are its dimensions?

The 25LC320/SN uses an 8-pin plastic SOIC package with 150 mil body width, as indicated by the "/SN" suffix in the part number and confirmed in Section 4.1 Package Marking Information. Its standardized footprint matches JEDEC MS-012AC, enabling drop-in compatibility with existing SOIC-8 layouts designed for similar serial EEPROMs like the 25C320 or 25AA320.

How many write/erase cycles can the 25LC320/SN endure, and what is its data retention period?

The 25LC320/SN is rated for 1 million write/erase cycles and guarantees data retention exceeding 200 years under normal operating conditions, as stated in the Features section and Table 1-1 DC Characteristics. These specifications are based on characterization (not 100% tested) and apply across the full industrial temperature range, ensuring long-term reliability for the 25LC320/SN in infrequently updated storage applications.

Can the 25LC320/SN be used in automotive applications requiring extended temperature range?

No - the 25LC320/SN is qualified only for the industrial temperature range (−40°C to +85°C), not the automotive grade (−40°C to +125°C). For automotive applications, Microchip specifies the 25LC320E variant (with "E" suffix), which shares the same electrical characteristics and SOIC-8 package but undergoes additional qualification testing. The 25LC320/SN must not be substituted in AEC-Q100-compliant designs without validation.