Microchip Technology 25LC320-I/SN

Overview

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

For engineers reviewing the 25LC320-I/SN datasheet, 25LC320-I/SN pinout, 25LC320-I/SN application, or 25LC320-I/SN equivalent, key selection criteria include SPI interface timing compliance at 2 MHz, industrial-grade reliability (1M write cycles, >200-year data retention), and SOIC-8 package compatibility with legacy board layouts.

Technical Context

The 25LC320-I/SN implements a standard SPI Mode 0,0 (CPOL=0, CPHA=0) interface with separate SI and SO lines, requiring CS, SCK, SI, SO, HOLD, and WP control signals. Its internal architecture includes an 8-bit instruction register, STATUS register with WIP/WEL/BP0/BP1 bits, and hardware-based block protection logic tied to WPEN bit and physical WP pin state.

Write operations require explicit WREN instruction before WRITE or WRSR commands; all writes are self-timed with 5 ms maximum internal cycle time. The device supports sequential read across address boundaries and automatic address rollover at 0FFFh, enabling continuous streaming of stored configuration data without host-side address management.

Key Specifications

Pinout & Package

25LC320-I/SN is housed in an 8-pin plastic SOIC (150 mil body) package per Microchip's standard marking convention "25LC320 I/SN YYWW NNN". Pin 1 is CS; pin 8 is VCC; pins 3 and 7 are WP and HOLD respectively; SO and SI are on pins 2 and 5; SCK is on pin 6; VSS is on pin 4.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA320-I/SN, the 25LC320-I/SN offers higher-speed operation (2 MHz vs. 1 MHz) at 2.5 V minimum, making it preferable in time-critical control loops; compared with 25LC320A-I/SN, it lacks the enhanced ESD hardening but remains fully functional in less aggressive ESD environments.

Availability

25LC320-I/SN is available at Aetrix Electronics and suitable for industrial PLC configuration storage, medical device calibration data retention, and automotive body control module settings requiring stable component supply across extended production lifecycles.

Supply support for 25LC320-I/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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25LC320 belongs to Microchip's SPI Serial EEPROM product line, designed specifically for reliable, low-power nonvolatile data storage in resource-constrained embedded systems across industrial, medical, and automotive markets.

FAQ

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

The 25LC320-I/SN supports a maximum SPI clock frequency of 2 MHz when operated within its specified VCC range of 2.5–5.5 V and industrial temperature range (–40°C to +85°C). This value is confirmed in the Device Selection Table on DS21227F-page 1 and verified in AC Characteristics Table 1-2, where FCLK = 2 MHz is listed for VCC = 2.5V to 5.5V. Exceeding this frequency may result in unreliable read/write operations.

Does the 25LC320-I/SN support hardware write protection?

Yes, the 25LC320-I/SN supports hardware write protection through the combination of the WP pin and the WPEN bit in the STATUS register. When WPEN = 1 and WP = low, writes to nonvolatile STATUS register bits are disabled. This feature is documented in Section 2.3 (Pin Descriptions) and Table 3-3 (Write-Protect Functionality Matrix) of DS21227F. The WP pin has no effect unless WPEN is set high.

What package type does the 25LC320-I/SN use?

The 25LC320-I/SN uses an 8-pin plastic SOIC (Small Outline Integrated Circuit) package with 150 mil body width, as indicated by the "/SN" suffix in the part number per Microchip's Product Identification System (DS21227F-page 23). This package is mechanically and electrically identical to industry-standard SOIC-8 footprints, enabling direct replacement in legacy designs.

How many write/erase cycles does the 25LC320-I/SN guarantee?

The 25LC320-I/SN guarantees 1 million write/erase cycles, as stated in the Features section (DS21227F-page 1) and confirmed in Table 1-2 (AC Characteristics) Note 2 on DS21227F-page 3. This endurance rating applies across the full industrial temperature range and is established by characterization-not 100% tested-but validated for reliability in long-life embedded applications.

Can the 25LC320-I/SN be used in systems with 3.3 V microcontrollers?

Yes, the 25LC320-I/SN is fully compatible with 3.3 V microcontrollers. Its VCC range of 2.5–5.5 V includes 3.3 V nominal supplies, and its input thresholds (VIH1 = 2.0 V min, VIL1 = 0.8 V max at VCC ≥ 2.7 V) ensure reliable logic-level recognition from standard 3.3 V GPIOs. DC Characteristics Table 1-1 (D1–D4) and SPI timing parameters in Table 1-2 confirm interoperability at 3.3 V.