Microchip Technology 25LC320/S

Overview

25LC320/S from Microchip Technology Inc. is a 32 Kbit (4096 × 8) SPI-compatible serial EEPROM with 2.5–5.5 V supply range, 2 MHz max clock frequency, and industrial temperature rating (–40°C to +85°C). It features 32-byte page write capability, hardware write protection via WP pin and STATUS register, and 1 million endurance cycles - deployed in embedded control modules for firmware parameter storage and calibration data retention.

For engineers reviewing the 25LC320/S datasheet, 25LC320/S pinout, 25LC320/S application, or 25LC320/S equivalent, this page delivers verified electrical specs, validated SPI timing constraints, confirmed package mapping (8-lead SOIC), and real-world use context for industrial microcontroller-based systems requiring nonvolatile configuration memory with low-power standby operation.

Technical Context

The 25LC320/S implements a standard SPI Mode 0,0 interface with separate SI (data-in) and SO (data-out) lines, CS-controlled selection, and HOLD pin for transaction suspension without reset. Its internal architecture includes an 8-bit instruction register, auto-incrementing address pointer for sequential reads, and a nonvolatile STATUS register controlling block protection (BP0/BP1) and write-enable latch (WEL).

Write operations require explicit WREN instruction before WRITE, support up to 32 bytes per page within same 32-byte-aligned boundary, and complete in ≤5 ms with self-timed erase/write cycles. Hardware write protection engages only when WPEN=1 and WP=low, leaving all other functions-including STATUS register writes-fully operational unless explicitly disabled.

Key Specifications

Pinout & Package

25LC320/S is packaged in an 8-lead SOIC (150 mil body), pin-compatible with industry-standard 25xx320 family layouts. Pin numbering follows JEDEC MS-012AA outline 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 25LC320/S, 25AA320T-I/SN offers wider voltage flexibility but reduced speed, while AT25DF321A-SH-B provides higher density at the cost of protocol incompatibility and design effort - making 25LC320/S optimal for cost-sensitive, 3.3 V industrial parameter storage where proven SPI simplicity and low-power standby are critical.

Availability

25LC320/S is available at Aetrix Electronics and suitable for industrial PLC configuration storage, medical device calibration memory, and automotive body control module applications requiring stable component supply, long-lifecycle assurance, and consistent parametric performance across production batches.

Supply support for 25LC320/S 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, serving industrial, automotive, and consumer markets with high-reliability semiconductor products.

The 25LC320/S belongs to Microchip's legacy 25xx320 serial EEPROM product line, designed specifically for low-power, SPI-based nonvolatile data storage in resource-constrained embedded systems requiring guaranteed data integrity and long-term retention.

FAQ

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

The 25LC320/S supports a maximum clock frequency of 2 MHz when VCC is between 2.5 V and 5.5 V. This specification is validated across the industrial temperature range (–40°C to +85°C) and enables efficient parameter reads/writes in time-critical embedded applications. Exceeding 2 MHz may result in timing violations and communication errors, especially at lower VCC levels or elevated temperatures.

Does the 25LC320/S support hardware write protection?

Yes, the 25LC320/S supports hardware write protection through the combination of the WP pin and the WPEN bit in its STATUS register. When WPEN = 1 and WP = low, writes to nonvolatile STATUS register bits are disabled. All other operations - including memory reads, instruction execution, and array writes - remain fully functional unless blocked by block protection bits (BP0/BP1).

What package type is used for the 25LC320/S?

The 25LC320/S uses an 8-lead SOIC (Small Outline Integrated Circuit) package with 150 mil body width and standard JEDEC MS-012AA footprint. This package is pin-compatible with other members of the 25xx320 family and widely supported by PCB assembly houses for automated placement and reflow soldering.

How many write/erase cycles can the 25LC320/S endure?

The 25LC320/S is rated for 1 million write/erase cycles per memory location, as specified in Microchip's DS21227F datasheet. This endurance level ensures reliable operation over the full product lifetime in applications involving frequent recalibration, logging, or configuration updates - such as industrial sensors or medical devices.

Is the 25LC320/S compatible with SPI Mode 0,0?

Yes, the 25LC320/S is fully compatible with SPI Mode 0,0 (CPOL = 0, CPHA = 0), where data is sampled on the rising edge of SCK and shifted out on the falling edge. It also supports Mode 1,1 per datasheet Figure 1-2 and Figure 1-3, enabling interoperability with diverse microcontroller SPI peripherals without protocol translation.