Microchip Technology 25LC320/P

Overview

25LC320/P from Microchip Technology Inc. is a 32 Kbit SPI serial EEPROM with 4096 × 8-bit organization, 2 MHz max clock frequency at 2.5–5.5 V, and industrial temperature range (−40°C to +85°C). It features 32-byte page write, 5 ms max internal write cycle time, and hardware write protection via WP pin and STATUS register. It is used in microcontroller-based systems for nonvolatile parameter storage, calibration data retention, and firmware configuration.

For engineers reviewing the 25LC320/P datasheet, 25LC320/P pinout, 25LC320/P application, or 25LC320/P equivalent, this page delivers verified electrical specs, SPI timing constraints, HOLD/CS/WP functional behavior, package-specific pin mapping, and real-world substitution guidance - all confirmed against Microchip DS21227F.

Technical Context

The 25LC320/P implements a standard SPI Mode 0,0 (CPOL=0, CPHA=0) interface with separate SI (data in) and SO (data out) lines, requiring CS, SCK, SI, SO, WP, HOLD, and VCC/VSS. Its internal architecture includes an 8-bit instruction register, auto-incrementing address pointer, and STATUS register with WIP, WEL, BP0/BP1, and WPEN bits.

Write operations require explicit WREN instruction before WRITE or WRSR, and CS must be raised after final data bit to initiate self-timed 5 ms erase/write. Block protection supports none/¼/½/all array segments; hardware write protection engages only when WP is low *and* WPEN is set high - both conditions are independently controllable and nonvolatile.

Key Specifications

Pinout & Package

25LC320/P is supplied in an 8-pin Plastic DIP (300 mil) package with through-hole mounting. Pin 1 is CS (Chip Select), pin 8 is VCC, and pin 4 is VSS (ground). The package supports manual prototyping and legacy PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA320/P and 25LC320T-I/SN, the 25LC320/P offers optimal trade-off between prototyping flexibility (DIP package), industrial temperature support, and 2 MHz SPI performance - making it ideal for bench validation and small-batch industrial controllers where manual assembly and timing headroom are priorities.

Availability

25LC320/P is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, automotive body control modules, and smart energy meter firmware requiring stable component supply and long-term obsolescence management.

Supply support for 25LC320/P 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 devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing infrastructure.

The 25LC320/P belongs to Microchip's serial EEPROM product line, engineered for reliable nonvolatile data storage in resource-constrained embedded systems where SPI interface simplicity, low power, and long-term data integrity are critical.

FAQ

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

The 25LC320/P supports up to 2 MHz SPI clock frequency when operated within its specified VCC range of 2.5 V to 5.5 V and industrial temperature range (−40°C to +85°C). This value is confirmed in the Device Selection Table of DS21227F and applies specifically to the 25LC320 variant - not the 25AA320 or 25C320. Exceeding 2 MHz may result in timing violations and unreliable communication.

Does the 25LC320/P support hardware write protection?

Yes, the 25LC320/P supports hardware write protection using the WP pin in conjunction with the WPEN bit in the STATUS register. When WP is low and WPEN is set to 1, writes to nonvolatile STATUS register bits are disabled. Memory array writes remain enabled unless block protection bits (BP0/BP1) are also set. This dual-control mechanism ensures robust safeguarding of critical configuration data in the 25LC320/P.

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

The 25LC320/P uses an 8-pin Plastic Dual In-line Package (PDIP) with 300 mil body width, designed for through-hole mounting and manual prototyping. Pin 1 is CS, pin 4 is VSS, pin 5 is SI, pin 6 is SCK, pin 7 is HOLD, and pin 8 is VCC. This package is explicitly listed in the Product Identification System section of DS21227F and matches the "/P" suffix in the part number.

How many write/erase cycles does the 25LC320/P guarantee?

The 25LC320/P guarantees 1 million write/erase cycles per memory location, as stated in Table 1-2 (AC Characteristics) of DS21227F under Note 2. This endurance rating is established by characterization and applies across the full industrial temperature range. It enables reliable usage in applications such as daily firmware logging, parameter tuning, and field-upgrade tracking over multi-year product lifecycles.

Can the 25LC320/P be used with 3.3 V microcontrollers?

Yes, the 25LC320/P is fully compatible with 3.3 V microcontrollers. Its VCC operating range is 2.5 V to 5.5 V, and all DC and AC specifications - including VIH/VIL thresholds, timing parameters, and drive strength - are validated at 3.3 V. The 25LC320/P requires no level-shifting circuitry when interfacing with standard 3.3 V SPI peripherals, simplifying design and reducing BOM cost.