Microchip Technology 25LC320-I/P

Overview

25LC320-I/P from Microchip Technology Inc. is a 32 Kbit SPI serial EEPROM with 4096 × 8-bit organization, 2.5–5.5 V supply range, and industrial temperature rating (–40°C to +85°C). It features 32-byte page write capability, 5 ms max internal write cycle time, and hardware write protection via WP pin and STATUS register. Used for nonvolatile parameter storage in microcontroller-based embedded systems requiring reliable, low-power data retention.

For engineers reviewing the 25LC320-I/P datasheet, 25LC320-I/P pinout, 25LC320-I/P application, or 25LC320-I/P equivalent, this page delivers verified electrical specs, SPI timing constraints, HOLD/CS/WP functional behavior, package-specific pin mapping, and real-world use cases in industrial control and sensor calibration systems.

Technical Context

The 25LC320-I/P implements a standard SPI Mode 0,0 interface with separate SI (data in) and SO (data out) lines, CS-controlled selection, and SCK-synchronized transfers. Its internal architecture includes an 8-bit instruction register, auto-incrementing address pointer for sequential reads, and a STATUS register with WIP, WEL, BP0/BP1, and WPEN bits.

Write operations require explicit WREN instruction before WRITE or WRSR, and are self-timed with automatic erase/write completion. Block protection supports four configurations (none, upper 1/4, upper 1/2, or full array), controlled by BP0/BP1 bits written via WRSR. The HOLD pin suspends ongoing SPI communication without resetting the sequence.

Key Specifications

Pinout & Package

25LC320-I/P is supplied in an 8-pin Plastic Dual In-line Package (PDIP, 300 mil body), with lead spacing compliant to JEDEC MS-001. Pin 1 is marked with a notch or dot; orientation follows standard DIP convention.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC320-I/P, 25AA320-I/P extends voltage flexibility downward to 1.8 V at reduced speed, while 25LC320T-I/SN maintains identical functionality in surface-mount form - both serve distinct layout and manufacturing requirements without altering core EEPROM behavior.

Availability

25LC320-I/P is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded system configuration, and power meter firmware settings requiring stable component supply and long-term obsolescence management.

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

The 25LC320-I/P belongs to Microchip's legacy SPI Serial EEPROM product line, engineered for robust, low-power nonvolatile storage in industrial and automotive environments where reliability and long-term data integrity are critical.

FAQ

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

The 25LC320-I/P supports up to 2 MHz maximum clock frequency when VCC is 2.5 V or higher. This specification is validated across the full industrial temperature range (–40°C to +85°C) and enables efficient data transfer in systems using 3.3 V microcontrollers. At lower voltages, the device is not rated for operation.

How does the HOLD pin function during an active SPI transaction on the 25LC320-I/P?

The HOLD pin on the 25LC320-I/P pauses an ongoing SPI sequence when pulled low while SCK is low. During hold, SI, SCK, and SO enter high-impedance states and ignore transitions. Communication resumes from the exact point of interruption when HOLD is raised high with SCK low - preserving command state without reinitialization.

Can the 25LC320-I/P be used in a 1.8 V system?

No, the 25LC320-I/P requires a minimum VCC of 2.5 V and is not specified for operation at 1.8 V. For 1.8 V compatibility, Microchip recommends the 25AA320-I/P, which shares identical pinout and instruction set but supports 1.8–5.5 V operation.

What write protection mechanisms are implemented in the 25LC320-I/P?

The 25LC320-I/P implements dual-layer write protection: (1) software-controlled block protection via BP0/BP1 bits in the STATUS register, enabling selective locking of 0%, 25%, 50%, or 100% of memory; and (2) hardware write protection using the WP pin in conjunction with the WPEN bit to lock the STATUS register itself.

Is the 25LC320-I/P still recommended for new designs?

No - Microchip explicitly states "Not recommended for new designs" in DS21227F, advising migration to the enhanced 25LC320A variant. The 25LC320-I/P remains available for legacy support and existing production, but new projects should evaluate the A-version for improved reliability and extended lifecycle assurance.