Microchip Technology 25LC320/WF

Overview

25LC320/WF 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/WF datasheet, 25LC320/WF pinout, 25LC320/WF application, or 25LC320/WF equivalent, key selection criteria include VCC operating range compatibility, SPI timing compliance at target clock speed, HOLD/CS timing margins, and block-level write-protection granularity for secure field updates.

Technical Context

The 25LC320/WF implements a standard SPI Mode 0,0 interface with separate SI (data-in) and SO (data-out) lines, requiring CS assertion and SCK synchronization for all operations. Its internal architecture includes a status register with WIP, WEL, BP0/BP1, and WPEN bits, enabling programmable 0%, 25%, 50%, or 100% array write protection.

Write cycles are self-timed (max 5 ms), supported by built-in power-on write-disable logic, write-enable latch control (WREN/WRDI), and hardware-level protection that remains active during voltage transients. The HOLD pin suspends ongoing transfers without resetting the internal address pointer, allowing deterministic resumption after higher-priority MCU interrupts.

Key Specifications

Pinout & Package

25LC320/WF is supplied in an 8-pin SOIC package (150 mil body width), pin-compatible with industry-standard 25XX320 family footprints. Package marking includes "25LC320" followed by temperature grade "I", date code, and traceability identifier.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC320/WF, 25AA320-I/SN offers wider voltage flexibility at reduced speed, while 25LC320A-I/SN provides identical functionality with superior ESD immunity - both maintain full software and layout compatibility but differ in supply range and qualification level.

Availability

25LC320/WF is available at Aetrix Electronics and suitable for industrial sensor calibration storage, embedded system configuration backup, and firmware parameter archiving requiring stable component supply across extended product lifecycles.

Supply support for 25LC320/WF 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 silicon and development tools.

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

FAQ

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

The 25LC320/WF 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 full industrial temperature range (−40°C to +85°C) and aligns with standard SPI peripheral timing budgets. Exceeding 2 MHz may result in read/write failures or timing violations per Table 1-2 AC characteristics.

Does the 25LC320/WF require external pull-up resistors on its SO or SI lines?

No, the 25LC320/WF does not require external pull-up resistors on SO or SI. The SO pin is internally driven and tri-stated when CS is high or HOLD is active; SI is a CMOS input with negligible leakage. Pull-ups are unnecessary unless shared-bus contention or specific MCU input threshold requirements dictate them - per DC Characteristics Table 1-1, VIH/VIL thresholds are rail-relative.

How does hardware write protection work on the 25LC320/WF?

Hardware write protection on the 25LC320/WF requires both the WP pin to be low and the WPEN bit (bit 7 of STATUS register) to be set high. When enabled, this combination disables writes to nonvolatile STATUS register bits - including BP0/BP1 - while allowing normal memory reads and writes. If WPEN = 0, the WP pin has no effect, permitting full STATUS register updates.

Can the 25LC320/WF be used in automotive applications rated for −40°C to +125°C?

No, the 25LC320/WF is specified only for the industrial temperature range (−40°C to +85°C). For automotive-grade operation up to +125°C, Microchip designates the 25LC320-E variant (e.g., 25LC320-E/SN). Using the /WF suffix part outside its qualified temperature range risks parametric drift, timing violation, or premature endurance failure.

What happens to the internal address pointer during a HOLD operation on the 25LC320/WF?

During a HOLD operation, the 25LC320/WF preserves its internal address pointer state exactly as it was when HOLD was asserted. Upon releasing HOLD (bringing it high while SCK is low), serial communication resumes from the same byte position - whether mid-read, mid-page-write, or mid-status-register access - with no loss of context or need for reinitialization.