Microchip Technology 25LC320-E/P

Overview

25LC320-E/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. It is used in microcontroller-based systems for nonvolatile parameter storage, calibration data retention, and firmware configuration.

For engineers reviewing the 25LC320-E/P datasheet, 25LC320-E/P pinout, 25LC320-E/P application, or 25LC320-E/P equivalent, this page delivers verified electrical specs, SPI timing constraints, package-specific pin mapping, block protection behavior, and real-world use context - all confirmed against Microchip DS21227F.

Technical Context

The 25LC320-E/P 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. Its internal architecture includes an 8-bit instruction register, auto-incrementing address pointer for sequential reads, and a nonvolatile STATUS register with BP0/BP1 block protection bits and WPEN enable control.

Write operations require explicit WREN instruction before WRITE, and completion is signaled by WIP bit clearing in the STATUS register. The device supports four protection levels (none, upper 1/4, upper 1/2, or full array), enforced by both software (WRSR) and hardware (WP pin + WPEN bit) mechanisms - with precise timing dependencies on SCK edge alignment for HOLD activation and CS deassertion.

Key Specifications

Pinout & Package

25LC320-E/P is supplied in an 8-pin Plastic DIP (300 mil) package with through-hole mounting. Pin 1 is marked with a notch or dot; pin numbering follows standard counter-clockwise convention from the marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC320-E/P, the 25AA320-I/P extends voltage range downward to 1.8 V at the cost of 50% lower SPI speed, while the 25LC320T-I/SN maintains identical functionality in surface-mount form - making them complementary rather than drop-in replacements.

Availability

25LC320-E/P is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, automotive ECU parameter storage, and consumer appliance firmware settings requiring stable component supply and long-term obsolescence management.

Supply support for 25LC320-E/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 infrastructure.

The 25LC320 belongs to Microchip's legacy SPI serial EEPROM product line, designed specifically for cost-sensitive, space-constrained embedded systems requiring reliable nonvolatile storage with minimal external components and direct MCU SPI integration.

FAQ

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

The 25LC320-E/P supports a maximum SPI clock frequency of 2 MHz when VCC is 2.5 V or higher. This specification is validated per Microchip DS21227F AC Characteristics Table 1-2, and applies across the full industrial temperature range (–40°C to +85°C). Exceeding 2 MHz may result in setup/hold violations or read corruption.

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

No, the 25LC320-E/P does not require external pull-ups on SO or SI. Its SO pin is actively driven and tri-stated when deselected or during HOLD, and SI is a CMOS input with negligible leakage. Pull-ups are unnecessary unless shared-bus contention or noise immunity in long traces demands them - which is outside the device's specified interface model.

How does the HOLD function behave during an active write cycle in the 25LC320-E/P?

The HOLD function has no effect during an internal write cycle in the 25LC320-E/P. Once CS is raised to initiate the 5 ms self-timed write, the device ignores HOLD transitions until the cycle completes and WIP clears. HOLD only suspends active SPI communication - not ongoing EEPROM programming.

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

No, the 25LC320-E/P is not rated for 1.8 V operation. Its absolute minimum VCC is 2.5 V, as defined in the Device Selection Table and DC Characteristics section of DS21227F. For 1.8 V systems, Microchip specifies the 25AA320-I/P variant, which shares the same pinout and instruction set but supports 1.8–5.5 V.

What happens to the write enable latch after issuing a WRITE command to the 25LC320-E/P?

After a successful WRITE command completes - including internal write cycle - the write enable latch (WEL bit) in the 25LC320-E/P is automatically reset to '0'. This means each subsequent write operation requires re-execution of the WREN instruction, enforcing explicit write-enable discipline and preventing accidental overwrites due to residual latch state.