Microchip Technology 25LC320A-I/SN

Overview

25LC320A-I/SN from Microchip Technology is a 32-Kbit SPI Serial EEPROM with 4096 × 8-bit organization, 32-byte page size, and industrial temperature range (–40°C to +85°C). It operates up to 10 MHz at 4.5–5.5 V, supports hardware write protection via WP pin and STATUS register, and delivers >1 million erase/write cycles with >200-year data retention - used in embedded system configuration storage, sensor calibration data logging, and firmware parameter backup.

For engineers reviewing the 25LC320A-I/SN datasheet, 25LC320A-I/SN pinout, 25LC320A-I/SN application, or 25LC320A-I/SN equivalent, key selection considerations include VCC range (2.5–5.5 V), HOLD/CS timing compliance, block protection granularity (none/¼/½/all), self-timed 5 ms write cycle, and SOIC-8 (SN) package compatibility with standard PCB footprints.

Technical Context

The 25LC320A-I/SN implements a SPI Mode 0,0 or Mode 1,1 interface with separate SI (data-in) and SO (data-out) lines, requiring CS low for device selection and SCK synchronization on rising/falling edges respectively. Its internal architecture includes a status register with WIP, WEL, BP0/BP1, and WPEN bits controlling write enable state and 4-level array protection.

It features dual write-protection layers: software-controlled via WRSR instruction and hardware-enforced when WP pin is low and WPEN bit is set. The HOLD pin enables mid-sequence suspension without resetting the SPI transaction, and all I/O pins meet ±1 µA leakage and 4 kV ESD specifications per JEDEC JESD22-A114.

Key Specifications

Pinout & Package

8-Lead Plastic Small Outline (SN) package - narrow body (3.90 mm), 1.27 mm pitch, surface-mount compatible with IPC-7351B SOIC-N footprint (5.40 mm pad spacing, 1.55 mm pad length).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA320A-I/SN and AT25DF321A-SHN-T, the 25LC320A-I/SN offers optimal balance of industrial temperature support, proven 32-Kbit SPI compatibility, and hardware write protection - making it ideal for cost-sensitive, long-lifecycle embedded systems where pinout stability and qualification rigor outweigh raw speed or density needs.

Availability

25LC320A-I/SN is available at Aetrix Electronics and suitable for industrial motor control, medical sensor calibration, and smart energy metering requiring stable component supply across extended production lifecycles.

Supply support for 25LC320A-I/SN 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 25LC320A belongs to Microchip's serial EEPROM product line, engineered for robust, low-power nonvolatile data storage in space-constrained industrial and automotive applications where reliability and qualification compliance are mandatory.

FAQ

What is the maximum clock frequency supported by the 25LC320A-I/SN?

The 25LC320A-I/SN supports up to 10 MHz clock frequency when VCC is between 4.5 V and 5.5 V. At 2.5 V ≤ VCC < 4.5 V, the maximum clock drops to 5 MHz, and at 1.8 V ≤ VCC < 2.5 V (not applicable to 25LC320A-I/SN due to its 2.5 V minimum VCC), it would be limited to 3 MHz. This graded timing ensures signal integrity across voltage ranges while maintaining backward compatibility with legacy 5 V systems.

Does the 25LC320A-I/SN require external pull-up resistors on its SPI lines?

The 25LC320A-I/SN does not require external pull-ups on SI, SCK, or CS - these inputs have CMOS thresholds and are actively driven by the host. However, SO is an open-drain output and requires an external pull-up resistor (typically 4.7 kΩ to VCC) to ensure valid logic-high levels during read operations and bus sharing with other SPI devices.

How does hardware write protection work on the 25LC320A-I/SN?

Hardware write protection on the 25LC320A-I/SN activates only when both the WP pin is held low AND the WPEN bit in the STATUS register is set to 1. When enabled, it blocks writes to nonvolatile STATUS register bits (BP0, BP1, WPEN) but allows normal memory reads, writes (if WEL=1), and volatile STATUS reads. This dual-condition design prevents accidental lockout during board bring-up.

Can the 25LC320A-I/SN be used in automotive applications?

Yes - the 25LC320A-I/SN is AEC-Q100 qualified for automotive use and rated for the Industrial temperature range (–40°C to +85°C), making it suitable for body control modules, infotainment configuration storage, and ADAS sensor calibration data retention. Its 5 µA standby current and 2.5–5.5 V operation align with 12 V automotive electrical system requirements including cold-crank scenarios.

What happens if a page write crosses a 32-byte boundary on the 25LC320A-I/SN?

If a page write command attempts to cross a 32-byte boundary on the 25LC320A-I/SN, data wrap around to the start of the current page instead of advancing to the next page. This causes unintended overwrites of earlier bytes in the same page. Firmware must enforce address alignment checks or split multi-page writes explicitly - the device provides no automatic boundary detection or error signaling for this condition.