Microchip Technology 25LC320A-I/P

Overview

25LC320A-I/P from Microchip Technology Inc. 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 at up to 10 MHz clock frequency, supports hardware write protection via WP pin and STATUS register, and delivers 5 µA standby current at 5.5V - ideal for battery-backed data logging in embedded control systems.

For engineers reviewing the 25LC320A-I/P datasheet, 25LC320A-I/P pinout, 25LC320A-I/P application, or 25LC320A-I/P equivalent, key selection considerations include its SPI interface timing compliance (T_CSS, T_CSH, T_su), block protection granularity (0%, 25%, 50%, or 100% array), HOLD pin suspend functionality, and AEC-Q100 qualification for automotive-grade reliability.

Technical Context

The 25LC320A-I/P implements a standard SPI Mode 0,0 (CPOL=0, CPHA=0) interface with separate SI and SO lines, requiring CS, SCK, SI, SO, WP, HOLD, VCC, and VSS. Its internal architecture includes a status register with WIP, WEL, BP0/BP1, and WPEN bits, enabling programmable block protection and hardware write-disable independent of software state.

It uses low-power CMOS technology with self-timed internal write cycles (≤5 ms), built-in power-on/off data protection, and ESD immunity >4 kV. The device supports sequential read, page write (up to 32 bytes within one 32-byte boundary), and hold-mode suspension without sequence reset - critical for interrupt-driven microcontroller environments.

Key Specifications

Pinout & Package

8-Lead PDIP (Plastic Dual In-Line Package), 300 mil body width, through-hole mounting. Pin 1 marked by notch or dot; pin numbering follows standard DIP convention (counterclockwise from notch).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA320A-I/P and AT25DF321A-SSH-T, the 25LC320A-I/P offers optimal balance of industrial temperature support, hardware write protection, HOLD functionality, and proven SPI EEPROM compatibility - making it the preferred choice for deterministic, safety-aware parameter storage where pin count, command simplicity, and legacy driver reuse are critical.

Availability

25LC320A-I/P is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, medical infusion pumps, and smart energy metering requiring stable component supply across extended product lifecycles.

Supply support for 25LC320A-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 25LC320A belongs to Microchip's serial EEPROM product line, engineered for reliable nonvolatile data storage in cost-sensitive, space-constrained embedded systems requiring SPI interface simplicity and industrial-grade robustness.

FAQ

What is the maximum operating voltage for the 25LC320A-I/P?

The 25LC320A-I/P supports a V_CC range of 2.5V to 5.5V. Operation above 5.5V violates absolute maximum ratings and risks permanent damage. At 5.5V, it achieves full 10 MHz clock performance and 5 mA read current; below 2.5V, the device is not guaranteed to function per specification.

Does the 25LC320A-I/P support page write operations, and what is the limit?

Yes, the 25LC320A-I/P supports page write operations with a fixed 32-byte page size. Up to 32 bytes can be written in a single transaction, but all bytes must reside within the same physical page boundary (e.g., addresses 0x000–0x01F). Crossing a boundary causes wraparound, overwriting earlier bytes in the page - firmware must enforce alignment.

How does the HOLD pin function during an active SPI transaction on the 25LC320A-I/P?

The HOLD pin on the 25LC320A-I/P suspends SPI communication mid-sequence: SO immediately enters high-impedance state, and SI/SCK transitions are ignored. To resume, HOLD must be pulled high while SCK is low; the device continues from the exact byte position where it paused, preserving the internal address pointer.

Is the 25LC320A-I/P pin-compatible with the 25AA320A-I/P?

Yes, the 25LC320A-I/P and 25AA320A-I/P share identical pinout, package dimensions, and SPI command set. The primary difference is V_CC range: 25AA320A supports 1.8–5.5V, while 25LC320A requires 2.5–5.5V. For designs operating ≥2.5V, they are functionally interchangeable with no PCB changes required.

What protection mechanisms prevent unintended writes to the 25LC320A-I/P memory array?

The 25LC320A-I/P employs multiple safeguards: (1) write enable latch reset on power-up, (2) mandatory WREN instruction before any write, (3) automatic WEL reset after each successful write, (4) hardware WP pin + WPEN bit combination, and (5) block protection bits (BP0/BP1) that lock memory segments. These layers ensure robust immunity to noise, brown-out, or software faults.