Microchip Technology 25LC320A-I/ST

Overview

25LC320A-I/ST 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 delivers 5 µA standby current at 5.5 V - used for nonvolatile configuration storage in microcontroller-based embedded systems.

For engineers reviewing the 25LC320A-I/ST datasheet, 25LC320A-I/ST pinout, 25LC320A-I/ST application, or 25LC320A-I/ST equivalent, key selection criteria include SPI interface compatibility, page-write timing (≤5 ms), block protection granularity (none/¼/½/all), and TSSOP-8 package suitability for space-constrained PCB layouts.

Technical Context

The 25LC320A-I/ST implements a standard SPI Mode 0,0 or Mode 1,1 interface with separate SI (data in) and SO (data out) lines, requiring CS, SCK, HOLD, and WP control signals. Its internal architecture includes an 8-bit instruction register, status register with WIP/WEL/BP0/BP1 bits, and EEPROM array with page latches enabling burst writes within 32-byte boundaries.

Write operations require explicit WREN instruction followed by CS high-to-low transition to initiate self-timed internal write cycle (TWC ≤ 5 ms); read operations support sequential addressing with automatic address roll-over at 0FFFh. HOLD pin suspends active transfers without resetting sequence state, preserving synchronization during host interrupt servicing.

Key Specifications

Pinout & Package

25LC320A-I/ST is packaged in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm pitch, 3.0 mm × 4.4 mm body, and exposed pad option (not electrically connected per datasheet Note 1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA320A-I/ST, the 25LC320A-I/ST offers tighter VCC specification (2.5–5.5 V) and lower cost for 3.3/5 V systems, while AT25DF041A-SSHN-B provides higher density and faster reads but requires firmware redesign due to command and timing incompatibility.

Availability

25LC320A-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, automotive body control modules, and smart energy meter firmware parameter storage requiring stable component supply and long-term lifecycle support.

Supply support for 25LC320A-I/ST 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 product line delivers SPI serial EEPROMs optimized for reliable, low-power nonvolatile storage in industrial, automotive, and medical applications where data integrity and long-term retention are critical.

FAQ

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

The 25LC320A-I/ST supports up to 10 MHz clock frequency when VCC is 4.5 V to 5.5 V. At 2.5 V ≤ VCC < 4.5 V, maximum clock drops to 5 MHz; below 2.5 V, it is limited to 3 MHz. These values are specified in Table 1-2 AC Characteristics and define the upper bound for SPI transfer speed in each voltage domain. The 25LC320A-I/ST must be operated within these limits to guarantee timing compliance and data integrity.

Does the 25LC320A-I/ST support hardware write protection?

Yes, the 25LC320A-I/ST supports hardware write protection using the WP pin in conjunction with the WPEN bit in the STATUS register. When WP is low and WPEN = 1, writes to nonvolatile STATUS register bits are disabled. All other functions remain operational. This feature prevents accidental corruption of protection settings during system power transitions or noise events. The 25LC320A-I/ST implements this per Section 2.3 and Table 3-4 of the datasheet.

What package type is used for the 25LC320A-I/ST?

The 25LC320A-I/ST uses an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch and 3.0 mm × 4.4 mm body dimensions. This is confirmed in the Device Selection Table and Package Types diagram on DS20001828H-page 1. The "ST" suffix explicitly denotes the TSSOP package variant, distinguishing it from MSOP (MS), PDIP (P), SOIC (SN), or TDFN (MNY) options.

How many write/erase cycles does the 25LC320A-I/ST guarantee?

The 25LC320A-I/ST guarantees more than 1 million erase/write cycles at +25°C and 5.5 V, as stated in Table 1-1 Electrical Characteristics (Param. No. D021). This endurance rating applies to both byte and page write operations and is validated through characterization. The 25LC320A-I/ST maintains this specification across its full industrial temperature range (−40°C to +85°C), though actual field lifetime may vary with operating conditions.

Is the 25LC320A-I/ST AEC-Q100 qualified?

Yes, the 25LC320A-I/ST is AEC-Q100 qualified for automotive applications, as explicitly noted in the Features section on DS20001828H-page 1. This qualification covers stress testing for temperature cycling, humidity, ESD, and electrical performance across the industrial temperature range (−40°C to +85°C), confirming suitability for automotive body electronics and infotainment subsystems. The 25LC320A-I/ST meets Grade 2 (−40°C to +105°C) or Grade 3 (−40°C to +125°C) depending on specific test lot - consult Microchip's official qualification report for exact grade assignment.