Microchip Technology 25LC320A-E/P

Overview

25LC320A-E/P from Microchip Technology Inc. is a 32-Kbit SPI Serial EEPROM with 4096 × 8-bit organization, 32-byte page size, and AEC-Q100 qualified Extended temperature support (–40°C to +125°C). It operates at up to 10 MHz clock frequency with 5 mA read/write current at 5.5 V and features hardware write protection via WP pin and STATUS register control. It is used in automotive body control modules for storing calibration data and configuration parameters.

For engineers reviewing the 25LC320A-E/P datasheet, 25LC320A-E/P pinout, 25LC320A-E/P application, or 25LC320A-E/P equivalent, key selection criteria include its 8-pin PDIP package, SPI interface compatibility with PIC® and other microcontrollers, extended-temperature operation, and block-level write protection granularity (none/¼/½/all array).

Technical Context

The 25LC320A-E/P implements a standard SPI Mode 0,0 or Mode 1,1 interface with separate SI (data-in) and SO (data-out) lines, CS-controlled selection, and HOLD pin for transaction suspension without reset. Its internal architecture includes an 8-bit instruction register, page latches, and high-voltage generator for EEPROM programming.

It supports self-timed internal write cycles (≤5 ms), sequential read with automatic address increment, and nonvolatile STATUS register bits (WIP, WEL, BP0/BP1, WPEN) enabling flexible hardware/software write protection. The device resets its write enable latch on power-up, WRDI, WRSR, or WRITE completion.

Key Specifications

Pinout & Package

8-Lead Plastic Dual In-Line Package (PDIP), 300 mil body width, through-hole mounting. RoHS-compliant matte tin lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA320A-I/P, the 25LC320A-E/P trades wider supply flexibility for guaranteed automotive qualification and higher temperature tolerance; versus AT25DF321A-SH-B, it offers simpler SPI protocol, deterministic 5 ms writes, and dedicated hardware write protection - essential for safety-critical parameter storage.

Availability

25LC320A-E/P is available at Aetrix Electronics and suitable for automotive electronics, industrial control systems, and medical device manufacturing requiring stable component supply across extended temperature and long product lifecycles.

Supply support for 25LC320A-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 microcontroller, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25LC320A-E/P belongs to Microchip's serial EEPROM product line, engineered for reliable, low-power nonvolatile storage in harsh environments - especially automotive, industrial, and medical applications demanding AEC-Q100 compliance and long-term data integrity.

FAQ

What is the maximum clock frequency supported by the 25LC320A-E/P?

The 25LC320A-E/P 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, the maximum clock drops to 5 MHz; below 2.5 V, it is limited to 3 MHz. These limits are defined in Table 1-2 AC Characteristics and ensure reliable setup/hold timing across voltage and temperature ranges.

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

The 25LC320A-E/P does not require external pull-ups on SI, SCK, or CS - these inputs have CMOS-compatible thresholds and function correctly with standard microcontroller GPIO drivers. However, SO and HOLD are active-high inputs with internal weak pull-downs; external pull-ups may be needed on SO only if shared-bus contention or noise immunity is a concern in high-noise environments.

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

In the 25LC320A-E/P, the HOLD pin suspends SPI communication while preserving the internal address pointer and instruction state. When pulled low while SCK is low, SO immediately tri-states, and subsequent SI/SCK transitions are ignored until HOLD returns high - allowing the host MCU to service interrupts without restarting the transaction.

Can the 25LC320A-E/P be used with 1.8 V microcontrollers?

No - the 25LC320A-E/P has a minimum VCC of 2.5 V and is not rated for 1.8 V operation. For 1.8 V systems, consider the pin-compatible 25AA320A-I/P (1.8–5.5 V), which shares the same instruction set and package options but lacks AEC-Q100 qualification and extended temperature range.

What write protection mechanisms are implemented in the 25LC320A-E/P?

The 25LC320A-E/P implements three layered write protection: (1) software-controlled STATUS register bits (BP0/BP1) for block-level array protection; (2) hardware WP pin enabled only when WPEN = 1; and (3) volatile write enable latch (WEL) that must be set via WREN before each write. All three must be satisfied for successful writes to occur.