Microchip Technology 25LC320AT-E/MS

Overview

25LC320AT-E/MS 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 up to 10 MHz at 4.5–5.5 V, features hardware write protection via WP pin and STATUS register, and delivers >1M erase/write cycles with >200-year data retention - deployed in automotive body control modules for configuration storage.

For engineers reviewing the 25LC320AT-E/MS datasheet, 25LC320AT-E/MS pinout, 25LC320AT-E/MS application, or 25LC320AT-E/MS equivalent, key selection criteria include SPI timing compliance at 125°C, block-level write protection granularity (none/¼/½/all), HOLD pin suspend capability, and MSOP-8 package compatibility with space-constrained automotive PCB layouts.

Technical Context

The 25LC320AT-E/MS implements a standard SPI Mode 0,0 interface with separate SI (data-in) and SO (data-out) lines, requiring CS assertion and SCK synchronization for all operations. Its internal architecture includes a status register with WIP, WEL, BP0/BP1, and WPEN bits, enabling programmable array protection and hardware write-disable when WP is low and WPEN=1.

Write sequencing mandates explicit WREN instruction before WRITE or WRSR commands, followed by CS high to initiate self-timed internal write cycles (≤5 ms). The HOLD pin suspends active transfers without resetting the sequence, tri-stating SO on falling edge and resuming on rising edge - critical for interrupt-driven microcontroller systems sharing the SPI bus.

Key Specifications

Pinout & Package

25LC320AT-E/MS is housed in an 8-lead MSOP (150-mil) package with exposed pad (optional VSS connection), optimized for thermal performance and board area efficiency in automotive modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC320AT-E/MS, the 25AA320AT-I/MS offers broader voltage flexibility but lacks extended temperature and automotive qualification, while the AT25DF041A-SSH-T provides higher density and faster erase at the expense of HOLD support, write-protection granularity, and automotive reliability assurance.

Availability

25LC320AT-E/MS is available at Aetrix Electronics and suitable for automotive body control units, industrial PLCs, and medical infusion pumps requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for 25LC320AT-E/MS 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 family is designed specifically for automotive and industrial applications demanding high reliability, extended temperature operation, and robust SPI EEPROM functionality in space-constrained layouts.

FAQ

What is the maximum clock frequency supported by the 25LC320AT-E/MS across its full voltage and temperature range?

The 25LC320AT-E/MS supports up to 10 MHz at VCC = 4.5–5.5 V and TA = −40°C to +125°C. At 2.5–4.5 V, maximum frequency drops to 5 MHz; below 2.5 V, it is limited to 3 MHz. These AC timing limits are explicitly defined in Table 1-2 of the DS20001828H datasheet and verified across AEC-Q100 stress conditions.

Does the 25LC320AT-E/MS support page write operations, and what is the maximum number of bytes per page?

Yes, the 25LC320AT-E/MS supports page write operations with a fixed 32-byte page size. Up to 32 bytes can be written in a single transaction, provided all addresses reside within the same physical page boundary (e.g., 0x0000–0x001F). Crossing boundaries causes wraparound, overwriting earlier bytes in the same page - software must enforce alignment.

How does hardware write protection work on the 25LC320AT-E/MS, and what conditions must be met to activate it?

Hardware write protection on the 25LC320AT-E/MS activates only when both the WP pin is driven low AND the WPEN bit (STATUS register bit 7) is set to 1. When active, it disables writes to nonvolatile STATUS register bits; all other functions remain operational. If WPEN = 0, the WP pin has no effect - enabling safe field updates even with WP grounded.

What is the role of the HOLD pin on the 25LC320AT-E/MS, and what timing constraints apply during assertion?

The HOLD pin on the 25LC320AT-E/MS suspends ongoing SPI communication without resetting the sequence. It must be asserted while SCK is low; otherwise, suspension waits until the next SCK high-to-low transition. SO tri-states immediately on HOLD low, and resumes output on HOLD high - both transitions are independent of SCK state, per Figure 1-1 in DS20001828H.

Is the 25LC320AT-E/MS pin-compatible with other members of the 25XX320A family, and which packages share identical pinouts?

Yes, the 25LC320AT-E/MS shares identical pinout and function mapping with all 25XX320A variants (e.g., 25AA320A, 25LC320A) across MSOP, SOIC, TSSOP, PDIP, and TDFN packages. Pin 1 is CS in all variants; pin numbering and signal assignments are consistent per Table 2-1, enabling direct substitution within the same package footprint.