25CS320-E/MS

Overview

The Microchip Technology 25CS320-E/MS is a 32-Kbit (4,096 x 8 bit) Serial EEPROM utilizing SPI-compatible bus communication. It features a page size of 32 bytes and supports byte or sequential reads and writes. The device operates within a voltage range of 1.7V to 5.5V, with high-speed clock frequencies up to 20 MHz at VCC ≥ 4.5V. It includes a Security Register with a preprogrammed 128-bit serial number and user-programmable ID pages. Built-in Error Correction Code (ECC) logic enhances reliability by correcting single-bit errors in four-byte readouts. The component offers legacy and enhanced write protection modes and is qualified for automotive applications under AEC-Q100 standards.

Feature Summary

• Integrated Security Register containing a factory-programmed 128-bit unique serial number and lockable user-programmable ID pages.
• Built-in Error Correction Code (ECC) logic capable of correcting one incorrectly read bit within a four-byte readout sequence.
• Configurable write protection schemes supporting both Legacy Block Protection and Enhanced User-Definable Memory Partitioning.
• Programmable Undervoltage Lockout Detection circuit to inhibit write sequences during brown-out events.

Applications

• Consumer electronics requiring reliable nonvolatile memory storage
• Industrial systems demanding dependable data retention
• Automotive applications meeting AEC-Q100 qualification standards

Procurement Notes

Verify the specific temperature grade suffix 'E' corresponds to the Extended range (-40°C to +125°C) required for your design environment. Confirm the MSOP package type matches your PCB footprint constraints. Ensure the ordering code aligns with the desired tape-and-reel quantity if applicable. Cross-reference the datasheet revision to confirm feature compatibility with existing firmware implementations.

Selection Notes

Select this component when system requirements include hardware-level serialization via the embedded 128-bit serial number. Choose the 25CS320 over standard EEPROMs if ECC functionality is necessary to mitigate data corruption risks without external processing overhead. Consider the Enhanced Write Protection mode for applications requiring granular memory partitioning rather than simple block protection.

Part Context

The 25CS320 belongs to Microchip's CS series of Serial EEPROMs, designed as a backward-compatible replacement for devices like the 25AA320A, 25LC320A, and AT25320B. It expands upon previous generations by adding security features and advanced error correction while maintaining pin compatibility and interface standards. This positioning allows for direct upgrades in existing designs needing improved reliability and identification capabilities.

Replacement Considerations

The datasheet explicitly states backward compatibility with the 25AA320A, 25LC320A, and AT25320B. Verify that the target application does not rely on undocumented behaviors specific to those legacy parts. Ensure that the host controller supports the additional opcodes required for ECC status reading and UVLO configuration if these features are utilized.