25CS320T-E/ST

Overview

The Microchip Technology 25CS320-E/ST is a 32-Kbit (4,096 x 8 bit) Serial EEPROM utilizing an SPI-compatible bus. It features a 128-bit factory-programmed serial number and a 32-byte user-programmable lockable ID page within its Security Register. The device supports up to 20 MHz clock frequency at VCC ≥ 4.5V and operates across a voltage range of 1.7V to 5.5V. It includes built-in Error Correction Code (ECC) logic for data integrity and offers configurable write protection via Legacy or Enhanced modes. The component is AEC-Q100 qualified and housed in an 8-lead SOIC package.

Feature Summary

• Integrated Security Register containing a unique 128-bit serial number and a 32-byte user-programmable lockable ID page.
• Built-in Error Correction Code (ECC) logic capable of correcting single-bit errors within four-byte readouts to enhance reliability.
• Configurable write protection supporting both Legacy Block Protection and Enhanced User-Definable Memory Partitioning modes.
• Programmable Undervoltage Lockout (UVLO) detection circuit that inhibits write sequences during brown-out events.

Applications

• Automotive systems requiring AEC-Q100 qualified nonvolatile memory storage.
• Industrial applications needing reliable data retention and enhanced write protection schemes.
• Consumer electronics utilizing SPI interfaces for configuration and calibration data storage.

Procurement Notes

Verify the specific suffix 'E' corresponds to the Extended temperature range (-40°C to +125°C) as defined in the datasheet electrical characteristics. Confirm the '/ST' designation matches the required 8-lead SOIC package type. Ensure the order quantity aligns with standard manufacturing packaging configurations provided by Microchip Technology Inc.

Selection Notes

Select this component when a 32-Kbit capacity is sufficient for application requirements. Choose the Extended temperature grade if operation above 85°C is necessary. Consider the Enhanced Write Protection mode if independent partition locking is required. Verify SPI compatibility with the host controller, specifically regarding Mode 0 and Mode 3 support.

Part Context

The 25CS320 belongs to the 25CS series of Serial EEPROMs from Microchip Technology. This series is designed for applications demanding high reliability and security features such as unique serialization. The device is backward compatible with other industry-standard 32-Kbit EEPROMs, facilitating drop-in replacements in existing designs while offering advanced features like ECC and programmable UVLO.

Replacement Considerations

The datasheet explicitly states backward compatibility with the 25AA320A, 25LC320A, and AT25320B Serial EEPROMs. These part numbers may serve as direct functional substitutes in legacy designs, though verification of pinout and command set alignment is recommended.

FAQ

How does the 25CS320 handle data integrity during read operations?

The device utilizes built-in Error Correction Code (ECC) logic that can correct up to one incorrectly read bit within a four-byte readout. An ECC Status bit in the STATUS register indicates if errors were detected and corrected.

What is the function of the HOLD pin on the 25CS320?

The HOLD pin allows the host to pause serial communication without resetting the sequence. While held, input transitions are ignored except for Chip Select, enabling the host to service higher priority interrupts.