25CS320T-E/SN

Overview

The Microchip Technology 25CS320-E/SN 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 configurable write protection modes.

Feature Summary

• Integrated Security Register with preprogrammed 128-bit unique serial number and lockable user ID page
• Built-in Error Correction Code (ECC) logic capable of correcting single-bit errors within four-byte readouts
• Configurable Enhanced Write Protection Mode allowing independent memory partitioning with unique protection behaviors
• Programmable Undervoltage Lockout Detection circuit to inhibit 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
• Consumer electronics requiring component serialization via unique serial numbers

Procurement Notes

Verify the specific temperature grade suffix matches the application requirements: 'I' for Industrial (-40°C to +85°C), 'E' for Extended (-40°C to +125°C), or 'H' for High Temperature (-40°C to +150°C). Ensure the SOIC package variant aligns with PCB layout constraints. Confirm supply voltage ranges meet system specifications for the selected operating temperature.

Selection Notes

Select this component when a globally unique identifier is required for manufacturing line serialization without external programming steps. Choose the 25CS320 over standard EEPROMs if enhanced write protection via memory partitions or ECC-based data reliability is necessary. Verify that the SPI interface modes (0 and 3) are compatible with the host controller's communication protocol.

Part Context

The 25CS320 belongs to Microchip's CS series of Serial EEPROMs, designed for high-reliability applications. It offers backward compatibility with legacy devices such as the 25AA320A, 25LC320A, and AT25320B. The device integrates advanced security and protection features not typically found in basic serial EEPROMs, making it suitable for secure data logging and identification tasks.

Replacement Considerations

The datasheet explicitly states backward compatibility with the 25AA320A, 25LC320A, and AT25320B. These parts may serve as functional substitutes in pin-compatible designs, though feature sets like ECC and enhanced write protection will differ.

FAQ

How does the 25CS320 handle data integrity during reads?

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 ECS bit in the STATUS register indicates if errors were detected and corrected.

What is the function of the HOLD pin?

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.