25CS640T-H/SN

Overview

The Microchip Technology 25CS640T-H/SN is a 64-Kbit (8,192 x 8 bit) SPI Serial EEPROM housed in an 8-lead SOIC package. It operates within a voltage range of 2.5V to 5.5V and supports clock frequencies up to 20 MHz at VCC ≥ 4.5V, 10 MHz at VCC ≥ 2.5V, and 5 MHz at VCC ≥ 1.7V. The device features a -40°C to +150°C extended temperature rating, self-timed write cycles of 4 ms maximum, and built-in Error Correction Code (ECC) logic for data integrity.

Feature Summary

• Includes a nonvolatile Security register with a factory-programmed 128-bit serial number and a user-programmable lockable ID page.
• Features configurable Enhanced Write Protection mode allowing independent memory partitioning with unique protection behaviors.
• Integrates Undervoltage Lockout Detection circuitry to inhibit write sequences during brown-out events.
• Provides JEDEC standard Manufacturer Read ID support for electronic device identification.

Applications

• Automotive applications requiring AEC-Q100 qualification and high-temperature reliability.
• Industrial systems needing dependable nonvolatile memory storage with enhanced write protection.
• Consumer electronics utilizing the 128-bit serial number for product serialization.

Procurement Notes

Verify that the ordering suffix 'H' corresponds to the Extended temperature range (-40°C to +150°C) and 'SN' indicates the 8-lead SOIC package. Confirm the specific revision level against the latest datasheet DS20005943D to ensure compatibility with system requirements.

Selection Notes

Select this component when operation above 125°C is required, as it exceeds the standard Industrial and Extended ratings. Ensure the supply voltage remains within the 2.5V to 5.5V range specified for the H-grade variant. Consider the ECC logic if single-bit error correction within four-byte readouts is necessary for application reliability.

Part Context

This part belongs to the 25CS640 family of 64-Kbit SPI Serial EEPROMs. It is backward compatible with 25AA640A/25LC640A and AT25C640B devices. The 'H' suffix denotes the highest temperature grade available in this series, designed for harsh environments where standard industrial components would fail.

Replacement Considerations

Direct substitutes include other 25CS640 variants with different packages or temperature grades, such as 25CS640-I/SN or 25CS640-E/ST, provided the thermal and interface requirements are met.