25LC256T-I/ST

Overview

The Microchip Technology 25LC256T-I/ST is a 256 Kbit (32K x 8) Serial Electrically Erasable PROM accessed via an SPI-compatible serial bus. It operates within a voltage range of 2.5V to 5.5V and supports clock frequencies up to 10 MHz at 5.5V. The device features self-timed erase and write cycles with a maximum duration of 5 ms. It includes block write protection capabilities, allowing none, 1/4, 1/2, or all of the array to be protected. The component is housed in an 8-lead TSSOP package and is rated for industrial temperature ranges from -40°C to +85°C.

Feature Summary

• Supports sequential read operations and page writes of up to 64 bytes within a single physical page boundary.
• Includes built-in power-on/off data protection circuitry and a write enable latch to prevent inadvertent writes.
• Features a HOLD input pin that allows suspension of serial communication without resetting the sequence.

Applications

• Microcontroller systems requiring non-volatile storage for configuration parameters.
• Industrial sensor nodes needing reliable calibration data retention.
• Embedded devices utilizing software-emulated SPI interfaces on controllers lacking hardware peripherals.

Procurement Notes

Verify the 'I' suffix confirms the Industrial temperature range (-40°C to +85°C). Confirm the 'ST' suffix corresponds to the 8-lead TSSOP package. Ensure the 'T' indicates tape and reel packaging if required by assembly equipment. Cross-reference the specific datasheet revision DS20001822H for accurate electrical characteristics.

Selection Notes

Select this part when a 256 Kbit capacity is required with SPI interface compatibility. Choose the 'I' grade for industrial environments over the 'E' grade which extends to +125°C. Consider the TSSOP package for surface mount applications where space is constrained compared to PDIP or SOIC options.

Part Context

This component belongs to the 25LC256 family of Serial EEPROMs manufactured by Microchip Technology. It shares functional similarities with the 25AA256 but differs in operating voltage requirements. The device is designed for direct interfacing with popular microcontroller families, including PIC microcontrollers, supporting both hardware and software SPI implementations.

Replacement Considerations

The 25LC256-I/ST is a compatible alternative differing only in bulk packaging instead of tape and reel. The 25AA256 series offers similar functionality but supports a lower minimum voltage of 1.8V. Verify package dimensions and pinout compatibility before substituting.