25LC256-I/SM

Overview

The Microchip Technology 25LC256-I/SM is a 256 Kbit (32,768 x 8-bit) Serial Electrically Erasable PROM. It operates within a voltage range of 1.8V to 5.5V and supports a maximum clock frequency of 10 MHz at 4.5V ≤ Vcc ≤ 5.5V. The device utilizes an SPI-compatible serial bus with separate data in (SI) and data out (SO) lines. It features self-timed erase and write cycles with a maximum duration of 5 ms. The component is housed in an 8-lead SOIJ package and is rated for industrial temperature operation from -40°C to +85°C.

Feature Summary

• Supports block write protection allowing selection of none, 1/4, 1/2, or all array segments.
• Includes built-in power-on/off data protection circuitry and a write enable latch.
• Features a hold pin to pause serial communication without resetting the sequence.

Applications

• Microcontroller systems requiring non-volatile data storage
• Industrial control applications
• Embedded systems utilizing SPI interfaces

Procurement Notes

Verify the specific suffix 'I' confirms the industrial temperature range (-40°C to +85°C). Confirm the 'SM' designation corresponds to the 8-lead SOIJ package type. Ensure the source documentation matches the exact part number 25LC256-I/SM to validate voltage and speed specifications.

Selection Notes

Select this component for designs requiring 256 Kbit of EEPROM capacity with SPI interface compatibility. The industrial temperature rating suits environments between -40°C and +85°C. Consider the 64-byte page size when designing write algorithms to prevent data wrap-around across page boundaries.

Part Context

This device belongs to the 25XX256 family, which includes the 25AA256 variant. The 25LC256 specifically supports a minimum supply voltage of 1.8V, whereas the 25AA256 supports down to 1.8V as well but may have different electrical characteristics. Both share the same memory organization and instruction set.

Replacement Considerations

The 25LC256T-I/SM is a tape-and-reel version of the same device. The 25LC256-I/SN offers the same electrical performance in an 8-lead Plastic Small Outline (SN) package.

FAQ

How does the HOLD pin function during serial communication?

The HOLD pin suspends transmission to the device while in the middle of a serial sequence without resetting the sequence. Transitions on SI, SCK, and SO pins are ignored while held low.

What happens if a page write crosses a physical page boundary?

If a page write command attempts to write across a physical page boundary, the data wraps around to the beginning of the current page instead of being written to the next page.