25AA040X-I/ST

Memory IC Overview

The Microchip Technology 25AA040X-I/ST is a 4 Kbit (512 x 8) serial Electrically Erasable PROM utilizing an SPI-compatible interface. It operates within a voltage range of 1.8V to 5.5V and supports a maximum clock frequency of 1 MHz in the Industrial temperature range (-40°C to +85°C). The device features a 16-byte page write capability, self-timed erase/write cycles with a maximum duration of 5 ms, and high reliability metrics including 1 million endurance cycles and over 200 years of data retention.

Memory IC Feature Summary

• Low-power CMOS technology with typical standby current of 500 nA
• Hardware write protection via dedicated WP pin and software block protection
• Built-in power-on/off data protection circuitry and write enable latch
• HOLD pin functionality allows pausing serial communication without sequence reset

Memory IC Applications

• Microcontroller system configuration storage
• Calibration data and parameter logging
• Non-volatile memory for industrial control systems
• Embedded device identification and security codes

Memory IC Procurement Notes

Verify that the 'X' suffix indicates the alternate pinout configuration specific to the TSSOP package. Confirm the 'I' designation matches the required -40°C to +85°C operating range. Ensure design compliance with the manufacturer's note stating this series is not recommended for new designs; consider the 25AA040A variant for future projects.

Memory IC Selection Notes

Select this component when a low-pin-count SPI EEPROM is required for 4 Kbit storage. The 1.8V minimum supply voltage makes it suitable for low-voltage logic interfaces. The TSSOP package offers a compact footprint for space-constrained PCB layouts. Verify that the 1 MHz clock speed meets the system's throughput requirements.

Memory IC Part Context

This part belongs to the 25XX040 family, which includes variants like the 25LC040 and 25C040 differentiated by supply voltage ranges and clock speeds. The 'X' suffix specifically denotes an alternate pinout arrangement available only in the ST (TSSOP) package type. This family provides a standard SPI interface compatible with most microcontrollers lacking dedicated hardware SPI ports.

Memory IC Replacement Considerations

Public confirmed substitute part numbers: 25AA040A-I/ST.