25C040/P

Memory IC Overview

The Microchip Technology 25C040/P is a 4 Kbit (512 x 8-bit) serial Electrically Erasable PROM housed in an 8-lead PDIP package. It operates within a voltage range of 4.5 V to 5.5 V and supports a maximum clock frequency of 3 MHz via a SPI-compatible interface. The device features a typical read current of 500 μA, write current of 3 mA, and standby current of 500 nA. It offers high reliability with 1 million endurance cycles and data retention exceeding 200 years. The operating temperature range for the Automotive (E) grade is -40°C to +125°C.

Memory IC Feature Summary

• Supports hardware write protection through a dedicated WP pin that disables array writes when low.
• Includes built-in power-on/off data protection circuitry and a self-timed write enable latch.
• Allows selective block write protection covering none, one-quarter, one-half, or all memory segments.

Memory IC Applications

• Industrial control systems requiring non-volatile data storage
• Automotive electronics operating under extended temperature conditions
• Microcontroller-based embedded applications needing configuration parameter retention

Memory IC Procurement Notes

Verify the specific suffix 'P' corresponds to the 8-lead Plastic DIP package before procurement. Confirm the 'E' designation indicates the Automotive grade (-40°C to +125°C) if required by your application environment. Ensure the supply voltage strictly adheres to the 4.5 V to 5.5 V operational limits specified for this variant.

Memory IC Selection Notes

Select this component for designs requiring robust automotive-grade thermal performance and standard 5V logic compatibility. The PDIP package facilitates through-hole prototyping and assembly. Consider the 3 MHz speed limit and 5 ms write cycle time when designing system timing constraints relative to higher-speed alternatives.

Memory IC Part Context

This part belongs to the 25XX040 family of 4 Kbit serial EEPROMs from Microchip Technology. It shares architectural similarities with the 25AA040 and 25LC040 but is distinguished by its specific 4.5 V to 5.5 V operating voltage range and extended temperature rating suitable for automotive environments.

Memory IC Replacement Considerations

Public confirmed substitute part numbers: 25C040-I/P (Industrial grade), 25C040-E/SN (SOIC package), 25C040-E/ST (TSSOP package).

Memory IC FAQ

How does the HOLD pin function during serial communication?

The HOLD pin allows the host to pause serial transmission without resetting the sequence. When pulled low while SCK is low, inputs are ignored except Chip Select. Communication resumes when HOLD is brought high while SCK is low.

What happens to the write enable latch upon power-up?

Upon power-up, the device enters low-power Standby mode, the SO pin goes into a high-impedance state, and the write enable latch is automatically reset, preventing inadvertent writes until a WREN instruction is issued.