25LC040A-I/P

Overview

The Microchip Technology 25LC040A-I/P is a 4 Kbit (512 x 8) Serial Electrically Erasable Programmable Read-Only Memory (EEPROM). It operates within a supply voltage range of 2.5V to 5.5V and supports a maximum clock frequency of 10 MHz at voltages between 4.5V and 5.5V. The device utilizes an SPI-compatible serial bus for communication, featuring separate data input (SI) and output (SO) lines controlled by Chip Select (CS) and Serial Clock (SCK). It is housed in an 8-lead PDIP package and functions reliably across an industrial temperature range of -40°C to +85°C.

Feature Summary

• Supports write page mode allowing up to 16 bytes to be written before initiating an internal cycle.
• Includes built-in hardware protection mechanisms such as power-on/off data protection and a dedicated write-protect pin.
• Features block write protection capabilities that allow selective protection of none, one-quarter, one-half, or the entire memory array.

Applications

• Direct interface with microcontrollers possessing built-in SPI ports
• Data storage applications requiring non-volatile retention
• Systems utilizing discrete I/O lines programmed to match SPI protocol

Procurement Notes

Verify the specific ordering suffix 'I' confirms the Industrial temperature grade (-40°C to +85°C) and the '/P' designation indicates the 8-lead PDIP package. Confirm the datasheet revision matches the required specifications for voltage ranges and timing parameters. Ensure compatibility with system voltage levels, noting the minimum operating voltage is 2.5V.

Selection Notes

Select this component when a 4 Kbit capacity is sufficient for application requirements. Choose this part over variants like the 25AA040A if the system design requires a minimum operating voltage of 2.5V rather than 1.8V. Consider the PDIP package only if through-hole mounting is necessary for the PCB layout.

Part Context

This device belongs to the 25XX040A family, which includes the 25AA040A variant. Both share identical memory organization and functional features but differ in their supported supply voltage ranges. The 25LC040A series is designed for industrial environments, whereas other family members may support extended automotive temperatures or lower voltage operations.

Replacement Considerations

The 25C040-I/P is a confirmed substitute within the same manufacturer's portfolio offering similar 4 Kbit SPI EEPROM functionality.

FAQ

How does the HOLD pin function during serial communication?

The HOLD pin allows the host to pause transmission without resetting the sequence. When pulled low while SCK is low, inputs are ignored and SO goes high-impedance. Communication resumes when HOLD is brought high while SCK is low.

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

If a page write attempts to cross a boundary, the data wraps around to the beginning of the current page, overwriting existing data instead of proceeding to the next page.