25AA320A-I/ST

Memory IC Overview

The Microchip Technology 25AA320A-I/ST is a 32-Kbit Serial Electrically Erasable PROM featuring a 4096 x 8-bit organization and a 32-byte page size. It operates on an SPI-compatible serial bus with a maximum clock frequency of 10 MHz at supply voltages between 4.5V and 5.5V, reducing to 5 MHz at 2.5V–4.5V and 3 MHz at 1.8V–2.5V. The device supports a supply voltage range of 1.8V to 5.5V, includes self-timed erase/write cycles with a maximum duration of 5 ms, and offers block write protection for none, 1/4, 1/2, or all of the array. It is housed in an 8-lead TSSOP package and functions within an industrial temperature range of -40°C to +85°C.

Memory IC Feature Summary

• Supports high-speed SPI communication with up to 10 MHz clock frequency
• Includes built-in hardware write protection via WP pin and STATUS register bits
• Features low-power CMOS technology with standby current as low as 5 µA
• Provides data retention exceeding 200 years and endurance over 1 million erase/write cycles

Memory IC Applications

• Microcontroller system data storage
• Configuration parameter logging
• Calibration data retention
• Device identification storage

Memory IC Procurement Notes

Verify that the ordering suffix matches the required package type and temperature grade. Confirm the specific voltage range requirements align with the 1.8V to 5.5V specification. Ensure compatibility with the host microcontroller's SPI interface timing constraints. Check for any specific automotive qualification needs if applicable to the target application environment.

Memory IC Selection Notes

Select this component when a 32-Kbit non-volatile memory solution is required with SPI interface compatibility. Consider the 1.8V minimum operating voltage for low-power applications compared to the 2.5V minimum of the 25LC320A variant. Evaluate the need for hardware write protection features and the specific industrial temperature range requirements for the deployment environment.

Memory IC Part Context

This part belongs to the 25AA320A/25LC320A family of 32-Kbit Serial EEPROMs. The 'I' suffix denotes the Industrial temperature range (-40°C to +85°C), while 'ST' indicates the 8-lead TSSOP package. It is functionally similar to the 25LC320A but supports a lower minimum supply voltage of 1.8V.

Memory IC Replacement Considerations

The 25LC320A-I/ST is a direct functional substitute with identical pinout and instructions, though it requires a minimum supply voltage of 2.5V instead of 1.8V. Other variants in the 25XX320A family share the same architecture but differ in voltage ranges or packages.

Memory IC FAQ

How does the HOLD pin function during serial communication?

The HOLD pin allows the user to pause serial communication without resetting the sequence. It must be pulled low while SCK is low to suspend operation, and brought high while SCK is low to resume.

What is the purpose of the Write Enable Latch (WEL)?

The WEL bit must be set by issuing the WREN instruction before any write operation can be completed. It is automatically reset after power-up, a successful write, or execution of the WRDI instruction.