11AA040-I/MS

Overview

The Microchip Technology 11AA040-I/MS is a 4 Kbit (512 x 8) serial electrically erasable programmable read-only memory (EEPROM). It operates on the UNI/O single I/O bus with a maximum clock frequency of 100 kHz. The device supports a supply voltage range from 1.8 V to 5.5 V and is housed in an 8-lead MSOP package. It features industrial temperature ratings from -40°C to +85°C, high endurance of 1,000,000 erase/write cycles, and data retention exceeding 200 years.

Feature Summary

• Supports the patented UNI/O single I/O serial interface bus using Manchester encoding for combined clock and data transmission.
• Includes a 16-byte page-write buffer to facilitate efficient sequential data writing operations.
• Features built-in write protection mechanisms including power-on/off data protection and a configurable write enable latch.
• Provides block write protection capabilities allowing users to protect none, one-quarter, one-half, or the entire memory array.

Applications

• Interfacing with microcontrollers requiring low-pin-count non-volatile storage
• ASIC applications needing simple serial configuration memory
• Systems utilizing discrete I/O lines for memory access

Procurement Notes

Verify the specific ordering suffix matches the required package type and temperature grade. Confirm that the 1.8V minimum operating voltage aligns with your system's power rails. Ensure the UNI/O protocol compatibility with your host controller before procurement.

Selection Notes

Select this component when a single-wire serial interface is preferred over multi-wire protocols like SPI or I2C. The 11AA040 offers a balance of density and simplicity. Consider the MSOP package for space-constrained surface-mount designs requiring industrial temperature stability.

Part Context

This part belongs to the 11AAXXX/11LCXXX family of serial EEPROMs. The 'AA' designation indicates support for low-voltage operation down to 1.8V, distinguishing it from the 'LC' series which requires a minimum of 2.5V. Both series share identical pinouts and command sets.

Replacement Considerations

The 11LC040-I/MS serves as a functional substitute within the same package but requires a minimum supply voltage of 2.5V instead of 1.8V. Verify voltage headroom in the target application before substituting.

FAQ

How does the UNI/O interface handle clock signals?

The UNI/O interface combines clock and data into a single serial bit stream (SCIO) using Manchester encoding. The receiver extracts the clock signal internally to decode timing and data values.

What happens if a page write crosses a physical boundary?

If a page write attempts to cross a physical page boundary, the address counter rolls over to the beginning of the current page. Data wraps around and overwrites existing content rather than proceeding to the next page.