Microchip Technology 11AA161T-I/MS

Overview

11AA161T-I/MS from Microchip Technology is a 16 Kbit (2,048 × 8) serial EEPROM with UNI/O® single I/O bus interface, operating from 1.8V to 5.5V, featuring 16-byte page write buffer, Schmitt-trigger SCIO input, and 1 µA max standby current at I-temp (–40°C to +85°C). It is used in space-constrained embedded systems for parameter storage, calibration data retention, and firmware configuration in industrial sensors and smart peripherals.

For engineers reviewing the 11AA161T-I/MS datasheet, 11AA161T-I/MS pinout, 11AA161T-I/MS application, or 11AA161T-I/MS equivalent, key selection considerations include its 1.8V low-voltage operation, UNI/O® bus timing tolerance (±0.5% frequency drift per byte), built-in block write protection (0%, 25%, 50%, or 100% array), and MSOP-8 package compatibility with high-density PCB layouts.

Technical Context

The 11AA161T-I/MS implements Manchester-encoded UNI/O® protocol over a single bidirectional SCIO line, eliminating need for separate clock and data lines. Its internal re-synchronization circuitry tracks master bit period (10–100 kHz) and tolerates ±0.06 UI input edge jitter and ±5% cumulative frequency deviation per command.

It integrates a status register with WIP and WEL flags, page latches for atomic 16-byte writes, and hardware write protection logic that enforces BP0/BP1-configured memory blocks. The device uses on-chip HV generator for EEPROM programming and features slope-controlled SCIO output to suppress ground bounce.

Key Specifications

Pinout & Package

11AA161T-I/MS is housed in an 8-lead MSOP (Mini Small Outline Package) with 0.65 mm lead pitch, optimized for automated SMT assembly and thermal performance in compact modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial EEPROM applications.

Compared with 11AA161T-I/MS, 11LC161T-I/MS offers identical packaging and industrial temperature support but excludes 1.8V operation, while AT24C16C-MAHM-T provides broader voltage range and higher speed but demands additional pins and protocol stack changes - making 11AA161T-I/MS optimal for minimal-pin, low-voltage, UNI/O®-based designs.

Availability

11AA161T-I/MS is available at Aetrix Electronics and suitable for industrial sensor calibration, smart actuator configuration, and medical device settings storage requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for 11AA161T-I/MS includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology Inc. is a leading provider of microcontroller, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 11AAxxx family was designed specifically for ultra-low-pin-count embedded systems needing reliable, low-voltage serial EEPROM - emphasizing single-wire simplicity, robust noise immunity, and extended data retention in cost-sensitive industrial applications.

FAQ

What is the UNI/O® interface used by the 11AA161T-I/MS?

The 11AA161T-I/MS uses Microchip's patented UNI/O® bus, a single-wire, Manchester-encoded serial interface where clock and data share the SCIO pin. This eliminates separate clock lines and simplifies routing. The 11AA161T-I/MS decodes timing from edge transitions, supporting bit rates up to 100 kbps with built-in jitter and drift tolerance - enabling reliable communication even with low-cost MCU GPIOs.

Does the 11AA161T-I/MS support 1.8V operation?

Yes, the 11AA161T-I/MS supports a VCC range of 1.8V to 5.5V, confirmed in the DEVICE SELECTION TABLE and Electrical Characteristics section of DS22067J. At 1.8V, it maintains full functionality including 16-byte page writes, STATUS register access, and UNI/O® timing compliance - unlike the 11LC161 variant, which requires minimum 2.5V.

How does write protection work on the 11AA161T-I/MS?

The 11AA161T-I/MS implements hardware block write protection via two nonvolatile BP0/BP1 bits in its STATUS register. These bits configure protection of 0%, 25%, 50%, or 100% of the memory array - set via WRSR command. Protection is enforced independently of software state, surviving power cycles, and cannot be overridden without first clearing the bits - ensuring critical calibration data remains immutable.

What package type is the 11AA161T-I/MS supplied in?

The 11AA161T-I/MS is supplied in an 8-lead MSOP (MS) package, as indicated by the suffix "/MS" in the part number and confirmed in the Package Types diagram and DEVICE SELECTION TABLE. This surface-mount package measures 3.0 × 3.0 × 1.0 mm with 0.65 mm lead pitch, supporting high-density PCB layouts and automated assembly.

Can the 11AA161T-I/MS be used in automotive applications?

No - the 11AA161T-I/MS is rated for Industrial temperature range only (–40°C to +85°C), as specified in the "Temp. Ranges" column of the DEVICE SELECTION TABLE. For automotive use, Microchip offers the 11LC161 variant (e.g., 11LC161T-E/MS) with –40°C to +125°C qualification and same 16Kbit density, but requiring minimum 2.5V VCC.