Microchip Technology 11AA160-I/TO

Overview

11AA160-I/TO from Microchip Technology Inc. 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 industrial control modules for nonvolatile parameter storage.

For engineers reviewing the 11AA160-I/TO datasheet, 11AA160-I/TO pinout, 11AA160-I/TO application, or 11AA160-I/TO equivalent, key selection considerations include its TO-92 package compatibility, 100 kbps UNI/O® bit rate, 1.8V minimum VCC operation, and block write protection configuration via STATUS register.

Technical Context

The 11AA160-I/TO implements Manchester-encoded UNI/O® protocol over a single bidirectional SCIO line, requiring master-controlled timing synchronization and re-synchronization on each MAK bit. Its internal architecture includes a 16-byte page latch, STATUS register with WIP/WEL/BP bits, and current-limited slope-controlled output driver.

It supports byte and page writes with self-timed erase/write cycles (max 10 ms), uses Schmitt-trigger inputs for noise immunity, and enforces hardware write protection through BP0/BP1 bits controlling 0%, 25%, 50%, or 100% array lock. Standby mode activates after NoMAK+SAK or standby pulse (≥600 µs high).

Key Specifications

Pinout & Package

11AA160-I/TO is housed in a 3-lead TO-92 package (top-down view: Pin 1 = VCC, Pin 2 = VSS, Pin 3 = SCIO). No NC pins are present in this variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 11LC160-I/TO, the 11AA160-I/TO enables direct 1.8V MCU integration without level translation, while AT24C128-PU offers greater capacity at the cost of interface overhead and package incompatibility.

Availability

11AA160-I/TO is available at Aetrix Electronics and suitable for industrial control, medical instrumentation, and smart metering applications requiring stable component supply and long-term obsolescence management.

Supply support for 11AA160-I/TO 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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory products, with global manufacturing and quality certifications.

The 11AA160-I/TO belongs to Microchip's UNI/O® serial EEPROM family, designed specifically for space- and pin-constrained embedded systems needing simple, robust, low-power nonvolatile storage.

FAQ

What is the UNI/O® interface used by the 11AA160-I/TO, and how does it differ from I²C or SPI?

The 11AA160-I/TO uses Microchip's patented UNI/O® bus-a single-wire, Manchester-encoded serial interface that embeds clock and data into one SCIO signal. Unlike I²C (2-wire, open-drain) or SPI (4-wire, separate clock/MOSI/MISO), UNI/O® requires only one GPIO, eliminates pull-ups, and handles timing synchronization autonomously. This simplifies firmware implementation on resource-limited MCUs and reduces PCB layer count.

Can the 11AA160-I/TO operate reliably at 1.8V, and what are the implications for active and standby current?

Yes, the 11AA160-I/TO is fully specified for 1.8V operation (VCC = 1.8–2.5V, TA = –20°C to +85°C). At 1.8V, typical active current is 1 mA and max standby current is 1 µA-enabling direct integration with 1.8V logic families and extending battery life in portable equipment. These values are validated per DS22067J-page 3, Table 1-1.

How does the STATUS register in the 11AA160-I/TO support safe write operations?

The 11AA160-I/TO STATUS register contains WIP (Write-In-Progress), WEL (Write-Enable Latch), and BP0/BP1 (Block Protection) bits. Software must poll WIP=0 before initiating new commands; WEL must be set via WREN before any write; BP bits configure protected memory regions. This enables atomic, fault-tolerant updates-critical for firmware parameter storage where partial writes could corrupt system behavior.

What package options are available for the 11AA160-I/TO, and why is TO-92 selected for certain designs?

The 11AA160-I/TO is specifically offered in the 3-lead TO-92 package (pinout: 1=VCC, 2=VSS, 3=SCIO). TO-92 provides low-cost through-hole mounting, mechanical robustness in high-vibration environments, and minimal PCB footprint-ideal for compact industrial sensors and legacy-compatible upgrades where SMT rework is impractical.

Does the 11AA160-I/TO support page writes across memory boundaries, and what happens if a write crosses a 16-byte page?

No-the 11AA160-I/TO restricts page writes to within a single 16-byte physical page (e.g., 0x00–0x0F). If a write command attempts to cross a boundary (e.g., writing 16 bytes starting at 0x0F), data wraps to the start of the same page (0x00), overwriting prior bytes. Application firmware must align addresses and limit transfers to avoid unintended corruption-verified in DS22067J-page 12, Figure 4-3 note.