Microchip Technology 11LC161T-I/TT

Overview

11LC161T-I/TT from Microchip Technology Inc. is a 16 Kbit serial EEPROM with UNI/O® single I/O bus interface, organized as 2,048 × 8 bits, operating from 2.5V to 5.5V, featuring 16-byte page write buffer, STATUS register, and industrial/automotive temperature range (−40°C to +125°C). It is used in embedded systems for nonvolatile parameter storage where pin count and board space are constrained.

For engineers reviewing the 11LC161T-I/TT datasheet, 11LC161T-I/TT pinout, 11LC161T-I/TT application, or 11LC161T-I/TT equivalent, key selection considerations include its 3-lead SOT-23 (TT) package, UNI/O® protocol timing compliance (10–100 kHz), block write protection (0%, 25%, 50%, or 100% array), endurance of 1 million cycles, and 200+ year data retention.

Technical Context

The 11LC161T-I/TT implements Manchester-encoded serial communication over a single SCIO line, extracting clock and data from one bidirectional signal. Its internal architecture includes a 16-byte page latch, STATUS register with WIP/WEL/BP bits, and current-limited slope-controlled output driver to suppress ground bounce.

It supports master-initiated commands including READ, CRRD, WRITE, WREN/WRDI, RDSR/WRSR, ERAL, and SETAL, with automatic re-synchronization on each MAK bit to tolerate frequency drift (±0.5%/byte) and edge jitter (±0.06 UI), enabling robust operation in electrically noisy environments.

Key Specifications

Pinout & Package

Package: 3-lead SOT-23 (TT suffix), surface-mount, footprint-compatible with TO-92 but significantly smaller.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 11AA161-I/TT, the 11LC161T-I/TT trades 1.8V operation for automotive temperature qualification; compared with 24LC16B-I/OT, it reduces GPIO usage and improves noise immunity at the cost of protocol-specific firmware integration.

Availability

11LC161T-I/TT is available at Aetrix Electronics and suitable for automotive body control units, industrial sensor nodes, medical diagnostic loggers, and motor drive calibration storage requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 11LC161T-I/TT 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 emphasis on embedded control and reliability-critical applications.

The 11LC161T-I/TT belongs to Microchip's UNI/O® serial EEPROM family, designed specifically for ultra-low-pin-count systems where minimizing interconnect complexity and board space is essential without sacrificing endurance or temperature performance.

FAQ

What is the UNI/O® interface used by the 11LC161T-I/TT?

The 11LC161T-I/TT uses Microchip's patented UNI/O® bus - a single-wire, Manchester-encoded serial interface that combines clock and data on the SCIO pin. This eliminates separate clock lines and reduces GPIO usage to one bidirectional pin, making it ideal for space-constrained designs. The 11LC161T-I/TT fully complies with UNI/O® timing specifications including 10–100 kHz bus frequency, ±0.06 UI input jitter tolerance, and automatic re-synchronization on every MAK bit.

Does the 11LC161T-I/TT support write protection, and how is it configured?

Yes, the 11LC161T-I/TT supports hardware-configurable block write protection via BP0 and BP1 bits in its nonvolatile STATUS register. These bits can be set using the WRSR command to protect 0%, 25%, 50%, or 100% of the memory array. Protection is active immediately after WRSR execution and persists through power cycles. The 11LC161T-I/TT also includes built-in power-on/off data protection and a write enable latch (WEL) that must be set via WREN before any write operation proceeds.

What is the maximum write speed and page size of the 11LC161T-I/TT?

The 11LC161T-I/TT supports a maximum bus frequency of 100 kHz (100 kbps), resulting in typical byte write times under 5 ms and full-page (16-byte) write cycles under 10 ms. Its page-write buffer holds up to 16 bytes, allowing burst writes within a single physical page boundary (0x00–0x0F, 0x10–0x1F, etc.). Crossing page boundaries causes wraparound - software must ensure address alignment to avoid unintended overwrites.

Is the 11LC161T-I/TT compatible with 1.8V systems?

No, the 11LC161T-I/TT operates from 2.5V to 5.5V only. For 1.8V operation, Microchip offers the pin-compatible 11AA161-I/TT variant, which shares the same 16K density, UNI/O® interface, and 3-lead SOT-23 (TT) package but is rated only for Industrial temperature (−40°C to +85°C). The 11LC161T-I/TT's 2.5V minimum VCC ensures robust noise margin and is optimized for automotive and industrial applications where higher supply rails are standard.

How does the 11LC161T-I/TT handle power loss during a write cycle?

The 11LC161T-I/TT incorporates built-in power-loss protection circuitry that monitors VCC and aborts write operations if supply voltage drops below the functional threshold. If power fails mid-write, the internal charge pump halts, and the EEPROM array retains its pre-write state - no partial or corrupted writes occur. Additionally, the device features automatic write-cycle termination upon NoMAK receipt, ensuring predictable behavior even during interrupted communication sequences.