Microchip Technology 11LC161T-E/TT

Overview

11LC161T-E/TT from Microchip Technology is a 16 Kbit (2,048 × 8) serial EEPROM with UNI/O® single I/O bus interface, operating from 2.5V to 5.5V across -40°C to +125°C (Automotive E-temp), featuring 16-byte page write buffer, 1 µA max standby current, and built-in block write protection for 0%, 25%, 50%, or 100% of memory array - used in automotive body control modules for storing calibration data and fault logs.

For engineers reviewing the 11LC161T-E/TT datasheet, 11LC161T-E/TT pinout, 11LC161T-E/TT application, or 11LC161T-E/TT equivalent, key selection considerations include its Automotive-grade temperature range, UNI/O® bus compatibility with minimal GPIO usage, Schmitt-trigger SCIO input for noise immunity in harsh environments, and page-write timing (max 10 ms) for firmware update logging.

Technical Context

The 11LC161T-E/TT implements Manchester-encoded UNI/O® protocol over a single bidirectional SCIO line, eliminating need for separate clock or chip-select signals. It uses internal re-synchronization circuitry tolerant to ±0.5% bus frequency drift per byte and ±0.06 UI edge jitter, enabling robust communication with low-cost microcontrollers lacking dedicated serial peripherals.

Its architecture includes a status register with WIP and WEL bits, nonvolatile BP0/BP1 bits for hardware-based block protection, and a current-limited slope-controlled SCIO driver that suppresses ground bounce while limiting output current to ±4 mA at 5.5V - critical for stable operation in electrically noisy automotive subsystems.

Key Specifications

Pinout & Package

11LC161T-E/TT is packaged in 3-lead SOT-23 (TT suffix), with SCIO as bidirectional serial data/clock line, VCC for supply, and VSS for ground - no NC pins. The compact 2.9 mm × 1.6 mm footprint suits space-constrained automotive PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 11LC161T-E/TT, the 11AA161-I/TT trades automotive qualification for wider voltage flexibility, while the AT24C128-MAHM-T offers greater density at the cost of increased pin count, reduced noise immunity, and absence of UNI/O®'s single-pin advantage - making 11LC161T-E/TT optimal for new automotive designs prioritizing GPIO conservation and EMI resilience.

Availability

11LC161T-E/TT is available at Aetrix Electronics and suitable for automotive body control units, engine management systems, and telematics loggers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 11LC161T-E/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 manufacturer specializing in microcontrollers, analog devices, and memory products for embedded control applications.

The 11LCxxx family was designed specifically for automotive and industrial systems needing ultra-low-power, single-pin serial memory with robust noise immunity - targeting applications where board space, GPIO count, and electrical harshness constrain traditional I²C or SPI solutions.

FAQ

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

The 11LC161T-E/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, chip-select, and data lines - reducing MCU pin count and PCB routing complexity. The 11LC161T-E/TT implements full protocol compliance including start header synchronization, MAK/NoMAK handshaking, and re-synchronization to tolerate bus timing variations.

Does the 11LC161T-E/TT support hardware write protection?

Yes, the 11LC161T-E/TT includes hardware-based block write protection controlled by nonvolatile BP0 and BP1 bits in its STATUS register. These bits allow locking 0%, 25%, 50%, or 100% of the 2,048-byte array - for example, protecting upper calibration pages while permitting runtime updates to lower parameter regions. Protection is enforced independently of software commands and persists through power cycles.

What is the maximum write speed and timing behavior of the 11LC161T-E/TT?

The 11LC161T-E/TT supports up to 100 kbps serial bus speed (100 kHz equivalent), with typical write cycle time of 5 ms for byte writes and 10 ms for page writes. Its self-timed write cycle includes auto-erase, and the STATUS register's WIP bit allows precise polling instead of fixed delays. The 16-byte page buffer enables burst writes - critical for minimizing host MCU intervention during firmware logging operations.

How does the 11LC161T-E/TT ensure reliability in automotive environments?

The 11LC161T-E/TT is qualified for Automotive E-temp (-40°C to +125°C), features >4 kV HBM ESD protection, Schmitt-trigger SCIO input for noise suppression, and slope-controlled output to eliminate ground bounce. Its 1,000,000 write endurance and >200-year data retention at 125°C meet AEC-Q100 stress requirements for mission-critical storage in ECUs, ensuring integrity of calibration data and fault logs over full vehicle service life.

Can the 11LC161T-E/TT be used with microcontrollers lacking dedicated serial peripherals?

Yes, the 11LC161T-E/TT is explicitly designed for host systems with minimal GPIO resources. Its UNI/O® protocol runs on any general-purpose I/O pin configured for open-drain or push-pull with external pull-up. Microchip provides reference firmware libraries for PIC® and other MCUs, and timing tolerances (±0.5% frequency drift, ±0.06 UI jitter) accommodate software-bitbanged implementations without dedicated hardware UART or I²C modules.