Microchip Technology 11LC040T-I/MS

Overview

11LC040T-I/MS from Microchip Technology Inc. is a 4 Kbit (512 × 8) serial EEPROM with UNI/O® single I/O bus interface, operating from 2.5V to 5.5V over -40°C to +85°C industrial temperature range. It features 16-byte page-write buffer, Schmitt-trigger SCIO input, output slope control, and built-in write protection including power-on/off circuitry and STATUS register with WIP/WEL bits. Used in embedded system configuration storage where minimal pin count and low standby current (<1 µA) are critical.

For engineers reviewing the 11LC040T-I/MS datasheet, 11LC040T-I/MS pinout, 11LC040T-I/MS application, or 11LC040T-I/MS equivalent, key selection criteria include UNI/O® bus compatibility, 4Kbit density in MSOP-8 package, 100 kbps max bit rate, industrial temp rating, and block write protection granularity (none/1/4/1/2/all).

Technical Context

The 11LC040T-I/MS implements Manchester-encoded UNI/O® protocol on a single bidirectional SCIO line, eliminating need for separate clock and data lines. Its internal timing recovery circuitry synchronizes to master clock period during start header and re-synchronizes on each MAK bit, tolerating ±0.50% frequency drift per byte and ±0.06 UI edge jitter.

It integrates a current-limited, slope-controlled SCIO driver to suppress ground bounce, plus Schmitt-trigger input for noise immunity. Memory array is organized as 512 × 8 bits with 16-byte page buffer; write cycles are self-timed (max 10 ms), and STATUS register provides real-time WIP and WEL status accessible even during active writes.

Key Specifications

Pinout & Package

11LC040T-I/MS is packaged in 8-lead MSOP (MS) with exposed pad, measuring 3.0 mm × 3.0 mm × 1.0 mm. Pin 1 is SCIO, Pin 2 is VSS, Pin 3 is NC, Pin 4 is NC, Pin 5 is NC, Pin 6 is NC, Pin 7 is VCC, Pin 8 is NC - consistent with MSOP footprint shown in DS22067J-page 2 diagram.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 11AA040T-I/MS, the 11LC040T-I/MS trades 1.8V operation for higher noise immunity above 2.5V; versus 24LC04B-I/MS, it replaces dual-wire I²C with single-wire UNI/O®, reducing pin count and eliminating pull-up dependencies while maintaining identical memory capacity and package fit.

Availability

11LC040T-I/MS is available at Aetrix Electronics and suitable for industrial sensor calibration storage, medical device configuration memory, and automotive body control module NVM requiring stable component supply and long-term obsolescence management.

Supply support for 11LC040T-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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 11LCxxx family was designed specifically for ultra-low-pin-count embedded systems needing reliable, low-power serial EEPROM-prioritizing single-wire simplicity, industrial temperature resilience, and robust noise immunity over legacy multi-wire interfaces.

FAQ

What is the UNI/O® interface used by the 11LC040T-I/MS, and how does it differ from I²C or SPI?

The 11LC040T-I/MS uses Microchip's patented UNI/O® bus-a single-wire, Manchester-encoded serial interface that combines clock and data on the SCIO pin. Unlike I²C (2-wire with pull-ups) or SPI (4-wire), UNI/O® requires only one GPIO, eliminates external components, and embeds timing recovery in the protocol. This reduces PCB complexity and firmware overhead compared to multi-signal interfaces.

Does the 11LC040T-I/MS support write protection, and how is it configured?

Yes, the 11LC040T-I/MS supports configurable block write protection via BP0/BP1 bits in its STATUS register. These bits-set using the WRSR command-allow locking none, 1/4, 1/2, or all of the 512-byte memory array. Protection is nonvolatile and persists through power cycles, preventing accidental overwrites of critical calibration or configuration data stored in the 11LC040T-I/MS.

What is the maximum write speed and endurance specification for the 11LC040T-I/MS?

The 11LC040T-I/MS supports up to 100 kbps bit rate and completes byte or page writes in ≤10 ms. Its endurance is rated at 1,000,000 erase/write cycles per memory location, verified at 25°C and VCC = 5.5V. This ensures long-term reliability in applications requiring frequent field updates, such as firmware parameter storage in the 11LC040T-I/MS.

Can the 11LC040T-I/MS operate from a 3.3V supply, and what are its current consumption values?

Yes, the 11LC040T-I/MS operates across 2.5V to 5.5V, fully supporting 3.3V systems. At VCC = 3.3V and TA = 85°C, its typical active current is ≤3 mA during read and ≤5 mA during write; standby current is ≤1 µA. These values enable energy-efficient operation in always-on or battery-powered devices using the 11LC040T-I/MS.

Is the 11LC040T-I/MS pin-compatible with other devices in the 11XX family, and what packages are supported?

Yes, the 11LC040T-I/MS shares identical pinout and functionality with other 11LCxxx and 11AAxxx variants in the MSOP-8 (MS) package, including 11LC010T-I/MS, 11LC020T-I/MS, and 11LC080T-I/MS. All use SCIO/VSS/NC/NC/NC/NC/VCC/NC pin mapping. This allows drop-in replacement across densities without PCB redesign - a key advantage of the 11LC040T-I/MS in scalable product families.