Microchip Technology 11LC040T-E/MS

Overview

11LC040T-E/MS from Microchip Technology Inc. is a 4 Kbit serial EEPROM with UNI/O® single-I/O bus interface, organized as 512 × 8 bits, operating from 2.5V to 5.5V, featuring 16-byte page write buffer, 1 µA max standby current (I-temp), and automotive-grade −40°C to +125°C temperature range. It is used in automotive body control modules for storing calibration data and configuration parameters.

For engineers reviewing the 11LC040T-E/MS datasheet, 11LC040T-E/MS pinout, 11LC040T-E/MS application, or 11LC040T-E/MS equivalent, key selection considerations include its UNI/O® bus compatibility, automotive temperature rating, 16-byte page buffer size, block write protection granularity, and SOT-23-3 package footprint constraints.

Technical Context

The 11LC040T-E/MS implements Manchester-encoded serial communication over a single SCIO line, extracting clock and data from one signal stream. Its internal architecture includes a status register with WIP and WEL bits, page latches, and slope-controlled output driver to suppress ground bounce.

It supports self-timed write cycles with auto-erase, Schmitt-trigger inputs for noise immunity, and re-synchronization circuitry tolerant to ±0.50% bus frequency drift per byte and ±0.06 UI edge jitter. Standby mode activation requires a TSTBY ≥600 µs high pulse on SCIO.

Key Specifications

Pinout & Package

Package: 3-lead SOT-23 (MS suffix), surface-mount, 2.9 mm × 1.6 mm footprint, lead-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 11LC040T-E/MS, the 11AA040T-I/MS offers lower-voltage operation but lacks automotive qualification, while the AT24C04D-MAHM-T provides I²C compatibility at the cost of pin count, protocol stack overhead, and package size - making 11LC040T-E/MS optimal for new automotive UNI/O®-based designs prioritizing pin efficiency and AEC-Q100 alignment.

Availability

11LC040T-E/MS is available at Aetrix Electronics and suitable for automotive body control units, industrial sensor nodes, medical infusion pumps, and smart meter firmware patch storage requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 11LC040T-E/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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory products, with broad automotive and industrial certification coverage.

The 11LCxxx family was designed specifically for cost- and space-constrained embedded systems requiring minimal pin count, ultra-low power, and robust serial EEPROM functionality - especially in automotive subsystems where UNI/O® simplifies integration with PIC® and other MCUs.

FAQ

What is the UNI/O® bus interface used by the 11LC040T-E/MS?

The 11LC040T-E/MS 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 the need for separate clock and data lines, reducing pin count and PCB routing complexity. The 11LC040T-E/MS implements this protocol with built-in re-synchronization circuitry to tolerate bus frequency drift and edge jitter, ensuring reliable communication in electrically noisy environments like automotive applications.

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

Yes, the 11LC040T-E/MS supports block write protection via two nonvolatile BP0/BP1 bits in its STATUS register. These bits can be programmed using the WRSR command to protect none, 1/4, 1/2, or the entire memory array. Protection is hardware-enforced and persists through power cycles. The 11LC040T-E/MS 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 - providing layered safeguards against accidental writes.

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

The 11LC040T-E/MS supports a maximum bit rate of 100 kbps (equivalent to 100 kHz), with typical write cycle time of 5 ms for byte or page writes. Its endurance is rated at 1,000,000 erase/write cycles per memory location, verified at 25°C and VCC = 5.5V. This endurance level supports frequent parameter updates in automotive and industrial applications over multi-year deployments without degradation.

Can the 11LC040T-E/MS operate at 1.8V?

No, the 11LC040T-E/MS is specified for VCC = 2.5V to 5.5V only. For 1.8V operation, Microchip offers the pin-compatible 11AA040T-I/MS variant, which shares the same 4 Kbit density, UNI/O® interface, and SOT-23-3 package but is rated only for industrial temperature range (−40°C to +85°C). The 11LC040T-E/MS is optimized for automotive voltage rails and higher-temperature reliability, not low-voltage operation.

What package type does the 'MS' suffix indicate for the 11LC040T-E/MS?

The 'MS' suffix in 11LC040T-E/MS denotes the 3-lead SOT-23 package - a compact, surface-mount plastic package measuring 2.9 mm × 1.6 mm with gull-wing leads. It is lead-free and RoHS compliant, qualified for automotive applications, and features terminals labeled SCIO (pin 1), VSS (pin 2), and VCC (pin 3). This package enables high-density placement in space-constrained modules such as door controllers and sensor transceivers.