Microchip Technology 11LC040-E/MS

Overview

11LC040-E/MS from Microchip Technology is a 4 Kbit (512 × 8) serial EEPROM with UNI/O® single-I/O bus interface, operating from 2.5V to 5.5V across -40°C to +125°C, featuring 16-byte page write buffer, Schmitt-trigger SCIO input, and built-in write protection for automotive sensor calibration storage.

For engineers reviewing the 11LC040-E/MS datasheet, 11LC040-E/MS pinout, 11LC040-E/MS application, or 11LC040-E/MS equivalent, key selection criteria include UNI/O® bus compatibility, automotive-grade temperature range, 100 kbps bit rate, standby current ≤1 µA at 125°C, and MSOP-8 package footprint.

Technical Context

The 11LC040-E/MS implements Manchester-encoded UNI/O® protocol over a single bidirectional SCIO line, eliminating need for separate clock and data lines. It uses internal re-synchronization circuitry tolerant to ±0.5% frequency drift per byte and ±0.06 UI edge jitter, enabling robust communication in electrically noisy automotive environments.

Its architecture includes a nonvolatile STATUS register with WIP and WEL bits, block write protection (BP0/BP1), and a current-limited slope-controlled SCIO driver that suppresses ground bounce and limits output current to ±4 mA at 5.5V - critical for reliable operation on shared I/O lines in space-constrained modules.

Key Specifications

Pinout & Package

11LC040-E/MS is housed in an 8-lead MSOP (MS) package - 3.0 mm × 3.0 mm × 1.0 mm body, 0.65 mm lead pitch, exposed pad optional - optimized for automated optical inspection and thermal dissipation in dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C04C-MAHM-T and BR24G04NUX-5TR, the 11LC040-E/MS uniquely delivers automotive-grade reliability with single-pin UNI/O® simplicity - reducing BOM cost and routing congestion where MCU GPIO is constrained, while maintaining equivalent density and endurance.

Availability

11LC040-E/MS is available at Aetrix Electronics and suitable for automotive control units, industrial sensors, and medical device calibration requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 11LC040-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 leading provider of microcontroller, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global manufacturing and support infrastructure.

The 11LC040-E/MS belongs to Microchip's 11XX UNI/O® EEPROM family, designed specifically for space- and pin-constrained embedded systems needing robust, low-power nonvolatile memory with minimal MCU resource usage.

FAQ

What is the UNI/O® bus interface used by the 11LC040-E/MS?

The 11LC040-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 separate clock lines, reduces MCU pin count, and simplifies PCB routing. The 11LC040-E/MS supports up to 100 kbps bit rate and includes built-in re-synchronization to tolerate frequency drift and edge jitter, making it suitable for electrically noisy automotive environments.

Does the 11LC040-E/MS require external components for basic operation?

Yes, the 11LC040-E/MS requires an external pull-up resistor (typically 4.7 kΩ) on the SCIO pin to VCC and a 0.1 µF ceramic bypass capacitor between VCC and VSS placed within 3 mm of the device. These components ensure reliable Manchester decoding, noise immunity, and stable power delivery during write cycles. No additional level shifters or clock generators are needed due to the self-clocking UNI/O® protocol.

How does write protection work on the 11LC040-E/MS?

The 11LC040-E/MS implements dual-layer write protection: (1) a volatile write enable latch (WEL) set via WREN command and cleared on power-up or WRDI, and (2) nonvolatile block protection bits (BP0/BP1) in the STATUS register configured via WRSR. Together, they allow selective protection of 0%, 25%, 50%, or 100% of the memory array. The 11LC040-E/MS also includes power-on/off data protection circuitry to prevent spurious writes during brown-out conditions.

What is the maximum write speed and endurance of the 11LC040-E/MS?

The 11LC040-E/MS supports a maximum bit rate of 100 kbps on the UNI/O® bus, with typical byte write time under 5 ms and page write (up to 16 bytes) under 10 ms. Its endurance is rated at 1,000,000 erase/write cycles per memory location, and data retention exceeds 200 years at 125°C - validated for automotive under-hood applications where thermal stress accelerates aging.

Is the 11LC040-E/MS pin-compatible with other devices in the 11XX family?

Yes, the 11LC040-E/MS in the MSOP-8 (MS) package shares identical pinout and footprint with all other 11XX family members offered in the same package - including 11LC010-E/MS, 11LC020-E/MS, 11LC080-E/MS, and 11LC160-E/MS. This enables density scalability without PCB redesign. However, device addressing differs only for 11XX1 variants (0xA1 address), so firmware must verify device code during initialization to avoid bus conflicts.