Microchip Technology 11LC040T-I/TT

Overview

11LC040T-I/TT 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 across -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 control. Used in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 11LC040T-I/TT datasheet, 11LC040T-I/TT pinout, 11LC040T-I/TT application, or 11LC040T-I/TT equivalent, key selection criteria include its 3-lead SOT-23 (TT) package, UNI/O® protocol compatibility, 100 kbps max bit rate, 1 µA standby current (max), and block write protection options for 0%, 25%, 50%, or 100% of memory array.

Technical Context

The 11LC040T-I/TT implements Manchester-encoded serial communication over a single SCIO line, extracting clock and data from one signal stream. Its internal architecture includes an 8-bit instruction register, page latches, HV generator, and EEPROM array with X/Y decoders and sense amplifiers.

It supports master-controlled bus timing with re-synchronization on each MAK bit, tolerating ±0.06 UI input edge jitter and ±0.5% per byte frequency drift. The device enters Standby mode after NoMAK/SAK termination or standby pulse, and Idle mode upon invalid address, command, or synchronization loss.

Key Specifications

Pinout & Package

11LC040T-I/TT is housed in a 3-lead SOT-23 package (TT suffix), with leads arranged as SCIO–VCC–VSS (pin 1–2–3, top-down view). This compact surface-mount package measures 2.9 mm × 1.6 mm × 1.1 mm and supports reflow soldering per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 11AA040T-I/TT and 25LC040A-I/P, the 11LC040T-I/TT delivers optimal balance of pin count reduction, noise robustness, and industrial temperature support - making it preferred for new designs prioritizing layout simplicity and EMI resilience.

Availability

11LC040T-I/TT is available at Aetrix Electronics and suitable for industrial automation, sensor module manufacturing, and embedded HMI development requiring stable component supply and long-term obsolescence management.

Supply support for 11LC040T-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 global manufacturing and quality certifications including ISO 9001 and AEC-Q200 for automotive components.

The 11LC040T-I/TT belongs to Microchip's 11XX family of UNI/O® serial EEPROMs, designed specifically for cost-sensitive, space-constrained embedded systems needing minimal GPIO usage and high reliability in harsh environments.

FAQ

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

The 11LC040T-I/TT uses Microchip's patented UNI/O® bus, a single-wire, Manchester-encoded serial interface that combines clock and data on the SCIO line. Unlike I²C (2-wire) or SPI (4-wire), UNI/O® eliminates dedicated clock and chip-select signals, reducing MCU pin count and PCB routing complexity. It operates at up to 100 kbps and includes built-in synchronization recovery for timing drift and jitter - a capability not inherent in standard I²C or SPI implementations.

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

Yes, the 11LC040T-I/TT supports configurable block write protection via two nonvolatile BP0/BP1 bits in its STATUS register. These bits can protect 0%, 25%, 50%, or 100% of the 512-byte memory array. Protection is set using the WRSR (Write Status Register) command after enabling writes with WREN. Physical protection is enforced by hardware - no software polling is required to enforce lock state.

What is the maximum write speed and page size for the 11LC040T-I/TT?

The 11LC040T-I/TT has a fixed page size of 16 bytes and supports page writes of up to 16 bytes per self-timed write cycle. The maximum write cycle time is 10 ms for full-page operations. Because it uses auto-erase, no separate erase command is needed - the write command internally erases and programs the target page. Write throughput is limited by bus bit rate (≤100 kbps) and internal timing, not external clocking.

Can the 11LC040T-I/TT operate reliably at 2.5V, and what are its current consumption specs at that voltage?

Yes, the 11LC040T-I/TT is fully specified for operation from 2.5V to 5.5V across the industrial temperature range (-40°C to +85°C). At VCC = 2.5V, typical active read current is 1 mA, write current is 3 mA, and maximum standby current is 1 µA. These values are confirmed in Table 1-1 (DC Characteristics) of DS22067J, making it suitable for 2.5V systems such as battery-backed industrial controllers.

What package type does the 11LC040T-I/TT use, and are there footprint-compatible alternatives?

The 11LC040T-I/TT uses the 3-lead SOT-23 package (TT suffix), with pinout SCIO–VCC–VSS (left-to-right, top-down view). It is footprint-compatible with other TT-suffixed 11XX family members (e.g., 11LC010T-I/TT, 11LC020T-I/TT) but not with SOIC, PDIP, or Chip Scale variants. No pin-compatible alternatives exist outside Microchip's 11XX UNI/O® family due to the unique single-I/O architecture.