Microchip Technology 11LC040-E/P

Overview

11LC040-E/P 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 +125°C (Automotive grade), 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 11LC040-E/P datasheet, 11LC040-E/P pinout, 11LC040-E/P application, or 11LC040-E/P equivalent, this page delivers verified electrical specs, UNI/O® timing constraints, package-specific terminal roles, automotive-grade reliability metrics, and direct alternatives with documented functional alignment and protection configuration differences.

Technical Context

The 11LC040-E/P implements Manchester-encoded UNI/O® protocol over a single bidirectional SCIO line, extracting clock and data from one signal stream; it uses internal re-synchronization circuitry tolerant to ±0.50% frequency drift per byte and ±0.06 UI edge jitter, with automatic phase adjustment on each MAK bit.

It integrates a status register with WIP and WEL flags, supports self-timed write cycles up to 10 ms, enforces Schmitt-trigger input thresholds (0.05×VCC hysteresis), and applies slope-controlled output drive to suppress ground bounce during writes - all within a 3-lead SOT-23 package footprint.

Key Specifications

Pinout & Package

11LC040-E/P is supplied in an 8-pin PDIP (Plastic Dual In-line Package) with through-hole mounting. Pin 1 is SCIO (Serial Clock/Data I/O), Pin 2 is VSS (Ground), Pin 3 is VCC (Supply Voltage), and Pins 4–8 are No Connect (NC).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 11AA040-I/P, the 11LC040-E/P provides guaranteed operation at 125°C and tighter ESD tolerance (4 kV), making it the sole drop-in option for automotive powertrain nodes; versus 24LC04B-I/P, it preserves single-I/O simplicity and eliminates clock/data arbitration overhead but mandates UNI/O®-specific host firmware.

Availability

11LC040-E/P is available at Aetrix Electronics and suitable for automotive body control units, engine management systems, and advanced driver assistance modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 11LC040-E/P 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 AEC-Q100 for automotive components.

The 11LC040-E/P belongs to Microchip's UNI/O® serial EEPROM family, designed specifically for cost-sensitive, space-constrained automotive and industrial systems requiring single-wire communication and extended temperature reliability.

FAQ

What is the maximum operating frequency of the 11LC040-E/P UNI/O® bus?

The 11LC040-E/P supports a maximum serial bus frequency of 100 kHz, corresponding to a 10 µs minimum bit period. This limit is defined by AC characteristics including input edge jitter tolerance (±0.06 UI), frequency drift tolerance (±0.50% per byte), and output edge jitter (±0.25 UI). Operation above 100 kHz risks synchronization loss and NoSAK responses during command execution. The 11LC040-E/P does not support higher rates even with optimized PCB layout or reduced capacitive loading.

Does the 11LC040-E/P require external pull-up resistors on the SCIO line?

Yes, the 11LC040-E/P requires an external pull-up resistor on the SCIO line to ensure proper logic high levels during idle and standby states. The datasheet specifies typical values of 4.7 kΩ to 10 kΩ depending on bus capacitance and speed requirements. Without this pull-up, the SCIO line cannot achieve valid VIH levels (≥0.7×VCC), causing failed start headers and persistent NoSAK responses. The 11LC040-E/P contains no internal pull-up.

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

Block write protection on the 11LC040-E/P is controlled by BP0 and BP1 bits in the nonvolatile STATUS register, set via the WRSR command. These bits configure protection for 0%, 25%, 50%, or 100% of the 512-byte array - specifically, BP1:BP0 = 00 protects none, 01 protects upper 1/4 (0x0C0–0x0FF), 10 protects upper 1/2 (0x080–0x0FF), and 11 protects entire array. Once set, protected blocks reject WRITE and WRSR commands until BP bits are cleared, providing hardware-level security against accidental overwrites.

Can the 11LC040-E/P be used with a 1.8V microcontroller?

No, the 11LC040-E/P is not rated for 1.8V operation. Its specified VCC range is 2.5V to 5.5V, and its input thresholds (VIH ≥0.7×VCC, VIL ≤0.3×VCC) are incompatible with 1.8V logic levels. Attempting to operate the 11LC040-E/P at 1.8V will result in unreliable SCIO communication, failed start headers, and intermittent NoSAK responses. For 1.8V systems, the pin-compatible 11AA040-I/P variant must be selected instead.

What is the write cycle time for a full page on the 11LC040-E/P?

The write cycle time for a full 16-byte page on the 11LC040-E/P is 10 ms maximum, as specified for ERAL and SETAL commands in Table 1-2. This includes internal auto-erase, programming, and verification - all self-timed with no host polling required beyond checking the WIP bit via RDSR. Individual byte writes also require up to 10 ms, as the device internally aligns all writes to page boundaries. The 11LC040-E/P does not support faster partial-page programming.