Microchip Technology 11LC040-I/P

Overview

11LC040-I/P from Microchip Technology Inc. is a 4 Kbit (512 × 8) serial EEPROM using the UNI/O® single I/O bus interface. It operates from 2.5V to 5.5V, draws only 1 mA active current and 1 µA standby current (max.), and supports 100 kbps bit rate with Manchester-encoded SCIO communication. It is used in space-constrained embedded systems for parameter storage, calibration data retention, and configuration memory.

For engineers reviewing the 11LC040-I/P datasheet, 11LC040-I/P pinout, 11LC040-I/P application, or 11LC040-I/P equivalent, key selection considerations include its 3-lead SOT-23/TO-92 package compatibility, industrial temperature range (–40°C to +85°C), page-write buffer (16 bytes), STATUS register control, and block write protection options (none, 1/4, 1/2, or full array).

Technical Context

The 11LC040-I/P implements a Manchester-encoded, single-wire UNI/O® bus protocol where clock and data are embedded in the SCIO signal. Its internal architecture includes a 16-byte page buffer, STATUS register with WIP/WEL/BP bits, and re-synchronization circuitry tolerant to ±0.50% frequency drift per byte and ±0.06 UI input edge jitter.

It features Schmitt-trigger inputs for noise immunity, output slope control to suppress ground bounce, and built-in power-on/off write protection. The device uses on-chip high-voltage generation for EEPROM programming and supports self-timed write cycles with no external timing components required.

Key Specifications

Pinout & Package

11LC040-I/P is packaged in an 8-lead PDIP (Plastic Dual In-line Package), denoted by the "P" suffix. This through-hole package supports manual prototyping and legacy PCB assembly.

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-I/P provides tighter VCC regulation tolerance above 2.5V and broader automotive qualification, while differing from 24LC04B-I/P in fundamental bus architecture-making it unsuitable for drop-in I²C replacement but optimal for minimal-pin-count UNI/O® implementations.

Availability

11LC040-I/P is available at Aetrix Electronics and suitable for industrial control systems, medical diagnostics equipment, and consumer appliance designs requiring stable component supply, long-term obsolescence management, and RoHS-compliant through-hole packaging.

Supply support for 11LC040-I/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 manufacturer specializing in microcontrollers, analog devices, and memory products, with a focus on embedded control and connectivity solutions.

The 11LC040-I/P belongs to Microchip's 11XX family of UNI/O® serial EEPROMs, designed specifically for ultra-low-pin-count systems where MCU GPIO resources are constrained and board space is at a premium.

FAQ

What is the UNI/O® interface used by the 11LC040-I/P?

The 11LC040-I/P uses Microchip's patented UNI/O® single-wire serial bus, which embeds clock and data in a Manchester-encoded bitstream on the SCIO pin. Unlike I²C or SPI, it requires only one I/O line plus power and ground, reducing MCU pin usage and simplifying PCB routing. The 11LC040-I/P implements full protocol compliance including start headers, MAK/NoMAK handshaking, and re-synchronization for frequency drift tolerance.

Does the 11LC040-I/P support write protection, and how is it configured?

Yes, the 11LC040-I/P supports hardware-based block write protection via two nonvolatile BP0 and BP1 bits in its STATUS register. These bits are programmed using the WRSR (Write Status Register) command and enable protection of none, 1/4, 1/2, or the entire 512-byte memory array. Protection is active immediately after WRSR execution and persists across power cycles, providing robust defense against accidental writes during firmware updates or brown-out conditions.

What is the maximum write speed and page size of the 11LC040-I/P?

The 11LC040-I/P has a fixed page size of 16 bytes and supports page-write operations up to that limit. A full page write completes in ≤10 ms (typical), while individual byte writes take ≤5 ms. The device does not support faster write speeds beyond these specifications - attempting to exceed the 100 kbps bus rate or issue commands before TWC completion will result in NoSAK responses or communication failure.

Can the 11LC040-I/P operate at 1.8V?

No, the 11LC040-I/P is specified for VCC = 2.5V to 5.5V only. Operation below 2.5V is not guaranteed and may result in unreliable read/write behavior or failure to enter standby mode. For 1.8V systems, the pin-compatible 11AA040-I/P variant should be selected - it shares identical density, package, and UNI/O® functionality but extends the lower VCC limit to 1.8V.

What packages are available for the 11LC040-I/P, and what does the "P" suffix indicate?

The "P" suffix in 11LC040-I/P denotes the 8-lead Plastic Dual In-line Package (PDIP), a through-hole package with 0.3-inch row spacing. This package is distinct from surface-mount variants like SN (SOIC), MS (MSOP), or MN (TDFN). The 11LC040-I/P is not offered in SOT-23 or TO-92 - those packages are used for lower-density variants (e.g., 11LC010-TT) and are not mechanically or electrically interchangeable with the PDIP version.