Microchip Technology 11AA040-I/P

Overview

11AA040-I/P from Microchip Technology is a 4 Kbit (512 × 8) serial EEPROM with UNI/O® single I/O bus interface, 1.8–5.5 V supply range, and industrial temperature rating (–40°C to +85°C). It features 16-byte page write buffer, Schmitt-trigger SCIO input, output slope control, and built-in write protection for embedded system configuration storage in space-constrained applications.

For engineers reviewing the 11AA040-I/P datasheet, 11AA040-I/P pinout, 11AA040-I/P application, or 11AA040-I/P equivalent, key selection criteria include its 1.8 V minimum operating voltage, 100 kbps Manchester-encoded serial interface, 1 µA max standby current, page-write capability, and 3-lead SOT-23 / 8-lead PDIP package options - all critical for low-power, single-wire microcontroller interfacing.

Technical Context

The 11AA040-I/P implements a Manchester-encoded UNI/O® protocol over a single bidirectional SCIO line, eliminating need for separate clock or chip-select signals. Its internal timing recovery circuitry synchronizes to master-generated bit periods and tolerates ±0.5% frequency drift per byte and ±0.06 UI edge jitter.

It integrates a write-enable latch, STATUS register (WIP/WEL/BP bits), and block write protection (none/¼/½/all array), with self-timed write cycles (5–10 ms) and automatic erase-before-write. Memory endurance is rated at 1,000,000 cycles with >200 years data retention.

Key Specifications

Pinout & Package

11AA040-I/P is packaged in 8-lead PDIP (Plastic Dual In-line Package), a through-hole format compatible with prototyping, legacy PCBs, and manual assembly. 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 11LC040-I/P, the 11AA040-I/P enables lower-voltage operation and reduced pin count; compared with AT24C04-PU, it eliminates I²C arbitration overhead and simplifies firmware but requires UNI/O®-capable host drivers.

Availability

11AA040-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-lifecycle support, and RoHS-compliant packaging.

Supply support for 11AA040-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 company specializing in microcontrollers, analog devices, and memory products for embedded applications.

The 11AA040-I/P belongs to Microchip's UNI/O® Serial EEPROM family, designed specifically for space- and pin-constrained systems needing simple, low-power, single-wire nonvolatile storage.

FAQ

What is the minimum operating voltage for the 11AA040-I/P?

The 11AA040-I/P supports a minimum supply voltage of 1.8 V, enabling direct interfacing with low-voltage microcontrollers and extending battery life in portable applications. This specification is validated across the full industrial temperature range (–40°C to +85°C) and distinguishes it from the 2.5 V minimum of the 11LC040-I/P variant. Operation below 1.8 V is not guaranteed and may result in unreliable read/write behavior.

Does the 11AA040-I/P require an external clock signal?

No, the 11AA040-I/P does not require an external clock signal. It uses Manchester encoding on the single SCIO line to embed clock information within the data stream, allowing the device to recover timing autonomously. The master device controls the bus frequency (10–100 kHz), and the 11AA040-I/P re-synchronizes on each MAK bit - eliminating clock distribution complexity and PCB routing overhead.

How many write cycles can the 11AA040-I/P endure?

The 11AA040-I/P is rated for 1,000,000 erase/write cycles per memory location under standard conditions (25°C, VCC = 5.5 V). This endurance is specified per page and supported by characterization data - not just sampled testing. Real-world endurance in 11AA040-I/P applications depends on write distribution across pages; wear-leveling firmware is recommended for cyclic logging use cases.

What package types are available for the 11AA040-I/P?

The 11AA040-I/P is offered in 8-lead PDIP (P), SOIC (SN), MSOP (MS), TDFN (MN), TO-92 (TO), SOT-23 (TT), and Chip Scale (CS) packages. The "-I/P" suffix specifically denotes the Industrial-grade 8-lead PDIP variant. All packages share identical pinout and electrical specifications, differing only in mechanical form factor and thermal characteristics - allowing drop-in substitution where board layout permits.

Can the 11AA040-I/P be used with a 5 V microcontroller?

Yes, the 11AA040-I/P operates across 1.8–5.5 V, making it fully compatible with 5 V microcontrollers. Its SCIO pin is 5 V tolerant when VCC = 5.5 V, and the Schmitt-trigger input ensures robust signal recognition despite voltage rail differences. No level-shifting circuitry is required, simplifying interface design and reducing component count in mixed-voltage systems.