Microchip Technology 93AA86B-I/MS

Overview

93AA86B-I/MS from Microchip Technology is a 16K-bit, 1024 × 16-bit organization serial EEPROM with Microwire-compatible 3-wire interface, operating from 1.8V to 5.5V across -40°C to +85°C industrial temperature range. It features self-timed erase/write cycles (5 ms), 1,000,000 endurance cycles, >200-year data retention, and power-on/off data protection. Used in microcontroller configuration storage and sensor calibration data logging.

For engineers reviewing the 93AA86B-I/MS datasheet, 93AA86B-I/MS pinout, 93AA86B-I/MS application, or 93AA86B-I/MS equivalent, key selection considerations include its fixed 16-bit word size (no ORG pin), MSOP-8 package compatibility, industrial-grade temperature support, and absence of PE/ORG pins-distinguishing it from 'C' variants.

Technical Context

The 93AA86B-I/MS implements a synchronous serial Microwire interface with CS, CLK, DI, and DO signals. It uses a dedicated 1024 × 16-bit memory array with no external word-size configuration required-unlike the 'C' series, which relies on the ORG pin. All instructions (READ, WRITE, ERASE, ERAL, EWEN, EWDS) are clocked in via DI on CLK rising edges, with DO providing both data output and Ready/Busy status polling.

Its internal logic enforces automatic erase-before-write, supports sequential read, and includes built-in power-on reset detection (VPOR = 1.5 V typical). The device enters Standby mode when CS is low, drawing only 1 µA typical ICCS, and requires no external write-enable control since it lacks a PE pin-programming is always enabled per its 'B' variant specification.

Key Specifications

Pinout & Package

8-pin MSOP (150-mil) package with exposed pad option; RoHS-compliant matte tin finish. Pin 1 marked by laser dot; pin 1 ID corner defined per JEDEC MO-187.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC86B-I/MS and AT25128B-MAHL-T, the 93AA86B-I/MS uniquely supports true 1.8 V operation while maintaining pin- and protocol-level compatibility with legacy Microwire controllers-making it the only drop-in solution for upgrading existing 93AA86A/B designs without voltage rail or firmware changes.

Availability

93AA86B-I/MS is available at Aetrix Electronics and suitable for industrial control systems, sensor calibration modules, and smart metering applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for 93AA86B-I/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, mixed-signal, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with high-reliability semiconductor products.

The 93AA86B-I/MS belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-power embedded systems requiring robust nonvolatile storage with minimal external components and proven Microwire interoperability.

FAQ

What is the memory organization of the 93AA86B-I/MS?

The 93AA86B-I/MS has a fixed 1024 × 16-bit organization totaling 16 Kbits. Unlike the 'C' variants, it does not feature an ORG pin-so word size is permanently set to 16 bits. This eliminates external configuration logic and simplifies PCB layout for applications requiring native 16-bit data storage, such as MCU register backups or sensor coefficient tables. The 93AA86B-I/MS delivers deterministic addressing without runtime mode selection.

Does the 93AA86B-I/MS require a Program Enable (PE) pin to write data?

No, the 93AA86B-I/MS does not have a PE pin and does not require external write-enable signaling. As a 'B' variant, it lacks both PE and ORG pins-programming is always enabled after issuing an EWEN command. This differs from 'C' versions where PE must be held high to permit writes. The 93AA86B-I/MS simplifies design by removing PE routing, making it ideal for space-constrained layouts where pin count and board real estate are critical.

What is the maximum clock frequency supported by the 93AA86B-I/MS?

The 93AA86B-I/MS supports up to 3 MHz clock frequency when VCC is 4.5 V to 5.5 V, 2 MHz at 2.5 V to 4.5 V, and 1 MHz at 1.8 V to 2.5 V. These graded limits ensure reliable timing margins across its full 1.8–5.5 V operating range. For example, at 3.3 V VCC, the device operates at ≤2 MHz-enabling robust communication with standard MCU SPI/Microwire peripherals without custom timing adjustments. The 93AA86B-I/MS maintains full functionality across all supported frequencies.

How does the 93AA86B-I/MS handle power loss during a write operation?

The 93AA86B-I/MS incorporates hardware-level power-loss protection: its internal voltage detector (VPOR = 1.5 V typical) disables all write operations when VCC drops below this threshold. This prevents partial writes and data corruption during brown-out or battery depletion events. Combined with automatic erase-before-write and self-timed cycles, the 93AA86B-I/MS guarantees atomicity-ensuring that either the full 16-bit word is written successfully or no change occurs. No external capacitors or supervisor ICs are needed.

Can the 93AA86B-I/MS be used as a direct replacement for the 93AA86A-I/MS?

No, the 93AA86B-I/MS is not a direct replacement for the 93AA86A-I/MS due to fundamental architectural differences: the 'A' variant is 2048 × 8-bit (8-bit words), while the 'B' variant is 1024 × 16-bit (16-bit words). Address mapping, data width, and instruction timing differ-requiring firmware modifications to accommodate 16-bit reads/writes instead of 8-bit. Although both share identical pinout and voltage specs, the 93AA86B-I/MS serves distinct applications where 16-bit alignment improves efficiency, not drop-in substitution.