Microchip Technology 93AA56A-I/MS

Overview

93AA56A-I/MS from Microchip Technology Inc. is a 2 Kbit (256 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 1.8–5.5 V supply range, industrial temperature rating (–40°C to +85°C), and MSOP-8 package. It features self-timed erase/write cycles, automatic ERAL before WRAL, and Ready/Busy status via DO pin - used for configuration storage in microcontroller-based sensor modules.

For engineers reviewing the 93AA56A-I/MS datasheet, 93AA56A-I/MS pinout, 93AA56A-I/MS application, or 93AA56A-I/MS equivalent, key selection criteria include its fixed 8-bit organization (no ORG pin), 1 million erase/write endurance, 200-year data retention, and compatibility with low-power embedded systems requiring nonvolatile parameter storage without hardware word-size switching.

Technical Context

This device implements a synchronous serial Microwire protocol with CS/CLK/DI/DO signals and no ORG pin - confirming fixed x8 memory mapping. Its internal architecture includes auto-erase-before-write logic, on-chip voltage detection (VPOR = 1.5 V), and power-on/off data protection circuitry that inhibits all operations below VCC threshold.

Timing behavior is defined by TWC = 6 ms write cycle time, TCSL ≥ 250 ns minimum chip select low time, and TPD ≤ 400 ns data output delay at 1.8 V. The DO pin serves dual function: serial data output during READ and active-low Ready/Busy indicator during programming - requiring CS high ≥250 ns after TCSL to sample status.

Key Specifications

Pinout & Package

8-pin MSOP (150 mil) package with exposed pad (optional VSS connection); Pb-free Matte Tin finish. Pin 1 marked by laser dot; pin 1 location confirmed per Microchip DS21794G-page 17.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC56A-I/MS and AT25020B-MAHL-T, the 93AA56A-I/MS uniquely supports 1.8 V operation while retaining Microwire compatibility and hardware Ready/Busy signaling - critical for ultra-low-power sensor nodes and brown-out resilient industrial controllers.

Availability

93AA56A-I/MS is available at Aetrix Electronics and suitable for motor control tuning storage, smart sensor calibration data, and industrial PLC I/O module ID requiring stable component supply across extended production lifecycles.

Supply support for 93AA56A-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 microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 93XX series EEPROMs were designed specifically for cost-sensitive, low-power embedded systems needing reliable serial nonvolatile storage - emphasizing simplicity, wide VCC range, and robust data retention without complex initialization sequences.

FAQ

What is the memory organization of the 93AA56A-I/MS?

The 93AA56A-I/MS has a fixed 256 × 8-bit (2 Kbit) organization with no ORG pin - unlike 'C' variants, it does not support x16 mode. This simplifies interface design by eliminating external logic for word-size selection and guarantees consistent 8-bit data framing in all applications.

Does the 93AA56A-I/MS require an external pull-up resistor on the DO pin?

No, the 93AA56A-I/MS does not require an external pull-up on DO. The pin actively drives high/low during READ and Ready/Busy status reporting, and enters High-Z only when CS is low or during status-clear sequences. External pull-ups may interfere with valid low-level status signaling.

How is data protection implemented during power transitions in the 93AA56A-I/MS?

The 93AA56A-I/MS incorporates hardware voltage detection (VPOR = 1.5 V) that disables all write/erase operations when VCC falls below this threshold. This prevents partial writes and data corruption during power-up, power-down, or brown-out events - no software intervention or external reset supervisor is needed.

Can the 93AA56A-I/MS be used in a shared bus configuration with DI and DO connected together?

Yes, but with caution: connecting DI and DO requires a current-limiting resistor (e.g., 10 kΩ) between pins to prevent bus conflict during the dummy zero preceding READ operations. Without it, undefined voltage levels may occur if address bit A0 is high, risking communication failure or excessive current draw.

What is the maximum clock frequency supported by the 93AA56A-I/MS at 1.8 V?

At VCC = 1.8 V, the 93AA56A-I/MS supports a maximum clock frequency of 1 MHz (per DS21794G Table 1-2, A1). This is lower than its 3 MHz rating at 4.5–5.5 V, reflecting reduced internal timing margins at minimum supply voltage - system firmware must adapt clock rate accordingly.