Microchip Technology 93AA56CT-I/MS

Overview

93AA56CT-I/MS from Microchip Technology is a 2 Kbit low-voltage serial EEPROM with 256 × 8-bit organization, supporting 1.8–5.5 V operation and Industrial temperature range (−40°C to +85°C). It features Microwire-compatible 3-wire serial interface (CS, CLK, DI, DO), automatic erase-before-write, and 1 million erase/write cycles. Used for configuration storage in microcontroller-based embedded systems requiring nonvolatile parameter retention.

For engineers reviewing the 93AA56CT-I/MS datasheet, 93AA56CT-I/MS pinout, 93AA56CT-I/MS application, or 93AA56CT-I/MS equivalent, key selection criteria include voltage compatibility (1.8–5.5 V), MSOP-8 package footprint, 8-bit word organization (no ORG pin function), industrial-grade reliability, and Microwire protocol timing compliance.

Technical Context

This device implements a synchronous serial Microwire interface with start-bit detection, opcode-driven command set (READ, WRITE, ERASE, ERAL, WRAL), and Ready/Busy status reporting via DO pin. Internal self-timed erase/write cycles eliminate external timing control.

Power-on data protection is enforced by internal voltage detection (VPOR = 1.5 V typical), and write operations require explicit EWEN enable followed by EWDS disable for robustness. The absence of ORG pin functionality confirms fixed 8-bit word size - consistent with 'A' suffix designation.

Key Specifications

Pinout & Package

8-pin MSOP (Micro Small Outline Package), 3.0 mm × 3.0 mm body, 0.65 mm pitch, exposed pad optional (VSS or floating).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC56AT-I/MS, the 93AA56CT-I/MS extends low-voltage operation to 1.8 V while maintaining identical pinout and command structure; versus AT25020B-MAHL-T, it retains Microwire compatibility but requires no CS/CLK/DI/DO signal reassignment.

Availability

93AA56CT-I/MS is available at Aetrix Electronics and suitable for smart sensor calibration, industrial PLC configuration, and medical device settings requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for 93AA56CT-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.

The 93XX series EEPROMs were designed for cost-sensitive, low-power embedded systems requiring reliable nonvolatile storage with minimal pin count and software overhead - especially where Microwire compatibility and wide VCC range are critical.

FAQ

What is the function of the ORG pin on the 93AA56CT-I/MS?

The ORG pin is not functional on the 93AA56CT-I/MS. As an 'A'-suffix variant, this device has fixed 256 × 8-bit organization and no ORG pin capability. The pin is internally unconnected (NC) and may be left floating or tied to VSS per PCB layout guidelines. This differs from 'C'-suffix parts like 93AA56CT-I/MS where ORG selects x8/x16 mode.

Does the 93AA56CT-I/MS support SPI communication?

No, the 93AA56CT-I/MS does not support SPI. It implements the Microwire serial protocol - a 3-wire interface using CS, CLK, and bidirectional DI/DO lines with start-bit detection and opcode-based commands. SPI requires four dedicated lines (CS, SCK, MOSI, MISO) and different framing; interfacing requires bit-banged Microwire, not hardware SPI peripherals.

What is the maximum clock frequency supported by the 93AA56CT-I/MS at 1.8 V?

At VCC = 1.8 V, the 93AA56CT-I/MS supports a maximum clock frequency of 1 MHz, as specified in Table 1-2 (A1). This limit ensures reliable setup/hold timing (TDIS, TDIH ≥250 ns) and output delay (TPD ≤400 ns) under worst-case low-voltage conditions.

How is write protection implemented on the 93AA56CT-I/MS?

Write protection on the 93AA56CT-I/MS uses dual hardware/software mechanisms: (1) Power-on write inhibit below ~1.5 V VCC, and (2) Erase/Write Enable/Disable (EWEN/EWDS) commands. The device powers up in EWDS state; an EWEN instruction must precede any ERASE or WRITE, and EWDS should follow to relock. This prevents accidental writes during noise or brown-out events.

Can the 93AA56CT-I/MS be used in automotive under-hood applications?

No, the 93AA56CT-I/MS is rated for Industrial temperature range (−40°C to +85°C), not Automotive (−40°C to +125°C). For under-hood use, consider the 93AA56CT-E/MS variant ('E' suffix), which is qualified to AEC-Q100 Grade 3 and supports the extended temperature range with identical functionality and pinout.