Microchip Technology 93AA66CT-I/MNY

Overview

93AA66CT-I/MNY from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 1.8–5.5 V supply range, and industrial temperature grade (–40°C to +85°C). It features ORG-pin-selectable 8-/16-bit word organization, self-timed erase/write cycles, automatic ERAL before WRAL, and Ready/Busy status signaling via DO pin - used in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 93AA66CT-I/MNY datasheet, 93AA66CT-I/MNY pinout, 93AA66CT-I/MNY application, or 93AA66CT-I/MNY equivalent, key selection criteria include voltage compatibility (1.8–5.5 V), ORG-pin configurability for x8/x16 data width, 1 million endurance cycles, >200-year data retention, and support for sequential read and auto-erase functionality in space-constrained industrial designs.

Technical Context

The 93AA66CT-I/MNY implements a synchronous serial Microwire interface with CS, CLK, DI, and DO signals plus ORG for memory width selection. Its internal architecture includes an address decoder, mode decode logic, and output buffer enabling single-instruction execution per clock-synchronized command sequence.

It supports two distinct memory organizations: when ORG = VSS, it operates as 512 × 8-bit; when ORG = VCC, it operates as 256 × 16-bit. All erase/write operations are self-timed and include automatic pre-erase (ERAL) before WRAL, with power-on/off data protection circuitry ensuring integrity during brownout conditions.

Key Specifications

Pinout & Package

93AA66CT-I/MNY is housed in an 8-lead MSOP (MS) package (3.0 mm × 3.0 mm × 1.0 mm), Pb-free matte tin finish, with exposed pad optionally connected to VSS.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC66CT-I/MNY, the 93AA66CT-I/MNY supports lower-voltage operation critical for battery-powered devices; compared with 93AA66AT-I/MNY, it adds ORG-based configurability essential for mixed-interface platforms - making it the optimal choice where voltage headroom and interface adaptability are both required.

Availability

93AA66CT-I/MNY is available at Aetrix Electronics and suitable for industrial sensor calibration, smart meter tamper logging, and automotive body control module applications requiring stable component supply, long-term obsolescence management, and traceable sourcing.

Supply support for 93AA66CT-I/MNY 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, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design, manufacturing, and sales operations.

The 93XX66 family was designed specifically for cost-sensitive, space-constrained embedded systems requiring robust nonvolatile storage with minimal pin count and ultra-low power consumption - targeting industrial controls, consumer electronics, and automotive subsystems.

FAQ

What is the memory organization of the 93AA66CT-I/MNY and how is it configured?

The 93AA66CT-I/MNY supports dual memory organizations: 512 × 8-bit (x8) or 256 × 16-bit (x16), selected by the logic level applied to the ORG pin. When ORG is tied to VSS (logic low), the device operates in x8 mode; when tied to VCC (logic high), it operates in x16 mode. This configuration is static and must be established before any instruction is issued. The 93AA66CT-I/MNY datasheet confirms this behavior in Section 2.0 and Table 1-1.

Does the 93AA66CT-I/MNY require external timing components for erase or write operations?

No, the 93AA66CT-I/MNY performs fully self-timed erase and write cycles. Once the instruction sequence is completed and CS falls (for 93AA versions), the internal logic automatically executes auto-erase followed by programming without external clocks or delay loops. Typical erase/write time is 6 ms, and ERAL/WRAL cycles are similarly autonomous - eliminating software timing dependencies and simplifying host firmware for the 93AA66CT-I/MNY.

How does the Ready/Busy status work on the 93AA66CT-I/MNY DO pin?

The DO pin of the 93AA66CT-I/MNY serves dual function: data output during READ and Ready/Busy status during erase/write. After initiating an ERASE, WRITE, ERAL, or WRAL command, bringing CS high for ≥250 ns (TCSL) enables status polling: DO = low indicates ongoing operation; DO = high indicates completion. Issuing a Start bit then lowering CS clears the status flag. This mechanism is documented in Sections 2.4–2.9 and Figure 2-1 of the 93AA66CT-I/MNY datasheet.

What is the minimum V_CC required to prevent unintended writes on the 93AA66CT-I/MNY?

The 93AA66CT-I/MNY incorporates internal power-on reset (POR) circuitry that inhibits all write operations when V_CC falls below approximately 1.5 V. This threshold is specified in Electrical Characteristics table D11 (VPOR) of the datasheet and ensures data integrity during power ramp-up, brownout, or battery depletion scenarios - a critical safeguard for reliable operation of the 93AA66CT-I/MNY in unregulated power environments.

Can the 93AA66CT-I/MNY be used in a 3-wire bus shared between multiple devices?

Yes, but only one 93AA66CT-I/MNY can be active per CS line. The device uses dedicated CS for chip selection and does not support true multi-drop addressing on a shared DI/DO/CLK bus. To connect multiple 93AA66CT-I/MNY units, each requires its own CS signal routed from the host controller; DI, DO, and CLK may be wired in parallel. This architecture avoids bus contention and is explicitly supported in the functional description of the 93AA66CT-I/MNY datasheet.