Microchip Technology 93AA46XT-I/SN

Overview

93AA46XT-I/SN from Microchip Technology Inc. is a 1K-bit (128 × 8 or 64 × 16) low-voltage serial EEPROM with Microwire interface, ORG-pin configurable memory organization, and industrial temperature range (−40°C to +85°C). It operates down to 1.8V, draws only 70 µA active read current and 2 µA standby current at 1.8V, and supports self-timed erase/write cycles with 1,000,000 endurance cycles and >200-year data retention. It is used in embedded system configuration storage, sensor calibration data logging, and power-sensitive portable instrumentation.

For engineers reviewing the 93AA46XT-I/SN datasheet, 93AA46XT-I/SN pinout, 93AA46XT-I/SN application, or 93AA46XT-I/SN equivalent, key selection criteria include its 1.8V–5.5V supply range, 8-pin SOIC-SN package with rotated pinout, ORG-selectable x8/x16 organization, 2 MHz max clock frequency at VCC ≥ 4.5V, and industrial-grade reliability for nonvolatile parameter storage in constrained environments.

Technical Context

The 93AA46XT-I/SN implements a synchronous 3-wire Microwire-compatible serial interface with CS, CLK, DI, and DO lines. Its internal logic includes an address counter, mode decode logic, and clock generator enabling sequential read, ERAL (Erase All), WRAL (Write All), and individual erase/write operations-all self-timed and initiated by CS falling edge.

Memory configuration is determined solely by the ORG pin: tied to VCC for 64 × 16-bit organization (1024 bits), or to VSS for 128 × 8-bit organization (1024 bits). Power-on reset circuitry inhibits programming until VCC exceeds 1.4V, and EWEN/EWDS commands enforce write protection independent of supply sequencing.

Key Specifications

Pinout & Package

8-pin SOIC package per JEDEC MS-012 standard (narrow body, 150 mil), marked "/SN" - this is the rotated pinout variant exclusive to SN packaging, differing from standard SOIC pin assignments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93AA46XT-I/SN, the 93AA46C-I/SN offers identical functionality with higher ESD immunity and official design support, while the AT25010B-MAHL-T trades Microwire compatibility for faster SPI throughput and broader voltage tolerance-making it suitable only when interface migration is acceptable.

Availability

93AA46XT-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration storage, embedded system configuration memory, and portable instrumentation data logging requiring stable component supply across extended production lifecycles.

Supply support for 93AA46XT-I/SN 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, headquartered in Chandler, Arizona, serving automotive, industrial, consumer, and communications markets.

The 93AAxx family was designed specifically for low-voltage, low-power serial nonvolatile memory applications where Microwire interface simplicity, wide supply range, and industrial temperature operation are essential - targeting cost-sensitive, space-constrained embedded systems.

FAQ

What is the memory organization flexibility of the 93AA46XT-I/SN?

The 93AA46XT-I/SN supports dual memory configurations via its ORG pin: when tied to VSS, it operates as 128 × 8-bit (1024 bits); when tied to VCC, it configures as 64 × 16-bit (1024 bits). This allows designers to optimize data access patterns - byte-oriented systems use x8 mode, while word-aligned firmware or parameter tables benefit from x16 mode. The 93AA46XT-I/SN does not support dynamic reconfiguration; ORG must be set at power-on and remain static during operation.

Does the 93AA46XT-I/SN require external timing components for erase or write operations?

No, the 93AA46XT-I/SN performs fully self-timed erase and write cycles - including automatic ERAL before WRAL - with no external RC networks or timing crystals required. Once the CS pin falls after loading address/data, the internal logic autonomously executes auto-erase and programming, completing in 4 ms per word (WRITE/ERASE), 8 ms (ERAL), or 16 ms (WRAL) typical. The 93AA46XT-I/SN exposes Ready/Busy status on the DO pin for polling-based synchronization.

What is the significance of the "XT" suffix and "/SN" package designation in 93AA46XT-I/SN?

The "XT" suffix denotes tape-and-reel packaging for automated assembly, while "/SN" specifies the narrow-body 8-pin SOIC package (150 mil) with rotated pinout - a variant offered exclusively in SN packaging per Microchip's product identification system. This pinout differs from standard SOIC; for example, VSS is at Pin 4 instead of Pin 8. The "I" indicates industrial temperature range (−40°C to +85°C). The 93AA46XT-I/SN is functionally identical to other 93AA46 variants but requires layout verification against the SN-specific pin map.

How does the 93AA46XT-I/SN protect against inadvertent writes during power transitions?

The 93AA46XT-I/SN integrates hardware power-on/power-off protection that inhibits all programming modes (EWEN, ERASE, WRITE, WRAL) until VCC rises above 1.4V, and re-enables protection when VCC falls below 1.4V. Additionally, it powers up in Erase/Write Disable (EWDS) mode, requiring an explicit EWEN instruction before any programming command executes. These dual safeguards prevent data corruption during brown-out, hot-swap, or noisy power-up sequences - a critical feature confirmed in the 93AA46XT-I/SN's functional description and electrical characteristics.

Is the 93AA46XT-I/SN compatible with standard SPI interfaces?

No, the 93AA46XT-I/SN implements a 3-wire Microwire interface (CS, CLK, DI/DO), not SPI. While both are synchronous serial protocols, Microwire uses separate DI and DO lines (or bidirectional with careful timing), lacks SPI's MOSI/MISO duality and mode configuration (CPOL/CPHA), and employs distinct instruction opcodes (e.g., EWEN, ERAL, WRAL). Direct SPI-to-Microwire translation is not possible without firmware-level protocol emulation. The 93AA46XT-I/SN requires a host with native Microwire support or bit-banged GPIO control matching its timing requirements.