Microchip Technology 93AA46/SN

Overview

93AA46/SN from Microchip Technology Inc. is a 1 Kbit (128 × 8 or 64 × 16) low-voltage serial EEPROM with Microwire interface, ORG-pin-selectable memory organization, and 1.8 V to 5.5 V single-supply operation. It delivers 70 µA typical active read current at 1.8 V, supports self-timed erase/write cycles, and is housed in an 8-lead SOIC (SN) package for industrial temperature range (–40°C to +85°C). It serves as nonvolatile configuration storage in embedded microcontroller systems requiring robust data retention.

For engineers reviewing the 93AA46/SN datasheet, 93AA46/SN pinout, 93AA46/SN application, or 93AA46/SN equivalent, key selection criteria include its 1.8 V minimum operating voltage, x8/x16 configurable organization via ORG pin, 1 million endurance cycles, >200-year data retention, and compatibility with legacy Microwire-based host controllers in space-constrained industrial designs.

Technical Context

The 93AA46/SN implements a synchronous 3-wire Microwire interface (CS, CLK, DI/DO) with start-bit detection and opcode-driven command execution. Its internal logic includes address counter, mode decode logic, and clock generator enabling sequential read, ERAL/WRAL bulk operations, and RDY/BSY status polling via DO pin.

Memory configuration is determined by the ORG pin: tied to V_CC selects 64 × 16-bit organization (128 words × 16 bits), while tied to V_SS selects 128 × 8-bit organization (128 bytes × 8 bits). Power-on reset inhibits programming until V_CC exceeds 1.4 V, and EWEN/EWDS commands enforce write protection independent of power state.

Key Specifications

Pinout & Package

8-lead SOIC (SN) package per JEDEC MS-012 standard, 150 mil body width, surface-mount compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93AA46/SN, the 93AA46C/SN offers identical functionality with higher ESD immunity and is designated for new designs, while AT25010B-MAU-2.7 requires interface and voltage redesign but provides broader distributor availability.

Availability

93AA46/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded controller configuration, and medical device settings storage requiring stable component supply across extended product lifecycles.

Supply support for 93AA46/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 U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and memory products for embedded control applications.

The 93AA46/SN belongs to Microchip's legacy Microwire Serial EEPROM product line, designed specifically for low-voltage, low-power nonvolatile storage in resource-constrained industrial and medical systems where interface simplicity and long-term data integrity are critical.

FAQ

What is the minimum operating voltage for the 93AA46/SN?

The 93AA46/SN operates down to 1.8 V, with guaranteed functionality across its full 1.8 V to 5.5 V supply range. At 1.8 V, it delivers 70 µA typical active read current and maintains full instruction set compliance, including ERAL and WRAL bulk operations. This low-voltage capability allows direct integration with modern ultra-low-power microcontrollers without level-shifting circuitry. The 93AA46/SN also includes hardware power-on reset that inhibits programming until V_CC exceeds 1.4 V, ensuring safe initialization even during brown-out conditions.

How does the ORG pin affect memory organization in the 93AA46/SN?

The ORG pin on the 93AA46/SN selects between two memory configurations: when tied to V_CC, it enables 64 × 16-bit (128-word) organization; when tied to V_SS, it enables 128 × 8-bit (128-byte) organization. This selection is static and must be made before device operation - floating ORG is only permitted at clock frequencies ≤1 MHz for x16 mode. The 93AA46/SN datasheet specifies distinct instruction sets and address widths for each mode, and the configuration directly determines opcode length, address bit count, and data output width during READ operations. This hardware-selectable flexibility allows one PCB design to support either byte- or word-oriented data structures without firmware modification.

Does the 93AA46/SN support sequential read operations?

Yes, the 93AA46/SN supports sequential read: when CS remains high after a READ instruction, the internal address counter automatically increments, allowing continuous output of consecutive memory locations on the DO pin synchronized to CLK. This eliminates the need to reissue the READ command and address for each byte or word, significantly accelerating bulk data retrieval - for example, loading full configuration tables or calibration arrays. Sequential read works identically in both x8 and x16 modes, with the DO pin outputting the appropriate number of bits per cycle (8 or 16) based on the ORG pin setting. The 93AA46/SN maintains this behavior across its entire operating voltage and temperature range.

What is the purpose of the NU pin on the 93AA46/SN?

Pin 5 on the 93AA46/SN is marked NU (Not Utilized) and is internally unconnected. Per the official Microchip datasheet DS20067K, this pin must remain unconnected in the PCB layout to prevent unintended coupling, noise injection, or potential latch-up. Unlike pins such as ORG or V_SS, NU has no electrical function or internal tie-off; connecting it to ground, V_CC, or any signal violates the device's validated design and may compromise reliability or parametric performance. The 93AA46/SN's pinout diagram explicitly identifies NU in both PDIP and SOIC (SN) package drawings, confirming its status as a true no-connect terminal across all revisions and temperature grades.

How does the 93AA46/SN indicate readiness during erase or write cycles?

The 93AA46/SN uses its DO pin to provide real-time Ready/Busy status during erase and write operations: when CS is brought high after ≥250 ns low time (TCSL), DO outputs low (logical 0) while programming is in progress and transitions to high (logical 1) upon completion. This polling mechanism eliminates reliance on fixed timing delays - for example, the typical 4 ms per-word WRITE cycle or 8 ms ERAL cycle - allowing the host MCU to proceed immediately upon readiness. The 93AA46/SN requires an external pull-up resistor on DO to reliably detect the high state after completion, as DO returns to high-Z when CS is low or during non-programming phases. This status signaling is fully functional across the device's 1.8–5.5 V supply range and –40°C to +85°C temperature specification.