Microchip Technology 93AA76CT-I/SN

Overview

93AA76CT-I/SN from Microchip Technology Inc. is an 8 Kbit, low-voltage, serial EEPROM with Microwire-compatible 3-wire interface, 1.8–5.5 V supply range, industrial temperature grade (–40°C to +85°C), and SOIC-8 package. It supports configurable 8-bit or 16-bit word organization via the ORG pin and includes Program Enable (PE) for hardware write protection. It is used in embedded system configuration storage, sensor calibration data retention, and power-fail-safe parameter backup.

For engineers reviewing the 93AA76CT-I/SN datasheet, 93AA76CT-I/SN pinout, 93AA76CT-I/SN application, or 93AA76CT-I/SN equivalent, key selection considerations include its dual-word-size flexibility, self-timed erase/write cycles, Ready/Busy status signaling, 1 million endurance cycles, and Pb-free SOIC-8 packaging suitable for industrial-grade reflow and long-term data retention.

Technical Context

The 93AA76CT-I/SN implements a synchronous serial Microwire interface with CS, CLK, DI, and DO lines, requiring a Start bit detection before instruction execution. Its internal logic decodes opcodes (e.g., READ, WRITE, ERAL) and manages address/data latching on rising CLK edges, with automatic ERAL preceding WRAL operations.

Memory organization is dynamically selected by the ORG pin: logic high enables 512 × 16-bit mode; logic low selects 1024 × 8-bit mode. The PE pin must be held high to enable programming; tying it low permanently inhibits all erase/write functions. Power-on reset and POR circuitry (1.5 V threshold) prevent spurious writes during brown-out conditions.

Key Specifications

Pinout & Package

8-lead SOIC (SN) package, 3.9 mm × 4.9 mm body, 1.27 mm pitch, Pb-free Matte Tin finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC76CT-I/SN and AT25DF041A-SSH-T, the 93AA76CT-I/SN uniquely supports 1.8 V operation and hardware-configurable word size - critical for ultra-low-power and mixed-signal MCU platforms where voltage headroom and bus-width alignment constrain design choices.

Availability

93AA76CT-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration storage, embedded system configuration backup, and power-fail-safe event logging requiring stable component supply, long-term obsolescence management, and RoHS-compliant sourcing.

Supply support for 93AA76CT-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, analog, and memory solutions, founded in 1989 and headquartered in Chandler, Arizona.

The 93XX series EEPROMs were designed for cost-sensitive, low-power embedded systems requiring robust nonvolatile storage with minimal pin count and flexible memory organization - targeting industrial controls, automotive subsystems, and IoT edge devices.

FAQ

What is the function of the ORG pin on the 93AA76CT-I/SN?

The ORG pin on the 93AA76CT-I/SN selects memory organization: logic high configures the device as 512 × 16-bit, while logic low configures it as 1024 × 8-bit. This hardware-selectable mode eliminates firmware changes when adapting to different MCU data bus widths. The 93AA76CT-I/SN requires ORG to be statically tied to VCC or VSS - floating is not permitted. This behavior is confirmed in DS21796M-page 5 and page 10.

Does the 93AA76CT-I/SN require external pull-up resistors on its I/O lines?

The 93AA76CT-I/SN does not require external pull-ups on CS, CLK, DI, or DO for basic operation, as its inputs meet TTL/CMOS thresholds across the 1.8–5.5 V range. However, Microchip recommends a 10 kΩ pull-down on CS (DS21796M-page 5, Note) and a current-limiting resistor between DI and DO in shared-bus configurations to prevent bus conflict (DS21796M-page 5, Section 2.2). These are design best practices, not absolute requirements.

How does the Program Enable (PE) pin affect write operations on the 93AA76CT-I/SN?

The PE pin on the 93AA76CT-I/SN must be held high to allow any erase or write operation - including EWEN, ERASE, WRITE, and WRAL. If PE is tied low, all programming functions are permanently disabled, even after issuing EWEN. This hardware lockout provides unconditional write protection independent of firmware state. The 93AA76CT-I/SN datasheet explicitly states PE "cannot be floated" and must be statically driven (DS21796M-page 11).

What is the maximum clock frequency supported by the 93AA76CT-I/SN at 3.3 V?

At VCC = 3.3 V, the 93AA76CT-I/SN supports a maximum clock frequency of 2 MHz, as specified in Table 1-2 (A1, FCLK) of DS21796M-page 3 for the 2.5 V ≤ VCC < 4.5 V range. This limit ensures reliable setup/hold timing for DI and DO signals. Exceeding 2 MHz may cause command misreads or data corruption, particularly under worst-case temperature and voltage conditions.

Can the 93AA76CT-I/SN retain data during a complete power loss?

Yes - the 93AA76CT-I/SN guarantees data retention for 200 years at +85°C (DS21796M-page 1), and its internal power-on reset circuitry (VPOR = 1.5 V typical) prevents write corruption during brown-out events. As long as the device completes any active write cycle before VCC drops below 1.5 V, stored data remains intact indefinitely after power removal. No external capacitors or backup power are required for retention.