Microchip Technology 93AA76C-I/SN

Overview

93AA76C-I/SN from Microchip Technology is an 8Kbit, low-voltage, serial EEPROM with Microwire-compatible 3-wire interface, supporting selectable 8-bit or 16-bit word organization via the ORG pin, write protection via the PE pin, and industrial temperature operation (–40°C to +85°C) in 8-lead SOIC package. It delivers 1 million erase/write cycles and >200 years data retention for embedded system configuration storage.

For engineers reviewing the 93AA76C-I/SN datasheet, 93AA76C-I/SN pinout, 93AA76C-I/SN application, or 93AA76C-I/SN equivalent, key selection criteria include VCC range (1.8–5.5V), ORG/PE pin dependency for memory configuration and write enable, Ready/Busy status polling on DO, self-timed erase/write timing (5 ms max), and compatibility with legacy Microwire controllers in space-constrained industrial designs.

Technical Context

The 93AA76C-I/SN implements a synchronous serial Microwire interface with CS, CLK, DI, and DO signals, where instruction execution begins only after detection of a Start condition (CS high + DI high on CLK rising edge). Its dual-word-size architecture requires external logic-level control of the ORG pin-logic high selects 512 × 16-bit mode, logic low selects 1024 × 8-bit mode.

Write operations require prior execution of EWEN, followed by valid opcode/address/data sequences; the PE pin must be held high during the final clock edge of WRITE/WRAL commands. The DO pin serves dual roles: serial data output during READ and active-low Ready/Busy indicator during erase/write cycles, with status validated only when CS is reasserted after ≥250 ns low time (TCSL).

Key Specifications

Pinout & Package

8-lead SOIC (SN) package with standard 150-mil width and 1.27 mm pitch; RoHS-compliant matte tin finish. Pin 1 marked by laser dot; pin 1 ID corner indicated by bevelled edge.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC76C-I/SN, the 93AA76C-I/SN supports lower-voltage operation critical for battery-backed systems; compared with 93AA76A-I/SN, it adds hardware-configurable word size and physical write disable - enhancing design flexibility and robustness in field-upgradable equipment.

Availability

93AA76C-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded system configuration, and medical device settings storage requiring stable component supply across extended product lifecycles.

Supply support for 93AA76C-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 microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 93AA76C-I/SN belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-power, nonvolatile storage in industrial and consumer electronics where Microwire interface compatibility and hardware-controlled memory configuration are essential.

FAQ

What is the function of the ORG pin on the 93AA76C-I/SN?

The ORG pin on the 93AA76C-I/SN selects memory word size: logic high configures the device as 512 × 16-bit, logic low configures it as 1024 × 8-bit. This pin must be hardwired to VCC or VSS before operation - floating is not permitted. Unlike the 93AA76A/B variants, the 93AA76C-I/SN requires this external logic level to determine instruction addressing and data width, making it adaptable to both byte- and word-oriented host systems.

How does the Program Enable (PE) pin protect against unintended writes on the 93AA76C-I/SN?

The PE pin on the 93AA76C-I/SN acts as a hardware gate for all programming operations: only when PE is held high can ERASE, WRITE, or WRAL instructions execute. If PE is tied low, all write functions are disabled regardless of EWEN state or command sequence. This provides fail-safe protection during power-up, reset, or noise events - a critical safeguard absent in 93AA76A-I/SN and 93AA76B-I/SN variants.

What is the maximum clock frequency supported by the 93AA76C-I/SN at 1.8 V?

At VCC = 1.8 V, the 93AA76C-I/SN supports a maximum clock frequency (FCLK) of 1 MHz, as specified in Table 1-2 of the DS21796M datasheet. This limit scales with supply voltage: 2 MHz at 2.5–4.5 V, and 3 MHz at 4.5–5.5 V. Designers must ensure clock timing parameters (TCKH, TCKL, TDIS, etc.) comply with the corresponding voltage bin to guarantee reliable instruction execution.

Does the 93AA76C-I/SN require an external pull-up resistor on the CS pin?

Yes - Microchip recommends a 10 kΩ external pull-down resistor on the CS pin of the 93AA76C-I/SN for added protection against accidental writes during power-up or noise coupling. While not strictly required for basic functionality, this resistor ensures CS remains low until intentionally asserted, preventing spurious Start conditions that could trigger unintended commands. The device itself has no internal CS pull-down.

Can the 93AA76C-I/SN be used in place of the 93AA76A-I/SN without hardware changes?

No - replacing 93AA76A-I/SN with 93AA76C-I/SN requires hardware modifications: the 93AA76C-I/SN introduces two additional pins (ORG and PE) not present on the 93AA76A-I/SN. These must be externally biased (typically ORG to VSS for 8-bit mode, PE to VCC for write enable) and routed on the PCB. Firmware may remain compatible if using only x8-mode instructions, but pinout and board layout are not interchangeable.