Microchip Technology 93AA76C-I/MS

Overview

93AA76C-I/MS from Microchip Technology Inc. is an 8 Kbit, low-voltage, serial Electrically Erasable PROM (EEPROM) with selectable 8-bit or 16-bit word organization via the ORG pin, program enable (PE) write protection, and industrial temperature range (–40°C to +85°C). It operates from 1.8 V to 5.5 V, supports Microwire-compatible 3-wire serial interface (CS/CLK/DI/DO), and delivers 1 million erase/write cycles with >200 years data retention - used in embedded system configuration storage and calibration data logging.

For engineers reviewing the 93AA76C-I/MS datasheet, 93AA76C-I/MS pinout, 93AA76C-I/MS application, or 93AA76C-I/MS equivalent, key selection considerations include ORG-pin-configurable memory width, PE-enabled hardware write lock, self-timed erase/write with Ready/Busy status on DO, and MSOP-8 packaging for space-constrained PCBs.

Technical Context

The 93AA76C-I/MS implements a synchronous Microwire-compatible serial interface with CS-controlled device selection, rising-edge clocked data transfer, and dual-mode memory organization: ORG = VSS selects 1024 × 8-bit (8K × 1), ORG = VCC selects 512 × 16-bit (8K × 1). It features dedicated Program Enable (PE) logic that must be driven high to permit erase/write operations - unlike A/B variants where programming is always enabled.

Internal operation includes automatic ERAL before WRAL, power-on/off data protection circuitry, and status reporting via DO pin (low = busy, high = ready) during self-timed erase/write cycles. The device enters Standby mode when CS is low, drawing only 1 µA typical ICCS, and requires no external timing components due to fully integrated auto-erase and write timing.

Key Specifications

Pinout & Package

8-lead MSOP (Micro Small Outline Package), 3.0 mm × 3.0 mm body, 0.65 mm pitch, Pb-free Matte Tin finish, exposed pad optional (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC76C-I/MS, the 93AA76C-I/MS extends low-voltage operation to 1.8 V for compatibility with modern ultra-low-power MCUs; compared with 93AA76C-I/SN, it reduces PCB area by 45% while maintaining identical timing, endurance, and functional behavior.

Availability

93AA76C-I/MS is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, and automotive body control modules requiring stable component supply, long-lifecycle assurance, and RoHS-compliant packaging.

Supply support for 93AA76C-I/MS 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, with global design, manufacturing, and sales operations.

The 93XX76 series was designed specifically for cost-sensitive, space-constrained embedded systems requiring reliable nonvolatile storage with hardware-controlled write protection and flexible memory organization - targeting industrial, medical, and automotive applications.

FAQ

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

The ORG pin on the 93AA76C-I/MS selects memory organization: tied to VCC enables 512 × 16-bit (x16) mode; tied to VSS enables 1024 × 8-bit (x8) mode. This pin is absent on 93AA76A/B variants. For the 93AA76C-I/MS, ORG must be hardwired - floating is not permitted - and determines instruction length, address width, and data bus width during READ/WRITE operations.

How does the PE pin protect memory on the 93AA76C-I/MS?

The PE (Program Enable) pin on the 93AA76C-I/MS must be driven high to allow any erase or write operation; if held low, all programming functions (ERASE, WRITE, WRAL, EWEN) are inhibited regardless of command sequence. This hardware-level lock prevents corruption during power glitches or firmware errors. Unlike 93AA76A/B, the 93AA76C-I/MS requires explicit PE = high before the final clock edge of each WRITE/WRAL cycle.

What is the maximum clock frequency supported by the 93AA76C-I/MS at 3.3 V?

At VCC = 3.3 V, the 93AA76C-I/MS supports a maximum clock frequency of 2 MHz, as specified in Table 1-2 (A1 parameter). This is derived from the 2.5 V ≤ VCC < 4.5 V bin, where FCLK max = 2 MHz. Operation above this frequency risks setup/hold violations and unreliable communication, especially under worst-case temperature and voltage conditions.

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

No, the 93AA76C-I/MS does not require an external pull-up on DO. The DO pin actively drives high/low during READ and Ready/Busy status reporting, and enters High-Z only when CS is low or during idle periods. However, if DI and DO are shorted (shared bus), a current-limiting resistor (e.g., 10 kΩ) is recommended between them to prevent bus conflict when A0 = high during the dummy zero phase of READ.

What is the purpose of the EWEN and EWDS commands in the 93AA76C-I/MS instruction set?

The EWEN (Erase/Write Enable) and EWDS (Erase/Write Disable) commands control programming permission: 93AA76C-I/MS powers up in EWDS mode, blocking all erase/write until EWEN is issued. After successful programming, issuing EWDS restores write protection. These commands add software-level control complementary to the hardware PE pin - enabling selective, temporary enablement of writes while maintaining default safety lockout.