Microchip Technology 93C76A-I/SN

Overview

93C76A-I/SN from Microchip Technology Inc. is an 8K-bit, 1024 × 8-bit organization serial EEPROM with Microwire-compatible 3-wire interface (CS/CLK/DI/DO), operating at 4.5–5.5 V, rated for industrial temperature (−40°C to +85°C), and housed in an 8-lead SOIC package (SN). It supports self-timed erase/write cycles, automatic ERAL before WRAL, and power-on/off data protection - used in embedded system configuration storage and calibration data retention.

For engineers reviewing the 93C76A-I/SN datasheet, 93C76A-I/SN pinout, 93C76A-I/SN application, or 93C76A-I/SN equivalent, key selection criteria include its fixed 8-bit word size (no ORG pin), absence of PE/ORG pins, 2 ms program cycle time, 1 million endurance cycles, and compatibility with legacy Microwire controllers in space-constrained industrial control modules.

Technical Context

The 93C76A-I/SN implements a synchronous serial interface compliant with Microwire protocol, requiring CS activation followed by rising-edge clocked instruction opcodes (e.g., READ=10, WRITE=01), address (10 bits), and data (8 bits). Its internal logic enforces EWEN/EWDS write-enable sequencing and uses DO pin for both data output and Ready/Busy status polling during erase/write operations.

Unlike 'C' variants, this 'A' version lacks ORG and PE pins - memory organization is permanently fixed at 1024 × 8-bit, and write protection relies solely on software-controlled EWEN/EWDS commands. Power-down protection activates below 3.8 V, and all timing parameters (e.g., TWC = 2 ms, FCLK ≤ 3 MHz at VCC ≥ 4.5 V) are validated across −40°C to +85°C.

Key Specifications

Pinout & Package

8-lead SOIC package (SN), 150 mil width, RoHS-compliant matte tin finish. Pin 1 marked with laser dot; pin 1 ID corner indicated on top marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93C76A-I/SN, the 93LC76A-I/SN offers broader voltage flexibility at identical pinout and command structure, while the AT25080B-SSHL-T trades Microwire compatibility for SPI simplicity and wider vendor support - neither is pin- or protocol-compatible without firmware adaptation.

Availability

93C76A-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, motor control configuration, and medical device settings requiring stable component supply and long-term obsolescence management.

Supply support for 93C76A-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 components, and nonvolatile memory solutions, headquartered in Chandler, Arizona.

The 93C76A-I/SN belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, space-constrained industrial and automotive subsystems requiring reliable, low-pin-count nonvolatile storage.

FAQ

What is the memory organization of the 93C76A-I/SN?

The 93C76A-I/SN has a fixed 1024 × 8-bit organization - it is an 'A' variant, meaning no ORG pin is present and word size cannot be reconfigured. This differs from 'B' (16-bit) and 'C' (pin-selectable) versions. All addressing and data transfers use 8-bit words, simplifying host firmware implementation and eliminating external logic for mode selection.

Does the 93C76A-I/SN have a Program Enable (PE) pin?

No, the 93C76A-I/SN does not include a Program Enable (PE) pin. PE is only present on 'C' variants (e.g., 93C76C). Write protection for the 93C76A-I/SN is implemented exclusively through software commands: EWEN (Erase/Write Enable) must precede any ERASE or WRITE operation, and EWDS (Erase/Write Disable) locks the array afterward. This eliminates external pin routing but requires strict firmware discipline.

What is the maximum clock frequency supported by the 93C76A-I/SN?

The 93C76A-I/SN supports a maximum clock frequency of 3 MHz when VCC is between 4.5 V and 5.5 V. At lower voltages (not applicable here, as 93C76A requires ≥4.5 V), the limit reduces to 2 MHz (2.5–4.5 V) or 1 MHz (1.8–2.5 V). For the 93C76A-I/SN, design must ensure CLK period ≥333 ns (high + low) and meet all AC timing specs including TCKH ≥200 ns and TCKL ≥100 ns.

How does the Ready/Busy status work on the 93C76A-I/SN?

During erase or write operations, the DO pin of the 93C76A-I/SN serves as a Ready/Busy indicator: DO = low indicates ongoing programming, and DO = high signals completion. To poll status, CS must be brought high for ≥250 ns after TCSL, then sampled on CLK edges. After completion, issuing a Start bit followed by CS low clears the status flag. No external interrupt is provided - polling is mandatory.

Is the 93C76A-I/SN RoHS compliant and lead-free?

Yes, the 93C76A-I/SN is RoHS compliant and features a Pb-free matte tin (Sn) finish on its 8-lead SOIC (SN) package, as confirmed in the device selection table and packaging section of DS21796M. The part meets JEDEC J-STD-609A Class 1 marking requirements, and the "e3" designation appears in package drawings. No lead content is present in solderable terminations or die attach.