Microchip Technology 93C76C-I/ST

Overview

93C76C-I/ST from Microchip Technology Inc. is an 8Kbit, 4.5–5.5V serial EEPROM with programmable 8-/16-bit word organization via the ORG pin and hardware write-protection via the PE pin. It supports Microwire-compatible 3-wire serial interface (CS/CLK/DI/DO), delivers 1M erase/write cycles, >200-year data retention, and operates across –40°C to +85°C industrial temperature range in 8-lead TSSOP package.

For engineers reviewing the 93C76C-I/ST datasheet, 93C76C-I/ST pinout, 93C76C-I/ST application, or 93C76C-I/ST equivalent, key selection considerations include VCC voltage dependency of ERAL/WRAL timing (≥4.5V required), ORG/PE pin logic-level configuration for memory width and write-enable control, Ready/Busy polling via DO, and compatibility with legacy Microwire controllers requiring self-timed erase/write cycles.

Technical Context

The 93C76C-I/ST implements a synchronous serial interface with Start-bit detection, opcode-driven command set (READ/EWEN/EWDS/ERASE/ERAL/WRITE/WRAL), and dual-mode memory organization selected by external logic on ORG. Its internal architecture includes address decoder, mode decode logic, clock register, and output buffer with High-Z DO during standby.

Write protection is enforced at both system and hardware levels: power-on default is EWDS mode (all programming disabled), requiring explicit EWEN before any ERASE or WRITE; additionally, the PE pin must be held high to enable programming - if PE = low, all write operations are inhibited regardless of EWEN state. VCC brown-out detection disables all operations below 3.8V.

Key Specifications

Pinout & Package

8-lead TSSOP (ST) package with exposed pad optional; pin 1 marked by laser dot. Pin functions are electrically identical to SOIC/PDIP variants but with reduced footprint and thermal profile.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC76C-I/ST and 93AA76C-I/ST, the 93C76C-I/ST offers highest noise immunity and write margin at 5 V systems but lacks flexibility in low-voltage operation - making it optimal for industrial 5 V rails where robustness outweighs voltage scalability.

Availability

93C76C-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive body control modules, and medical device configuration requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for 93C76C-I/ST 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, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 93C76C-I/ST belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-pin-count embedded systems requiring reliable nonvolatile storage with minimal external components and Microwire protocol compatibility.

FAQ

What is the minimum VCC required for ERAL and WRAL operations in the 93C76C-I/ST?

The 93C76C-I/ST requires VCC ≥ 4.5 V for proper execution of ERAL (Erase All) and WRAL (Write All) commands. Below this threshold, these operations will not initiate or complete reliably. This is explicitly defined in the Electrical Characteristics table (VPOR = 3.8 V, but ERAL/WRAL timing spec A14/A15 applies only at 4.5–5.5 V). Always verify VCC stability during bulk erase/write sequences.

How does the PE pin affect programming behavior in the 93C76C-I/ST?

The PE (Program Enable) pin on the 93C76C-I/ST must be driven high to allow any erase or write operation - even after successful EWEN execution. If PE is low, all programming is permanently inhibited regardless of software state. This hardware lock provides fail-safe protection against firmware errors or voltage transients corrupting memory contents.

Can the 93C76C-I/ST be used interchangeably with the 93C46 or 93C56 in existing designs?

Yes, the 93C76C-I/ST is functionally and electrically compatible with earlier 93C46/93C56 Microwire EEPROMs: same 8-pin TSSOP footprint, identical instruction set, timing, and pinout. However, its larger 8 Kbit capacity and added ORG/PE pins require no change to host code if ORG is fixed and PE is tied high - making it a seamless capacity upgrade.

What happens to the DO pin during a write cycle in the 93C76C-I/ST?

During an erase or write cycle, the DO pin of the 93C76C-I/ST outputs Ready/Busy status: logic low indicates programming is in progress, logic high signals completion. This status is only valid if CS is brought high after ≥250 ns low time (TCSL). After completion, DO returns to High-Z unless actively reading - enabling efficient polling without dedicated status lines.

Is the 93C76C-I/ST RoHS compliant and what finish is used on its leads?

Yes, the 93C76C-I/ST is Pb-free and RoHS compliant. Its leads use Matte Tin (Sn) finish per JEDEC standard, confirmed in the Packaging Information section. The "I" suffix denotes Industrial temperature grade (–40°C to +85°C), and "ST" specifies 8-lead TSSOP package with standard lead finish - no additional plating or special handling required.