Microchip Technology AT93C66-10PC-2.5

Overview

AT93C66-10PC-2.5 from Microchip Technology (formerly Atmel) is a 4-kbit serial EEPROM with 3-wire interface, supporting 512 × 8 or 256 × 16 organization selectable via ORG pin, operating at V_CC = 2.5V to 5.5V, and featuring 10 ms max self-timed write cycle. It delivers high reliability with 1 million write cycles and 100-year data retention, used in industrial control panels for nonvolatile configuration storage.

For engineers reviewing the AT93C66-10PC-2.5 datasheet, AT93C66-10PC-2.5 pinout, AT93C66-10PC-2.5 application, or AT93C66-10PC-2.5 equivalent, this page provides verified electrical specs, package mapping, functional timing behavior, and real-world use context for low-voltage embedded systems requiring robust serial memory.

Technical Context

The AT93C66-10PC-2.5 implements a synchronous 3-wire serial interface (CS, SK, DI/DO) with instruction-based command set including READ, WRITE, ERASE, EWEN, and WRAL/ERAL. Its dual-word-width architecture (8-bit or 16-bit mode) is controlled by the ORG pin state, enabling flexible memory mapping without external logic.

Write operations are self-timed and require prior EWEN activation; READY/BUSY status is returned on DO when CS is raised during t_WP. The device supports 500 kHz maximum clock frequency at 2.5V, with input leakage ≤1.0 µA and ESD protection >4000V HBM - critical for noise-prone industrial environments.

Key Specifications

Pinout & Package

AT93C66-10PC-2.5 uses an 8-pin PDIP (package code 8P3) with 0.300" body width and standard through-hole mounting. Pin 1 is marked with a notch or dot; orientation follows JEDEC MS-001 BA standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95640-WMN6TP and 25LC040A-I/P, AT93C66-10PC-2.5 offers unique ORG-pin configurability and 3-wire simplicity at the cost of lower clock speed - optimal for GPIO-limited MCUs where pin count and layout density outweigh raw throughput needs.

Availability

AT93C66-10PC-2.5 is available at Aetrix Electronics and suitable for industrial control panels, medical device calibration storage, automotive body modules, smart energy meters, and programmable power supplies requiring stable component supply across extended temperature and voltage ranges.

Supply support for AT93C66-10PC-2.5 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 acquired Atmel in 2016 and maintains full product support, documentation, and manufacturing continuity for the AT93C family of serial EEPROMs.

The AT93C66 belongs to Microchip's legacy serial EEPROM product line, designed specifically for cost-sensitive, low-pin-count embedded systems needing reliable nonvolatile storage with minimal MCU interface overhead.

FAQ

What is the memory organization of AT93C66-10PC-2.5?

The AT93C66-10PC-2.5 provides 4096 bits organized as either 512 × 8 or 256 × 16, selected by the ORG pin: tied to V_CC for 16-bit mode, grounded for 8-bit mode. An internal ~1 MΩ pull-up defaults to x16 if ORG is left unconnected. This dual-mode capability allows flexible data alignment without external logic, and is fully supported in the AT93C66-10PC-2.5 datasheet revision 0172L.

Does AT93C66-10PC-2.5 support 2.5V-only operation?

Yes, AT93C66-10PC-2.5 is rated for V_CC = 2.5V to 5.5V operation. At 2.5V, it guarantees 500 kHz maximum clock frequency and 10 µA max standby current (ISB2), with full instruction set functionality including READ, WRITE, and EWEN. It does not support 1.8V operation - that variant is designated with "-1.8" suffix, not present in AT93C66-10PC-2.5.

How is write protection implemented in AT93C66-10PC-2.5?

AT93C66-10PC-2.5 uses instruction-level write protection: programming commands (WRITE, ERASE, WRAL, ERAL) are only accepted after an EWEN instruction is issued. The part powers up in EWDS (Erase/Write Disable) state, blocking all writes until EWEN is executed. No hardware write-protect pin exists; protection relies entirely on correct command sequencing, as defined in the AT93C66-10PC-2.5 instruction set table.

What package type does AT93C66-10PC-2.5 use?

AT93C66-10PC-2.5 uses an 8-pin PDIP (Plastic Dual Inline Package) with 0.300" body width, package code 8P3 per Atmel's ordering guide. It features through-hole mounting, standard JEDEC MS-001 BA footprint, and pin 1 identified by a notch or dot. This package is distinct from SOIC (8S1/8S2) or TSSOP (8T) variants offered in other AT93C66 ordering codes.

Can AT93C66-10PC-2.5 be used in automotive applications?

AT93C66-10PC-2.5 is rated for commercial temperature range (0°C to +70°C) and is not qualified to AEC-Q100. For automotive use, Microchip offers industrial-grade variants like AT93C66-10PI-2.5 (−40°C to +85°C) or automotive-grade versions with extended qualification. The "PC" suffix in AT93C66-10PC-2.5 explicitly denotes commercial temperature grade, limiting its deployment to non-safety-critical cabin or infotainment subsystems unless derated and validated per OEM requirements.