Microchip Technology 93LC66CT-E/MNY

Overview

93LC66CT-E/MNY from Microchip Technology Inc. is a 4 Kbit (512 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, operating from 2.5 V to 5.5 V, rated for automotive temperature range (−40°C to +125°C), and featuring self-timed erase/write cycles, automatic ERAL/WRAL support, and Ready/Busy status signaling via DO pin - used in automotive body control modules for storing calibration data and configuration settings.

For engineers reviewing the 93LC66CT-E/MNY datasheet, 93LC66CT-E/MNY pinout, 93LC66CT-E/MNY application, or 93LC66CT-E/MNY equivalent, key selection criteria include its automotive-grade temperature rating, 512 × 8-bit fixed organization (no ORG pin), 1 million erase/write endurance, 200-year data retention, and compatibility with legacy Microwire host controllers requiring minimal firmware changes.

Technical Context

This device implements a synchronous serial interface with CS, CLK, and DI/DO pins, supporting opcode-driven command execution (READ, WRITE, ERASE, ERAL, WRAL, EWEN/EWDS). It uses internal auto-erase-before-write logic and provides hardware-level power-on/off data protection without external circuitry.

Unlike C-variant parts, the 93LC66T-E/MNY has no ORG pin (fixed 8-bit word size), eliminating external configuration logic. Its timing is voltage-dependent: max clock frequency is 2 MHz at VCC = 2.5 V, rising to 3 MHz at VCC ≥ 4.5 V, with write cycle time fixed at 6 ms across its operating voltage range.

Key Specifications

Pinout & Package

93LC66CT-E/MNY is packaged in an 8-lead 2×3 mm DFN (MNY) with exposed pad, pin-compatible with SOIC-8 and TSSOP-8 footprints but offering improved thermal performance and board space savings.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC66B-I/MNY, the 93LC66CT-E/MNY offers automotive qualification and fixed 8-bit access - critical for cost-sensitive body electronics. Versus AT25DF041A-MAHN-T, it delivers deterministic 6 ms writes, hardware data protection, and direct Microwire drop-in compatibility without driver porting.

Availability

93LC66CT-E/MNY is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor systems, and medical device design requiring stable component supply, long-term lifecycle assurance, and AEC-Q200-aligned reliability.

Supply support for 93LC66CT-E/MNY 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 memory solutions, headquartered in Chandler, Arizona, serving automotive, industrial, and consumer markets globally.

The 93LC66 series belongs to Microchip's legacy Microwire-compatible EEPROM product line, designed specifically for cost-sensitive, low-pin-count embedded systems needing robust nonvolatile storage with minimal software overhead.

FAQ

What is the memory organization of the 93LC66CT-E/MNY?

The 93LC66CT-E/MNY is a fixed 512 × 8-bit (4 Kbit) EEPROM with no ORG pin - unlike C-variants, it does not support 16-bit mode. This eliminates external configuration logic and guarantees byte-aligned data access, making it ideal for MCUs without native 16-bit serial peripheral support. The 93LC66CT-E/MNY uses dedicated 8-bit communication per the device selection table.

Does the 93LC66CT-E/MNY require an external pull-up on the DO pin?

No, the 93LC66CT-E/MNY does not require an external pull-up on the DO pin. Its DO output is actively driven high or low during read/status operations and enters High-Z when CS is low or during standby. A pull-up may cause bus contention if DI and DO are shorted; Microchip recommends a series resistor if bidirectional bus sharing is implemented. The 93LC66CT-E/MNY specification confirms DO operates as a true tri-state output.

How is write protection implemented on the 93LC66CT-E/MNY?

Write protection on the 93LC66CT-E/MNY is implemented via hardware-enabled Erase/Write Disable (EWDS) mode: the device powers up in EWDS state, blocking all erase/write commands until an explicit EWEN instruction is issued. After each write, executing EWDS restores protection. This dual-layer scheme - combined with VCC-based POR lockout below 1.5 V - prevents accidental corruption during power transients or firmware errors. The 93LC66CT-E/MNY datasheet mandates EWDS post-write for safety-critical use.

Can the 93LC66CT-E/MNY be used with a 3.3 V microcontroller without level shifting?

Yes, the 93LC66CT-E/MNY operates natively from 2.5 V to 5.5 V, making it fully compatible with 3.3 V microcontrollers without level shifting. Its VIH1 threshold is 2.0 V (min) at VCC ≥ 2.7 V, and VOL1 is guaranteed ≤ 0.4 V at IOL = 2.1 mA - well within 3.3 V logic margins. All timing parameters in Table 1-2 are validated down to 2.5 V, confirming robust interoperability with standard 3.3 V IO interfaces. The 93LC66CT-E/MNY is widely deployed in 3.3 V automotive clusters.

What package type does the 93LC66CT-E/MNY use, and is it RoHS compliant?

The 93LC66CT-E/MNY uses an 8-lead 2×3 mm DFN package with exposed thermal pad (MNY suffix), Pb-free with matte tin finish, and fully RoHS compliant per EU Directive 2011/65/EU. Package drawings confirm compliance with JEDEC MO-229, and the exposed pad may be connected to VSS for enhanced thermal dissipation - critical for under-hood automotive applications. The 93LC66CT-E/MNY marking "L66CT" appears on the top surface per DS21795E-page 14.