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Home > Products > Integrated Circuits (ICs) > Memory > Memory

Microchip Technology 93LC66AT-E/SN

Name: 93LC66AT-E/SN
Brand: Microchip Technology
SKU: 93LC66AT-E/SN
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 93LC66AT-E/SN

Manufacturer:: Microchip Technology

Category:: Memory

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: 93LC66AT-E/SN.pdf

Description:: IC EEPROM 4KBIT MICROWIRE 8SOIC

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Product details

Overview

93LC66AT-E/SN from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, Microwire-compatible 3-wire interface (CS/CLK/DI/DO), and automotive-grade temperature range (−40°C to +125°C). It features self-timed erase/write cycles, automatic ERAL before WRAL, power-on/off data protection, and 1,000,000 endurance cycles - used for configuration storage in engine control units and infotainment systems.

For engineers reviewing the 93LC66AT-E/SN datasheet, 93LC66AT-E/SN pinout, 93LC66AT-E/SN application, or 93LC66AT-E/SN equivalent, key selection criteria include V_CC range (2.5–5.5 V), automotive qualification (E-temp), SOIC-8 package compatibility, and absence of ORG pin (fixed x8 mode).

Technical Context

The 93LC66AT-E/SN implements a synchronous serial Microwire protocol with start-bit detection, opcode-driven instruction set (READ/WRITE/ERASE/ERAL/WRAL/EWEN/EWDS), and Ready/Busy status signaled via DO pin during programming. It requires no external timing components and supports sequential read without address retransmission.

Its internal architecture includes an address decoder, data register, mode decode logic, and output buffer, with all operations controlled by CS-active-high enable and CLK-synchronized bit transfers on rising edges. The device powers up in EWDS mode and requires explicit EWEN before any write/erase command.

Key Specifications

Parameter	Value and Actual Design Meaning
Memory size	4 Kbit (512 × 8-bit), fixed x8 organization - no ORG pin; eliminates external configuration logic.
V_CC range	2.5 V to 5.5 V - supports wide supply rails including 3.3 V and 5 V systems without level shifting.
Endurance	1,000,000 erase/write cycles - enables frequent calibration or logging updates in automotive ECUs.
Data retention	>200 years at 25°C - ensures long-term reliability across vehicle lifetime without refresh.
Write cycle time	6 ms typical (T_WC) - defines minimum interval between successive WRITE commands.
Operating temp	−40°C to +125°C (Automotive E-grade) - qualified for under-hood and transmission control applications.
Interface	3-wire Microwire (CS/CLK/DI/DO) - minimal GPIO usage; compatible with legacy microcontrollers lacking SPI hardware.

Pinout & Package

8-pin SOIC (SN) package with standard pinout: Pin 1 = CS, Pin 2 = CLK, Pin 3 = DI, Pin 4 = DO, Pin 5 = VSS, Pin 6 = NC (no internal connection), Pin 7 = NC, Pin 8 = VCC. No ORG pin - confirms fixed 8-bit organization per device family specification.

Pin/Terminal	Circuit Role	Design Meaning
CS	Chip Select	Active-high enable; must be held ≥250 ns low between instructions; initiates self-timed write on falling edge (93LC series).
CLK	Serial Clock	Rising-edge synchronized I/O; clock can pause mid-transfer; no clock required during auto-erase/write cycle.
DI	Data Input	Accepts start bit, opcode, address, and data; high impedance when not selected; requires pull-down if shared with DO.
DO	Data Output / Status	Outputs read data or Ready/Busy (low = busy); enters High-Z on CS falling edge; status valid only after T_CSL.
VSS	Ground	Reference for all I/O and internal logic; must be connected before VCC during power-up sequencing.
VCC	Power Supply	2.5–5.5 V; POR threshold at 1.5 V; voltage detect disables all operations below threshold.
Pins 6 & 7	No Connection	Internally unconnected; may be left floating or tied to VSS/VCC per layout best practice; no functional impact.

Key Features

Feature	Design Value
Self-timed erase/write	Eliminates need for external timing circuitry or software delay loops; cycle completion signaled via DO pin.
Automatic ERAL before WRAL	Guarantees full-array erase prior to bulk write, preventing partial-data corruption during firmware update sequences.
Power-on/off data protection	Hardware-level lockout below V_CC = 1.5 V prevents inadvertent writes during brown-out or power ramp conditions.
EWEN/EWDS security	Explicit enable/disable commands prevent accidental overwrites; device powers up in locked (EWDS) state.
Ready/Busy polling	DO pin provides real-time status during programming - enables non-blocking host firmware operation.

Applications

Engine Control Unit (ECU)	Infotainment System
Use Scenario: Storing trim values for fuel injection timing and knock sensor calibration across vehicle lifetime. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed during boot and runtime recalibration. Use Value: 1M endurance and >200-year retention ensure calibration integrity over 15+ year service life without maintenance.	Use Scenario: Holding user preferences (volume, equalizer, display brightness) and radio station presets. IC Role / Device Role / Timing Role: Low-power serial EEPROM interfaced to MCU via GPIO-banged Microwire. Use Value: 2.5 V minimum V_CC allows direct connection to 3.3 V infotainment SoC rails without regulator overhead.
Advanced Driver Assistance (ADAS)	Body Control Module (BCM)
Use Scenario: Saving camera alignment offsets and radar calibration coefficients after factory setup or service reset. IC Role / Device Role / Timing Role: Automotive-qualified persistent memory for safety-critical parameter storage. Use Value: −40°C to +125°C operation meets AEC-Q100 Grade 1 requirements for under-hood ADAS sensors.	Use Scenario: Retaining door lock configuration, window position memory, and lighting profiles across ignition cycles. IC Role / Device Role / Timing Role: Serial configuration storage accessed during BCM initialization sequence. Use Value: Microwire interface reduces MCU pin count vs. I²C/SPI, simplifying cost-sensitive body electronics designs.

Engine Control Unit (ECU)

Infotainment System

Use Scenario: Storing trim values for fuel injection timing and knock sensor calibration across vehicle lifetime.

IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed during boot and runtime recalibration.

Use Value: 1M endurance and >200-year retention ensure calibration integrity over 15+ year service life without maintenance.

Use Scenario: Holding user preferences (volume, equalizer, display brightness) and radio station presets.

IC Role / Device Role / Timing Role: Low-power serial EEPROM interfaced to MCU via GPIO-banged Microwire.

Use Value: 2.5 V minimum V_CC allows direct connection to 3.3 V infotainment SoC rails without regulator overhead.

Advanced Driver Assistance (ADAS)

Body Control Module (BCM)

Use Scenario: Saving camera alignment offsets and radar calibration coefficients after factory setup or service reset.

IC Role / Device Role / Timing Role: Automotive-qualified persistent memory for safety-critical parameter storage.

Use Value: −40°C to +125°C operation meets AEC-Q100 Grade 1 requirements for under-hood ADAS sensors.

Use Scenario: Retaining door lock configuration, window position memory, and lighting profiles across ignition cycles.

IC Role / Device Role / Timing Role: Serial configuration storage accessed during BCM initialization sequence.

Use Value: Microwire interface reduces MCU pin count vs. I²C/SPI, simplifying cost-sensitive body electronics designs.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
93LC66B-E/SN	16-bit organization (256 × 16), same V_CC/temp/package - requires ORG pin tied to VSS for x8 emulation.	Not pin-compatible: ORG pin occupies Pin 6 (NC on 93LC66AT-E/SN); requires PCB redesign.	Select only if 16-bit word access is needed and layout allows ORG routing.
AT25DF041A-SHN-T	4 Mbit SPI NOR Flash, 2.7–3.6 V only, no built-in erase/write disable - lacks EWEN/EWDS security.	Higher density but incompatible interface (SPI vs. Microwire); no automotive temp rating (−40°C to +85°C only).	Use only for non-automotive, higher-density applications where security and E-temp are not required.

Compared with 93LC66B-E/SN, the 93LC66AT-E/SN offers true pin compatibility and eliminates ORG routing complexity; compared with AT25DF041A-SHN-T, it delivers automotive qualification, lower V_CC support, and hardware write protection - critical for safety-relevant configuration storage.

Availability

93LC66AT-E/SN is available at Aetrix Electronics and suitable for automotive control units, infotainment systems, and ADAS modules requiring stable component supply with guaranteed lifecycle continuity and traceable sourcing.

Supply support for 93LC66AT-E/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 microcontroller, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 93LCxx family was designed specifically for cost-sensitive, low-power serial EEPROM applications in automotive, industrial, and consumer systems - emphasizing robustness, ease of integration, and long-term data integrity.

FAQ

What is the memory organization of the 93LC66AT-E/SN?

The 93LC66AT-E/SN has a fixed 512 × 8-bit (4 Kbit) organization. It belongs to the 'A' variant of the 93LC66 family and does not include an ORG pin - confirming dedicated 8-bit communication without external configuration. This differs from 'B' (256 × 16-bit) and 'C' (pin-selectable) variants.

Does the 93LC66AT-E/SN support automotive temperature range?

Yes, the 93LC66AT-E/SN is rated for −40°C to +125°C (Automotive E-grade), as indicated by the 'E' suffix in the part number. This qualification meets AEC-Q100 stress test requirements for under-hood and transmission control applications where thermal stability is critical.

What package type is used for the 93LC66AT-E/SN?

The 93LC66AT-E/SN uses an 8-pin SOIC package denoted by the '/SN' suffix. Its pinout matches industry-standard SOIC-8: CS (1), CLK (2), DI (3), DO (4), VSS (5), NC (6), NC (7), VCC (8). No ORG pin is present, consistent with 'A' variant specifications.

How does write protection work on the 93LC66AT-E/SN?

The 93LC66AT-E/SN implements hardware-based write protection via EWEN (Erase/Write Enable) and EWDS (Erase/Write Disable) instructions. It powers up in EWDS mode, blocking all erase/write operations until EWEN is issued. After each write, executing EWDS restores protection - preventing accidental overwrites during system noise or brown-out events.

What is the maximum clock frequency supported by the 93LC66AT-E/SN?

The 93LC66AT-E/SN supports up to 3 MHz clock frequency when V_CC ≥ 4.5 V, 2 MHz at 2.5 V ≤ V_CC < 4.5 V, and 1 MHz at 1.8 V ≤ V_CC < 2.5 V. Since its V_CC range starts at 2.5 V, the practical maximum is 2 MHz for full automotive operating range compliance.

93LC66AT-E/SN Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Active

Programmable:: Verified

Memory Type:: Non-Volatile

Memory Format:: EEPROM

Technology:: EEPROM

Memory Size:: 4Kbit

Memory Organization:: 512 x 8

Memory Interface:: Microwire

Clock Frequency:: 2 MHz

Write Cycle Time - Word, Page:: 6ms

Access Time:: -

Voltage - Supply:: 2.5V ~ 5.5V

Operating Temperature:: -40°C ~ 125°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

93LC66AT-E/SN FAQ

1.How can I place an order for 93LC66AT-E/SN through Aetrix?

Please submit a Request for Quotation (RFQ) for 93LC66AT-E/SN on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 93LC66AT-E/SN reliable?

The price and inventory of 93LC66AT-E/SN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66AT-E/SN is usually 5 days.

3.What payment methods are accepted for 93LC66AT-E/SN?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66AT-E/SN transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 93LC66AT-E/SN?

93LC66AT-E/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 93LC66AT-E/SN order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 93LC66AT-E/SN?

For technical support, including 93LC66AT-E/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66AT-E/SN requirements.

6.How does Aetrix verify that 93LC66AT-E/SN is sourced from the original manufacturer or authorized distributors?

All 93LC66AT-E/SN products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 93LC66AT-E/SN meets industry standards.

7.What is the process for return or replacement of 93LC66AT-E/SN?

All 93LC66AT-E/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66AT-E/SN, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 93LC66AT-E/SN part is unused and in its original packaging.

Return procedure for 93LC66AT-E/SN:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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