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Microchip Technology 93LC66CT-I/SN
- Part No.:
- 93LC66CT-I/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93LC66CT-I/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,822
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Product details
Overview
93LC66CT-I/SN from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, operating across 2.5–5.5 V supply and supporting Industrial temperature range (−40°C to +85°C). It features Microwire-compatible 3-wire serial interface (CS/CLK/DI/DO), self-timed erase/write cycles (6 ms typical), and power-on/off data protection - deployed in embedded system configuration storage, sensor calibration memory, and industrial controller parameter retention.
For engineers reviewing the 93LC66CT-I/SN datasheet, 93LC66CT-I/SN pinout, 93LC66CT-I/SN application, or 93LC66CT-I/SN equivalent, key selection criteria include VCC range compatibility (2.5–5.5 V), 8-bit x512 organization (no ORG pin), SOIC-8 package footprint, 1M endurance cycles, and Ready/Busy status via DO pin during write operations.
Technical Context
This device implements a synchronous serial Microwire interface with start-bit detection, opcode-driven command set (READ/WRITE/ERASE/ERAL/WRAL/EWEN/EWDS), and internal auto-erase-before-write logic. It uses CMOS technology for low-power operation and includes on-chip voltage detection (VPOR = 1.5 V) for automatic write inhibition below safe VCC.
Memory access is controlled by CS-active-high selection, rising-edge clocked data transfer, and dedicated DI/DO lines with high-impedance output control. The ORG pin is NC (no connection) on this 'A'-version part, fixing 8-bit word width and eliminating external configuration logic required for 'C' variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit organization) |
| VCC range | 2.5 V to 5.5 V - supports single-supply operation in 3.3 V and 5 V systems |
| Endurance | 1,000,000 erase/write cycles - enables long-term field reprogramming in maintenance-critical applications |
| Data retention | 200 years at +25°C - ensures nonvolatile storage integrity over product lifetime without refresh |
| Write cycle time | 6 ms max - defines minimum interval between successive write commands |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - requires no additional protocol translation in legacy MCU designs |
| Temp range | −40°C to +85°C (Industrial grade) - qualified for use in factory automation and outdoor electronics |
Pinout & Package
8-pin SOIC (SN) package with standard 150-mil body width and Pb-free Matte Tin finish. Pin 1 marked by laser dot; pin 1 ID corner located at top-left when notch faces up.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable signal; must be held low ≥250 ns between instructions to reset internal state |
| CLK | Serial Clock | Rising-edge synchronized I/O timing; clock can pause mid-transfer without corruption |
| DI | Data Input | Accepts start bit, opcodes, addresses, and write data; not internally pulled |
| DO | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); enters High-Z on CS falling edge |
| VSS | Ground | Reference return path for all digital and analog functions |
| NC | No Connection | Pin 7 is unconnected internally - must be left floating or tied to GND per layout best practice |
| VCC | Power Supply | Primary supply input; internal POR circuit disables writes below 1.5 V |
| ORG | Organization Select | No internal connection on 93LC66A-series - fixed 8-bit mode; unused pin |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates need for external timing control or software delay loops - simplifies firmware integration |
| Automatic ERAL before WRAL | Ensures full-array write reliability without requiring separate erase command in bootloaders |
| Ready/Busy status on DO | Enables polling-based write completion detection without interrupt or timer overhead |
| Power-on/off data protection | Hardware-enforced write inhibit below VPOR threshold prevents corruption during brown-out events |
| 1,000,000 endurance cycles | Supports frequent field updates (e.g., logging, calibration, firmware patching) over 10+ years of operation |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Memory |
|---|---|
Use Scenario: Storing I/O mapping, PID tuning parameters, and alarm thresholds in programmable logic controllers deployed in harsh factory environments. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed infrequently during commissioning or maintenance; retains values across AC power loss. Use Value: Eliminates battery-backed SRAM and associated failure modes; withstands 85°C ambient and repeated firmware updates. | Use Scenario: Holding sensor offset/gain coefficients and regulatory compliance settings in portable diagnostic equipment requiring traceable calibration history. IC Role / Device Role / Timing Role: Secure, tamper-resistant parameter store written once per calibration event and read at power-up. Use Value: 200-year data retention meets FDA long-term recordkeeping requirements; 1M endurance supports recalibration every 3 months for 27 years. |
| Automotive Body Control Module Settings | Smart Energy Meter Tariff Tables |
Use Scenario: Saving user preferences (window position, mirror angle, lighting profiles) in automotive BCMs where EEPROM must operate across −40°C to +85°C. IC Role / Device Role / Timing Role: Low-power serial memory interfaced directly to 8-bit microcontroller with Microwire peripheral. Use Value: SOIC-8 footprint matches legacy designs; 2.5 V min VCC enables operation during cold-crank battery dips. | Use Scenario: Storing time-of-use tariff schedules and billing history in utility-grade electricity meters with 15+ year field life. IC Role / Device Role / Timing Role: Field-updatable lookup table accessed during real-time energy accumulation calculations. Use Value: 6 ms write time allows tariff updates during meter idle periods; RoHS-compliant Pb-free finish meets global environmental mandates. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66B-I/SN | 256 × 16-bit organization; same VCC/temp range; ORG pin NC | Requires 16-bit data path alignment; incompatible with existing 8-bit firmware interfaces | Select only if system architecture mandates 16-bit word access and memory map permits halving address space |
| AT25040B-MAHL-T | SPI interface (4-wire), 512 × 8-bit, 1.8–5.5 V, 2 MHz max clock, 5 ms write time | Requires SPI peripheral instead of Microwire; different instruction set and status reporting | Choose when migrating to SPI-based platforms or needing higher clock frequency than Microwire's 3 MHz limit |
Compared with 93LC66B-I/SN, the 93LC66CT-I/SN provides native 8-bit word width without address remapping; versus AT25040B-MAHL-T, it maintains legacy Microwire compatibility but trades lower maximum clock rate for simpler timing constraints and proven integration in cost-sensitive 8-bit MCU systems.
Availability
93LC66CT-I/SN is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, and automotive body electronics requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for 93LC66CT-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 devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93LC66 series belongs to Microchip's legacy serial EEPROM product line, designed specifically for low-power, pin-efficient nonvolatile storage in resource-constrained embedded systems using Microwire or compatible interfaces.
FAQ
What is the memory organization of the 93LC66CT-I/SN?
The 93LC66CT-I/SN is an 'A'-version device with fixed 512 × 8-bit organization. The ORG pin is not connected internally, so no external configuration is needed - it operates exclusively in 8-bit mode, unlike 'C' variants that require ORG pin control for x8/x16 selection.
Does the 93LC66CT-I/SN require an Erase/Write Enable (EWEN) command before programming?
Yes, the 93LC66CT-I/SN powers up in Erase/Write Disable (EWDS) mode. An EWEN instruction must be issued before any ERASE or WRITE operation. After successful programming, executing EWDS restores write protection - a critical step to prevent accidental overwrites during normal operation.
What is the function of the DO pin on the 93LC66CT-I/SN during write operations?
During write operations, the DO pin on the 93LC66CT-I/SN serves as a Ready/Busy status indicator: logic low means programming is in progress, and logic high indicates completion. This status is valid only after CS is brought high for ≥250 ns following the write command - enabling reliable polling without interrupts.
Can the 93LC66CT-I/SN be used in 1.8 V systems?
No, the 93LC66CT-I/SN has a minimum VCC of 2.5 V and is not rated for 1.8 V operation. For 1.8 V systems, consider the 93AA66A-I/SN variant, which supports 1.8–5.5 V and shares identical pinout and instruction set but includes different voltage detection and timing specifications.
Is the 93LC66CT-I/SN RoHS compliant and Pb-free?
Yes, the 93LC66CT-I/SN is RoHS compliant and features a Pb-free Matte Tin (Sn) finish on its SOIC-8 package, meeting JEDEC J-STD-609 Category 1 requirements. The marking "3L66AT" on the top surface confirms Pb-free status per Microchip's standard package coding.
93LC66CT-I/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, 256 x 16
- Memory Interface:
- Microwire
- Clock Frequency:
- 3 MHz
- Write Cycle Time - Word, Page:
- 6ms
- Access Time:
- -
- Voltage - Supply:
- 2.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
93LC66CT-I/SN FAQ
1.How can I place an order for 93LC66CT-I/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66CT-I/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 93LC66CT-I/SN reliable?
The price and inventory of 93LC66CT-I/SN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66CT-I/SN is usually 5 days.
3.What payment methods are accepted for 93LC66CT-I/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66CT-I/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66CT-I/SN?
93LC66CT-I/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66CT-I/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 93LC66CT-I/SN?
For technical support, including 93LC66CT-I/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66CT-I/SN requirements.
6.How does Aetrix verify that 93LC66CT-I/SN is sourced from the original manufacturer or authorized distributors?
All 93LC66CT-I/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 93LC66CT-I/SN meets industry standards.
7.What is the process for return or replacement of 93LC66CT-I/SN?
All 93LC66CT-I/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66CT-I/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 93LC66CT-I/SN part is unused and in its original packaging.
Return procedure for 93LC66CT-I/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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