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Microchip Technology 93LC66CT-I/MS
- Part No.:
- 93LC66CT-I/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
93LC66CT-I/MS.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,492
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Product details
Overview
93LC66CT-I/MS from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 256 × 16-bit organization (dedicated x16), and industrial temperature range (–40°C to +85°C). It operates from 2.5V to 5.5V, supports self-timed erase/write cycles, and features Ready/Busy status signaling via DO pin - used in embedded system configuration storage and calibration data retention.
For engineers reviewing the 93LC66CT-I/MS datasheet, 93LC66CT-I/MS pinout, 93LC66CT-I/MS application, or 93LC66CT-I/MS equivalent, key selection considerations include its fixed 16-bit word width (no ORG pin), MSOP-8 package footprint, 6 ms program cycle time, and compatibility with legacy Microwire controllers requiring deterministic timing and hardware write protection.
Technical Context
The 93LC66CT-I/MS implements a synchronous serial interface with CS, CLK, and DI/DO pins, using rising-edge clocking for instruction and data transfer. Its internal architecture includes an address decoder, mode decode logic, and output buffer, enabling sequential read and discrete address erase/write operations without external address latching.
It supports full memory erase (ERAL) and write-all (WRAL) commands, both requiring VCC ≥ 4.5V. Write enable/disable (EWEN/EWDS) provides hardware-level write protection, and power-on data protection ensures integrity during brown-out conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (256 × 16-bit organization) |
| VCC range | 2.5V to 5.5V - supports single-supply operation in 3.3V and 5V systems |
| Interface | Microwire-compatible 3-wire serial (CS, CLK, DI/DO) - no SPI mode or dual I/O |
| Write cycle time | 6 ms typical - defines minimum interval between successive write/erase commands |
| Data retention | >200 years at 25°C - ensures long-term calibration or configuration persistence |
| Endurance | 1,000,000 erase/write cycles - suitable for field-updatable parameter storage |
| Temp range | –40°C to +85°C (Industrial grade) - validated for extended ambient operation |
Pinout & Package
8-pin MSOP (Micro Small Outline Package), 3.0 mm × 4.9 mm body, 0.65 mm pitch, exposed pad optional (VSS or floating).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable; must be held low ≥250 ns between instructions to reset internal state |
| CLK | Serial Clock | Rising-edge synchronized timing for opcode, address, and data transfer; stoppable mid-sequence |
| DI | Data Input | Accepts Start bit, instruction opcodes, addresses, and write data; shares net with DO only with current-limiting resistor |
| DO | Data Output / Status | Outputs read data or Ready/Busy signal (low = busy); enters High-Z on CS falling edge |
| VSS | Ground | Reference return path for all signals and internal logic; connects to exposed pad if used |
| NC | No Connection | Pin 7 is unconnected internally - must be left floating or tied to VSS per layout best practice |
| VCC | Power Supply | Primary supply input; voltage detect threshold is 1.5V for POR - prevents spurious writes below safe level |
| ORG | Organization select | Not present on 93LC66T variants - this device is fixed x16; pin 6 is NC per datasheet Table 3-1 |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates need for external timing control - internal state machine manages auto-erase before write |
| Hardware write protection | EWEN/EWDS commands enforce explicit enable before programming - prevents accidental overwrites |
| Ready/Busy status on DO | Enables polling-based firmware flow control without interrupt or additional GPIO |
| Power-on/off data protection | Internal circuitry inhibits all operations when VCC drops below 1.5V - guarantees data integrity during power transitions |
| Industry-standard Microwire interface | Direct drop-in replacement for legacy 93LCxx devices - no protocol translation required in existing drivers |
Applications
| Industrial Sensor Calibration | Embedded System Configuration |
|---|---|
Use Scenario: Storing factory-calibrated sensor offset/gain coefficients in programmable logic controllers and analog front-end modules. IC Role / Device Role / Timing Role: Nonvolatile parameter storage with guaranteed 200-year retention and 1M endurance under periodic field updates. Use Value: Eliminates recalibration labor and enables traceable, version-controlled sensor characterization across product lifecycles. | Use Scenario: Holding boot-time configuration flags, network MAC addresses, and user preferences in HVAC controllers and smart meters. IC Role / Device Role / Timing Role: Serial configuration memory interfaced directly to MCU GPIO or dedicated Microwire peripheral. Use Value: Reduces BOM count by replacing parallel EEPROM or battery-backed SRAM while maintaining deterministic 6 ms write latency. |
| Medical Device Settings | Automotive Body Control Module |
Use Scenario: Retaining therapy parameters and usage logs in portable diagnostic equipment operating across wide temperature ranges. IC Role / Device Role / Timing Role: Industrial-grade EEPROM ensuring data integrity during repeated thermal cycling and low-power standby modes. Use Value: Meets IEC 60601-1 reliability requirements for patient-critical settings storage without external supervision circuitry. | Use Scenario: Storing door lock actuator profiles, mirror position presets, and lighting configuration in automotive BCMs. IC Role / Device Role / Timing Role: 16-bit word-access EEPROM supporting fast bulk reads of multi-byte configuration sets. Use Value: Enables x16 data transfers reducing bus transaction count by 50% vs. 8-bit variants - critical for real-time CAN message synchronization. |
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 | Same 256×16 organization and electrical specs, but in 8-lead SOIC package (5.0 mm × 4.0 mm) | SOIC footprint requires larger PCB area and lacks MSOP's thermal performance for high-density layouts | Select when board space allows and hand-soldering or legacy reflow profiles are used |
| AT25128B-MAHL-T | 128 Kbit SPI EEPROM, 3.3V-only, 20 MHz max clock, no ERAL/WRAL commands | Lacks Microwire compatibility and hardware write-disable sequence - requires driver rewrite | Select only if migrating to SPI infrastructure and higher density is needed; not a drop-in replacement |
Compared with 93LC66B-I/SN, the 93LC66CT-I/MS offers identical functionality in a 35% smaller footprint and improved thermal dissipation; compared with AT25128B-MAHL-T, it preserves legacy Microwire timing and command set but trades density for proven interoperability in cost-sensitive industrial designs.
Availability
93LC66CT-I/MS is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded system configuration, and medical device settings requiring stable component supply and long-term lifecycle support.
Supply support for 93LC66CT-I/MS 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 nonvolatile memory solutions, headquartered in Chandler, Arizona.
The 93LC66 series belongs to Microchip's legacy Microwire EEPROM product line, designed specifically for cost-sensitive, low-power embedded systems requiring simple, deterministic serial memory with robust data retention and hardware write protection.
FAQ
What is the memory organization of the 93LC66CT-I/MS?
The 93LC66CT-I/MS has a fixed 256 × 16-bit organization - meaning it stores 256 words of 16 bits each, totaling 4 Kbit. Unlike 'C' variants, it does not have an ORG pin; the 'T' suffix denotes this dedicated x16 configuration. This eliminates external logic for word-size selection and simplifies interface design in systems requiring 16-bit parameter storage.
Does the 93LC66CT-I/MS require an external pull-up resistor on the DO pin?
No, the 93LC66CT-I/MS does not require an external pull-up on DO. The DO pin actively drives high or low during read or status polling and enters High-Z when CS is low or during idle states. However, if DI and DO are shorted (shared bus), a current-limiting resistor (typically 1–10 kΩ) is mandatory to prevent bus conflict during the dummy-zero phase of read operations.
What is the minimum VCC required for reliable operation of the 93LC66CT-I/MS?
The 93LC66CT-I/MS requires VCC ≥ 2.5V for guaranteed operation across its full industrial temperature range (–40°C to +85°C). Its power-on reset circuit activates below 1.5V, disabling all commands to prevent corruption. Operation below 2.5V is not characterized and may result in unpredictable behavior or incomplete write cycles.
Can the 93LC66CT-I/MS be used in automotive applications?
The 93LC66CT-I/MS is rated for Industrial temperature (–40°C to +85°C), not Automotive (–40°C to +125°C). For automotive use, Microchip specifies the 93LC66B-E/MS variant - identical functionality but qualified to AEC-Q100 Grade 3. Using the 93LC66CT-I/MS in under-hood environments risks parametric failure outside its validated thermal envelope.
How does write protection work on the 93LC66CT-I/MS?
Write protection on the 93LC66CT-I/MS is enforced via EWEN (Erase/Write Enable) and EWDS (Erase/Write Disable) commands. The device powers up in EWDS mode - all erase/write operations are blocked until EWEN is issued. After any write, issuing EWDS restores protection. This hardware-level scheme prevents accidental overwrites without relying on software flags or voltage supervisors.
93LC66CT-I/MS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not 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-MSOP
93LC66CT-I/MS FAQ
1.How can I place an order for 93LC66CT-I/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66CT-I/MS 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/MS reliable?
The price and inventory of 93LC66CT-I/MS 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/MS is usually 5 days.
3.What payment methods are accepted for 93LC66CT-I/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66CT-I/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66CT-I/MS?
93LC66CT-I/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66CT-I/MS 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/MS?
For technical support, including 93LC66CT-I/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66CT-I/MS requirements.
6.How does Aetrix verify that 93LC66CT-I/MS is sourced from the original manufacturer or authorized distributors?
All 93LC66CT-I/MS 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/MS meets industry standards.
7.What is the process for return or replacement of 93LC66CT-I/MS?
All 93LC66CT-I/MS units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66CT-I/MS, 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/MS part is unused and in its original packaging.
Return procedure for 93LC66CT-I/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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