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Microchip Technology 93C66CT-E/MS
- Part No.:
- 93C66CT-E/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
93C66CT-E/MS.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,650
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Product details
Overview
93C66CT-E/MS from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 8-bit organization, designed for nonvolatile memory storage in embedded control systems. It operates within 4.5–5.5 V supply range, supports Microwire-compatible 3-wire serial interface (CS, CLK, DI/DO), and delivers 1 million erase/write cycles with >200 years data retention. It is used in industrial sensor calibration storage and power meter configuration registers.
For engineers reviewing the 93C66CT-E/MS datasheet, 93C66CT-E/MS pinout, 93C66CT-E/MS application, or 93C66CT-E/MS equivalent, key selection criteria include its 4.5–5.5 V VCC range, MSOP-8 package, 8-bit x 512 organization, ERAL/WRAL auto-erase support, and automotive-grade −40°C to +125°C operation.
Technical Context
The 93C66CT-E/MS implements a synchronous Microwire-compatible serial interface with chip-select–gated clocking and self-timed erase/write cycles. Its internal logic requires an EWEN command before any programming and enforces VCC ≥ 4.5 V for ERAL and WRAL operations.
It features dedicated Ready/Busy status output on DO during erase/write, sequential read capability under continuous CS high, and hardware-level power-on/off data protection. The ORG pin is not present-this is an 'A'-type device with fixed 8-bit organization and NC at pin 6.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit organization) |
| VCC range | 4.5 V to 5.5 V - ensures compatibility with 5 V microcontroller I/O and prevents operation below safe programming threshold |
| Endurance | 1,000,000 erase/write cycles - supports frequent field firmware updates or runtime parameter logging |
| Data retention | >200 years at 25°C - guarantees long-term calibration data integrity without refresh |
| Operating temperature | −40°C to +125°C (Automotive E grade) - qualified for under-hood and industrial control environments |
| Interface | Microwire-compatible 3-wire serial (CS, CLK, DI/DO) - minimal GPIO usage, no address bus required |
| Write cycle time | 2 ms typical - enables fast configuration writes without blocking host MCU execution |
Pinout & Package
8-pin MSOP (Micro Small Outline Package), 3.0 mm × 3.0 mm body, 0.65 mm pitch, exposed pad optional (VSS or floating), Pb-free Matte Tin finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held low ≥250 ns between instructions; deselects device into standby mode |
| 2 (CLK) | Serial Clock | Synchronizes all data transfers; rising edge clocks in opcode/address/data; stoppable mid-sequence |
| 3 (DI) | Data Input | Accepts Start bit, instruction opcodes, addresses, and write data; shares bidirectional path with DO in some layouts |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy signal (low = busy); enters High-Z when CS low or after status read |
| 5 (VSS) | Ground | Reference return for all signals and internal circuitry; connects to exposed pad if used |
| 6 (NC) | No Connect | Pin 6 is internally unconnected - must be left floating or tied to VSS per layout best practice |
| 7 (NC) | No Connect | Second NC pin (per MSOP pinout table); no internal connection; avoid routing signals here |
| 8 (VCC) | Power Supply | 4.5–5.5 V supply input; internal POR circuit triggers at ~3.8 V; powers all logic and memory array |
Key Features
| Feature | Design Value |
|---|---|
| Auto-erase before write | Eliminates need for separate erase command - simplifies firmware and reduces write latency |
| ERAL and WRAL commands | Enables full-array erase or program in single instruction - critical for factory reset or firmware recovery |
| Ready/Busy polling via DO | Allows host MCU to avoid fixed delays - improves system responsiveness and timing predictability |
| EWEN/EWDS security lock | Prevents accidental writes by requiring explicit enable before each programming sequence - enhances field reliability |
| Pb-free & RoHS compliant | Meets global environmental compliance requirements for automotive and industrial manufacturing |
Applications
| Industrial Sensor Calibration Storage | Smart Energy Meter Configuration |
|---|---|
Use Scenario: Storing factory-trimmed sensor offset/gain coefficients and temperature compensation tables in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile configuration memory holding calibration data accessed at power-up and updated during maintenance. Use Value: Enables plug-and-play sensor replacement without manual recalibration; leverages 1M endurance for periodic field updates. | Use Scenario: Retaining tariff schedules, billing counters, and communication module settings in DIN-rail mounted electricity meters. IC Role / Device Role / Timing Role: Secure, long-life parameter store interfaced to metering SoC via Microwire to minimize pin count. Use Value: Supports 200-year data retention and automotive-grade temp range - ensures accuracy over 15+ year product lifetime. |
| Automotive Body Control Module (BCM) | Medical Diagnostic Equipment Setup |
Use Scenario: Saving user preferences (lighting profiles, mirror positions) and fault log history in vehicle BCMs operating across −40°C to +125°C. IC Role / Device Role / Timing Role: Automotive-qualified EEPROM providing robust NVM for safety-critical configuration storage. Use Value: Qualified to AEC-Q100 stress tests; ERAL/WRAL support enables secure factory reprogramming without disassembly. | Use Scenario: Storing device-specific calibration constants, regulatory compliance flags, and operator-defined test protocols in portable ultrasound units. IC Role / Device Role / Timing Role: Trusted configuration memory with tamper-resistant write-enable protocol (EWEN/EWDS). Use Value: Meets IEC 62304 software lifecycle requirements through deterministic write timing and data integrity safeguards. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93C66B-I/MS | Same 4 Kbit capacity and MSOP-8 package, but 16-bit organization (256 × 16) and Industrial (−40°C to +85°C) grade only | Requires host firmware rework for 16-bit word access; unsuitable for automotive thermal environments | Select only if system uses 16-bit data paths and operates exclusively within industrial temperature range |
| AT25DF041A-MAU-T | 4 Mbit SPI Flash (not EEPROM); sector-erase architecture; no built-in auto-erase; different command set and timing | Lacks byte-level write capability and true EEPROM endurance; requires external wear-leveling for frequent updates | Consider only for bulk code storage where rewrite frequency is low and SPI interface is already present |
Compared with 93C66B-I/MS, the 93C66CT-E/MS offers automotive qualification and native 8-bit access, eliminating firmware conversion overhead; versus AT25DF041A-MAU-T, it provides guaranteed 1M-cycle endurance and true byte-write without software wear leveling - essential for parameter logging and calibration.
Availability
93C66CT-E/MS is available at Aetrix Electronics and suitable for industrial sensor calibration storage, smart energy meter configuration, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for 93C66CT-E/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 devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93Cxx series was designed specifically for cost-sensitive, low-pin-count embedded systems requiring reliable, low-power serial EEPROM - targeting automotive, industrial, and consumer applications where Microwire compatibility and extended temperature operation are critical.
FAQ
What is the memory organization of the 93C66CT-E/MS?
The 93C66CT-E/MS is an 'A'-type device with fixed 8-bit organization (512 × 8-bit), meaning it stores and accesses data in 8-bit bytes. Unlike 'C' variants, it has no ORG pin - pin 6 is NC - and does not support 16-bit mode. This simplifies interface design for 8-bit microcontrollers and eliminates external configuration logic.
Does the 93C66CT-E/MS require an external pull-up resistor on the DO line?
Yes, a pull-up resistor (typically 4.7 kΩ to VCC) is recommended on the DO line of the 93C66CT-E/MS to ensure valid logic-high levels during Read and Ready/Busy status polling. The DO pin is open-drain during active output and enters High-Z when CS is low or after status read completion - without pull-up, the signal may float unpredictably.
Can the 93C66CT-E/MS be used with a 3.3 V microcontroller?
No - the 93C66CT-E/MS requires a minimum VCC of 4.5 V and is not rated for 3.3 V operation. Its absolute maximum VCC is 7.0 V, but functional operation is specified only from 4.5 V to 5.5 V. Using it with a 3.3 V host violates the datasheet's VCC range and risks unreliable communication or failed writes.
What is the purpose of the EWEN and EWDS commands in the 93C66CT-E/MS?
The EWEN (Erase/Write Enable) and EWDS (Erase/Write Disable) commands in the 93C66CT-E/MS provide hardware-level write protection. The device powers up in EWDS state; an EWEN must precede every ERASE or WRITE operation. After programming, issuing EWDS disables further writes - preventing accidental corruption during noise events or firmware glitches. This is critical for field-deployed 93C66CT-E/MS applications.
How does the 93C66CT-E/MS handle power loss during a write cycle?
The 93C66CT-E/MS incorporates power-on/off data protection circuitry that inhibits all operations when VCC drops below ~3.8 V. If power fails mid-write, the internal write cycle aborts safely and leaves memory unchanged - no partial writes or corrupted data occur. This behavior is intrinsic to the 93C66CT-E/MS silicon design and requires no external capacitors or supervision circuits.
93C66CT-E/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:
- 2ms
- Access Time:
- -
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-MSOP
93C66CT-E/MS FAQ
1.How can I place an order for 93C66CT-E/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66CT-E/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 93C66CT-E/MS reliable?
The price and inventory of 93C66CT-E/MS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93C66CT-E/MS is usually 5 days.
3.What payment methods are accepted for 93C66CT-E/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66CT-E/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66CT-E/MS?
93C66CT-E/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66CT-E/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 93C66CT-E/MS?
For technical support, including 93C66CT-E/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66CT-E/MS requirements.
6.How does Aetrix verify that 93C66CT-E/MS is sourced from the original manufacturer or authorized distributors?
All 93C66CT-E/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 93C66CT-E/MS meets industry standards.
7.What is the process for return or replacement of 93C66CT-E/MS?
All 93C66CT-E/MS units undergo pre-shipment inspection (PSI). If there is an issue with 93C66CT-E/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 93C66CT-E/MS part is unused and in its original packaging.
Return procedure for 93C66CT-E/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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