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Microchip Technology 93C66CT-I/MC
- Part No.:
- 93C66CT-I/MC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-VFDFN Exposed Pad
- Datasheet:
-
93C66CT-I/MC.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,852
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Product details
Overview
93C66CT-I/MC from Microchip Technology Inc. is a 4 Kbit serial EEPROM with Microwire-compatible 3-wire interface, 4.5–5.5 V supply range, and 8-bit organization (no ORG pin). It delivers 1 million erase/write cycles, >200-year data retention, and industrial temperature operation (–40°C to +85°C) in an 8-lead 2x3 DFN package. Used for configuration storage in embedded controllers and power management ICs.
For engineers reviewing the 93C66CT-I/MC datasheet, 93C66CT-I/MC pinout, 93C66CT-I/MC application, or 93C66CT-I/MC equivalent, key selection criteria include its fixed 8-bit word size, 2 ms write cycle time, VCC-dependent POR threshold (3.8 V), Ready/Busy status via DO pin, and compatibility with legacy Microwire host controllers requiring minimal I/O overhead.
Technical Context
The 93C66CT-I/MC implements a synchronous serial interface with CS, CLK, and DI/DO pins, supporting READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS instructions. Its internal architecture includes address decoder, mode decode logic, and output buffer, with self-timed erase/write cycles initiated by CLK rising edge on final data bit (93C-series behavior).
Power-on reset protection activates below 3.8 V, preventing unintended writes. The device powers up in EWDS (Erase/Write Disable) state and requires explicit EWEN before programming. No ORG pin is present-organization is permanently fixed at 512 × 8-bit, distinguishing it from 'C' variants with configurable word size.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8-bit), fixed x8 organization - no ORG pin required or present. |
| VCC Range | 4.5 V to 5.5 V - supports standard 5 V systems; POR triggers below 3.8 V to block writes. |
| Write Cycle Time | 2 ms - self-timed; enables deterministic firmware timing without polling overhead beyond status check. |
| Endurance | 1,000,000 erase/write cycles - suitable for frequent calibration or runtime parameter logging. |
| Data Retention | >200 years at 25°C - ensures long-term reliability in unattended equipment. |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - minimal GPIO usage; no SPI mode bits or mode register. |
| Temp Range | –40°C to +85°C (Industrial grade) - validated for industrial control, metering, and automotive body electronics. |
Pinout & Package
8-lead 2x3 DFN (MC) package with exposed pad (may be connected to VSS or left floating); pin 1 marked by laser dot. Pin functions are fully defined per DS21795E-page 12.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held low ≥250 ns between commands; deselects device into standby but allows ongoing write to complete. |
| 2 (CLK) | Serial Clock | Synchronizes all data transfers; rising edge clocks in opcode/address/data; rising edge on final data bit initiates write cycle (93C-specific behavior). |
| 3 (DI) | Data Input | Accepts Start bit, instruction opcodes, addresses, and write data; high impedance when not selected. |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); enters High-Z on CS falling edge; requires CS high ≥250 ns to sample status. |
| 5 (NC) | No Connect | Internally unconnected; must be left floating or tied to VSS/VCC per layout best practice - no functional role. |
| 6 (ORG/NC) | No Connect | Not bonded; labeled ORG/NC in generic diagrams but absent on 93C66A/B - confirms fixed 8-bit organization. |
| 7 (VSS) | Ground | Reference for all I/O and internal circuitry; exposed pad may be connected here to improve thermal performance. |
| 8 (VCC) | Power Supply | 4.5–5.5 V supply; POR circuit blocks operations below 3.8 V to prevent corruption during brownout. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates need for external timing control; 2 ms max duration enables predictable firmware delay or interrupt-driven status polling. |
| Automatic ERAL before WRAL | WRAL command internally executes full array erase prior to write - simplifies bulk update logic and guarantees consistent initialization. |
| Power-On/Off Data Protection | POR circuit disables all write/erase functions below 3.8 V, preventing corruption during power ramp-up/down or brownout conditions. |
| Ready/Busy Status via DO | Enables real-time status monitoring without additional pins; DO low = active programming, DO high = ready - reduces need for fixed delays. |
| Industry Standard 3-Wire Interface | Compatible with legacy Microwire controllers and simple GPIO bit-banged implementations - no SPI mode configuration or clock polarity constraints. |
Applications
| Industrial Sensor Calibration Storage | Smart Power Supply Configuration |
|---|---|
Use Scenario: Storing factory-trimmed sensor offset/gain coefficients and linearization tables in programmable temperature/humidity sensors. IC Role / Device Role / Timing Role: Nonvolatile configuration memory holding calibration data accessed at startup and updated during field recalibration. Use Value: Enables single-device calibration across production batches; 1M endurance supports periodic field updates without wear-out concerns. | Use Scenario: Holding digital setpoints, protection thresholds, and communication parameters in digitally controlled AC/DC power supplies. IC Role / Device Role / Timing Role: Serial configuration store interfaced directly to MCU's GPIO or dedicated Microwire peripheral. Use Value: Allows firmware-independent parameter tuning via service tools; >200-year retention ensures settings survive decades of operation. |
| Automotive Body Control Module Settings | Legacy Industrial PLC I/O Mapping |
Use Scenario: Saving user-configurable lighting profiles, window position limits, and mirror memory positions in vehicle body control units. IC Role / Device Role / Timing Role: Low-pin-count EEPROM providing persistent storage for end-user preferences and adaptive settings. Use Value: Industrial temp rating (–40°C to +85°C) meets under-hood and cabin environmental requirements; 5 V compatibility aligns with legacy automotive MCU buses. | Use Scenario: Storing I/O assignment tables, scaling factors, and alarm hysteresis values in modular PLC backplanes with fixed 5 V rails. IC Role / Device Role / Timing Role: Microwire-compatible memory used by main controller to load hardware configuration at boot. Use Value: Fixed 8-bit interface simplifies driver development; 2 ms write time enables fast reconfiguration during maintenance mode. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66AT-I/MC | Wider VCC range (2.5–5.5 V); same 512×8 organization; POR at 1.5 V; 6 ms write cycle. | Better suited for mixed-voltage systems or battery-backed 3.3 V designs; slower write impacts high-frequency update scenarios. | Select when operating below 4.5 V or requiring lower POR threshold; verify timing margins for 6 ms writes. |
| 93AA66AT-I/MC | Ultra-low VCC range (1.8–5.5 V); same 512×8 organization; POR at 1.5 V; 6 ms write cycle; higher endurance spec at low VCC. | Enables direct integration into 1.8 V logic domains; not recommended for pure 5 V systems due to reduced noise margin. | Choose for energy-constrained or multi-rail systems; avoid if system lacks 1.8 V rail or requires strict 5 V timing compliance. |
Compared with 93LC66AT-I/MC and 93AA66AT-I/MC, the 93C66CT-I/MC offers faster 2 ms writes and tighter 4.5–5.5 V operation ideal for stable 5 V industrial environments, but lacks voltage flexibility - making it optimal where speed and 5 V robustness outweigh wide-supply adaptability.
Availability
93C66CT-I/MC is available at Aetrix Electronics and suitable for industrial sensor calibration, smart power supply configuration, and automotive body control module settings requiring stable component supply, long-life data retention, and proven Microwire interoperability.
Supply support for 93C66CT-I/MC 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, serving industrial, automotive, and consumer markets with high-reliability silicon and development tools.
The 93C66 series belongs to Microchip's legacy Microwire-compatible serial EEPROM product line, designed specifically for cost-sensitive, low-pin-count nonvolatile storage in 5 V embedded systems requiring deterministic timing and robust power-fail protection.
FAQ
What is the memory organization of the 93C66CT-I/MC?
The 93C66CT-I/MC has a fixed 512 × 8-bit organization with no ORG pin. Unlike 'C' variants, it does not support word-size selection - it is permanently configured for 8-bit serial communication. This is confirmed by its part number suffix 'A' (93C66A family) and absence of ORG functionality in the MC package pinout.
Does the 93C66CT-I/MC support 16-bit operation?
No, the 93C66CT-I/MC does not support 16-bit operation. It is a member of the 'A' variant group (93C66A), which provides only 8-bit organization. 16-bit capability requires either a 'B' (fixed 256 × 16) or 'C' (pin-selectable) variant - neither applies to the 93C66CT-I/MC.
What is the write cycle time for the 93C66CT-I/MC?
The 93C66CT-I/MC has a guaranteed maximum write cycle time of 2 ms for both individual WRITE and ERASE operations. This self-timed duration is specific to the 93C-series and shorter than the 6 ms required by 93AA/93LC variants, enabling faster firmware response in update-critical applications.
How does the Power-On Reset (POR) function on the 93C66CT-I/MC?
The 93C66CT-I/MC incorporates a POR circuit that inhibits all erase/write operations when VCC falls below 3.8 V. This threshold is higher than the 1.5 V used in 93AA/93LC devices, ensuring robust protection in 5 V systems experiencing brownout - a key differentiator for industrial-grade reliability.
Is an EWEN command required before every write operation on the 93C66CT-I/MC?
Yes, the 93C66CT-I/MC powers up in EWDS (Erase/Write Disable) mode. An EWEN instruction must be issued before any ERASE or WRITE command can execute. After successful programming, issuing EWDS restores protection - a mandatory step to prevent accidental overwrites during normal operation.
93C66CT-I/MC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-VFDFN Exposed Pad
- 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:
- 2ms
- Access Time:
- -
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN (2x3)
93C66CT-I/MC FAQ
1.How can I place an order for 93C66CT-I/MC through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66CT-I/MC 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-I/MC reliable?
The price and inventory of 93C66CT-I/MC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93C66CT-I/MC is usually 5 days.
3.What payment methods are accepted for 93C66CT-I/MC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66CT-I/MC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66CT-I/MC?
93C66CT-I/MC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66CT-I/MC 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-I/MC?
For technical support, including 93C66CT-I/MC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66CT-I/MC requirements.
6.How does Aetrix verify that 93C66CT-I/MC is sourced from the original manufacturer or authorized distributors?
All 93C66CT-I/MC 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-I/MC meets industry standards.
7.What is the process for return or replacement of 93C66CT-I/MC?
All 93C66CT-I/MC units undergo pre-shipment inspection (PSI). If there is an issue with 93C66CT-I/MC, 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-I/MC part is unused and in its original packaging.
Return procedure for 93C66CT-I/MC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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