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Microchip Technology 93LC66CT-I/MC
- Part No.:
- 93LC66CT-I/MC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-VFDFN Exposed Pad
- Datasheet:
-
93LC66CT-I/MC.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,602
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Product details
Overview
93LC66CT-I/MC from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 256 × 16-bit organization (ORG pin enabled), and industrial temperature range (–40°C to +85°C). It features self-timed erase/write cycles, automatic ERAL before WRAL, power-on/off data protection, and 1,000,000 endurance cycles - used in microcontroller configuration storage and calibration data retention.
For engineers reviewing the 93LC66CT-I/MC datasheet, 93LC66CT-I/MC pinout, 93LC66CT-I/MC application, or 93LC66CT-I/MC equivalent, key selection criteria include VCC range (2.5–5.5 V), ORG-configurable x16 mode, DFN-8 package with exposed pad, Ready/Busy status via DO pin, and compatibility with legacy Microwire controllers in space-constrained embedded systems.
Technical Context
The 93LC66CT-I/MC implements a synchronous serial interface with CS, CLK, DI, and DO pins, requiring a Start bit (CS high + DI high on first CLK rising edge) to initiate command sequences. Its internal logic supports full instruction set including READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS - all executed with precise timing windows defined per VCC level.
Memory operation relies on external ORG pin control: tied to VCC for 256 × 16-bit mode, enabling 16-bit data transfers per address; tied to VSS for 512 × 8-bit mode. The device enters Standby mode when CS is low, drawing only 1 µA typical ICCS, and asserts Ready/Busy status on DO during active programming - verified by polling after minimum TCSL (250 ns).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (256 × 16-bit when ORG = VCC) |
| VCC Range | 2.5 V to 5.5 V - supports dual-supply systems and brown-out immunity down to 2.5 V |
| Interface | Microwire-compatible 3-wire serial (CS, CLK, DI/DO) - no SPI mode or 4-wire requirement |
| Write Cycle Time | 6 ms typical - self-timed auto-erase + write; no external delay needed |
| Endurance | 1,000,000 erase/write cycles - validated at 25°C, VCC = 5.0 V |
| Data Retention | 200 years - ensures long-term calibration storage without refresh |
| Temperature Range | –40°C to +85°C (Industrial grade) - qualified for extended ambient operation |
Pinout & Package
8-pin 2×3 mm DFN (MC) package with exposed thermal pad (may be connected to VSS or left floating); pin 1 marked by laser dot. Pin functions are fixed per Microchip standard: CS (1), CLK (2), DI (3), DO (4), VSS (5), NC (6), ORG (7), VCC (8).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - CS | Chip Select | Active-high enable; must be held ≥250 ns low between instructions; initiates self-timed cycle on falling edge for 93LC devices |
| 2 - CLK | Serial Clock | Rising-edge synchronized I/O; clock can pause mid-transfer; no clocks required during write cycle |
| 3 - DI | Data Input | Accepts Start bit, opcode, address, and data; shares bus with DO only with series resistor to prevent conflict |
| 4 - DO | Data Output / Status | Outputs read data or Ready/Busy (low = busy); enters High-Z on CS falling edge |
| 5 - VSS | Ground | Reference for all signals; connects to exposed pad in DFN for thermal management |
| 6 - NC | No Connection | Internally unconnected; must remain floating or grounded per layout best practice |
| 7 - ORG | Organization Select | Logic high → 256 × 16-bit mode; logic low → 512 × 8-bit mode; must be stable before command start |
| 8 - VCC | Power Supply | 2.5–5.5 V input; includes internal POR circuit triggering at ~1.5 V threshold |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates need for external timing control or software delays - hardware-managed 6 ms cycle |
| Automatic ERAL before WRAL | Ensures full-array readiness prior to bulk write, preventing partial-program corruption |
| Power-On/Off Data Protection | Hardware lockout below 1.5 V VCC prevents inadvertent writes during power ramp |
| Ready/Busy Status via DO | Enables non-blocking polling instead of fixed delays - reduces system latency during writes |
| 1,000,000 Endurance Cycles | Supports frequent field updates (e.g., metering logs, sensor calibration) over product lifetime |
Applications
| Smart Energy Meters | Industrial PLC I/O Modules |
|---|---|
Use Scenario: Storing tariff tables, firmware checksums, and accumulated kWh readings across power cycles. IC Role / Device Role / Timing Role: Nonvolatile configuration and event-log memory interfaced to MCU via Microwire peripheral. Use Value: 200-year data retention and 1M endurance ensure decade-long field reliability without battery backup. | Use Scenario: Holding I/O mapping definitions, calibration coefficients, and fault-history records in modular controllers. IC Role / Device Role / Timing Role: Serial EEPROM providing parameter storage accessible during boot and runtime via deterministic 3-wire protocol. Use Value: ORG-selectable x16 mode enables compact 16-bit register access, reducing transaction count vs. x8 alternatives. |
| Automotive Body Control Units | Medical Diagnostic Handhelds |
Use Scenario: Saving seat/mirror position presets, lighting profiles, and diagnostic trouble codes (DTCs) in BCMs. IC Role / Device Role / Timing Role: Low-power EEPROM operating from 2.5 V supply with robust ESD protection (>4 kV) for automotive environments. Use Value: Industrial-grade –40°C to +85°C rating meets AEC-Q100 Class 2 requirements without derating. | Use Scenario: Storing patient-specific calibration offsets, usage counters, and regulatory audit logs in portable diagnostics. IC Role / Device Role / Timing Role: Secure, tamper-resistant memory for FDA-critical data with hardware write-protection (EWEN/EWDS). Use Value: Power-on data protection and explicit erase-enable sequence prevent accidental overwrite during power transitions. |
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 | SOIC-8 package; no ORG pin - fixed 256 × 16-bit organization; same VCC range and timing | Requires PCB redesign for SOIC footprint; lacks ORG flexibility but simplifies routing | Select when board space allows SOIC and x16 mode is permanently required |
| AT25040B-MAHL-T | SPI interface (4-wire), 512 × 8-bit only, 1.8–5.5 V VCC, 5 ms write time, same endurance | Requires SPI controller instead of Microwire; no ORG pin or x16 option | Select when migrating to SPI-based platforms or needing lower 1.8 V operation |
Compared with 93LC66B-I/SN, the 93LC66CT-I/MC offers smaller DFN footprint and ORG configurability; compared with AT25040B-MAHL-T, it retains Microwire compatibility and supports x16 mode - critical for legacy controller integration and bandwidth-sensitive calibration storage.
Availability
93LC66CT-I/MC is available at Aetrix Electronics and suitable for smart energy meters, industrial PLC I/O modules, and automotive body control units requiring stable component supply, long-term data integrity, and RoHS-compliant packaging.
Supply support for 93LC66CT-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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona.
The 93LC66 series belongs to Microchip's legacy Microwire-compatible EEPROM product line, designed specifically for cost-sensitive, low-power embedded systems requiring simple 3-wire nonvolatile storage with industrial temperature resilience.
FAQ
What is the function of the ORG pin on the 93LC66CT-I/MC?
The ORG pin on the 93LC66CT-I/MC selects memory organization: logic high (VCC) configures 256 × 16-bit mode; logic low (VSS) configures 512 × 8-bit mode. This pin is functional only on 'C' variants like the 93LC66CT-I/MC - it is NC on 'A' and 'B' versions. Stable logic level must be applied before command initiation.
Does the 93LC66CT-I/MC support SPI communication?
No, the 93LC66CT-I/MC does not support SPI. It implements a Microwire-compatible 3-wire serial interface (CS, CLK, DI/DO) with specific timing and instruction encoding distinct from SPI. It lacks an independent SI/SO pair and requires Start-bit detection - incompatible with standard SPI master peripherals without firmware adaptation.
What is the maximum clock frequency supported by the 93LC66CT-I/MC at 3.3 V VCC?
At VCC = 3.3 V (within 2.5–5.5 V range), the 93LC66CT-I/MC supports a maximum clock frequency of 2 MHz, as specified in Table 1-2 (A1: FCLK). This applies to both read and write operations; exceeding this limit risks setup/hold violations and command misinterpretation.
How is data protection implemented during power transitions in the 93LC66CT-I/MC?
The 93LC66CT-I/MC uses hardware-based power-on/off data protection: internal circuitry inhibits all write operations when VCC falls below ~1.5 V. Additionally, the device powers up in EWDS (Erase/Write Disable) mode, requiring an explicit EWEN command before any erase or write - preventing corruption during brown-out or reset conditions.
Is the exposed pad on the 93LC66CT-I/MC's DFN package electrically connected?
Yes, the exposed pad on the 93LC66CT-I/MC (DFN-8, MC package) may be connected to VSS for improved thermal performance and grounding, or left floating per design requirements. Microchip documentation states it is not internally bonded to any signal - connection choice depends on PCB thermal and EMI goals, with no electrical impact on functionality.
93LC66CT-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:
- 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-DFN (2x3)
93LC66CT-I/MC FAQ
1.How can I place an order for 93LC66CT-I/MC through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66CT-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 93LC66CT-I/MC reliable?
The price and inventory of 93LC66CT-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 93LC66CT-I/MC is usually 5 days.
3.What payment methods are accepted for 93LC66CT-I/MC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66CT-I/MC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66CT-I/MC?
93LC66CT-I/MC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66CT-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 93LC66CT-I/MC?
For technical support, including 93LC66CT-I/MC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66CT-I/MC requirements.
6.How does Aetrix verify that 93LC66CT-I/MC is sourced from the original manufacturer or authorized distributors?
All 93LC66CT-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 93LC66CT-I/MC meets industry standards.
7.What is the process for return or replacement of 93LC66CT-I/MC?
All 93LC66CT-I/MC units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66CT-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 93LC66CT-I/MC part is unused and in its original packaging.
Return procedure for 93LC66CT-I/MC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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