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Microchip Technology 93LC66CT-I/ST
- Part No.:
- 93LC66CT-I/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
93LC66CT-I/ST.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,565
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Product details
Overview
93LC66CT-I/ST from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 256 × 16-bit organization, 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 Ready/Busy status signaling via DO pin - used in embedded system configuration storage and sensor calibration retention.
For engineers reviewing the 93LC66CT-I/ST datasheet, 93LC66CT-I/ST pinout, 93LC66CT-I/ST application, or 93LC66CT-I/ST equivalent, key selection considerations include VCC range (2.5–5.5 V), ORG pin dependency for x16 mode, TSSOP-8 package footprint, 3 MHz max clock frequency at 4.5–5.5 V, and 1 million erase/write endurance.
Technical Context
The 93LC66CT-I/ST implements a synchronous serial Microwire interface with CS, CLK, DI, and DO signals. Its memory array is organized as 256 words × 16 bits, selected by tying ORG high (VCC); no internal connection on A/B variants makes ORG functional only on 'C' versions like this one. All instructions - READ, WRITE, ERASE, ERAL, WRAL - are initiated by a Start bit followed by opcode, address, and data, with timing governed by TCKH/TCKL and TCSL constraints.
Internal logic includes an address counter for sequential read, output buffer with High-Z control, and status monitoring circuitry that drives DO low during active erase/write. Power-on reset disables write operations until EWEN is issued, and VCC detection (1.5 V threshold) prevents corruption below safe operating voltage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (256 × 16-bit organization) |
| VCC Range | 2.5 V to 5.5 V - supports mixed-voltage systems including 3.3 V and 5 V rails |
| Clock Frequency | Up to 3 MHz at 4.5–5.5 V - enables fast configuration loading without MCU overhead |
| Endurance | 1,000,000 erase/write cycles - suitable for field-updatable parameter storage |
| Data Retention | 200 years at 25°C - ensures long-term calibration data integrity |
| Temperature Range | –40°C to +85°C (Industrial grade) - validated for industrial control and automotive cabin modules |
| Interface | 3-wire Microwire-compatible serial (CS, CLK, DI/DO) - minimal GPIO usage on resource-constrained MCUs |
Pinout & Package
93LC66CT-I/ST is housed in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch, JEDEC MO-153 compliant, and Pb-free Matte Tin finish. Pin 1 marked by laser dot; exposed pad not present.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held low ≥250 ns between commands to reset internal logic |
| 2 (CLK) | Serial Clock | Rising-edge synchronized I/O; stoppable mid-transfer for flexible MCU timing |
| 3 (DI) | Data Input | Accepts Start bit, opcodes, addresses, and write data; shares bus with DO when externally wired |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy signal (low = busy); enters High-Z on CS fall |
| 5 (VSS) | Ground | Reference for all digital and analog functions; requires low-impedance PCB return path |
| 6 (ORG) | Organization Select | Logic high selects x16 mode (256 × 16); tied to VCC for this part's fixed configuration |
| 7 (NC) | No Connection | Internally unconnected; must be left floating or tied to VSS/VCC per layout best practice |
| 8 (VCC) | Power Supply | Supplies core logic and memory array; includes POR circuitry triggering at 1.5 V |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates external timing control - internal cycle completes in ≤6 ms (TWC), freeing MCU resources |
| Automatic ERAL before WRAL | Guarantees full-array readiness prior to bulk write, preventing partial-program corruption |
| Ready/Busy via DO pin | Enables polling-based firmware flow without dedicated interrupt lines or timeout loops |
| Power-On/Off Data Protection | Hardware lockout below 1.5 V VCC prevents inadvertent writes during brown-out or startup |
| 100% Tested Read/Write at 2.5 V | Validated operation down to minimum supply - critical for battery-backed or energy-harvesting designs |
Applications
| Industrial Sensor Calibration Storage | Embedded System Configuration Memory |
|---|---|
Use Scenario: Storing factory-trimmed gain/offset coefficients for analog sensor front-ends in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile parameter register accessed infrequently during commissioning or recalibration. Use Value: 200-year data retention and 1M endurance ensure calibration survives full product lifecycle without refresh. | Use Scenario: Holding user-defined settings (display brightness, network ID, alarm thresholds) in HVAC control panels. IC Role / Device Role / Timing Role: Serial configuration store interfaced to 8-bit MCU with limited GPIO. Use Value: 3-wire Microwire interface reduces pin count vs. SPI; TSSOP-8 footprint fits compact UI PCBs. |
| Automotive Body Control Module (BCM) | Medical Device Usage Log |
Use Scenario: Recording door lock actuation history and mirror position presets in 12 V automotive cabins. IC Role / Device Role / Timing Role: Industrial-grade EEPROM operating across –40°C to +85°C ambient. Use Value: VCC detection at 1.5 V prevents writes during ignition transients; RoHS compliance meets automotive standards. | Use Scenario: Logging timestamped therapy session counts and error events in portable diagnostic equipment. IC Role / Device Role / Timing Role: Tamper-resistant audit trail storage with deterministic write latency (≤6 ms). Use Value: EWEN/EWDS command sequence enforces intentional write activation, reducing accidental overwrite risk. |
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/ST | No ORG pin; fixed 256 × 16-bit organization; identical VCC range and timing | Same pinout and function but lacks ORG flexibility - simpler for x16-only designs | Select if ORG pin routing is unnecessary and board layout must avoid unused pin |
| AT25040B-SSHL-T | SPI interface (4-wire), 512 × 8-bit, 1.8–5.5 V, 20 MHz clock, SOIC-8 | Higher speed and lower voltage support, but requires extra CS line and different protocol stack | Choose for faster configuration loads or designs already using SPI peripherals |
Compared with 93LC66B-I/ST, the 93LC66CT-I/ST adds ORG configurability at no cost to timing or endurance; versus AT25040B-SSHL-T, it trades SPI speed for reduced pin count and legacy Microwire compatibility in space-constrained 8-bit systems.
Availability
93LC66CT-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration storage, embedded system configuration memory, and automotive body control module applications requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for 93LC66CT-I/ST 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, 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 configuration and calibration storage in cost-sensitive industrial and automotive applications where Microwire compatibility and proven reliability are prioritized.
FAQ
What is the memory organization of the 93LC66CT-I/ST?
The 93LC66CT-I/ST is configured as 256 words × 16 bits (4 Kbit total), selected by tying the ORG pin high (to VCC). This x16 organization is fixed for this specific variant and confirmed in the Device Selection Table and Pin Function Table of DS21795E.
Does the 93LC66CT-I/ST require an external pull-up on the DO pin?
No, the 93LC66CT-I/ST does not require an external pull-up on the DO pin. The DO pin actively drives high/low during read or Ready/Busy status reporting and enters High-Z when inactive. External pull-ups may interfere with valid logic levels and are not recommended per Microchip's application guidance in Section 2.2.
Can the 93LC66CT-I/ST operate reliably at 2.5 V?
Yes, the 93LC66CT-I/ST is fully specified and tested for operation at 2.5 V, including AC timing (min 2 MHz clock), DC parameters (e.g., VOL2 ≤ 0.2 V at 100 µA), and functional instruction execution. This is explicitly stated in the Device Selection Table and Table 1-2 AC Characteristics for the 'LC' family.
What is the purpose of the NC pin (Pin 7) on the 93LC66CT-I/ST?
Pin 7 on the 93LC66CT-I/ST is labeled NC (No Connection) and has no internal connection. It must be left floating or optionally tied to VSS or VCC for mechanical stability - but never driven by external logic, as it is electrically isolated from the die per the Pin Function Table and Package Types diagram in DS21795E.
How does the 93LC66CT-I/ST handle power loss during a write cycle?
The 93LC66CT-I/ST incorporates power-on/off data protection circuitry that inhibits all operations when VCC falls below ~1.5 V. If power drops mid-write, the internal auto-erase/write cycle halts safely and the memory contents remain uncorrupted - verified by the Absolute Maximum Ratings and Functional Description sections of DS21795E.
93LC66CT-I/ST Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP (0.173", 4.40mm 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-TSSOP
93LC66CT-I/ST FAQ
1.How can I place an order for 93LC66CT-I/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66CT-I/ST 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/ST reliable?
The price and inventory of 93LC66CT-I/ST 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/ST is usually 5 days.
3.What payment methods are accepted for 93LC66CT-I/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66CT-I/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66CT-I/ST?
93LC66CT-I/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66CT-I/ST 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/ST?
For technical support, including 93LC66CT-I/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66CT-I/ST requirements.
6.How does Aetrix verify that 93LC66CT-I/ST is sourced from the original manufacturer or authorized distributors?
All 93LC66CT-I/ST 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/ST meets industry standards.
7.What is the process for return or replacement of 93LC66CT-I/ST?
All 93LC66CT-I/ST units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66CT-I/ST, 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/ST part is unused and in its original packaging.
Return procedure for 93LC66CT-I/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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