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Microchip Technology 93LC66AT-I/OT
- Part No.:
- 93LC66AT-I/OT
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- SOT-23-6
- Datasheet:
-
93LC66AT-I/OT.pdf
- Description:
- IC EEPROM 4KBIT MIC WIRE SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:29,333
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Product details
Overview
93LC66AT-I/OT from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, designed for nonvolatile memory storage in space-constrained embedded systems. It operates across 2.5–5.5 V, supports Microwire-compatible 3-wire serial interface (CS/CLK/DI/DO), delivers 1 million erase/write cycles, and retains data for >200 years. It is used in industrial sensor calibration, power supply configuration, and firmware parameter storage where reliable, low-power serial memory is required.
For engineers reviewing the 93LC66AT-I/OT datasheet, 93LC66AT-I/OT pinout, 93LC66AT-I/OT application, or 93LC66AT-I/OT equivalent, key selection criteria include its SOT-23-6 package, industrial temperature range (−40°C to +85°C), 8-bit fixed word size (no ORG pin), self-timed write/erase, and Ready/Busy status signaling via DO pin.
Technical Context
The 93LC66AT-I/OT implements a synchronous serial Microwire interface with start-bit detection, opcode-driven command set (READ, WRITE, ERASE, ERAL, WRAL, EWEN/EWDS), and hardware-based power-on/off data protection. Its internal architecture includes an address decoder, mode decode logic, and output buffer, with all programming operations requiring prior EWEN enable and automatic auto-erase before write.
It features dedicated 8-bit communication (no ORG pin), uses CS-active-high selection, clocks data on rising CLK edges, and provides device status via DO pin-low during active erase/write, high when ready, and high-Z otherwise. Standby current is ≤5 µA at 2.5 V, and write current peaks at 2 mA under 2.5 V/2 MHz conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8-bit) - fixed x8 organization, no ORG pin; eliminates external configuration logic. |
| VCC Range | 2.5 V to 5.5 V - supports wide input rails including 3.3 V and 5 V systems without level shifting. |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - minimal GPIO usage, compatible with legacy microcontrollers. |
| Endurance | 1,000,000 erase/write cycles - enables frequent field updates in telemetry or calibration applications. |
| Data Retention | >200 years at 25°C - ensures long-term reliability in unattended infrastructure equipment. |
| Temp Range | −40°C to +85°C (Industrial grade) - validated for operation in factory automation and outdoor electronics. |
| Write Time | 6 ms typical (TWC) - deterministic self-timed cycle allows precise timing budgeting in real-time firmware. |
| Standby Current | ≤5 µA at 2.5 V - critical for battery-backed or energy-harvesting designs requiring ultra-low quiescent power. |
Pinout & Package
Package: SOT-23-6 (lead-free, matte tin finish), 2.9 mm × 1.6 mm footprint, suitable for high-density PCB layouts and automated assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: DO | Data Output / Ready-Busy Indicator | Tri-state output delivering read data or status: low = busy, high = ready, high-Z = idle or deselected. |
| 2: VSS | Ground Reference | Primary return path for all internal circuitry; must be low-impedance connection to minimize noise coupling. |
| 3: DI | Data Input | Serial input for opcodes, addresses, and write data; clocked on rising CLK edge; requires clean signal integrity. |
| 4: VCC | Power Supply | 2.5–5.5 V supply; internal POR circuit activates below 1.5 V threshold to prevent spurious writes during brownout. |
| 5: CS | Chip Select | Active-high enable; minimum 250 ns low time (TCSL) required between commands; deselects device into standby mode. |
| 6: CLK | Serial Clock | Synchronizes all data transfers; rising edge clocks in DI and clocks out DO; stoppable at any point without corruption. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates need for external timing control or polling delays beyond TWC (6 ms); simplifies firmware driver design. |
| Automatic ERAL before WRAL | Ensures full-array write integrity without separate erase command-reduces software overhead and failure risk. |
| Power-On/Off Data Protection | Hardware lockout prevents writes when VCC drops below 1.5 V, protecting memory during power ramp-up/down. |
| Ready/Busy Status on DO | Enables efficient polling instead of fixed delays; avoids unnecessary CPU wait states during programming. |
| Sequential Read Mode | Allows continuous read across multiple addresses with single CS assertion-reduces transaction overhead by ~40% vs. random access. |
| Pb-free & RoHS Compliant | Meets global environmental compliance requirements; matte tin finish ensures solderability and wire-bond compatibility. |
Applications
| Industrial Sensor Calibration | Power Supply Configuration |
|---|---|
Use Scenario: Storing temperature-compensated offset/gain coefficients in smart pressure transmitters deployed in oil & gas plants. IC Role / Device Role / Timing Role: Nonvolatile parameter storage with infrequent updates but mission-critical retention over 15+ years. Use Value: Eliminates external backup batteries or supercaps; leverages >200-year data retention and −40°C to +85°C operation. | Use Scenario: Holding digital trim values for DC-DC converter feedback networks in telecom rectifiers. IC Role / Device Role / Timing Role: Serial configuration memory interfaced directly to MCU GPIOs with minimal board area. Use Value: SOT-23-6 footprint saves >70% board space vs. SOIC-8; 2.5 V min VCC supports low-voltage control rails. |
| Firmware Parameter Storage | Embedded System Bootloader Settings |
Use Scenario: Saving user-defined operational modes (e.g., sleep duration, alarm thresholds) in portable medical monitors. IC Role / Device Role / Timing Role: Low-power serial EEPROM accessed only during setup or recovery; standby current ≤5 µA extends battery life. Use Value: 1M endurance supports daily field recalibration over 27 years; no external voltage supervisor needed. | Use Scenario: Storing bootloader jump addresses and security flags in industrial PLC modules. IC Role / Device Role / Timing Role: Trusted configuration store verified at boot; protected by EWEN/EWDS lockout sequence. Use Value: Hardware write-protection prevents accidental corruption during firmware update or ESD events. |
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/OT | 16-bit organization (256 × 16), same VCC/temp range and package - requires ORG pin tied to VSS for x8 emulation, but not present on A/B variants. | Not pin-compatible: 93LC66B-I/OT has identical pinout but expects 16-bit data framing; firmware must restructure all read/write sequences. | Select only if system already uses 16-bit data paths and can accommodate revised command timing and opcode handling. |
| AT25040B-MAHL-T | SPI interface (4-wire), 4 Kbit (512 × 8), 1.8–5.5 V, SOIC-8/SN-8 - lacks Ready/Busy pin; relies on WIP bit polling via STATUS register. | Different interface protocol and package; requires PCB redesign and driver rewrite; no DO status pin reduces real-time responsiveness. | Choose when migrating to SPI ecosystem or needing higher clock rates (up to 20 MHz); avoid if DO-based polling is embedded in existing firmware. |
Compared with 93LC66B-I/OT and AT25040B-MAHL-T, the 93LC66AT-I/OT offers native x8 Microwire compatibility, integrated Ready/Busy signaling on DO, and drop-in firmware compatibility for legacy 3-wire designs-making it optimal for cost-sensitive, space-constrained industrial upgrades.
Availability
93LC66AT-I/OT is available at Aetrix Electronics and suitable for industrial sensor calibration, power supply configuration, and firmware parameter storage requiring stable component supply across extended product lifecycles.
Supply support for 93LC66AT-I/OT 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, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93LC66A/B/C family was engineered specifically for low-voltage, low-pin-count serial memory applications in industrial and automotive systems where reliability, small footprint, and proven Microwire compatibility are essential.
FAQ
What is the memory organization of the 93LC66AT-I/OT?
The 93LC66AT-I/OT is a fixed 512 × 8-bit (4 Kbit) device with no ORG pin-unlike 'C' variants, it does not support word-size selection. This eliminates external configuration logic and guarantees consistent 8-bit data framing in all applications. The 93LC66AT-I/OT is fully compatible with legacy Microwire controllers expecting x8 addressing and data transfer.
Does the 93LC66AT-I/OT require an external pull-up resistor on the DO pin?
No, the 93LC66AT-I/OT does not require an external pull-up on DO. Its DO pin is actively driven high or low during READ or Ready/Busy status reporting, and enters high-impedance (high-Z) state otherwise. However, if DI and DO are shorted (shared bus), a series resistor (typically 100–470 Ω) is recommended to prevent bus conflict during the dummy-zero phase of READ operations.
How is write protection implemented on the 93LC66AT-I/OT?
Write protection on the 93LC66AT-I/OT is enforced through the EWEN (Erase/Write Enable) and EWDS (Erase/Write Disable) instructions. The device powers up in EWDS mode-blocking all ERASE/WRITE commands until EWEN is issued. After each write, executing EWDS restores protection. This two-step hardware lockout prevents accidental overwrites during noise events or firmware glitches, and is independent of VCC monitoring.
What is the maximum clock frequency supported by the 93LC66AT-I/OT at 3.3 V?
At VCC = 3.3 V (within 2.5–5.5 V range), the 93LC66AT-I/OT supports a maximum clock frequency of 2 MHz, per Table 1-2 (A1). This is confirmed for industrial temperature range (−40°C to +85°C) and applies to all instructions (READ, WRITE, ERASE, etc.). Exceeding 2 MHz may cause timing violations in setup/hold windows (e.g., TDIS, TCKH), leading to command misreads or failed writes.
Can the 93LC66AT-I/OT be used in automotive applications?
The 93LC66AT-I/OT is rated for Industrial temperature range (−40°C to +85°C), not Automotive (−40°C to +125°C). While it shares the same die as automotive-grade 93LC66AE/OT variants, the 93LC66AT-I/OT is not qualified to AEC-Q100 or tested for 125°C operation. For automotive use, specify 93LC66AE/OT or equivalent A-grade part with full qualification documentation.
93LC66AT-I/OT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SOT-23-6
- 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
- Memory Interface:
- Microwire
- Clock Frequency:
- 2 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:
- SOT-23-6
93LC66AT-I/OT FAQ
1.How can I place an order for 93LC66AT-I/OT through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66AT-I/OT 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 93LC66AT-I/OT reliable?
The price and inventory of 93LC66AT-I/OT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66AT-I/OT is usually 5 days.
3.What payment methods are accepted for 93LC66AT-I/OT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66AT-I/OT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66AT-I/OT?
93LC66AT-I/OT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66AT-I/OT 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 93LC66AT-I/OT?
For technical support, including 93LC66AT-I/OT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66AT-I/OT requirements.
6.How does Aetrix verify that 93LC66AT-I/OT is sourced from the original manufacturer or authorized distributors?
All 93LC66AT-I/OT 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 93LC66AT-I/OT meets industry standards.
7.What is the process for return or replacement of 93LC66AT-I/OT?
All 93LC66AT-I/OT units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66AT-I/OT, 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 93LC66AT-I/OT part is unused and in its original packaging.
Return procedure for 93LC66AT-I/OT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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