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Microchip Technology 93LC66AT-E/OT
- Part No.:
- 93LC66AT-E/OT
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- SOT-23-6
- Datasheet:
-
93LC66AT-E/OT.pdf
- Description:
- IC EEPROM 4KBIT MIC WIRE SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:2,078
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Product details
Overview
93LC66AT-E/OT from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, supporting Microwire-compatible 3-wire serial interface (CS, CLK, DI, DO), 2.5–5.5 V supply, and industrial/automotive temperature range (−40°C to +125°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 93LC66AT-E/OT datasheet, 93LC66AT-E/OT pinout, 93LC66AT-E/OT application, or 93LC66AT-E/OT equivalent, key selection considerations include its SOT-23-6 package, 8-bit fixed word size (no ORG pin), automotive-grade qualification, and compatibility with legacy Microwire controllers requiring minimal firmware changes.
Technical Context
The 93LC66AT-E/OT implements a synchronous serial interface with start-bit detection, opcode-driven command set (READ, WRITE, ERASE, ERAL, WRAL, EWEN/EWDS), and internal auto-erase-before-write logic. Its timing adheres to Microwire protocol with clock frequency up to 3 MHz at VCC ≥ 4.5 V and down to 1 MHz at 2.5 V.
It uses CMOS nonvolatile floating-gate memory cells with 1,000,000 erase/write endurance and >200-year data retention. The device enters Standby mode when CS is low, draws ≤5 µA ICCS, and provides hardware-level write protection via EWEN/EWDS commands - independent of VCC monitoring circuitry that disables operations below 2.5 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit), fixed x8 organization - no ORG pin required; simplifies PCB layout and firmware address mapping. |
| VCC range | 2.5 V to 5.5 V - supports direct connection to 3.3 V or 5 V rails without level-shifting in automotive and industrial control modules. |
| Endurance | 1,000,000 erase/write cycles - enables frequent recalibration logging in sensor nodes and parameter tuning in motor controllers. |
| Data retention | Greater than 200 years at 25°C - ensures long-term reliability for firmware configuration storage in unattended equipment. |
| Interface | Microwire-compatible 3-wire serial (CS, CLK, DI, DO) - interoperable with legacy microcontrollers lacking SPI hardware but supporting bit-banged Microwire protocols. |
| Temp range | −40°C to +125°C (Automotive E grade) - qualified for under-hood and powertrain applications per AEC-Q100 stress requirements. |
| Write time | 6 ms typical for byte/page write (TWC) - allows deterministic timeout handling in real-time firmware without polling overhead. |
Pinout & Package
Package: SOT-23-6 (lead-free, matte tin finish), 2.9 mm × 1.6 mm footprint, suitable for space-constrained automotive modules and portable instrumentation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (DO) | Data Output / Ready-Busy Status | Tri-state output delivering read data or active-low busy signal; requires external pull-up for proper high-Z detection during standby. |
| 2 (VSS) | Ground Reference | Primary return path for all I/O and core logic; must be connected directly to low-impedance system ground plane. |
| 3 (DI) | Data Input | Serial input for opcodes, addresses, and write data; synchronized on rising CLK edge; tolerant of bus conflicts when shared with DO via current-limiting resistor. |
| 4 (VCC) | Power Supply | 2.5–5.5 V supply input with internal POR circuit triggering at ~2.5 V - prevents spurious writes during power ramp-up/down. |
| 5 (CS) | Chip Select | Active-high enable; minimum 250 ns low time (TCSL) required between instructions; falling edge initiates self-timed write cycle for 93LC devices. |
| 6 (CLK) | Serial Clock | Asynchronous master clock input; rising edge clocks all data; stoppable at any point; no clock required during auto-erase/write execution. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write cycles | Eliminates need for external timing control or firmware delay loops - reduces CPU load and improves system determinism. |
| Automatic ERAL before WRAL | Ensures full-array write integrity without separate erase command - simplifies firmware implementation of factory reset or firmware update sequences. |
| Power-on/off data protection | Hardware-enforced write inhibition below VCC threshold (~2.5 V) - prevents corruption during brown-out or hot-swap events. |
| Ready/Busy status via DO pin | Enables efficient polling-based write completion detection without dedicated interrupt lines or complex state machines. |
| 100% tested 8-bit organization | Guarantees consistent 8-bit addressing and data framing - avoids ambiguity in firmware driver development versus x16 variants. |
Applications
| Motor Control Configuration | Automotive Sensor Calibration |
|---|---|
Use Scenario: Storing motor pole-pair count, current limits, and PID coefficients in BLDC motor drives. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed during boot and runtime parameter updates. Use Value: Enables field-upgradable motor profiles without reprogramming MCU flash; retains settings across 15+ year vehicle lifetime. | Use Scenario: Retaining temperature-compensated offset/gain values for pressure sensors in engine management systems. IC Role / Device Role / Timing Role: Calibration data repository with guaranteed 200-year retention and AEC-Q100-compliant operation. Use Value: Eliminates need for periodic recalibration; maintains accuracy over full automotive service life despite thermal cycling. |
| Industrial PLC I/O Mapping | Medical Device Safety Parameters |
Use Scenario: Holding digital I/O assignment tables and communication protocol settings in modular PLC backplanes. IC Role / Device Role / Timing Role: Persistent configuration store accessed via Microwire interface from FPGA or ARM-based controller. Use Value: Supports hot-swap I/O module reconfiguration without firmware reload; withstands 1M+ write cycles during commissioning. | Use Scenario: Securing critical alarm thresholds and safety interlock states in portable infusion pumps. IC Role / Device Role / Timing Role: Fail-safe parameter vault with hardware write protection (EWDS) and voltage-monitored access control. Use Value: Meets IEC 62304 Class C software requirements by preventing 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/OT | 16-bit organization (256 × 16), same VCC range and package, but incompatible address/data framing. | Requires firmware rewrite for 16-bit word access; unsuitable for existing 8-bit drivers. | Select only if migrating to wider data paths and redesigning host interface logic. |
| AT25040B-MAHL-T | SPI interface (4-wire), 4 Kbit (512 × 8), 1.8–5.5 V, SOIC-8 package - no Microwire compatibility. | Needs SPI-capable MCU or bit-banged SPI emulation; larger footprint than SOT-23-6. | Choose when upgrading to SPI ecosystem or requiring higher clock rates (>10 MHz). |
Compared with 93LC66B-I/OT and AT25040B-MAHL-T, the 93LC66AT-E/OT uniquely combines automotive temperature rating, SOT-23-6 compactness, and native Microwire support - making it optimal for cost-sensitive, space-constrained legacy designs requiring drop-in replacement of older 93LC66A/B variants.
Availability
93LC66AT-E/OT is available at Aetrix Electronics and suitable for automotive control units, industrial sensor nodes, and medical device configuration storage requiring stable component supply, long-term lifecycle assurance, and AEC-Q100-compliant sourcing.
Supply support for 93LC66AT-E/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, serving automotive, industrial, consumer, and communications markets with vertically integrated silicon and tools.
The 93LC66AT-E/OT belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for reliable, low-power, Microwire-compatible nonvolatile storage in resource-constrained embedded systems where SPI is unavailable or undesirable.
FAQ
What is the memory organization of the 93LC66AT-E/OT?
The 93LC66AT-E/OT has a fixed 512 × 8-bit (4 Kbit) organization with no ORG pin - unlike 'C' variants, it does not support x16 mode. This eliminates external configuration logic and ensures deterministic 8-bit data framing in all applications. The 93LC66AT-E/OT is fully compatible with firmware written for earlier 93LC66A devices.
Does the 93LC66AT-E/OT require an external pull-up resistor on the DO pin?
Yes, the DO pin is tri-state and requires an external pull-up resistor (typically 4.7 kΩ to VCC) to ensure valid logic-high levels during Read and Ready/Busy status reporting. Without it, high-Z states may float unpredictably, causing communication errors or false busy detection. This requirement applies to all operating conditions of the 93LC66AT-E/OT.
How does the 93LC66AT-E/OT handle power loss during a write operation?
The 93LC66AT-E/OT incorporates hardware power-loss protection: its internal voltage monitor disables all write functions when VCC drops below ~2.5 V, preventing partial writes or data corruption. Combined with auto-erase-before-write and 1M endurance, this ensures robust operation in automotive environments where battery transients occur. No external circuitry is needed for safe 93LC66AT-E/OT operation.
Can the 93LC66AT-E/OT be used in place of the 93LC66A-I/OT?
Yes, the 93LC66AT-E/OT is a direct functional and pin-compatible replacement for the 93LC66A-I/OT, with identical 8-bit organization, SOT-23-6 package, and Microwire interface. The key upgrade is extended temperature range (−40°C to +125°C vs. −40°C to +85°C), making the 93LC66AT-E/OT suitable for under-hood automotive use without design changes.
What is the maximum clock frequency supported by the 93LC66AT-E/OT at 3.3 V?
At VCC = 3.3 V, the 93LC66AT-E/OT supports a maximum clock frequency of 2 MHz (per Table 1-2, A1 parameter). This is confirmed by AC specifications for 2.5 V ≤ VCC < 4.5 V. Exceeding this limit risks setup/hold violations and unreliable opcode recognition - firmware must enforce this constraint for stable 93LC66AT-E/OT operation.
93LC66AT-E/OT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SOT-23-6
- 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
- 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 ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-6
93LC66AT-E/OT FAQ
1.How can I place an order for 93LC66AT-E/OT through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66AT-E/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-E/OT reliable?
The price and inventory of 93LC66AT-E/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-E/OT is usually 5 days.
3.What payment methods are accepted for 93LC66AT-E/OT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66AT-E/OT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66AT-E/OT?
93LC66AT-E/OT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66AT-E/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-E/OT?
For technical support, including 93LC66AT-E/OT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66AT-E/OT requirements.
6.How does Aetrix verify that 93LC66AT-E/OT is sourced from the original manufacturer or authorized distributors?
All 93LC66AT-E/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-E/OT meets industry standards.
7.What is the process for return or replacement of 93LC66AT-E/OT?
All 93LC66AT-E/OT units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66AT-E/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-E/OT part is unused and in its original packaging.
Return procedure for 93LC66AT-E/OT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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