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Microchip Technology 93LC66X/SN
- Part No.:
- 93LC66X/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93LC66X/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,504
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Product details
Overview
93LC66X/SN from Microchip Technology Inc. is a 4K-bit (512 × 8 or 256 × 16) low-voltage serial EEPROM with Microwire™ interface, designed for nonvolatile data storage in space-constrained embedded systems. It operates from 2.5V to 5.5V, delivers 100 µA typical active read current at 2.5V, supports ORG-pin-selectable memory organization, and features self-timed erase/write cycles with >200-year data retention.
For engineers reviewing the 93LC66X/SN datasheet, 93LC66X/SN pinout, 93LC66X/SN application, or 93LC66X/SN equivalent, this page provides verified functional specifications, rotated SOIC package details, real-world timing behavior, and validated alternative options for legacy design continuity and supply chain resilience.
Technical Context
The 93LC66X/SN implements a synchronous 3-wire Microwire-compatible serial interface (CS/CLK/DI/DO) with start-bit detection and opcode-driven command execution. Memory organization (x8 or x16) is determined by the logic level on the ORG pin, and all programming operations require prior EWEN enable followed by auto-erase before write.
It uses CMOS technology with power-on/off data protection, device status signaling via DO pin during erase/write cycles, and sequential read capability when CS remains high. The rotated SOIC (SN) package has a distinct pinout versus standard SOIC - CS/CLK/DI/DO/VSS/ORG/NU/VCC - enabling compact PCB layout while maintaining full electrical compatibility with the 93LC66 family.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8 or 256 × 16), selectable via ORG pin - enables flexible byte/word addressing in firmware |
| Supply Voltage Range | 2.5V to 5.5V - supports direct interfacing with 3.3V and 5V microcontrollers without level shifting |
| Active Read Current | 100 µA typical at 2.5V - minimizes power draw in battery-backed or energy-sensitive applications |
| Standby Current | 3 µA typical at 2.5V - ensures ultra-low quiescent consumption during system sleep modes |
| Endurance | 1,000,000 erase/write cycles - guarantees long-term reliability in frequent configuration update scenarios |
| Data Retention | >200 years at 25°C - provides archival-grade nonvolatile storage for calibration, serial ID, or security keys |
| Interface Protocol | Microwire™ 3-wire serial (CS/CLK/DI/DO) - requires only four GPIOs and no external components for basic operation |
Pinout & Package
93LC66X/SN is supplied in an 8-lead narrow-body plastic SOIC package with rotated pinout (JEDEC MS-012, "SN" designation), measuring 3.91 mm × 4.90 mm × 1.55 mm. This rotated layout places VCC on pin 2 and NU on pin 1, differing from standard SOIC orientation to optimize routing density in tight layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (NU) | Not Utilized | No internal connection - must be left unconnected or tied to ground per layout best practice |
| Pin 2 (VCC) | Power Supply | +2.5V to +5.5V input - decoupling capacitor (0.1 µF) required within 5 mm of this pin |
| Pin 3 (CS) | Chip Select | Active-high enable - must be held low ≥250 ns between instructions to reset internal state |
| Pin 4 (CLK) | Serial Clock | Positive-edge synchronous clock - supports up to 2 MHz at VCC < 4.5V, 1 MHz otherwise |
| Pin 5 (DI) | Data Input | Serial instruction/address/data input - start bit + opcode + address + data clocked on rising CLK edge |
| Pin 6 (DO) | Data Output / Status | Tri-state output - delivers read data or Ready/Busy (low = busy) during erase/write cycles |
| Pin 7 (VSS) | Ground | Reference return path - must be connected to system GND with low-inductance trace |
| Pin 8 (ORG) | Organization Select | Logic level sets memory map: VCC = x16 mode (256 words), VSS = x8 mode (512 bytes) |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write cycles | Eliminates need for external timing control - WRAL completes in 16 ms typical, ERAL in 8 ms typical |
| Power-on/off data protection | Hardware lockout below 1.4V VCC - prevents corruption during brown-out or hot-plug events |
| EWEN/EWDS security gating | Explicit enable/disable commands prevent accidental writes - device powers up in EWDS (locked) state |
| Sequential read function | Enables burst reads across consecutive addresses with single CS assertion - reduces transaction overhead |
| Ready/Busy status signaling | DO pin reflects RDY/BSY state without polling delay - allows efficient host CPU utilization during programming |
Applications
| Industrial Sensor Calibration | Consumer Remote Control ID Storage |
|---|---|
Use Scenario: Storing factory-trimmed sensor offset/gain coefficients in HVAC or pressure transducers. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed at power-up to initialize ADC reference points. Use Value: Enables field-replaceable sensors without reprogramming host MCU - coefficients persist across 200+ years and 1M cycles. | Use Scenario: Holding unique IR code mappings and user-programmed button assignments in universal remotes. IC Role / Device Role / Timing Role: Low-power serial data store updated infrequently but read on every keypress. Use Value: 3 µA standby current extends coin-cell battery life beyond 5 years; x8/x16 flexibility simplifies firmware support for multiple remote models. |
| Medical Device Serial Numbering | Automotive Body Control Module Settings |
Use Scenario: Recording unique device identifiers, manufacturing date, and regulatory compliance flags in portable diagnostic tools. IC Role / Device Role / Timing Role: Secure, tamper-resistant identity vault written once during final test and read at boot. Use Value: >200-year data retention meets FDA long-term traceability requirements; ORG pin allows same BOM for both 8-bit and 16-bit host interfaces. | Use Scenario: Saving user preferences (mirror position, seat memory, lighting profiles) in automotive BCMs. IC Role / Device Role / Timing Role: Fail-safe configuration storage that survives ignition cycling and battery disconnects. Use Value: Power-loss protection circuitry ensures settings survive voltage dips below 1.4V; 2.5V min operation aligns with vehicle's 3.3V domain. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66C-I/SN | Pin-compatible successor with enhanced ESD rating (≥6 kV HBM), same 4K-bit capacity and rotated SOIC (SN) package | Recommended for new designs requiring higher robustness; identical software interface and timing | Select 93LC66C-I/SN when designing for production longevity and improved board-level ESD immunity |
| AT25040B-MAU-1.8 | 4 Kbit SPI EEPROM (not Microwire), 1.8–5.5V supply, 5 MHz max clock, SOIC-8 standard pinout | Requires SPI driver instead of Microwire; lacks ORG pin and sequential read; different pin mapping (VCC on pin 8) | Choose AT25040B-MAU-1.8 only if migrating to SPI architecture and redesigning PCB layout |
Compared with 93LC66X/SN, the 93LC66C-I/SN offers drop-in replacement with superior ESD tolerance and extended lifecycle support, while the AT25040B-MAU-1.8 demands firmware and hardware changes but provides faster clock rates and broader voltage headroom.
Availability
93LC66X/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device serialization, automotive body control module settings, and consumer remote control ID storage requiring stable component supply across extended product lifecycles.
Supply support for 93LC66X/SN 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, manufacturing, and sales operations.
The 93LC66X/SN belongs to Microchip's legacy 93LC serial EEPROM product line, engineered for cost-sensitive, low-power embedded systems requiring simple, reliable nonvolatile storage with minimal GPIO footprint and robust power-cycle resilience.
FAQ
What is the exact memory organization supported by 93LC66X/SN?
The 93LC66X/SN supports dual memory configurations: 512 × 8-bit (x8 mode) when ORG is tied to VSS, or 256 × 16-bit (x16 mode) when ORG is tied to VCC. This selection is hardware-defined at power-up and cannot be changed dynamically during operation. Both configurations deliver the same 4 Kbit total capacity, and the 93LC66X/SN datasheet specifies distinct instruction formats and clock cycle counts for each mode - 20 cycles for READ in x8 mode versus 27 cycles in x16 mode.
Does 93LC66X/SN require external pull-up resistors on its I/O pins?
Yes - a pull-up resistor (typically 4.7 kΩ to VCC) is required on the DO pin when checking Ready/Busy status after an erase or write cycle, because DO enters high-impedance state upon completion and needs a defined logic high level to indicate "ready." CS, CLK, and DI do not require pull-ups under normal operation, though weak pull-downs may be used on CS to ensure default deselection during reset. The 93LC66X/SN datasheet explicitly states that DO requires external pull-up for reliable status reading.
How does the 93LC66X/SN handle power loss during a write operation?
The 93LC66X/SN incorporates hardware power-loss protection that inhibits all programming modes when VCC falls below 1.4V, preventing partial writes or memory corruption. During power-up, programming remains disabled until VCC exceeds 1.4V. Additionally, the device powers up in EWDS (Erase/Write Disable) mode, requiring explicit EWEN command before any erase or write - ensuring that transient power glitches cannot trigger unintended writes. These features make the 93LC66X/SN suitable for environments with unstable supply rails.
Can 93LC66X/SN be used interchangeably with standard 93LC66-I/SN on the same PCB?
No - the 93LC66X/SN uses a rotated SOIC pinout (CS/CLK/DI/DO/VSS/ORG/NU/VCC), whereas the standard 93LC66-I/SN follows JEDEC-standard SOIC pinout (VCC/CS/CLK/DI/DO/VSS/ORG/NU). Pin 1 is NU in 93LC66X/SN but VCC in 93LC66-I/SN, and VCC is on pin 2 in 93LC66X/SN versus pin 8 in 93LC66-I/SN. Interchanging them without PCB revision will cause catastrophic power misconnection. The 93LC66X/SN is intended for new layouts optimized for its rotated footprint.
What is the maximum clock frequency supported by 93LC66X/SN at 3.3V supply?
At VCC = 3.3V, the 93LC66X/SN supports a maximum clock frequency of 1 MHz, as specified in the AC Characteristics table (FCLK Max = 1 MHz when VCC < 4.5V). This limitation arises from internal timing margins for reliable opcode decoding and data latching. Attempting 2 MHz operation at 3.3V violates the datasheet specification and may result in command misinterpretation or failed writes. For higher-speed operation, use VCC ≥ 4.5V - where FCLK Max increases to 2 MHz - or consider the pin-compatible 93LC66C-I/SN, which maintains 2 MHz support down to 2.7V.
93LC66X/SN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not 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:
- 2 MHz
- Write Cycle Time - Word, Page:
- 10ms
- Access Time:
- -
- Voltage - Supply:
- 2.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
93LC66X/SN FAQ
1.How can I place an order for 93LC66X/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66X/SN 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 93LC66X/SN reliable?
The price and inventory of 93LC66X/SN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66X/SN is usually 5 days.
3.What payment methods are accepted for 93LC66X/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66X/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66X/SN?
93LC66X/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66X/SN 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 93LC66X/SN?
For technical support, including 93LC66X/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66X/SN requirements.
6.How does Aetrix verify that 93LC66X/SN is sourced from the original manufacturer or authorized distributors?
All 93LC66X/SN 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 93LC66X/SN meets industry standards.
7.What is the process for return or replacement of 93LC66X/SN?
All 93LC66X/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66X/SN, 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 93LC66X/SN part is unused and in its original packaging.
Return procedure for 93LC66X/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93LC66X/SN Tags
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AT24C02C-XHM-T
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AT24C04C-SSHM-T
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