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Microchip Technology 93LC66B-I/MS
- Part No.:
- 93LC66B-I/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
93LC66B-I/MS.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:720
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Product details
Overview
93LC66B-I/MS from Microchip Technology Inc. is a 4 Kbit (256 × 16-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, operating from 2.5V to 5.5V over -40°C to +85°C, featuring self-timed erase/write cycles, automatic ERAL/WRAL, and Ready/Busy status output - used for nonvolatile configuration storage in embedded controllers and sensor modules.
For engineers reviewing the 93LC66B-I/MS datasheet, 93LC66B-I/MS pinout, 93LC66B-I/MS application, or 93LC66B-I/MS equivalent, key selection considerations include its fixed 16-bit word organization (no ORG pin), MSOP-8 package compatibility, industrial temperature rating, and support for sequential read and write-all operations with 1M endurance cycles.
Technical Context
The 93LC66B-I/MS implements a synchronous serial Microwire interface with CS, CLK, DI, and DO signals; all instructions (READ, WRITE, ERASE, ERAL, WRAL, EWEN/EWDS) are initiated by a Start bit followed by opcode, address, and data on the rising edge of CLK. It uses internal auto-erase before write and supports full-array erase (ERAL) and full-array write (WRAL) with VCC ≥ 4.5V.
Its memory array is organized as 256 words × 16 bits, with no ORG pin (dedicated x16 mode), and includes power-on/off data protection, high-impedance DO during standby, and status polling via DO pin during programming - enabling robust, low-power nonvolatile storage in resource-constrained systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (256 × 16-bit) - provides compact, byte-aligned nonvolatile storage for firmware parameters or calibration data. |
| VCC range | 2.5V to 5.5V - supports direct interfacing with 3.3V and 5V microcontrollers without level shifting. |
| Endurance | 1,000,000 erase/write cycles - ensures long-term reliability in frequently updated configuration applications. |
| Data retention | Greater than 200 years - guarantees data integrity across product lifetime without refresh. |
| Write cycle time | 6 ms typical (TWC) - defines minimum delay between write commands; enables predictable timing in real-time firmware. |
| Operating temperature | -40°C to +85°C (Industrial grade) - validated for use in industrial control, automotive body electronics, and outdoor IoT nodes. |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - minimizes GPIO usage and PCB footprint vs. SPI or I²C. |
Pinout & Package
Package: 8-lead MSOP (MS), Pb-free Matte Tin finish, 3.0 mm × 4.9 mm body, 0.65 mm pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable signal; must be held low ≥250 ns between instructions to reset internal logic. |
| 2 (CLK) | Serial Clock | Synchronizes all data transfers; rising edge clocks in opcodes, addresses, and data; stoppable mid-transfer. |
| 3 (DI) | Data Input | Receives Start bit, instruction opcodes, addresses, and write data; requires external pull-up if shared with DO. |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); enters High-Z when CS is low or during standby. |
| 5 (VSS) | Ground | Reference return path for all digital and power circuits; must be low-impedance for noise immunity. |
| 6 (NC) | No Internal Connection | Unbonded pad; must be left floating or tied to VSS per layout best practice - no functional role. |
| 7 (ORG) | Organization Select | Not connected internally on 93LC66B - designated NC; x16 mode is hardwired and cannot be changed. |
| 8 (VCC) | Power Supply | Primary supply input; includes internal POR circuitry that inhibits operation below 1.5V for data protection. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates need for external timing control or firmware delays - simplifies driver implementation and improves system responsiveness. |
| Automatic ERAL before WRAL | Ensures clean memory state prior to bulk write, preventing partial writes or data corruption without host intervention. |
| Ready/Busy status on DO | Enables efficient polling-based programming flow without dedicated interrupt lines or fixed timeout loops. |
| Power-on/off data protection | Hardware-level lockout prevents inadvertent writes during brown-out or power ramp - critical for field-deployed devices. |
| 16-bit dedicated organization | Optimizes throughput for 16-bit MCU peripherals and eliminates software bit-packing overhead for word-aligned data. |
Applications
| Industrial Sensor Calibration | Embedded Controller Configuration |
|---|---|
Use Scenario: Storing factory-calibrated offset/gain coefficients for analog sensor front-ends in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile parameter store accessed at boot and during field recalibration; interfaces via 3-wire Microwire at ≤2 MHz. Use Value: Enables plug-and-play sensor replacement with retained calibration, reducing maintenance downtime and eliminating manual setup. | Use Scenario: Holding user-defined settings (baud rate, I/O mapping, alarm thresholds) in HVAC control panels. IC Role / Device Role / Timing Role: Configuration EEPROM directly connected to 8/16-bit MCU GPIOs; supports sequential read for fast boot-time load. Use Value: Preserves settings across power cycles and firmware updates without requiring battery backup or complex NVM emulation. |
| Automotive Body Control Module | Medical Diagnostic Instrument |
Use Scenario: Storing seat/mirror position memory and lighting profiles in 12V automotive body ECUs. IC Role / Device Role / Timing Role: Industrial-grade EEPROM interfaced to CAN-linked microcontroller; operates reliably across -40°C to +85°C ambient. Use Value: Meets AEC-Q100 stress requirements for non-safety-critical memory functions with zero failure-in-field history. | Use Scenario: Retaining device-specific calibration constants and usage logs in portable ECG monitors. IC Role / Device Role / Timing Role: Low-power serial EEPROM powered from regulated 3.3V rail; draws ≤1 µA in standby to extend battery life. Use Value: Achieves >200-year data retention for regulatory audit trails and eliminates need for periodic data refresh or backup. |
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 | Same electrical specs and pinout, but in 8-lead SOIC package (5.0 mm × 4.0 mm) - larger footprint, higher thermal mass. | Preferred for through-hole prototyping or legacy board rework where MSOP footprint is unavailable. | Select for ease of hand-soldering or compatibility with existing SOIC footprints; not suitable for space-constrained designs. |
| AT25040B-MAHL-T | 4 Kbit SPI interface (4-wire), 1.8–5.5V, 20 MHz max clock; no ERAL/WRAL; different command set and status reporting. | Requires SPI-capable MCU peripheral and revised firmware driver; lacks auto-erase-all functionality. | Choose only if migrating to SPI architecture or needing higher clock speed; adds driver complexity and removes bulk-erase convenience. |
Compared with 93LC66B-I/SN, the 93LC66B-I/MS offers identical functionality in a 35% smaller footprint ideal for compact PCBs; versus AT25040B-MAHL-T, it retains Microwire simplicity and built-in ERAL/WRAL but trades off maximum clock speed for deterministic low-power timing.
Availability
93LC66B-I/MS is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical diagnostics requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for 93LC66B-I/MS 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, with global design and manufacturing operations.
The 93LC66B belongs to Microchip's legacy 93XX series of Microwire-compatible serial EEPROMs, designed specifically for cost-sensitive, low-power embedded systems requiring simple, reliable nonvolatile storage without complex protocol stacks.
FAQ
What is the memory organization of the 93LC66B-I/MS?
The 93LC66B-I/MS has a fixed 256 × 16-bit (4 Kbit) organization. Unlike 'C' variants, it lacks an ORG pin and is permanently configured for 16-bit word access - no external logic is needed to select word size, simplifying hardware design and firmware driver development for the 93LC66B-I/MS.
Does the 93LC66B-I/MS support automatic erase before write?
Yes, the 93LC66B-I/MS performs automatic erase before each write operation - a core feature of its self-timed programming cycle. This eliminates the need for separate erase commands prior to writing, streamlining firmware logic and ensuring data integrity without host-managed erase sequencing for the 93LC66B-I/MS.
What is the purpose of the NC pin on the 93LC66B-I/MS?
Pin 6 on the 93LC66B-I/MS is labeled NC (No Internal Connection) - it is not bonded to the die and serves no electrical function. It may be left floating or connected to VSS per PCB layout guidelines, but must never be driven high or used as a signal line, as this could compromise reliability of the 93LC66B-I/MS.
Can the 93LC66B-I/MS operate at 1.8V?
No, the 93LC66B-I/MS requires a minimum VCC of 2.5V and is not rated for 1.8V operation. For 1.8V systems, consider the 93AA66B-I/MS variant instead, which supports 1.8–5.5V. Using the 93LC66B-I/MS below 2.5V risks undefined behavior, failed writes, or data corruption - always verify supply voltage compliance for the 93LC66B-I/MS.
How is Ready/Busy status monitored on the 93LC66B-I/MS?
Ready/Busy status is reported on the DO pin: logic low indicates ongoing erase/write, logic high means operation complete. To read status, bring CS high after ≥250 ns low time (TCSL), then sample DO on CLK rising edges - no additional commands are required, enabling efficient polling during programming of the 93LC66B-I/MS.
93LC66B-I/MS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 4Kbit
- Memory Organization:
- 256 x 16
- 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:
- 8-MSOP
93LC66B-I/MS FAQ
1.How can I place an order for 93LC66B-I/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66B-I/MS 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 93LC66B-I/MS reliable?
The price and inventory of 93LC66B-I/MS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66B-I/MS is usually 5 days.
3.What payment methods are accepted for 93LC66B-I/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66B-I/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66B-I/MS?
93LC66B-I/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66B-I/MS 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 93LC66B-I/MS?
For technical support, including 93LC66B-I/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66B-I/MS requirements.
6.How does Aetrix verify that 93LC66B-I/MS is sourced from the original manufacturer or authorized distributors?
All 93LC66B-I/MS 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 93LC66B-I/MS meets industry standards.
7.What is the process for return or replacement of 93LC66B-I/MS?
All 93LC66B-I/MS units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66B-I/MS, 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 93LC66B-I/MS part is unused and in its original packaging.
Return procedure for 93LC66B-I/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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