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Microchip Technology 93LC66B-I/SN
- Part No.:
- 93LC66B-I/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93LC66B-I/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,446
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Product details
Overview
93LC66B-I/SN from Microchip Technology Inc. is a 4 Kbit, 256 × 16-bit organization serial EEPROM with Microwire-compatible 3-wire interface, operating from 2.5 V to 5.5 V over industrial temperature range (–40°C to +85°C), and housed in an 8-lead SOIC package. 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 for configuration storage in microcontroller-based embedded systems.
For engineers reviewing the 93LC66B-I/SN datasheet, 93LC66B-I/SN pinout, 93LC66B-I/SN application, or 93LC66B-I/SN equivalent, key selection considerations include its fixed 16-bit word size (no ORG pin), 6 ms typical erase/write cycle time, 1 million endurance cycles, 200-year data retention, and compatibility with low-power industrial control and sensor calibration firmware storage.
Technical Context
The 93LC66B-I/SN implements a synchronous serial Microwire interface with CS, CLK, DI, and DO signals. It operates exclusively in x16 mode (256 words × 16 bits), eliminating need for ORG pin configuration. All instructions - READ, WRITE, ERASE, ERAL, WRAL, EWEN, EWDS - are initiated by a Start bit followed by opcode and address/data on rising CLK edges.
Internal logic includes auto-erase-before-write, automatic ERAL prior to WRAL execution, and hardware-level power-on reset protection that inhibits programming below 1.5 V. The DO pin serves dual function: serial data output during READ and Ready/Busy status indicator during erase/write operations - asserted low while busy, high when complete.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (256 × 16-bit organization); supports fixed 16-bit word access without external ORG control. |
| VCC Range | 2.5 V to 5.5 V; enables direct interfacing with 3.3 V and 5 V microcontrollers without level-shifting. |
| Endurance | 1,000,000 erase/write cycles; ensures long-term reliability in frequent calibration or logging applications. |
| Data Retention | Greater than 200 years at +85°C; guarantees nonvolatile storage integrity across product lifetime. |
| Write Cycle Time | 6 ms typical (TWC); defines minimum interval between successive write commands in time-critical firmware updates. |
| Interface Protocol | Microwire-compatible 3-wire serial (CS/CLK/DI/DO); requires no additional control lines beyond standard SPI-like timing. |
| Temperature Range | Industrial: –40°C to +85°C; validated for use in factory automation, HVAC, and industrial HMI systems. |
Pinout & Package
8-lead SOIC (SN) package with standard pinout: Pin 1 = CS, Pin 2 = CLK, Pin 3 = DI, Pin 4 = DO, Pin 5 = VSS, Pin 6 = NC (no internal connection), Pin 7 = NC, Pin 8 = VCC. No ORG pin present - device is dedicated x16 configuration.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable; must be held low ≥250 ns between instructions; deselects device into standby mode. |
| CLK | Serial Clock | Synchronizes all data transfers; rising edge clocks in opcode/address/data; stoppable mid-sequence. |
| DI | Data Input | Accepts Start bit, instruction opcodes, addresses, and write data; must be stable before first CLK rising edge. |
| DO | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); enters High-Z when CS is low or during non-read states. |
| VSS | Ground | Reference for all digital and analog circuitry; requires low-impedance connection to system ground plane. |
| VCC | Power Supply | Supplies core logic and memory array; internal voltage detector disables writes below 1.5 V. |
| Pins 6 & 7 | No Connection | Internally unconnected; may be left floating or tied to VSS per layout best practices; no functional impact. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates need for external timing control - host MCU only monitors DO pin for completion signal. |
| Automatic ERAL before WRAL | Guarantees full-array erase prior to bulk write, preventing partial-data corruption during firmware updates. |
| Power-On/Off Data Protection | Hardware lockout prevents accidental writes during brown-out or power ramp-up/down transitions. |
| Ready/Busy Status on DO | Enables polling-based operation without interrupt lines - simplifies firmware integration on resource-constrained MCUs. |
| Industry Standard 3-Wire Interface | Reduces PCB routing complexity vs. parallel EEPROMs; compatible with existing Microwire drivers in legacy codebases. |
Applications
| Industrial Sensor Calibration | Microcontroller Configuration Storage |
|---|---|
Use Scenario: Storing 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; retains values across power cycles and field reconfiguration. Use Value: Enables field-adjustable calibration without requiring flash reprogramming; supports >1M recalibration cycles over product life. | Use Scenario: Holding boot-time configuration flags (e.g., UART baud rate, display brightness, I/O mapping) for ARM Cortex-M based HMI modules. IC Role / Device Role / Timing Role: Dedicated configuration EEPROM interfaced via GPIO-banged Microwire to avoid consuming dedicated SPI peripheral. Use Value: Reduces BOM cost vs. integrated flash alternatives; decouples firmware from hardware-specific settings. |
| Automated Test Equipment Settings | Medical Device Parameter Backup |
Use Scenario: Saving user-defined test profiles and pass/fail thresholds in benchtop DMMs and signal analyzers. IC Role / Device Role / Timing Role: Persistent settings register accessed during initialization and updated via service menu. Use Value: Ensures consistent test behavior across units; supports traceable calibration history via timestamped WRAL writes. | Use Scenario: Backing up therapy parameters (e.g., infusion rate, alarm limits) in portable insulin pumps and nebulizers. IC Role / Device Role / Timing Role: Safety-critical nonvolatile memory with guaranteed 200-year retention and 1M endurance under battery-backed operation. Use Value: Meets IEC 62304 Class C software requirements for data persistence without periodic refresh. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66A-I/SN | Same 4 Kbit capacity but 512 × 8-bit organization; no ORG pin; identical VCC range and timing. | Requires 8-bit data path alignment; better suited for byte-addressed legacy firmware or systems with narrow data buses. | Select when firmware expects byte-wise access or when migrating from older 8-bit microcontrollers with limited GPIO flexibility. |
| AT25040B-MAU-1.8 | 4 Kbit SPI EEPROM (8-bit only); 1.8–5.5 V supply; 5 ms max write cycle; supports SPI Mode 0/3. | Uses standard SPI protocol instead of Microwire; requires different driver stack and clock polarity handling. | Choose for new designs targeting SPI-native MCUs (e.g., STM32, ESP32) where Microwire support is unavailable or undesired. |
Compared with 93LC66A-I/SN, the 93LC66B-I/SN provides native 16-bit word access reducing instruction count for multi-byte writes; versus AT25040B-MAU-1.8, it offers Microwire compatibility and tighter integration with legacy Microchip ecosystem designs, though at the cost of SPI interoperability.
Availability
93LC66B-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, microcontroller configuration storage, and automated test equipment settings requiring stable component supply, long-term obsolescence management, and RoHS-compliant packaging.
Supply support for 93LC66B-I/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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93LC66B-I/SN belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for low-power, pin-efficient nonvolatile storage in space-constrained embedded systems where Microwire interface compatibility and industrial temperature operation are critical.
FAQ
What is the memory organization of the 93LC66B-I/SN?
The 93LC66B-I/SN has a fixed 256 × 16-bit organization - meaning it stores 256 words of 16 bits each, totaling 4 Kbit. Unlike 'C' variants, it lacks an ORG pin and operates exclusively in x16 mode, eliminating configuration overhead and ensuring deterministic 16-bit data access in firmware.
Does the 93LC66B-I/SN require an external ORG pin connection?
No, the 93LC66B-I/SN does not have an ORG pin. Pins 6 and 7 are marked NC (no internal connection) in the SOIC package. Its 16-bit organization is hardwired, making it simpler to integrate than ORG-configurable variants like the 93LC66C-I/SN.
What is the maximum clock frequency supported by the 93LC66B-I/SN?
The 93LC66B-I/SN supports up to 3 MHz clock frequency when VCC is 4.5 V to 5.5 V, 2 MHz at 2.5 V to 4.5 V, and 1 MHz at 1.8 V to 2.5 V. These AC specifications are defined in Table 1-2 of DS21795E and apply across its rated industrial temperature range.
How does the Ready/Busy status work on the 93LC66B-I/SN?
The DO pin of the 93LC66B-I/SN outputs Ready/Busy status during erase/write cycles: logic low indicates ongoing operation, logic high signals completion. To read status, CS must be brought high for ≥250 ns after TCSL; issuing a Start bit then lowering CS clears the status flag.
Is the 93LC66B-I/SN RoHS compliant and Pb-free?
Yes, the 93LC66B-I/SN is Pb-free and RoHS compliant, with a Matte Tin (Sn) finish on its leads. This is explicitly stated in the "Features" section of DS21795E and confirmed in Microchip's packaging documentation for the SN (SOIC) variant.
93LC66B-I/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:
- 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-SOIC
93LC66B-I/SN FAQ
1.How can I place an order for 93LC66B-I/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66B-I/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 93LC66B-I/SN reliable?
The price and inventory of 93LC66B-I/SN 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/SN is usually 5 days.
3.What payment methods are accepted for 93LC66B-I/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66B-I/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66B-I/SN?
93LC66B-I/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66B-I/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 93LC66B-I/SN?
For technical support, including 93LC66B-I/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66B-I/SN requirements.
6.How does Aetrix verify that 93LC66B-I/SN is sourced from the original manufacturer or authorized distributors?
All 93LC66B-I/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 93LC66B-I/SN meets industry standards.
7.What is the process for return or replacement of 93LC66B-I/SN?
All 93LC66B-I/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66B-I/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 93LC66B-I/SN part is unused and in its original packaging.
Return procedure for 93LC66B-I/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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