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Microchip Technology 93LC66B/SN
- Part No.:
- 93LC66B/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93LC66B/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:516
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Product details
Overview
93LC66B/SN from Microchip Technology Inc. is a 4 Kbit (256 × 16-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, operating from 2.5 V to 5.5 V, rated for Industrial (-40°C to +85°C) and Automotive (-40°C to +125°C) temperature ranges, and housed in an 8-lead SOIC package (SN). It delivers nonvolatile storage for configuration data in embedded microcontroller systems.
For engineers reviewing the 93LC66B/SN datasheet, 93LC66B/SN pinout, 93LC66B/SN application, or 93LC66B/SN equivalent, key selection criteria include its dedicated 16-bit word organization, self-timed erase/write cycles (6 ms typical), Ready/Busy status via DO pin, 1 million endurance cycles, and Pb-free RoHS-compliant packaging - all critical for reliable firmware parameter retention in space-constrained industrial controllers.
Technical Context
The 93LC66B/SN implements a synchronous serial Microwire interface with CS, CLK, and DI/DO pins, requiring no external ORG pin (fixed x16 organization). Its internal logic supports full instruction set including READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS, with status polling enabled via DO pin during programming.
It features power-on/off data protection, automatic ERAL before WRAL, and voltage-detect circuitry (VPOR = 2.5 V min), ensuring data integrity across brown-out conditions. All operations are self-timed with no external timing components required, and clock frequency scales with VCC (up to 3 MHz at VCC ≥ 4.5 V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (256 × 16-bit) - fixed x16 organization enables compact 16-bit MCU register mapping without bit-shifting overhead. |
| VCC range | 2.5 V to 5.5 V - supports direct interfacing with 3.3 V and 5 V logic domains without level shifters. |
| Endurance | 1,000,000 erase/write cycles - ensures >10 years of daily reconfiguration in field-deployed instrumentation. |
| Data retention | >200 years at 25°C - guarantees long-term calibration and serial number persistence in unpowered storage. |
| Write cycle time | 6 ms typical (TWC) - deterministic latency allows precise timeout handling in real-time firmware drivers. |
| Interface | 3-wire Microwire (CS/CLK/DI/DO) - minimal GPIO usage on resource-limited MCUs; no I²C pull-ups or SPI SS arbitration needed. |
| Temp range | -40°C to +125°C (Automotive E-grade) - qualified for under-hood automotive control modules and industrial motor drives. |
Pinout & Package
8-lead SOIC package (SN), 3.9 mm × 4.9 mm body, 1.27 mm pitch, Pb-free Matte Tin finish. Pin 1 marked by laser dot or notch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable; must be held low ≥250 ns between instructions; deselects device into standby (ICCS ≤ 5 µA). |
| CLK | Serial Clock | Synchronizes all data transfers; rising edge clocks in opcodes, addresses, and data; stoppable mid-sequence. |
| DI | Data Input | Accepts Start bit, instruction opcodes, address bits, and write data; shares no internal connection with DO. |
| DO | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); enters High-Z when CS is low or after status read. |
| VSS | Ground | Reference for all digital and analog circuitry; requires low-impedance connection to minimize noise coupling. |
| NC | No Connection | Pin 7 in SOIC/SN package - internally unconnected; must remain floating or tied to ground per layout best practice. |
| VCC | Power Supply | Supplies core logic and memory array; includes on-chip POR detection (2.5 V threshold) for automatic write inhibition during power ramp. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates need for external timing components or software delay loops - simplifies driver implementation and improves reliability. |
| Ready/Busy status on DO | Enables efficient polling-based firmware flow control without interrupt overhead or fixed wait states. |
| Automatic ERAL before WRAL | Guarantees clean memory state prior to bulk write - prevents partial writes and eliminates separate erase command in configuration updates. |
| EWEN/EWDS security lock | Prevents accidental overwrites during runtime; device powers up in EWDS mode, requiring explicit enable before any write operation. |
| Pb-free & RoHS compliant | Meets global environmental compliance requirements for industrial and automotive production without lead-free soldering process changes. |
Applications
| Industrial Sensor Calibration | Automotive Body Control Module |
|---|---|
Use Scenario: Storing factory-trimmed sensor offset/gain coefficients and linearization tables in pressure or temperature transmitters. IC Role / Device Role / Timing Role: Nonvolatile configuration storage with guaranteed 200-year data retention and 1M-cycle endurance for periodic recalibration. Use Value: Eliminates external trim potentiometers and reduces BOM count while enabling field-updatable calibration via MCU UART interface. | Use Scenario: Holding door lock actuator profiles, mirror position memory, and lighting dimming curves in vehicle body electronics. IC Role / Device Role / Timing Role: Automotive-grade (E-temp) serial EEPROM interfaced directly to 16-bit MCU GPIOs for robust parameter storage. Use Value: Supports AEC-Q100-relevant reliability with built-in POR and EWDS lock, reducing risk of corruption during battery transients. |
| Medical Infusion Pump Settings | Smart Energy Meter Firmware Parameters |
Use Scenario: Retaining drug library definitions, dose limits, and alarm thresholds across power cycles in Class II medical devices. IC Role / Device Role / Timing Role: Safety-critical configuration store with deterministic 6 ms write latency and automatic ERAL+WRAL atomic update capability. Use Value: Enables IEC 62304-compliant firmware updates without external supervision or dual-bank memory architecture. | Use Scenario: Storing tariff schedules, metering constants, and communication protocol keys in ANSI C12.22-compliant smart meters. IC Role / Device Role / Timing Role: Secure, tamper-resistant parameter storage with EWEN/EWDS lock and voltage-monitoring POR circuitry. Use Value: Meets ANSI C12.22 Annex D security requirements for nonvolatile memory integrity during brown-out events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66A/SN | Same 4 Kbit capacity but 512 × 8-bit organization; identical VCC, temp range, and package. | Requires byte-aligned MCU access; less efficient for 16-bit register maps or dual-byte parameters. | Select when system uses 8-bit data paths or legacy 8-bit MCU peripherals. |
| AT25040B-MAHL-T | SPI interface (4-wire), 4 Kbit (512 × 8), 1.8–5.5 V, same endurance and retention, SOIC-8 package. | Requires SPI peripheral instead of generic GPIO bit-banging; no Ready/Busy pin - relies on fixed 5 ms timeout. | Select when existing design already uses SPI peripherals and firmware supports fixed-delay write handling. |
Compared with 93LC66A/SN, the 93LC66B/SN provides native 16-bit word access for tighter MCU register alignment and reduced software overhead; compared with AT25040B-MAHL-T, it offers deterministic status polling and lower pin count, but requires Microwire-compatible bit-bang drivers instead of hardware SPI.
Availability
93LC66B/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive body control modules, medical infusion pump settings, and smart energy meter firmware parameters requiring stable component supply across multi-year production lifecycles.
Supply support for 93LC66B/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 devices, and memory solutions, headquartered in Chandler, Arizona, with global manufacturing and support infrastructure.
The 93LC66B/SN belongs to Microchip's legacy 93XX series of Microwire-compatible serial EEPROMs, designed specifically for cost-sensitive, space-constrained embedded systems requiring robust nonvolatile storage with minimal GPIO footprint.
FAQ
What is the memory organization of the 93LC66B/SN?
The 93LC66B/SN has a fixed 256 × 16-bit (4 Kbit) organization. Unlike 'C' variants, it does not use the ORG pin - the x16 word size is hardwired. This enables direct 16-bit MCU register mapping without software bit manipulation, reducing firmware complexity and improving access efficiency in applications like motor control parameter storage.
Does the 93LC66B/SN require an external ORG pin connection?
No, the 93LC66B/SN does not require or support an ORG pin. As a 'B'-suffix device, its 16-bit organization is fixed internally. Pin 6 in the SOIC (SN) package is NC (No Connection), and tying it to VCC or VSS has no functional effect. This simplifies PCB layout and eliminates configuration errors associated with ORG pin misrouting.
What is the maximum clock frequency supported by the 93LC66B/SN?
The 93LC66B/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. However, since the 93LC66B/SN operates from 2.5 V minimum, its practical max is 2 MHz across its full rated VCC range. This allows reliable bit-banged Microwire communication on most 8/16-bit MCUs without high-speed peripheral dependencies.
How does the Ready/Busy status work on the 93LC66B/SN?
The DO pin of the 93LC66B/SN outputs Ready/Busy status during erase/write cycles: logic low indicates ongoing operation; logic high signals completion. To poll, bring CS high for ≥250 ns after initiating the command, then sample DO. Issuing a new Start bit clears the status. This eliminates fixed timeouts and enables optimal firmware scheduling in real-time systems using the 93LC66B/SN.
Is the 93LC66B/SN qualified for automotive applications?
Yes, the 93LC66B/SN is qualified for Automotive (E-grade) operation from -40°C to +125°C and meets AEC-Q100 stress test requirements per Microchip's qualification documentation. Its on-chip power-on reset (VPOR = 2.5 V), EWEN/EWDS write protection, and 1M-cycle endurance make it suitable for body control modules, infotainment configuration storage, and other under-hood or cabin applications where reliability under thermal and electrical stress is critical.
93LC66B/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:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
93LC66B/SN FAQ
1.How can I place an order for 93LC66B/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66B/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/SN reliable?
The price and inventory of 93LC66B/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/SN is usually 5 days.
3.What payment methods are accepted for 93LC66B/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66B/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66B/SN?
93LC66B/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66B/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/SN?
For technical support, including 93LC66B/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66B/SN requirements.
6.How does Aetrix verify that 93LC66B/SN is sourced from the original manufacturer or authorized distributors?
All 93LC66B/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/SN meets industry standards.
7.What is the process for return or replacement of 93LC66B/SN?
All 93LC66B/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66B/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/SN part is unused and in its original packaging.
Return procedure for 93LC66B/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93LC66B/SN Tags
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AT24C02C-XHM-T
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AT21CS01-STUM10-T
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93LC46BT-I/OT
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AT24C04C-SSHM-T
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