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Microchip Technology 93LC66AT-E/MS
- Part No.:
- 93LC66AT-E/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
93LC66AT-E/MS.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,611
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Product details
Overview
93LC66AT-E/MS from Microchip Technology is a 4 Kbit (512 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 2.5–5.5 V supply range, and automotive-grade temperature operation (–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 automotive body control modules for storing calibration and configuration data.
For engineers reviewing the 93LC66AT-E/MS datasheet, 93LC66AT-E/MS pinout, 93LC66AT-E/MS application, or 93LC66AT-E/MS equivalent, key selection criteria include its automotive temperature rating, MSOP-8 package footprint, 8-bit organization (no ORG pin), 1 million endurance cycles, and compatibility with legacy Microwire controllers in safety-critical embedded systems.
Technical Context
The 93LC66AT-E/MS implements a synchronous serial interface using CS, CLK, and DI/DO signals with start-bit detection and opcode-driven command execution. Its memory array is organized as 512 words × 8 bits, fixed by internal design (no ORG pin), eliminating external configuration logic required by 'C' variants.
It supports full instruction set including READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS - all executed via rising-edge clocked serial bitstreams. Ready/Busy status is actively driven on DO during programming, enabling polling-based firmware synchronization without timers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit); fixed x8 organization - no ORG pin needed, simplifying PCB layout and firmware initialization. |
| VCC range | 2.5 V to 5.5 V; supports wide input rails common in automotive 3.3 V and 5 V domains without level-shifting. |
| Endurance | 1,000,000 erase/write cycles; ensures reliable reprogramming over vehicle lifetime in ECU configuration storage. |
| Data retention | >200 years at +25°C; guarantees nonvolatile data integrity across product lifecycle without refresh. |
| Write cycle time | 6 ms typical (TWC); enables deterministic firmware timeout handling for write confirmation. |
| Temperature grade | Automotive (E): –40°C to +125°C; qualified for under-hood and transmission control unit environments. |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO); interoperable with legacy microcontrollers lacking SPI hardware. |
Pinout & Package
8-pin MSOP (MS) package, 3.0 mm × 3.0 mm × 1.0 mm body, exposed pad optional, Pb-free Matte Tin finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 CS | Chip Select | Active-high enable; must be held ≥250 ns low between instructions to reset internal state and avoid bus contention. |
| 2 CLK | Serial Clock | Rising-edge synchronized I/O; clock can pause mid-transfer, easing timing margins for slow microcontrollers. |
| 3 DI | Data Input | Accepts start bit, opcodes, addresses, and write data; high-impedance when not selected. |
| 4 DO | Data Output / Status | Outputs read data or Ready/Busy (low = busy); enters High-Z on CS falling edge - prevents bus conflicts. |
| 5 VSS | Ground | Reference return path; must be low-inductance connection to support fast transient current during write cycles. |
| 6 NC | No Connection | Internally unconnected; must be left floating or tied to VSS per layout guidelines - no pull-up/down required. |
| 7 VCC | Power Supply | 2.5–5.5 V input; includes internal POR circuitry that blocks writes below 2.5 V (typical 1.5 V detect threshold). |
| 8 ORG | Organization select | Not connected (NC) on 93LC66A/B devices; permanently configured for 8-bit mode - no external bias needed. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates external timing components and firmware delay loops - write completion signaled via DO pin polling. |
| Automatic ERAL before WRAL | Guarantees full-array erase prior to bulk write, preventing stale data corruption without explicit command sequencing. |
| Power-on/off data protection | Hardware-enforced write inhibition when VCC drops below 1.5 V, preventing partial writes during brown-out conditions. |
| Ready/Busy status on DO | Enables real-time status monitoring without additional GPIO pins - reduces MCU resource usage in space-constrained ECUs. |
| 1,000,000 endurance cycles | Supports frequent recalibration logging (e.g., battery management, sensor offset updates) over 15+ year vehicle service life. |
Applications
| Automotive Body Control Module | Industrial PLC Configuration Storage |
|---|---|
Use Scenario: Storing door lock actuator calibration, mirror position presets, and lighting profiles in a vehicle body controller. IC Role / Device Role / Timing Role: Nonvolatile configuration register holding user-customized settings persisting across ignition cycles. Use Value: Enables field-updatable personalization without requiring reprogramming of main MCU flash - reducing service time and warranty claims. | Use Scenario: Retaining I/O mapping, scaling factors, and alarm thresholds in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: Dedicated parameter store accessed only during boot or maintenance mode - isolated from real-time scan cycle. Use Value: Decouples firmware versioning from configuration updates, allowing independent revision control and validation of operational parameters. |
| Medical Infusion Pump Settings | Smart Energy Meter Calibration Data |
Use Scenario: Securing drug library limits, flow rate safety bounds, and user access levels in Class II medical infusion devices. IC Role / Device Role / Timing Role: Tamper-resistant parameter vault with hardware write-protection (EWEN/EWDS) and voltage-monitored access control. Use Value: Meets IEC 62304 software safety requirements by isolating critical safety parameters from main application memory. | Use Scenario: Storing meter-specific CT/PT ratios, tariff schedules, and cryptographic keys in ANSI C12.22-compliant smart meters. IC Role / Device Role / Timing Role: Secure, long-retention storage for metrology-critical constants updated infrequently during commissioning or firmware upgrade. Use Value: Ensures billing accuracy over 20-year deployment without drift or corruption - validated by >200-year data retention spec. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66BT-E/MS | 16-bit organization (256 × 16), same VCC/temp/package - requires firmware address/data width adaptation. | Used where wider data paths reduce transaction count (e.g., firmware patch storage), but incompatible with existing 8-bit drivers. | Select only if system architecture benefits from 16-bit word access and software can be modified to handle dual-byte addressing. |
| AT25DF041A-MAU-T | SPI interface (4-wire), 4 Mbit density, 2.7–3.6 V only, no ERAL/WRAL - lacks Microwire compatibility and automotive temp grade. | Suitable for high-density, low-pin-count designs with SPI masters, but requires voltage translation and new driver stack. | Choose only when migrating to SPI ecosystem and higher capacity is mandatory - not drop-in compatible with 93LC66AT-E/MS. |
Compared with 93LC66BT-E/MS, the 93LC66AT-E/MS offers simpler firmware integration for 8-bit systems; compared with AT25DF041A-MAU-T, it provides guaranteed automotive qualification, Microwire legacy support, and deterministic 6 ms write timing - critical for ASIL-B functional safety partitions.
Availability
93LC66AT-E/MS is available at Aetrix Electronics and suitable for automotive electronics, industrial control systems, and medical device manufacturing requiring stable component supply with full traceability and extended lifecycle support.
Supply support for 93LC66AT-E/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 microcontroller, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, serving automotive, industrial, communications, and consumer markets.
The 93LC66A/B/C series was designed specifically for cost-sensitive, low-power embedded systems requiring robust serial EEPROM with Microwire compatibility and extended temperature reliability - targeting automotive body electronics and industrial controls.
FAQ
What is the memory organization of the 93LC66AT-E/MS?
The 93LC66AT-E/MS is a fixed 512 × 8-bit (4 Kbit) EEPROM with no ORG pin - it operates exclusively in x8 mode. Unlike 'C' variants, it does not support runtime word-size selection, simplifying hardware design and eliminating external ORG biasing components. This configuration is confirmed in the Device Selection Table and Pin Function Table of DS21795E.
Does the 93LC66AT-E/MS support automotive temperature range?
Yes, the 93LC66AT-E/MS is rated for the automotive temperature range of –40°C to +125°C (E grade), as explicitly stated in the Device Selection Table and Electrical Characteristics section of DS21795E. This qualification makes it suitable for under-hood and transmission control applications where ambient thermal stress exceeds industrial limits.
What package type is used for the 93LC66AT-E/MS?
The 93LC66AT-E/MS uses an 8-pin MSOP (Mini Small Outline Package) with 3.0 mm × 3.0 mm body and 0.65 mm lead pitch, designated as 'MS' in Microchip's packaging codes. Package drawings and marking details are provided in DS21795E pages 12–14 and confirmed in the Device Selection Table.
How does write protection work on the 93LC66AT-E/MS?
The 93LC66AT-E/MS implements hardware-assisted write protection via EWEN (Erase/Write Enable) and EWDS (Erase/Write Disable) commands. It powers up in EWDS mode, blocking all erase/write operations until EWEN is issued. After each write, executing EWDS restores protection - a requirement emphasized in Section 2.6 of DS21795E to prevent accidental corruption.
Is the 93LC66AT-E/MS Microwire-compatible?
Yes, the 93LC66AT-E/MS is fully Microwire-compatible, supporting the standard 3-wire serial interface (CS/CLK/DI/DO) with start-bit detection, opcode-based instruction set, and synchronous clocking on CLK rising edges. This compatibility is documented in the device description, Functional Description, and Instruction Set tables of DS21795E.
93LC66AT-E/MS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not 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:
- 8-MSOP
93LC66AT-E/MS FAQ
1.How can I place an order for 93LC66AT-E/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66AT-E/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 93LC66AT-E/MS reliable?
The price and inventory of 93LC66AT-E/MS 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/MS is usually 5 days.
3.What payment methods are accepted for 93LC66AT-E/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66AT-E/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66AT-E/MS?
93LC66AT-E/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66AT-E/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 93LC66AT-E/MS?
For technical support, including 93LC66AT-E/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66AT-E/MS requirements.
6.How does Aetrix verify that 93LC66AT-E/MS is sourced from the original manufacturer or authorized distributors?
All 93LC66AT-E/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 93LC66AT-E/MS meets industry standards.
7.What is the process for return or replacement of 93LC66AT-E/MS?
All 93LC66AT-E/MS units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66AT-E/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 93LC66AT-E/MS part is unused and in its original packaging.
Return procedure for 93LC66AT-E/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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