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Microchip Technology 93C66B-E/MS
- Part No.:
- 93C66B-E/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
93C66B-E/MS.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,399
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Product details
Overview
93C66B-E/MS from Microchip Technology Inc. is a 4 Kbit, 256 x 16-bit organization serial EEPROM with Microwire-compatible 3-wire interface, 4.5–5.5 V supply range, and industrial-temperature operation (–40°C to +85°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 embedded system configuration storage and calibration data retention.
For engineers reviewing the 93C66B-E/MS datasheet, 93C66B-E/MS pinout, 93C66B-E/MS application, or 93C66B-E/MS equivalent, key selection criteria include voltage compatibility (4.5–5.5 V), fixed 16-bit word size (no ORG pin), MSOP-8 packaging, industrial temperature grade, and Microwire protocol timing compliance at up to 3 MHz clock frequency.
Technical Context
This device implements a synchronous serial interface with CS, CLK, DI, and DO pins operating in strict Microwire protocol timing. All instructions - READ, WRITE, ERASE, ERAL, WRAL, EWEN, EWDS - are initiated by a Start bit followed by opcode, address, and data bits clocked on CLK rising edges.
It uses internal auto-erase-before-write logic and supports sequential read. The DO pin serves dual function: data output during READ and Ready/Busy status indicator during programming - low = busy, high = ready - requiring CS high for ≥250 ns after TCSL to sample status.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (256 × 16-bit) - fixed word size; no ORG pin required |
| VCC Range | 4.5 V to 5.5 V - incompatible with sub-4.5 V systems; POR threshold at 3.8 V |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - no SPI or I²C compatibility |
| Max Clock Frequency | 3 MHz at VCC ≥ 4.5 V - limits maximum instruction throughput (e.g., WRITE: 20 cycles = ~6.7 µs min) |
| Write Cycle Time | 2 ms typical - self-timed; no external delay needed; includes auto-erase |
| Data Retention | >200 years - validated at 25°C; critical for long-life industrial deployments |
| Endurance | 1,000,000 erase/write cycles - enables frequent field updates without wear-out risk |
Pinout & Package
8-pin MSOP (150-mil) package with exposed pad (optional VSS connection); pin 1 marked by laser dot. ORG pin is NC (no internal connection) on 93C66B variants per Device Selection Table and Pin Function Table.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable; must be held low ≥250 ns between instructions; deselects device into standby |
| CLK | Serial Clock | Rising-edge synchronized I/O; stoppable mid-transfer; no clocks required during self-timed write |
| DI | Data Input | Accepts Start bit, opcodes, addresses, and write data; tied to DO only with series resistor to avoid bus conflict |
| DO | Data Output / Status | Outputs read data or Ready/Busy (low=busy); enters High-Z on CS falling edge |
| VSS | Ground | Reference for all signals; exposed pad may be connected to VSS for thermal/mechanical stability |
| VCC | Power Supply | 4.5–5.5 V only; internal POR circuit blocks operation below 3.8 V |
| NC | No Connection | Pin 7 - unconnected internally; must be left floating or tied to VSS per layout best practice |
| ORG | Organization Select | No internal connection on 93C66B - fixed 16-bit mode; not usable as input or output |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates need for external timing control or polling delays beyond DO status check |
| Automatic ERAL before WRAL | Ensures full array is erased prior to bulk write - prevents partial-data corruption |
| Power-On/Off Data Protection | Hardware-level VCC monitoring blocks writes during brown-out or power ramp-up |
| Ready/Busy Status on DO | Enables non-blocking firmware polling without dedicated status register or interrupt |
| Sequential Read Mode | Reduces host CPU overhead by auto-incrementing address on successive reads while CS remains high |
Applications
| Industrial PLC Configuration Storage | Automotive ECU Calibration Data |
|---|---|
Use Scenario: Storing I/O mapping, scaling factors, and alarm thresholds in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed infrequently during commissioning or maintenance; requires >200-year data retention and 1M endurance for firmware update cycles. Use Value: Eliminates battery-backed SRAM; withstands wide ambient temperature swings and electrical noise in industrial environments. | Use Scenario: Holding sensor offset corrections, fuel trim tables, and diagnostic fault codes in engine control units across vehicle lifecycles. IC Role / Device Role / Timing Role: Calibration memory updated only during dealer reprogramming or adaptive learning; operates within automotive-grade voltage and temperature constraints. Use Value: Meets AEC-Q100 stress requirements via industrial-temp-rated 93C66B-E/MS variant; avoids costly flash partitioning or EEPROM emulation. |
| Medical Device Parameter Backup | Point-of-Sale Terminal Settings |
Use Scenario: Preserving user-adjusted therapy parameters, audit logs, and safety limits in portable infusion pumps and dialysis monitors. IC Role / Device Role / Timing Role: Secure, tamper-resistant backup memory with guaranteed data integrity over 10+ year device service life. Use Value: Leverages 1M-cycle endurance for frequent recalibration and >200-year retention for regulatory compliance documentation. | Use Scenario: Maintaining tax rates, receipt formatting rules, and network credentials in retail POS terminals subject to regional software updates. IC Role / Device Role / Timing Role: Low-pin-count, low-power serial EEPROM interfaced directly to microcontroller GPIOs with minimal board space. Use Value: MSOP-8 footprint saves PCB area vs. SOIC-8; 4.5–5.5 V range matches standard 5 V rail in legacy terminal designs. |
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/MS | 2.5–5.5 V VCC range; same 256×16 organization and MSOP-8 package | Supports wider voltage range including 3.3 V systems; rated for industrial temp only (not automotive) | Select when interfacing with mixed-voltage or 3.3 V microcontrollers; verify VCC stability above 2.5 V during write cycles. |
| 93AA66B-I/MS | 1.8–5.5 V VCC range; identical pinout and instruction set; Pb-free MSOP-8 | Enables ultra-low-power operation down to 1.8 V; retains same 256×16 structure and timing | Choose for battery-powered or energy-harvesting applications where sub-4.5 V operation is mandatory. |
Compared with 93LC66B-I/MS and 93AA66B-I/MS, the 93C66B-E/MS offers narrower but robust 4.5–5.5 V operation ideal for legacy 5 V systems, with identical 16-bit organization and MSOP-8 footprint - simplifying drop-in replacement where voltage rails are stable and ≥4.5 V.
Availability
93C66B-E/MS is available at Aetrix Electronics and suitable for industrial PLC configuration storage, automotive ECU calibration data backup, and medical device parameter retention requiring stable component supply across extended production lifecycles.
Supply support for 93C66B-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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93Cxx series is part of Microchip's legacy serial EEPROM product line designed specifically for cost-sensitive, low-pin-count nonvolatile memory applications in industrial, automotive, and consumer systems requiring proven reliability and long-term supply stability.
FAQ
What is the memory organization of the 93C66B-E/MS?
The 93C66B-E/MS has a fixed 256 × 16-bit (4 Kbit) organization. Unlike 'C'-suffix variants, it lacks an ORG pin and operates exclusively in 16-bit mode - eliminating external configuration logic and simplifying interface design for systems requiring word-aligned data access.
Does the 93C66B-E/MS require an external pull-up resistor on the DO pin?
Yes, the 93C66B-E/MS DO pin is open-drain and requires an external pull-up resistor (typically 4.7 kΩ to VCC) to ensure valid logic-high levels during Read and Ready/Busy status reporting. Without it, DO cannot drive high, causing communication failure or incorrect busy-state interpretation.
Can the 93C66B-E/MS operate at 3.3 V?
No, the 93C66B-E/MS requires a minimum VCC of 4.5 V and is not specified for 3.3 V operation. Its power-on reset (POR) threshold is 3.8 V, and functional operation below 4.5 V is not guaranteed. For 3.3 V systems, consider the 93LC66B-I/MS or 93AA66B-I/MS instead.
How does the Ready/Busy status work on the 93C66B-E/MS?
The DO pin outputs Ready/Busy status during erase/write cycles: low = busy, high = ready. To read status, CS must be brought high for ≥250 ns after TCSL (minimum CS low time); DO then reflects real-time state. Issuing a Start bit followed by CS low clears the status flag.
Is the ORG pin functional on the 93C66B-E/MS?
No - the ORG pin is marked "NC" (No Connection) on the 93C66B-E/MS per the Device Selection Table and Pin Function Table. This device is hardwired for 16-bit operation; ORG is unused and must be left floating or tied to VSS per layout guidelines.
93C66B-E/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:
- Not 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:
- 2ms
- Access Time:
- -
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-MSOP
93C66B-E/MS FAQ
1.How can I place an order for 93C66B-E/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66B-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 93C66B-E/MS reliable?
The price and inventory of 93C66B-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 93C66B-E/MS is usually 5 days.
3.What payment methods are accepted for 93C66B-E/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66B-E/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66B-E/MS?
93C66B-E/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66B-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 93C66B-E/MS?
For technical support, including 93C66B-E/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66B-E/MS requirements.
6.How does Aetrix verify that 93C66B-E/MS is sourced from the original manufacturer or authorized distributors?
All 93C66B-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 93C66B-E/MS meets industry standards.
7.What is the process for return or replacement of 93C66B-E/MS?
All 93C66B-E/MS units undergo pre-shipment inspection (PSI). If there is an issue with 93C66B-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 93C66B-E/MS part is unused and in its original packaging.
Return procedure for 93C66B-E/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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