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Microchip Technology 93C66B-E/SN
- Part No.:
- 93C66B-E/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93C66B-E/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:299
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Product details
Overview
93C66B-E/SN from Microchip Technology Inc. is a 4 Kbit, 256 x 16-bit organization, low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 4.5–5.5 V supply range, and industrial/automotive temperature support (−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 configuration storage.
For engineers reviewing the 93C66B-E/SN datasheet, 93C66B-E/SN pinout, 93C66B-E/SN application, or 93C66B-E/SN equivalent, key selection criteria include its fixed 16-bit word size (no ORG pin), 2 ms program cycle time, 1 million endurance cycles, 200-year data retention, and compatibility with legacy Microwire host controllers requiring minimal firmware changes.
Technical Context
The 93C66B-E/SN implements a synchronous serial interface using CS, CLK, and DI/DO lines with start-bit detection and opcode-based command execution. Its internal architecture includes an address decoder, mode decode logic, and output buffer, supporting READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS instructions.
Unlike C-variant parts, the 93C66B has no ORG pin and operates exclusively in 16-bit mode. Erase/write initiation uses the rising edge of CLK on the final data bit (not CS fall), and VCC must be ≥4.5 V for ERAL and WRAL operations. Ready/Busy status is polled via DO while CS is high after ≥250 ns low time.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (256 × 16-bit) - provides compact nonvolatile storage for calibration tables or device IDs in space-constrained automotive PCBs. |
| VCC Range | 4.5 V to 5.5 V - matches standard 5 V automotive rail; excludes lower-voltage operation, eliminating need for level-shifting in 5 V systems. |
| Endurance | 1,000,000 erase/write cycles - supports frequent field updates in telematics or ECU reprogramming applications. |
| Data Retention | >200 years at +25°C - ensures long-term reliability across vehicle lifetime without refresh mechanisms. |
| Program Cycle Time | 2 ms (TWC) - enables fast write completion during microcontroller idle windows without blocking real-time tasks. |
| Interface Protocol | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - integrates directly with legacy MCU peripherals without SPI-to-Microwire translation firmware. |
| Temperature Range | −40°C to +125°C (Automotive E grade) - qualified for under-hood deployment including engine control units and transmission modules. |
Pinout & Package
93C66B-E/SN is packaged in an 8-lead SOIC (SN) with Pb-free Matte Tin finish. Pin 1 is CS, Pin 2 is CLK, Pin 3 is DI, Pin 4 is DO, Pin 5 is VSS, Pin 6 is NC (no internal connection), Pin 7 is NC, and Pin 8 is VCC. The ORG pin is absent - confirming fixed 16-bit operation per device family specification.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS (Pin 1) | Chip Select | Active-high enable; must be held low ≥250 ns between commands; deselects device into standby but allows ongoing write completion. |
| CLK (Pin 2) | Serial Clock | Synchronizes all data transfers; rising edge clocks in opcodes, addresses, and data; rising edge on final bit initiates 93C-series write cycle. |
| DI (Pin 3) | Data Input | Accepts start bit, instruction opcodes, memory addresses, and write data; requires stable setup/hold timing relative to CLK. |
| DO (Pin 4) | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); enters High-Z when CS is low or during non-read operations. |
| VSS (Pin 5) | Ground | Reference return path for all I/O and internal circuitry; must be low-impedance to ensure noise immunity during programming. |
| NC (Pin 6 & 7) | No Connection | Unused pins; must remain unconnected - not tied to VSS/VCC or routed on PCB to avoid parasitic coupling. |
| VCC (Pin 8) | Power Supply | 4.5–5.5 V supply; voltage detect threshold is 3.8 V - prevents inadvertent writes during brown-out conditions. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates external timing control - microcontroller only monitors DO for completion, reducing firmware complexity and CPU overhead. |
| Automatic ERAL before WRAL | Guarantees full-array erase prior to bulk write, preventing stale data remnants and simplifying firmware logic for factory provisioning. |
| Power-on/off data protection | Hardware-level lockout below 3.8 V VCC prevents corruption during power ramp-up/down - critical for ignition-switched automotive systems. |
| Ready/Busy status on DO | Enables polling-based flow control without dedicated interrupt lines, conserving MCU GPIO resources in cost-sensitive designs. |
| 16-bit fixed organization | Optimizes throughput for 16-bit MCU interfaces - halves clock cycles vs. 8-bit variants for same data volume, improving write efficiency. |
Applications
| Engine Control Unit (ECU) Calibration Storage | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: Storing fuel map coefficients, spark timing offsets, and sensor compensation values that require field updates via diagnostic tools. IC Role / Device Role / Timing Role: Nonvolatile configuration memory interfaced directly to 16-bit automotive MCU via Microwire peripheral. Use Value: 1M endurance and 200-year retention ensure reliable recalibration over 15+ year vehicle life without wear leveling firmware. | Use Scenario: Holding door lock logic states, window position memory, and lighting profiles across ignition cycles. IC Role / Device Role / Timing Role: Persistent parameter store accessed during BCM boot and runtime; reads occur during initialization, writes during user interaction. Use Value: 2 ms write time enables responsive UI feedback (e.g., window position save within 50 ms of button release). |
| Telematics Control Unit (TCU) Firmware Patch Storage | Transmission Control Module (TCM) Gear Ratio Tables |
Use Scenario: Storing OTA firmware patches and cryptographic keys in secure boot partitions before main MCU validation. IC Role / Device Role / Timing Role: Secure auxiliary memory isolated from main flash; accessed only by trusted bootloader during update sequence. Use Value: Hardware write-protection (EWEN/EWDS) prevents accidental overwrite during network stack operation or power transients. | Use Scenario: Maintaining adaptive shift-point tables updated based on driving behavior and oil temperature history. IC Role / Device Role / Timing Role: High-reliability parameter bank written ~10×/hour during dynamic driving; read continuously during gear selection logic. Use Value: −40°C to +125°C rating ensures consistent performance in hot transmission sump environments without derating. |
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 | 2.5–5.5 V VCC range; Industrial (−40°C to +85°C) grade only; identical 256 × 16-bit organization and pinout. | Not qualified for automotive under-hood use; suitable for cabin electronics or industrial panels where ambient temp stays ≤85°C. | Select when 5 V system has brown-out risk below 2.5 V or when automotive AEC-Q100 qualification is unnecessary. |
| AT25128B-MAHL-T | SPI interface (4-wire), 128 Kbit capacity, 1.8–5.5 V, 10 MHz max clock; no Ready/Busy pin - relies on WIP flag polling. | Requires SPI host driver instead of Microwire; larger memory supports multi-application partitioning but increases cost and footprint. | Choose for new designs needing higher density or SPI-native MCUs; avoid if legacy Microwire hardware/firmware reuse is required. |
Compared with 93LC66B-I/SN, the 93C66B-E/SN offers automotive-grade temperature support and tighter VCC min/max (4.5–5.5 V), ensuring robustness in noisy 5 V rails; versus AT25128B-MAHL-T, it retains Microwire compatibility and deterministic 2 ms write latency but trades off capacity and interface flexibility.
Availability
93C66B-E/SN is available at Aetrix Electronics and suitable for automotive ECU calibration storage, body control module parameter retention, and telematics secure patch storage requiring stable component supply across extended production lifecycles.
Supply support for 93C66B-E/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 design and manufacturing operations.
The 93Cxx EEPROM product line targets cost-sensitive, high-reliability embedded systems requiring simple, proven serial nonvolatile memory - especially automotive, industrial, and consumer applications where Microwire compatibility and AEC-Q100 compliance are essential.
FAQ
What is the memory organization of the 93C66B-E/SN?
The 93C66B-E/SN has a fixed 256 × 16-bit organization (4 Kbit total), with no ORG pin - unlike C-variant parts. This means it always operates in 16-bit mode, accepting 16-bit data words per address and requiring 8-bit addresses (A7–A0) for full array access. The absence of ORG simplifies PCB layout and eliminates configuration errors.
Does the 93C66B-E/SN support 3.3 V operation?
No, the 93C66B-E/SN does not support 3.3 V operation. Its specified VCC range is strictly 4.5 V to 5.5 V, as confirmed in the Device Selection Table and Electrical Characteristics section. Attempting operation below 4.5 V may cause unpredictable behavior or failure to execute erase/write commands due to the 3.8 V VCC detect threshold.
How is the Ready/Busy status monitored on the 93C66B-E/SN?
The Ready/Busy status is monitored on the DO pin: DO outputs low during active erase/write cycles and high when complete. To read status, CS must be brought high for ≥250 ns after the command initiation, then DO sampled. Issuing a Start bit followed by CS low clears the status. DO returns to High-Z when CS is low or during non-status operations.
What is the write endurance and data retention of the 93C66B-E/SN?
The 93C66B-E/SN guarantees 1,000,000 erase/write cycles and data retention exceeding 200 years at +25°C. These values are characterized and specified in the AC Characteristics table (A16) and Features list. Endurance is tested at 25°C and 5.0 V VCC; retention is extrapolated from accelerated testing per industry standards.
Is the 93C66B-E/SN pin-compatible with other 93XX66 devices in SOIC-8 package?
Yes, the 93C66B-E/SN is pin-compatible with all 93XX66A/B/C variants in the 8-lead SOIC (SN) package - including 93AA66B, 93LC66B, and 93C66A - sharing identical pinout (CS/CLK/DI/DO/VSS/NC/NC/VCC). However, functional compatibility requires matching VCC range, temperature grade, and organization (e.g., 93C66A is 8-bit and incompatible for 16-bit data paths).
93C66B-E/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:
- 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-SOIC
93C66B-E/SN FAQ
1.How can I place an order for 93C66B-E/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66B-E/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 93C66B-E/SN reliable?
The price and inventory of 93C66B-E/SN 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/SN is usually 5 days.
3.What payment methods are accepted for 93C66B-E/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66B-E/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66B-E/SN?
93C66B-E/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66B-E/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 93C66B-E/SN?
For technical support, including 93C66B-E/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66B-E/SN requirements.
6.How does Aetrix verify that 93C66B-E/SN is sourced from the original manufacturer or authorized distributors?
All 93C66B-E/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 93C66B-E/SN meets industry standards.
7.What is the process for return or replacement of 93C66B-E/SN?
All 93C66B-E/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93C66B-E/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 93C66B-E/SN part is unused and in its original packaging.
Return procedure for 93C66B-E/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93C66B-E/SN Tags
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