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Microchip Technology 93C66BT-I/SN
- Part No.:
- 93C66BT-I/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93C66BT-I/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,032
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Product details
Overview
93C66BT-I/SN from Microchip Technology Inc. is a 4 Kbit serial EEPROM with 512 × 8-bit organization, operating over 4.5–5.5 V supply and rated for industrial temperature (−40°C to +85°C). It uses Microwire-compatible 3-wire serial interface (CS/CLK/DI/DO), supports self-timed erase/write cycles, automatic ERAL/WRAL, and power-on/off data protection. It is used in embedded system configuration storage where low-voltage nonvolatile memory with sequential read and status polling is required.
For engineers reviewing the 93C66BT-I/SN datasheet, 93C66BT-I/SN pinout, 93C66BT-I/SN application, or 93C66BT-I/SN equivalent, key selection criteria include its fixed 8-bit word size (no ORG pin), 2 ms write cycle time, 1 million endurance cycles, 200-year data retention, and SOIC-8 package compatibility with legacy board layouts.
Technical Context
The 93C66BT-I/SN implements a synchronous serial Microwire interface with start-bit detection, opcode-driven command set (READ/WRITE/ERASE/ERAL/WRAL/EWEN/EWDS), and Ready/Busy status output via DO pin. Its internal logic requires CS high ≥250 ns between instructions and supports clock stopping during transmission.
It features dedicated 8-bit organization ('A' variant), no ORG pin (NC), and voltage-based write enable: VCC must be ≥4.5 V for ERAL and WRAL operations. Power-on reset disables erase/write until explicit EWEN command is issued, ensuring robust data integrity during brown-out conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit) - fixed word width; no ORG pin needed |
| VCC range | 4.5 V to 5.5 V - restricts use to 5 V systems; no low-voltage operation |
| Write cycle time | 2 ms - self-timed; enables deterministic firmware timing without external delay loops |
| Endurance | 1,000,000 erase/write cycles - supports frequent calibration or logging updates |
| Data retention | >200 years at 25°C - ensures long-term reliability in unattended equipment |
| Interface | Microwire 3-wire serial (CS/CLK/DI/DO) - minimal GPIO usage; no SPI mode or dual I/O |
| Temp range | −40°C to +85°C (Industrial) - validated for factory automation and industrial control cabinets |
Pinout & Package
93C66BT-I/SN is supplied in 8-lead SOIC (SN) package per JEDEC MS-012, with standard pinout and Pb-free Matte Tin finish. Pin 1 is marked by laser dot; exposed pad not present.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held low ≥250 ns between commands to reset internal state |
| 2 (CLK) | Serial Clock | Rising-edge synchronized I/O; clock can be paused mid-transfer without corruption |
| 3 (DI) | Data Input | Accepts start bit, opcodes, addresses, and write data; tied to VSS/VCC for EWEN/EWDS |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy (low = busy); enters High-Z on CS fall |
| 5 (VSS) | Ground | Reference for all I/O and internal logic; must be low-impedance return path |
| 6 (NC) | No Connect | Internally unconnected; must be left floating or tied to VSS per layout best practice |
| 7 (NC) | No Connect | Same as Pin 6; not bonded; no electrical function |
| 8 (VCC) | Power Supply | 4.5–5.5 V only; voltage detect threshold at 3.8 V prevents writes during brown-out |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates need for external timing control or firmware wait states; 2 ms guaranteed max |
| Automatic ERAL before WRAL | Ensures full array overwrite without separate erase command - simplifies firmware update routines |
| Power-on/off data protection | Hardware lockout below 3.8 V VCC prevents partial writes during power ramp-up/down |
| Ready/Busy status on DO | Enables polling-based operation without interrupt lines or fixed delays - reduces MCU resource usage |
| Sequential read mode | Continuous data stream across address boundaries when CS remains high - accelerates bulk reads |
Applications
| Industrial PLC Configuration Storage | Automotive Body Control Module NVM |
|---|---|
Use Scenario: Storing calibrated sensor offsets, I/O mapping, and user-defined logic parameters in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile configuration register bank accessed via microcontroller's GPIO bit-banged Microwire interface. Use Value: 1M endurance supports field recalibration; 200-year retention guarantees parameter persistence across product lifetime. | Use Scenario: Holding door lock settings, mirror position presets, and lighting profiles in automotive body electronics. IC Role / Device Role / Timing Role: Dedicated 5 V EEPROM interfaced to 8-bit MCU with limited SPI peripherals. Use Value: Fixed 8-bit organization matches byte-addressed MCU access; 4.5–5.5 V range aligns with vehicle battery nominal voltage. |
| Medical Device Calibration Data | Point-of-Sale Terminal Settings |
Use Scenario: Archiving factory calibration coefficients and usage counters in portable diagnostic instruments. IC Role / Device Role / Timing Role: Secure, tamper-resistant storage element isolated from main processor bus. Use Value: EWEN/EWDS commands prevent accidental overwrites during firmware updates or service mode. | Use Scenario: Retaining tax rates, receipt formatting rules, and operator PINs in retail terminals operating 24/7. IC Role / Device Role / Timing Role: Low-pin-count serial NVM sharing PCB space with display driver and thermal printer controller. Use Value: SOIC-8 footprint allows drop-in replacement of legacy EEPROMs; no redesign needed. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93C66AT-I/SN | Same 512×8 organization, but rated for 1.8–5.5 V; includes ORG pin (NC on A-version) | Supports wider VCC range including 3.3 V systems; same SOIC-8 package and pinout | Select if migrating to mixed-voltage designs or requiring lower standby current at 3.3 V |
| AT25040B-SSHL-T | SPI interface (4-wire), 512×8, 1.8–5.5 V, 5 ms write time, no ERAL/WRAL | Requires SPI peripheral instead of bit-banged Microwire; lacks auto-erase-all functionality | Choose when existing design already uses SPI peripherals and firmware can manage discrete erase steps |
Compared with 93C66AT-I/SN, the 93C66BT-I/SN trades voltage flexibility for tighter 4.5–5.5 V regulation tolerance and faster 2 ms write time; versus AT25040B-SSHL-T, it retains Microwire compatibility and integrated ERAL/WRAL but requires GPIO bit-banging instead of hardware SPI.
Availability
93C66BT-I/SN is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical device calibration storage requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for 93C66BT-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.
The 93C66BT-I/SN belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-pin-count nonvolatile storage in 5 V embedded systems with strict data integrity requirements.
FAQ
What is the memory organization of the 93C66BT-I/SN?
The 93C66BT-I/SN has a fixed 512 × 8-bit organization. It is an 'A'-type device with no ORG pin (marked NC), meaning it operates exclusively in 8-bit mode and does not support 16-bit word access. This is confirmed in the Device Selection Table and Pin Function Table of DS21795E, where 93C66A variants are explicitly listed as 8-bit with no ORG pin.
Does the 93C66BT-I/SN support 3.3 V operation?
No, the 93C66BT-I/SN does not support 3.3 V operation. Its specified VCC range is strictly 4.5 V to 5.5 V, as stated in the Device Selection Table and Electrical Characteristics section of DS21795E. Attempting to operate below 4.5 V may result in failed writes or undefined behavior due to the 3.8 V VCC detect threshold.
What is the purpose of the NC pins on the 93C66BT-I/SN?
Pins 6 and 7 on the 93C66BT-I/SN are No Connect (NC) terminals - internally unconnected and unbonded. They must be left floating or tied to VSS per PCB layout best practices. These pins exist for package compatibility across the 93XX66 family (e.g., 'C' versions use Pin 6 for ORG), but serve no function in the 93C66BT-I/SN.
How does the Ready/Busy status work on the 93C66BT-I/SN?
The DO pin of the 93C66BT-I/SN outputs Ready/Busy status during erase/write cycles: DO = low indicates ongoing operation; DO = high signals completion. Status is only valid after CS is brought high for ≥250 ns post-command. Issuing a Start bit then lowering CS clears the status flag, enabling reliable polling without external timers.
Can the 93C66BT-I/SN be used in automotive applications?
The 93C66BT-I/SN is rated for Industrial temperature (−40°C to +85°C), not Automotive (−40°C to +125°C). While it may function in some under-hood environments, it is not qualified or tested for AEC-Q100 Grade 2 or Grade 1. For automotive use, Microchip recommends the 93C66B-E/SN or 93C66C-E/SN variants explicitly listed for E-temp range in the Device Selection Table.
93C66BT-I/SN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- 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 ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
93C66BT-I/SN FAQ
1.How can I place an order for 93C66BT-I/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66BT-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 93C66BT-I/SN reliable?
The price and inventory of 93C66BT-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 93C66BT-I/SN is usually 5 days.
3.What payment methods are accepted for 93C66BT-I/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66BT-I/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66BT-I/SN?
93C66BT-I/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66BT-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 93C66BT-I/SN?
For technical support, including 93C66BT-I/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66BT-I/SN requirements.
6.How does Aetrix verify that 93C66BT-I/SN is sourced from the original manufacturer or authorized distributors?
All 93C66BT-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 93C66BT-I/SN meets industry standards.
7.What is the process for return or replacement of 93C66BT-I/SN?
All 93C66BT-I/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93C66BT-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 93C66BT-I/SN part is unused and in its original packaging.
Return procedure for 93C66BT-I/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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