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Microchip Technology 93C66BT-I/ST
- Part No.:
- 93C66BT-I/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
93C66BT-I/ST.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,522
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Product details
Overview
93C66BT-I/ST from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, designed for nonvolatile memory storage in embedded control systems. It operates over 4.5–5.5 V, supports Microwire-compatible 3-wire serial interface (CS/CLK/DI/DO), features self-timed erase/write cycles, and delivers 1,000,000 endurance cycles with >200 years data retention. Used in industrial sensor calibration and power supply configuration.
For engineers reviewing the 93C66BT-I/ST datasheet, 93C66BT-I/ST pinout, 93C66BT-I/ST application, or 93C66BT-I/ST equivalent, key selection criteria include its 4.5–5.5 V supply range, TSSOP-8 package, industrial temperature grade (–40°C to +85°C), Ready/Busy status signaling via DO, and compatibility with legacy Microwire controllers requiring no protocol translation.
Technical Context
The 93C66BT-I/ST implements a synchronous serial Microwire interface with start-bit detection, opcode-driven instruction set (READ/WRITE/ERASE/ERAL/WRAL/EWEN/EWDS), and hardware-based data protection. Its internal logic decodes 3-bit opcodes followed by 9-bit address and optional 8-bit data on the DI line, outputting data or status on DO synchronized to CLK rising edges.
It uses auto-erase-before-write architecture with fixed 2 ms program cycle time (TWC) and 15 ms Write All (WRAL) timing at VCC ≥ 4.5 V. Power-on reset circuitry inhibits operation below 3.8 V, and the ORG pin is NC - confirming fixed x8 organization per device family designation 'A'.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit), fixed x8 organization - no ORG pin required, simplifies PCB layout vs. C-series variants. |
| VCC range | 4.5–5.5 V - compatible with 5 V logic systems; operation disabled below 3.8 V for data integrity. |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - interoperable with legacy microcontrollers without SPI mode conversion. |
| Write cycle time | 2 ms max (TWC) - enables fast firmware parameter updates without blocking host CPU for extended periods. |
| Endurance | 1,000,000 erase/write cycles - suitable for applications requiring frequent field calibration or logging. |
| Data retention | >200 years at 25°C - ensures long-term reliability in unattended industrial equipment. |
| Temperature range | –40°C to +85°C (Industrial grade) - validated for use in motor drives, PLC I/O modules, and HVAC controllers. |
Pinout & Package
93C66BT-I/ST is housed in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch, JEDEC MO-153 compliant, and Pb-free Matte Tin finish. Pin 1 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 instructions; deselects device into standby but allows ongoing write completion. |
| 2 (CLK) | Serial Clock | Synchronizes all data transfers; rising edge clocks in opcodes, addresses, and data; stoppable mid-sequence without corruption. |
| 3 (DI) | Data Input | Accepts start bit, 3-bit opcode, 9-bit address, and 8-bit data; high-impedance when not selected. |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); enters High-Z on CS falling edge; requires CS high ≥250 ns to sample status. |
| 5 (VSS) | Ground | Reference return path for all signals; must be low-impedance to minimize noise during write cycles. |
| 6 (NC) | No Connection | Internally unconnected; must be left floating or tied to VSS per layout best practice - no functional role. |
| 7 (ORG) | Organization Select | No internal connection (NC) on 'A' devices - confirms fixed 8-bit word size; not routed to die. |
| 8 (VCC) | Power Supply | 4.5–5.5 V supply; internal POR circuit disables operation below 3.8 V to prevent partial writes. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates external timing control - host only needs to monitor DO for Ready/Busy, reducing firmware complexity. |
| Automatic ERAL before WRAL | Ensures full array overwrite without separate erase command - simplifies bulk configuration updates in one instruction. |
| Power-on/off data protection | Hardware lockout below 3.8 V prevents corruption during brown-out or hot-plug events - critical for industrial power supplies. |
| Industry-standard Microwire interface | Direct drop-in replacement for legacy 93C46/93C56 designs - no driver modification needed in existing 5 V systems. |
| 1,000,000 endurance cycles | Supports daily recalibration over 27 years - validated for use in medical device calibration tables and energy meter tariff storage. |
Applications
| Industrial Sensor Calibration | Power Supply Configuration |
|---|---|
Use Scenario: Storing factory-trimmed offset/gain coefficients for analog sensor front-ends in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile parameter storage with infrequent writes and frequent reads; accessed via microcontroller's Microwire peripheral during boot or maintenance mode. Use Value: Enables field-replaceable sensor modules without reprogramming host firmware - coefficients persist across power cycles and firmware updates. | Use Scenario: Holding voltage/current limit settings, soft-start profiles, and fault recovery parameters in AC-DC and DC-DC power supplies. IC Role / Device Role / Timing Role: Configuration memory mapped to system controller; written once at manufacturing and read at power-up. Use Value: Allows single hardware design to support multiple output configurations via software-defined parameters - reduces BOM variants. |
| Motor Drive Parameter Storage | Embedded System Bootloader Settings |
Use Scenario: Saving user-adjusted PID loop gains, acceleration profiles, and thermal derating curves in servo drive firmware. IC Role / Device Role / Timing Role: Persistent storage for runtime-tunable parameters; accessed via dedicated I²C-to-Microwire bridge or direct GPIO bit-banging. Use Value: Permits OEM-specific tuning without modifying core firmware - parameters survive firmware upgrades and factory resets. | Use Scenario: Storing bootloader jump address, secure boot flags, and watchdog timeout values in safety-critical embedded controllers. IC Role / Device Role / Timing Role: Early-boot configuration store; read within first 100 µs of VCC stabilization to configure processor boot mode. Use Value: Ensures deterministic boot behavior independent of flash programming state - critical for ASIL-B automotive modules. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93C66B-I/ST | 16-bit organization (256 × 16), same VCC range and package - requires ORG pin tied to VCC (not NC). | Used where wider data bus reduces transaction count (e.g., storing 16-bit ADC calibration words). | Select only if system requires native 16-bit word access and can route ORG to VCC; not pin-compatible due to ORG functionality. |
| 93LC66A-I/ST | Wider VCC range (2.5–5.5 V), identical 8-bit organization and TSSOP-8 package - no ORG pin, same pinout. | Preferred for mixed-voltage systems (e.g., 3.3 V MCU with 5 V peripherals) where 5 V-only operation is unnecessary. | Drop-in replacement for 93C66BT-I/ST in 3.3 V designs; retains identical timing and instruction set - verified pin-to-pin and functionally compatible. |
Compared with 93C66BT-I/ST, 93LC66A-I/ST extends voltage flexibility without sacrificing speed or endurance, while 93C66B-I/ST trades pin compatibility for higher data throughput per transaction - choice depends on supply architecture and word-width requirements.
Availability
93C66BT-I/ST is available at Aetrix Electronics and suitable for industrial automation, power electronics, and embedded control applications requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for 93C66BT-I/ST 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 was engineered specifically for cost-sensitive, low-power serial EEPROM applications in industrial and automotive systems, emphasizing robustness, long data retention, and seamless integration with legacy Microwire controllers.
FAQ
What is the memory organization of the 93C66BT-I/ST?
The 93C66BT-I/ST has a fixed 512 × 8-bit (4 Kbit) organization. As a member of the 'A' variant family, it does not use the ORG pin - which is internally disconnected (NC) - and therefore always operates in x8 mode, eliminating configuration uncertainty during design-in.
Does the 93C66BT-I/ST require an external pull-up resistor on the DO pin?
Yes, the 93C66BT-I/ST 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 polling. This is mandatory for reliable communication and matches Microwire bus requirements.
What is the maximum clock frequency supported by the 93C66BT-I/ST?
The 93C66BT-I/ST supports up to 3 MHz clock frequency when VCC is 4.5–5.5 V. At this rate, READ and WRITE instructions complete in 20 clock cycles (≈6.7 µs), enabling rapid parameter access in time-critical embedded systems.
How does the 93C66BT-I/ST protect against accidental writes during power transitions?
The 93C66BT-I/ST incorporates hardware power-on reset (POR) that disables all write functions until VCC rises above 3.8 V. Additionally, it powers up in Erase/Write Disable (EWDS) mode, requiring an explicit EWEN command before any ERASE or WRITE instruction executes - providing dual-layer protection.
Is the 93C66BT-I/ST pin-compatible with the 93C46 series?
No, the 93C66BT-I/ST is not pin-compatible with the 93C46 series. While both use TSSOP-8 packages, the 93C66BT-I/ST assigns Pin 6 as NC and Pin 7 as ORG (NC), whereas the 93C46 uses Pin 6 as ORG and Pin 7 as VCC - requiring PCB layout revision for migration.
93C66BT-I/ST Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP (0.173", 4.40mm 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:
- 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-TSSOP
93C66BT-I/ST FAQ
1.How can I place an order for 93C66BT-I/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66BT-I/ST 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/ST reliable?
The price and inventory of 93C66BT-I/ST 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/ST is usually 5 days.
3.What payment methods are accepted for 93C66BT-I/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66BT-I/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66BT-I/ST?
93C66BT-I/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66BT-I/ST 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/ST?
For technical support, including 93C66BT-I/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66BT-I/ST requirements.
6.How does Aetrix verify that 93C66BT-I/ST is sourced from the original manufacturer or authorized distributors?
All 93C66BT-I/ST 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/ST meets industry standards.
7.What is the process for return or replacement of 93C66BT-I/ST?
All 93C66BT-I/ST units undergo pre-shipment inspection (PSI). If there is an issue with 93C66BT-I/ST, 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/ST part is unused and in its original packaging.
Return procedure for 93C66BT-I/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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