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Microchip Technology 93LC66BT-I/OT
- Part No.:
- 93LC66BT-I/OT
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- SOT-23-6
- Datasheet:
-
93LC66BT-I/OT.pdf
- Description:
- IC EEPROM 4KBIT MIC WIRE SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:11,734
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Product details
Overview
93LC66BT-I/OT from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, operating across 2.5–5.5 V, supporting Industrial temperature range (−40°C to +85°C), and packaged in Pb-free 6-lead SOT-23. It implements Microwire-compatible 3-wire serial interface (CS, CLK, DI, DO) with Ready/Busy status signaling and self-timed erase/write cycles for embedded configuration storage.
For engineers reviewing the 93LC66BT-I/OT datasheet, 93LC66BT-I/OT pinout, 93LC66BT-I/OT application, or 93LC66BT-I/OT equivalent, key selection criteria include voltage compatibility (2.5–5.5 V), SOT-23 footprint constraints, 8-bit word size requirement, industrial-grade reliability, and support for sequential read and automatic ERAL/WRAL operations.
Technical Context
The 93LC66BT-I/OT uses CMOS-based Microwire protocol with synchronous serial communication: instructions and data are clocked on CLK rising edge; DO provides both memory output and real-time Ready/Busy status during programming. It lacks an ORG pin (fixed 8-bit x512 organization), distinguishing it from 'C' variants.
Its internal architecture includes auto-erase-before-write, automatic ERAL before WRAL, power-on/off data protection, and EWEN/EWDS command-based write enable/disable logic - all implemented without external timing components and independent of host clock rate within specified AC limits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit), fixed x8 organization - no ORG pin required, simplifying PCB layout and firmware address handling. |
| VCC range | 2.5 V to 5.5 V - supports direct interfacing with 3.3 V and 5 V microcontrollers without level shifting. |
| Endurance | 1,000,000 erase/write cycles - enables long-term field calibration or parameter logging in industrial control systems. |
| Data retention | Greater than 200 years at 25°C - ensures nonvolatile storage integrity over product lifetime without refresh. |
| Write cycle time | 6 ms typical (TWC) - defines minimum interval between successive write commands; impacts firmware polling or timeout design. |
| Max clock frequency | 3 MHz at VCC ≥ 4.5 V; 2 MHz at 2.5 V ≤ VCC < 4.5 V - sets upper bound for serial transaction throughput in host MCU driver. |
| Standby current | 1 µA (I-temp) - critical for battery-powered devices where EEPROM must remain powered but inactive for extended periods. |
Pinout & Package
6-lead SOT-23 package (package code OT), compact footprint (2.9 mm × 1.6 mm × 1.1 mm), Pb-free Matte Tin finish, no exposed pad. Pin 1 marked by laser dot; pin 1 = DO, pin 2 = VSS, pin 3 = DI, pin 4 = VCC, pin 5 = CS, pin 6 = CLK.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| DO (Pin 1) | Data Output / Status Indicator | Serial data output during READ; active-low Ready/Busy signal during erase/write - requires host polling or interrupt-driven status check. |
| VSS (Pin 2) | Ground Reference | Primary return path for all I/O and core logic; must be low-impedance connection to minimize noise coupling into serial interface. |
| DI (Pin 3) | Data Input | Serial input for Start bit, opcodes, addresses, and write data - driven by host MCU GPIO; high-impedance when not actively clocked. |
| VCC (Pin 4) | Power Supply | Supplies core logic and I/O buffers; requires local 100 nF decoupling capacitor placed near pin to suppress switching noise. |
| CS (Pin 5) | Chip Select | Active-high enable; must be held low ≥250 ns (TCSL) between commands to reset internal state and avoid spurious instruction latching. |
| CLK (Pin 6) | Serial Clock | Synchronizes all data transfers; rising edge clocks in DI bits and clocks out DO bits - tolerant of clock pauses during transmission. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write cycles | Eliminates need for external timing circuitry or host-controlled delays - firmware only waits for DO status or fixed 6 ms timeout. |
| Automatic ERAL before WRAL | Guarantees full-array erase prior to bulk write, preventing partial-data corruption without requiring separate ERAL command sequence. |
| Power-on/off data protection | Hardware-level inhibition below VCC threshold (1.5 V) prevents inadvertent writes during brown-out or power ramp-up sequences. |
| Industry-standard 3-wire Microwire interface | Enables drop-in replacement with legacy 93XX-series EEPROMs and compatibility with widely supported MCU peripheral drivers. |
| 1 µA standby current | Reduces system quiescent power in always-on applications such as smart sensors or energy-harvesting nodes. |
Applications
| Industrial Sensor Calibration | Consumer Appliance Configuration |
|---|---|
Use Scenario: Storing factory-trimmed sensor offset/gain coefficients and user-adjusted thresholds in temperature/humidity transmitters. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed infrequently during power-up or service mode; supports sequential read for fast coefficient loading. Use Value: Enables field-replaceable sensor modules without reprogramming host MCU firmware - coefficients persist across 200+ years and 1M cycles. | Use Scenario: Retaining user preferences (e.g., cooking time, temperature presets, language setting) in microwave ovens and washing machines. IC Role / Device Role / Timing Role: Low-power backup memory updated only on menu save; interfaces via 3-wire bus shared with display controller. Use Value: 1 µA standby current extends battery life in backup clock circuits; 2.5–5.5 V operation matches appliance main rail or LDO output. |
| Automotive Body Control Module | Medical Diagnostic Equipment |
Use Scenario: Storing seat/mirror position memory and lighting profiles in 12 V automotive systems with local 3.3 V regulation. IC Role / Device Role / Timing Role: Dedicated configuration store isolated from main MCU flash; accessed via dedicated GPIO-banged Microwire driver. Use Value: −40°C to +85°C rating meets AEC-Q100 Grade 3 requirements; ERAL/WRAL support simplifies factory initialization routines. | Use Scenario: Logging calibration constants and usage counters in portable ultrasound or glucose meters with coin-cell backup. IC Role / Device Role / Timing Role: Tamper-resistant parameter vault - write-protected via EWEN/EWDS commands and voltage-based lockout. Use Value: Hardware data protection prevents accidental overwrite during low-VCC conditions; 200-year retention ensures compliance with medical device lifecycle mandates. |
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 | 8-lead SOIC package; same 512×8 organization, 2.5–5.5 V, I-temp; includes NC pin instead of ORG. | Requires larger PCB area; better thermal dissipation and hand-solderability; no SOT-23 footprint constraint. | Select when board space allows SOIC and manual assembly or rework is preferred over SMT miniaturization. |
| AT25040B-MAHL-T | 4 Kbit SPI interface (4-wire), 1.8–5.5 V, 1M endurance, 200 yr retention; different command set and timing. | Requires SPI peripheral instead of GPIO-banged Microwire; wider VCC range enables direct 1.8 V MCU interfacing. | Select when migrating to SPI ecosystem or needing lower 1.8 V operation; requires firmware driver rewrite and layout change. |
Compared with 93LC66B-I/SN, the 93LC66BT-I/OT saves >60% board area and suits high-density layouts; compared with AT25040B-MAHL-T, it retains Microwire compatibility for legacy designs but lacks 1.8 V support and requires software polling instead of SPI-ready interrupts.
Availability
93LC66BT-I/OT is available at Aetrix Electronics and suitable for industrial sensor calibration, consumer appliance configuration, and automotive body control modules requiring stable component supply, long-term obsolescence management, and RoHS-compliant sourcing.
Supply support for 93LC66BT-I/OT 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, and Flash-IP solutions, headquartered in Chandler, Arizona, serving industrial, automotive, and consumer markets globally.
The 93LC66BT-I/OT belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-power, nonvolatile memory applications requiring simple 3-wire interface and robust data retention in space-constrained environments.
FAQ
What is the memory organization and capacity of the 93LC66BT-I/OT?
The 93LC66BT-I/OT is a 4 Kbit serial EEPROM with fixed 512 × 8-bit organization. It does not include an ORG pin, confirming its 'A'-series designation and eliminating configuration ambiguity. This structure delivers byte-addressable storage ideal for storing small configuration tables, calibration data, or device identifiers without word-alignment overhead. The 93LC66BT-I/OT supports direct 8-bit read/write access aligned with common microcontroller data buses.
Does the 93LC66BT-I/OT require an external pull-up resistor on the DO pin?
No, the 93LC66BT-I/OT does not require an external pull-up on DO. Its DO pin features an active push-pull output during READ and Ready/Busy assertion, capable of driving standard TTL/CMOS logic levels directly. However, if DI and DO are shorted (shared bus configuration), a series resistor (typically 1–10 kΩ) is recommended to prevent bus contention during the dummy-zero phase of READ operations - a design consideration explicitly noted in the 93LC66BT-I/OT datasheet.
How does write protection work on the 93LC66BT-I/OT?
Write protection on the 93LC66BT-I/OT is enforced through hardware-based EWEN (Erase/Write Enable) and EWDS (Erase/Write Disable) commands. The device powers up in EWDS mode, blocking all erase/write operations until an explicit EWEN command is issued. After any write, executing EWDS restores protection - a mandatory step per datasheet guidance to prevent accidental overwrites. Voltage-based lockout below 1.5 V adds a second layer, inhibiting writes during brown-out conditions. The 93LC66BT-I/OT does not support software write-protect bits or block-lock features.
What is the maximum clock frequency supported by the 93LC66BT-I/OT at 3.3 V operation?
At 3.3 V supply (within the 2.5–5.5 V range), the 93LC66BT-I/OT supports a maximum clock frequency of 2 MHz. This is specified in Table 1-2 (AC Characteristics) under condition "2.5 V ≤ VCC < 4.5 V". Exceeding this frequency risks setup/hold violations on DI and incorrect opcode/address latching. The 93LC66BT-I/OT's TCKH (clock high time) and TCKL (clock low time) minimums are 250 ns and 200 ns respectively at this voltage, defining the practical timing margin for reliable communication.
Can the 93LC66BT-I/OT be used in automotive applications requiring AEC-Q200 qualification?
No, the 93LC66BT-I/OT is rated for Industrial temperature range (−40°C to +85°C) and is not AEC-Q200 qualified. While its temperature range overlaps with Grade 3 automotive requirements, AEC-Q200 mandates additional stress testing (e.g., vibration, solderability, board flex) and traceability protocols not covered by the 93LC66BT-I/OT's qualification. For automotive use, Microchip offers the 93LC66BT-E/OT variant (E-temp, −40°C to +125°C), but even that part requires separate AEC-Q200 validation by the end customer - the 93LC66BT-I/OT itself carries no automotive qualification documentation.
93LC66BT-I/OT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SOT-23-6
- 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:
- 6ms
- Access Time:
- -
- Voltage - Supply:
- 2.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-6
93LC66BT-I/OT FAQ
1.How can I place an order for 93LC66BT-I/OT through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66BT-I/OT 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 93LC66BT-I/OT reliable?
The price and inventory of 93LC66BT-I/OT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66BT-I/OT is usually 5 days.
3.What payment methods are accepted for 93LC66BT-I/OT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66BT-I/OT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66BT-I/OT?
93LC66BT-I/OT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66BT-I/OT 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 93LC66BT-I/OT?
For technical support, including 93LC66BT-I/OT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66BT-I/OT requirements.
6.How does Aetrix verify that 93LC66BT-I/OT is sourced from the original manufacturer or authorized distributors?
All 93LC66BT-I/OT 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 93LC66BT-I/OT meets industry standards.
7.What is the process for return or replacement of 93LC66BT-I/OT?
All 93LC66BT-I/OT units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66BT-I/OT, 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 93LC66BT-I/OT part is unused and in its original packaging.
Return procedure for 93LC66BT-I/OT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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