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Microchip Technology 93C66AT-E/OT
- Part No.:
- 93C66AT-E/OT
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- SOT-23-6
- Datasheet:
-
93C66AT-E/OT.pdf
- Description:
- IC EEPROM 4KBIT MIC WIRE SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:1,401
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Product details
Overview
93C66AT-E/OT from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, designed for nonvolatile memory storage in space-constrained embedded systems. It operates over 4.5–5.5 V, supports Microwire-compatible 3-wire serial interface (CS/CLK/DI/DO), delivers 1 million erase/write cycles, and retains data >200 years. Used in industrial control parameter storage and power-up configuration retention.
For engineers reviewing the 93C66AT-E/OT datasheet, 93C66AT-E/OT pinout, 93C66AT-E/OT application, or 93C66AT-E/OT equivalent, key selection criteria include its 4.5–5.5 V supply range, SOT-23-6 package, automotive-grade temperature rating (−40°C to +125°C), and absence of ORG pin-confirming fixed 8-bit word size and simplified interface design.
Technical Context
The 93C66AT-E/OT implements a synchronous Microwire-compatible serial protocol with start-bit detection, opcode-driven instruction set (READ/WRITE/ERASE/ERAL/WRAL/EWEN/EWDS), and Ready/Busy status polling via DO pin. Its self-timed write cycle completes in 2 ms, initiated by CLK rising edge on final data bit.
Power-on protection disables programming below 3.8 V; EWEN/EWDS commands enforce explicit write-enable discipline. The device uses CMOS technology for low standby current (≤5 µA) and integrates on-chip auto-erase before write, eliminating external erase steps.
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 | 4.5 V to 5.5 V - compatible with standard 5 V logic rails and automotive 5 V supplies; no level-shifting needed. |
| Endurance | 1,000,000 erase/write cycles - supports frequent field updates in calibration or logging applications. |
| Data Retention | >200 years at 25°C - ensures long-term reliability in unattended or maintenance-free deployments. |
| Write Cycle Time | 2 ms typical - enables fast parameter updates without blocking host MCU execution for extended periods. |
| Interface | 3-wire Microwire-compatible (CS/CLK/DI/DO) - minimal GPIO usage; no SPI mode bits or CS polarity configuration required. |
| Temp Range | −40°C to +125°C (Automotive E grade) - qualified for under-hood and industrial ambient environments. |
| Standby Current | ≤5 µA at VCC = 5.5 V - critical for battery-backed or energy-harvesting systems requiring ultra-low quiescent power. |
Pinout & Package
93C66AT-E/OT is housed in a Pb-free 6-lead SOT-23 package (JEDEC MO-178AA), measuring 2.9 mm × 1.6 mm × 1.1 mm, with gull-wing leads and exposed pad option (not connected per datasheet). Pin 1 is marked by laser dot; pin 1 ID corner is bottom-left when viewed top-down with marking side up.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| DO (Pin 1) | Data Output / Ready-Busy Indicator | Outputs read data on CLK rising edge; drives low during active erase/write - enables polling without additional status lines. |
| VSS (Pin 2) | Ground Reference | Primary return path for all I/O and internal circuitry; must be low-impedance to ensure stable timing and noise immunity. |
| DI (Pin 3) | Data Input | Accepts start bit, opcodes, addresses, and write data on CLK rising edge - bidirectional use with DO requires series resistor to prevent bus conflict. |
| VCC (Pin 4) | Power Supply | 4.5–5.5 V supply; internal POR circuit triggers at ~3.8 V - prevents corruption during brown-out conditions. |
| CS (Pin 5) | Chip Select | Active-high enable; minimum 250 ns low time between instructions required - defines command boundaries and resets internal state. |
| CLK (Pin 6) | Serial Clock | Synchronizes all data transfers; rising edge clocks in DI and clocks out DO - stoppable at any point for host flexibility. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | 2 ms typical cycle time with automatic erase-before-write - eliminates need for external timing control or erase verification. |
| Power-On Data Protection | Internal voltage detector disables writes below 3.8 V - prevents inadvertent corruption during power ramp-up or dropout. |
| EWEN/EWDS Command Lock | Explicit write-enable sequence required before each programming operation - adds firmware-level safety against accidental writes. |
| Sequential Read Mode | Continuous clocking while CS remains high auto-increments address - reduces host CPU overhead for bulk reads. |
| Ready/Busy Polling | DO pin doubles as status indicator - avoids fixed delays and enables deterministic timing in real-time systems. |
| Pb-Free & RoHS Compliant | Matte tin finish on all packages - meets global environmental compliance requirements for industrial and automotive production. |
Applications
| Industrial Sensor Calibration Storage | Automotive ECU Configuration Memory |
|---|---|
Use Scenario: Storing factory-calibrated sensor offset/gain coefficients in programmable logic controllers and pressure transmitters. IC Role / Device Role / Timing Role: Nonvolatile parameter register accessed at power-on and during field recalibration routines. Use Value: 1M endurance supports repeated recalibration across product lifetime; 125°C rating ensures reliability in enclosed control cabinets. | Use Scenario: Holding vehicle-specific configuration data (e.g., transmission shift maps, lighting profiles) in body control modules. IC Role / Device Role / Timing Role: Boot-time configuration loader interfaced to microcontroller via minimal GPIO resources. Use Value: −40°C to +125°C operation matches automotive under-hood thermal requirements; 2 ms write enables fast reprogramming during dealer updates. |
| Medical Device Settings Backup | Smart Meter Firmware Parameter Storage |
Use Scenario: Preserving user-adjusted therapy parameters and audit logs in portable infusion pumps and diagnostic monitors. IC Role / Device Role / Timing Role: Secure, tamper-resistant memory supplementing main MCU flash for critical settings. Use Value: >200-year data retention guarantees integrity over multi-decade device service life; low 5 µA standby current extends battery runtime. | Use Scenario: Storing tariff tables, communication keys, and metering constants in ANSI C12.19-compliant electricity meters. IC Role / Device Role / Timing Role: Field-updatable configuration store accessed during meter initialization and firmware upgrades. Use Value: Microwire interface minimizes MCU pin count; 4.5–5.5 V range aligns with meter's regulated 5 V rail, avoiding extra regulators. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66BT-E/OT | 16-bit organization (256 × 16), same 4.5–5.5 V range and SOT-23-6 package - requires ORG pin tied to VCC (not present on 93C66AT-E/OT). | Optimized for 16-bit MCU interfaces; incompatible with existing 8-bit firmware addressing logic. | Select only if migrating to wider data paths and redesigning firmware address mapping. |
| AT25040B-MAHL-T | SPI interface (4-wire), 512 × 8-bit, 1.8–5.5 V, SOIC-8 - different protocol, larger footprint, broader VCC range. | Requires SPI peripheral and additional CS line; not drop-in for Microwire-based designs. | Choose when SPI is already used elsewhere in system and board space allows SOIC-8. |
Compared with 93LC66BT-E/OT and AT25040B-MAHL-T, the 93C66AT-E/OT offers the narrowest VCC window but highest automotive temperature rating and smallest footprint - making it optimal for cost- and space-sensitive 5 V automotive modules where Microwire compatibility is mandated.
Availability
93C66AT-E/OT is available at Aetrix Electronics and suitable for industrial sensor calibration storage, automotive ECU configuration memory, and medical device settings backup requiring stable component supply across extended production lifecycles.
Supply support for 93C66AT-E/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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93Cxx family was engineered specifically for low-power, serial nonvolatile memory applications in automotive, industrial, and medical systems where reliability, small footprint, and Microwire compatibility are essential.
FAQ
What is the memory organization of the 93C66AT-E/OT?
The 93C66AT-E/OT has a fixed 512 × 8-bit (4 Kbit) organization. Unlike 'C' variants, it lacks an ORG pin - confirming dedicated x8 operation without external configuration. This simplifies hardware design and eliminates ambiguity in firmware address calculation.
Does the 93C66AT-E/OT require an external pull-up resistor on the DO pin?
No, the 93C66AT-E/OT does not require an external pull-up on DO. The pin actively drives high/low during read and Ready/Busy states. However, if DI and DO are shorted (shared bus), a series resistor is mandatory to prevent bus conflict during the dummy zero phase of read operations.
What is the minimum VCC required for reliable write operation of the 93C66AT-E/OT?
The 93C66AT-E/OT requires VCC ≥ 4.5 V for all write operations. Its internal power-on reset circuit disables programming below ~3.8 V, and datasheet-specified write timing (TWC = 2 ms) and endurance ratings are guaranteed only within the 4.5–5.5 V range.
Can the 93C66AT-E/OT be used in place of the 93AA66AT-I/OT?
No - the 93C66AT-E/OT is not a direct replacement for the 93AA66AT-I/OT. They differ in VCC range (4.5–5.5 V vs. 1.8–5.5 V), temperature grade (E vs. I), and power-on detection threshold (3.8 V vs. 1.5 V). Substitution would risk functional failure outside the 93C66AT-E/OT's specified operating window.
How is the Ready/Busy status monitored on the 93C66AT-E/OT?
Ready/Busy status is monitored by polling the DO pin: DO = low indicates ongoing erase/write; DO = high signals completion. To sample status, CS must be brought high for ≥250 ns after initiating the operation - then read DO on the next CLK rising edge.
93C66AT-E/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:
- 512 x 8
- 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:
- SOT-23-6
93C66AT-E/OT FAQ
1.How can I place an order for 93C66AT-E/OT through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66AT-E/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 93C66AT-E/OT reliable?
The price and inventory of 93C66AT-E/OT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93C66AT-E/OT is usually 5 days.
3.What payment methods are accepted for 93C66AT-E/OT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66AT-E/OT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66AT-E/OT?
93C66AT-E/OT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66AT-E/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 93C66AT-E/OT?
For technical support, including 93C66AT-E/OT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66AT-E/OT requirements.
6.How does Aetrix verify that 93C66AT-E/OT is sourced from the original manufacturer or authorized distributors?
All 93C66AT-E/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 93C66AT-E/OT meets industry standards.
7.What is the process for return or replacement of 93C66AT-E/OT?
All 93C66AT-E/OT units undergo pre-shipment inspection (PSI). If there is an issue with 93C66AT-E/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 93C66AT-E/OT part is unused and in its original packaging.
Return procedure for 93C66AT-E/OT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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