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Microchip Technology 93C66AT-I/MC
- Part No.:
- 93C66AT-I/MC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-VFDFN Exposed Pad
- Datasheet:
-
93C66AT-I/MC.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,535
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Product details
Overview
93C66AT-I/MC from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, 4.5–5.5 V supply range, and industrial temperature grade (−40°C to +85°C). It uses Microwire-compatible 3-wire serial interface (CS/CLK/DI/DO), supports self-timed erase/write cycles, and features power-on/off data protection - deployed in embedded system configuration storage and calibration data retention.
For engineers reviewing the 93C66AT-I/MC datasheet, 93C66AT-I/MC pinout, 93C66AT-I/MC application, or 93C66AT-I/MC equivalent, key selection criteria include VCC operating range (4.5–5.5 V), 8-bit x512 organization, DFN-8 package with exposed pad, industrial temp rating, and Microwire timing compliance at up to 3 MHz clock frequency.
Technical Context
This device implements a synchronous serial Microwire interface with dedicated CS, CLK, DI, and DO pins - no ORG pin (as confirmed for 'A' variant), eliminating word-size configuration logic. All instructions (READ, WRITE, ERASE, ERAL, WRAL) are initiated via rising-edge clocked bit sequences starting with a Start condition (CS high + DI high).
Internal architecture includes auto-erase-before-write, automatic ERAL before WRAL, and Ready/Busy status signaled on DO during programming. Power-on reset circuitry holds the device in EWDS (Erase/Write Disable) state until explicit EWEN command enables write operations - ensuring robust data integrity during power transitions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit organization) |
| VCC operating range | 4.5 V to 5.5 V - requires stable regulated supply; below 3.8 V disables all operations |
| Clock frequency | Up to 3 MHz at VCC ≥ 4.5 V - defines maximum instruction throughput and timing margin |
| Write cycle time | 2 ms typical - determines minimum latency between successive write commands |
| Data retention | 200 years - ensures long-term reliability in unpowered storage applications |
| Endurance | 1,000,000 erase/write cycles - supports frequent field updates in calibration or logging use cases |
| Interface protocol | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - requires no additional level-shifting for 5 V microcontrollers |
Pinout & Package
93C66AT-I/MC is packaged in an 8-lead 2×3 mm DFN (Dual Flat No-lead) with exposed thermal pad (package code MC), RoHS-compliant matte tin finish. Pin 1 is marked by laser dot; exposed pad may be connected to VSS or left floating per layout requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable - must be held high ≥250 ns between instructions; falling edge initiates write/erase on 93AA/93LC, rising CLK edge on 93C |
| 2 (CLK) | Serial Clock | Synchronizes all data transfers - opcodes, addresses, and data clocked on rising edge; stoppable at any point |
| 3 (DI) | Data Input | Accepts Start bit, instruction opcodes, address bits, and write data - must be stable before first rising CLK edge after CS high |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy status (low = busy) - enters High-Z when CS low or during non-read operations |
| 5 (NC) | No Connection | Internally unconnected - must be left floating or tied to VSS/VCC per PCB routing needs; not usable as ORG |
| 6 (ORG) | Organization Select | Not present on 93C66A - NC on this variant; only applicable to 'C' versions for x8/x16 configuration |
| 7 (VSS) | Ground | Reference for all I/O and internal logic - must be low-impedance connection, especially critical for DFN thermal pad grounding |
| 8 (VCC) | Power Supply | 4.5–5.5 V supply input - includes internal POR detection at 3.8 V; decoupling capacitor required within 10 mm |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates external timing control - internal state machine manages auto-erase and programming, freeing MCU resources |
| Automatic ERAL before WRAL | Guarantees full-array readiness - removes need for separate ERAL command prior to bulk write, simplifying firmware |
| Power-on/off data protection | Hardware-enforced lockout - blocks all writes when VCC < 3.8 V, preventing corruption during brown-out or power ramp |
| Ready/Busy status on DO | Enables polling-based operation - allows MCU to avoid fixed delays and optimize response time during programming |
| EWEN/EWDS security model | Explicit write-enable discipline - prevents accidental overwrites; device powers up in locked (EWDS) state |
Applications
| Industrial Sensor Calibration Storage | Embedded System Configuration Memory |
|---|---|
Use Scenario: Storing factory-trimmed sensor offset/gain coefficients in HVAC controllers and pressure transmitters. IC Role / Device Role / Timing Role: Nonvolatile parameter storage accessed infrequently during commissioning or recalibration; operates at ≤1 MHz clock due to slow sensor update rates. Use Value: 200-year data retention ensures calibration remains valid across product lifetime without battery backup. | Use Scenario: Holding user-configurable settings (network IP, display brightness, alarm thresholds) in medical infusion pumps and diagnostic equipment. IC Role / Device Role / Timing Role: Serial configuration store interfaced directly to MCU GPIOs; accessed during boot and menu navigation. Use Value: Microwire compatibility eliminates need for SPI-to-Microwire translation logic, reducing BOM count and firmware complexity. |
| Automotive Body Control Module (BCM) Settings | Consumer Appliance User Preference Storage |
Use Scenario: Retaining seat/mirror position memory and lighting profiles in 12 V automotive BCMs with local 5 V regulation. IC Role / Device Role / Timing Role: Low-power EEPROM co-located with microcontroller; operates only during ignition-on or service mode. Use Value: 1M endurance supports daily reprogramming over 10+ years of vehicle ownership without wear-out risk. | Use Scenario: Saving cooking presets, timer values, and language selections in smart ovens and washing machines. IC Role / Device Role / Timing Role: Standalone serial memory attached to 8-bit MCU; accessed during UI interaction or power-up initialization. Use Value: DFN-8 package (MC) enables compact placement near front-panel controls, minimizing trace length and EMI susceptibility. |
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/MC | 16-bit x256 organization (vs. 8-bit x512); identical VCC range, package, and timing | Requires 16-bit MCU interface or software bit-packing; incompatible with existing 8-bit read/write routines | Select only if system bus width or firmware already supports 16-bit access and memory map alignment favors 256-word addressing |
| 93LC66A-I/MC | Wider VCC range (2.5–5.5 V); same 8-bit x512 organization and DFN-8 package | Supports direct connection to 3.3 V systems without level shifters; suitable for mixed-voltage designs where 5 V supply is unavailable | Prefer when migrating from 5 V to 3.3 V platforms or consolidating BOMs across voltage domains |
Compared with 93C66B-I/MC, 93C66AT-I/MC offers native 8-bit data alignment for simpler firmware integration; compared with 93LC66A-I/MC, it trades wider supply flexibility for higher noise immunity and guaranteed 5 V timing performance - making it optimal for legacy 5 V industrial control systems.
Availability
93C66AT-I/MC is available at Aetrix Electronics and suitable for industrial sensor calibration storage, embedded system configuration memory, and automotive body control module settings requiring stable component supply across extended production lifecycles.
Supply support for 93C66AT-I/MC 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 93C66AT-I/MC belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-pin-count nonvolatile storage in space-constrained industrial and automotive applications where Microwire compatibility and robust power-supply immunity are essential.
FAQ
What is the function of the ORG pin on the 93C66AT-I/MC?
The ORG pin is not functional on the 93C66AT-I/MC. As a member of the 'A' variant series, this device has fixed 8-bit organization and no ORG pin - Pin 6 is designated NC (No Connection) per the datasheet. Only 'C' variants (e.g., 93C66C) use ORG to select between x8 and x16 modes. Attempting to drive Pin 6 will have no effect on 93C66AT-I/MC operation.
Does the 93C66AT-I/MC support 3.3 V operation?
No, the 93C66AT-I/MC does not support 3.3 V operation. Its specified VCC range is strictly 4.5 V to 5.5 V. Below 4.5 V - and especially below the 3.8 V POR threshold - the device inhibits all write operations and may fail to execute instructions reliably. For 3.3 V systems, consider the pin-compatible 93LC66A-I/MC instead, which operates from 2.5 V to 5.5 V.
How is the Ready/Busy status signaled on the 93C66AT-I/MC?
The 93C66AT-I/MC signals Ready/Busy status on the DO pin: DO = low indicates ongoing erase or write operation; DO = high indicates completion and readiness for next instruction. This status is only valid when CS is brought high for ≥250 ns after the programming command - DO remains in High-Z if CS stays low throughout the cycle. Polling DO avoids fixed timing delays in firmware.
What is the maximum clock frequency supported by the 93C66AT-I/MC?
The 93C66AT-I/MC supports a maximum clock frequency of 3 MHz when VCC is between 4.5 V and 5.5 V. At this speed, timing parameters such as TCKH (clock high time) and TCKL (clock low time) are guaranteed to meet 200 ns and 100 ns respectively. Operation above 3 MHz violates AC specifications and risks command misinterpretation or data corruption.
Is the exposed pad on the 93C66AT-I/MC's DFN package required to be grounded?
The exposed pad on the 93C66AT-I/MC (package code MC) may be connected to VSS or left electrically floating - both configurations are acceptable per Microchip's packaging specification. However, grounding the pad improves thermal dissipation and reduces ground impedance, which is recommended for applications with frequent write cycles or elevated ambient temperatures. No solder mask opening is required if left unconnected.
93C66AT-I/MC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-VFDFN Exposed Pad
- 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 ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN (2x3)
93C66AT-I/MC FAQ
1.How can I place an order for 93C66AT-I/MC through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66AT-I/MC 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-I/MC reliable?
The price and inventory of 93C66AT-I/MC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93C66AT-I/MC is usually 5 days.
3.What payment methods are accepted for 93C66AT-I/MC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66AT-I/MC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66AT-I/MC?
93C66AT-I/MC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66AT-I/MC 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-I/MC?
For technical support, including 93C66AT-I/MC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66AT-I/MC requirements.
6.How does Aetrix verify that 93C66AT-I/MC is sourced from the original manufacturer or authorized distributors?
All 93C66AT-I/MC 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-I/MC meets industry standards.
7.What is the process for return or replacement of 93C66AT-I/MC?
All 93C66AT-I/MC units undergo pre-shipment inspection (PSI). If there is an issue with 93C66AT-I/MC, 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-I/MC part is unused and in its original packaging.
Return procedure for 93C66AT-I/MC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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