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Microchip Technology 93C66AT-E/MS
- Part No.:
- 93C66AT-E/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
93C66AT-E/MS.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,591
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Product details
Overview
93C66AT-E/MS from Microchip Technology Inc. is a 4 Kbit (512 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 4.5–5.5 V supply range, and industrial temperature grade (–40°C to +85°C). It features self-timed erase/write cycles, automatic ERAL/WRAL support, and Ready/Busy status signaling via DO pin - used for configuration storage in microcontroller-based embedded systems.
For engineers reviewing the 93C66AT-E/MS datasheet, 93C66AT-E/MS pinout, 93C66AT-E/MS application, or 93C66AT-E/MS equivalent, key selection criteria include its fixed 8-bit organization (no ORG pin), MSOP-8 package compatibility, 2 ms write cycle time, and VCC-dependent power-on data protection threshold of 3.8 V.
Technical Context
This device implements a synchronous serial interface using CS, CLK, and DI/DO lines with start-bit detection and opcode-driven command execution. It supports READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS instructions - all clocked on rising CLK edges, with status polling enabled via DO during active programming.
Memory architecture is organized as 512 words × 8 bits with no internal address counter wraparound limitation. Write operations include auto-erase before write, and full-array operations (ERAL/WRAL) require VCC ≥ 4.5 V and prior EWEN activation. Standby current is ≤ 5 µA at I-temp range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit), fixed x8 organization - no ORG pin; simplifies interface design for 8-bit microcontrollers. |
| VCC operating range | 4.5 V to 5.5 V - requires stable 5 V rail; power-on reset triggers at 3.8 V, preventing corruption during brown-out. |
| Write cycle time | 2 ms typical - enables fast firmware parameter updates without blocking host MCU for extended periods. |
| Endurance | 1,000,000 erase/write cycles - suitable for applications requiring frequent calibration or logging data. |
| Data retention | 200 years at 25°C - ensures long-term reliability in unpowered storage of critical configuration data. |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - minimal GPIO usage; no SPI mode bits or mode configuration needed. |
| Temperature grade | Industrial (–40°C to +85°C) - validated for use in industrial control panels and automotive body electronics. |
Pinout & Package
8-pin MSOP (150 mil) package with exposed pad (optional VSS connection), Pb-free Matte Tin finish. Pin 1 marked by laser dot; pin 1 ID corner defined per JEDEC MO-187.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held low ≥250 ns between commands; initiates self-timed write on falling edge for 93C versions. |
| 2 (CLK) | Serial Clock | Rising-edge synchronized I/O; clock can pause mid-transfer; no clock required during auto-erase/write cycle. |
| 3 (DI) | Data Input | Accepts start bit, opcodes, addresses, and write data; tied high with pull-up for start condition detection. |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy (low = busy); enters High-Z on CS fall; status valid only after TCSL delay. |
| 5 (VSS) | Ground | Reference for all I/O and internal logic; exposed pad may be connected to VSS for thermal/mechanical stability. |
| 6 (NC) | No Connect | Internally unconnected; must be left floating or tied to VSS - not usable as ORG or any functional signal. |
| 7 (ORG) | Organization Select | Not present on 93C66A/B devices - permanently disabled; pin 7 is NC, not ORG, per Device Selection Table and Pin Function Table. |
| 8 (VCC) | Power Supply | 4.5–5.5 V supply; POR circuit activates at 3.8 V; decoupling capacitor (0.1 µF) required near pin. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates need for external timing control or watchdog timeout - host MCU polls DO pin for completion. |
| Automatic ERAL before WRAL | Ensures clean memory state before bulk write; removes requirement for separate ERAL command in initialization sequences. |
| Power-on/off data protection | Hardware-level lockout below 3.8 V prevents spurious writes during power ramp-up/down - no software safeguards needed. |
| Ready/Busy status signaling | Real-time feedback via DO pin allows efficient polling instead of fixed delays - reduces average write latency by >30% vs. worst-case timing. |
| Industry-standard Microwire interface | Interoperable with legacy 8051, PIC, and ARM Cortex-M peripherals without protocol translation or bit-banging overhead. |
Applications
| Industrial Sensor Calibration | Automotive Body Control Module |
|---|---|
Use Scenario: Storing factory-trimmed sensor offset/gain coefficients and real-time calibration updates in HVAC or pressure transducers. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed during boot and runtime via 3-wire interface; 2 ms write time enables field recalibration without system interruption. Use Value: Eliminates need for external OTP or flash; 200-year data retention ensures calibration integrity over product lifetime. | Use Scenario: Holding door lock actuator profiles, mirror position presets, and lighting dimming curves in vehicle interior modules. IC Role / Device Role / Timing Role: Dedicated 8-bit serial EEPROM interfaced to 8-bit MCU; operates across –40°C to +85°C with no derating. Use Value: Supports 1M endurance for daily user adjustments; VCC lockout at 3.8 V prevents corruption during battery voltage sag. |
| Medical Device Configuration | POS Terminal Firmware Parameters |
Use Scenario: Secure storage of regulatory-compliant device settings (e.g., alarm thresholds, audit log flags) in portable diagnostic equipment. IC Role / Device Role / Timing Role: Tamper-resistant nonvolatile memory with hardware write disable (EWDS); accessed only during setup or service mode. Use Value: EWEN/EWDS commands provide deterministic write-enable gating - meets IEC 62304 software safety requirements. | Use Scenario: Maintaining tax rate tables, receipt format templates, and peripheral handshake parameters in retail point-of-sale terminals. IC Role / Device Role / Timing Role: Low-pin-count serial EEPROM sharing bus with display driver and thermal printer controller. Use Value: MSOP-8 footprint saves PCB area vs. SOIC-8; 5 µA standby current extends battery backup life in offline operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66AT-I/MS | Wider VCC range (2.5–5.5 V); same 512×8 organization and MSOP-8 package; supports I-temp only. | Enables single-BOM design across 3.3 V and 5 V systems; lacks 93C66AT-E/MS's 4.5–5.5 V optimization and E-temp option. | Select when mixed-voltage board design or future 3.3 V migration is planned. |
| AT25040B-MAU-1.8 | SPI interface (4-wire), 4 Kbit (512×8), 1.8–5.5 V, SOIC-8; no ERAL/WRAL; max 20 MHz clock. | Requires additional chip select line and SPI peripheral; no auto-erase-all or write-all commands - increases firmware complexity. | Select when existing SPI infrastructure exists and bulk memory operations are infrequent. |
Compared with 93LC66AT-I/MS, the 93C66AT-E/MS offers tighter VCC tolerance and higher noise immunity at 5 V, while AT25040B-MAU-1.8 trades Microwire simplicity for SPI speed and broader voltage flexibility - neither is pin-compatible, but both serve overlapping configuration storage roles.
Availability
93C66AT-E/MS is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive body control modules, medical device configuration, and POS terminal firmware parameter storage requiring stable component supply across extended production lifecycles.
Supply support for 93C66AT-E/MS 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, with global design and manufacturing operations.
The 93Cxx series is part of Microchip's legacy serial EEPROM portfolio designed specifically for cost-sensitive, space-constrained embedded systems requiring robust nonvolatile storage with minimal interface overhead.
FAQ
What is the function of the ORG pin on the 93C66AT-E/MS?
The ORG pin is not functional on the 93C66AT-E/MS. As a '66A' variant, it has fixed 8-bit organization and no ORG pin - pin 7 is designated NC (No Internal Connection) per the Device Selection Table and Pin Function Table. External logic driving ORG has no effect on this part.
Does the 93C66AT-E/MS support 16-bit word access?
No, the 93C66AT-E/MS does not support 16-bit word access. It is a dedicated 512 × 8-bit (x8) device. Only '66B' and '66C' variants support x16 organization; the 'A' suffix explicitly denotes fixed 8-bit operation, confirmed in the Device Selection Table and Functional Description section.
What is the minimum VCC required for reliable write operation of the 93C66AT-E/MS?
The minimum VCC for reliable write operation is 4.5 V. The datasheet specifies VCC range as 4.5–5.5 V, and ERAL/WRAL functions require VCC ≥ 4.5 V. Additionally, the power-on reset threshold is 3.8 V - writing below 4.5 V risks incomplete programming or data corruption.
Can the 93C66AT-E/MS be used in automotive applications requiring AEC-Q200 qualification?
No, the 93C66AT-E/MS is rated for Industrial temperature range (–40°C to +85°C), not Automotive (–40°C to +125°C). The 'E' suffix in the part number refers to packaging (MSOP), not temperature grade - the temperature grade is 'I', as confirmed in the Device Selection Table and Package Marking Information.
How does the Ready/Busy status work on the 93C66AT-E/MS during a write cycle?
During a write cycle, the DO pin outputs Ready/Busy status: logic low indicates programming is in progress; logic high means completion. Status is only valid after CS is brought high for ≥250 ns (TCSL), and DO returns to High-Z on CS fall. A Start bit followed by CS low clears the status flag.
93C66AT-E/MS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm 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:
- 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:
- 8-MSOP
93C66AT-E/MS FAQ
1.How can I place an order for 93C66AT-E/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66AT-E/MS 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/MS reliable?
The price and inventory of 93C66AT-E/MS 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/MS is usually 5 days.
3.What payment methods are accepted for 93C66AT-E/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66AT-E/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66AT-E/MS?
93C66AT-E/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66AT-E/MS 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/MS?
For technical support, including 93C66AT-E/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66AT-E/MS requirements.
6.How does Aetrix verify that 93C66AT-E/MS is sourced from the original manufacturer or authorized distributors?
All 93C66AT-E/MS 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/MS meets industry standards.
7.What is the process for return or replacement of 93C66AT-E/MS?
All 93C66AT-E/MS units undergo pre-shipment inspection (PSI). If there is an issue with 93C66AT-E/MS, 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/MS part is unused and in its original packaging.
Return procedure for 93C66AT-E/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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