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Microchip Technology 93AA66A-I/MS
- Part No.:
- 93AA66A-I/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
93AA66A-I/MS.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,013
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Product details
Overview
93AA66A-I/MS from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with fixed 8-bit organization, 512 × 8-bit memory array, 1.8–5.5 V supply range, and industrial temperature rating (–40°C to +85°C). It uses Microwire-compatible 3-wire serial interface (CS, CLK, DI, DO) and supports self-timed erase/write cycles in an 8-lead MSOP package for embedded system configuration storage.
For engineers reviewing the 93AA66A-I/MS datasheet, 93AA66A-I/MS pinout, 93AA66A-I/MS application, or 93AA66A-I/MS equivalent, key selection criteria include voltage compatibility (1.8–5.5 V), guaranteed 1 million erase/write cycles, >200-year data retention, Ready/Busy status signaling via DO, and Pb-free MSOP packaging suitable for space-constrained industrial control modules.
Technical Context
The 93AA66A-I/MS implements a synchronous serial Microwire interface with start-bit detection, opcode-driven command set (READ, WRITE, ERASE, ERAL, WRAL), and hardware-based power-on/off data protection. It operates without an ORG pin-unlike 'C' variants-so memory organization is permanently fixed at 8-bit words.
Internal logic includes auto-erase-before-write, automatic ERAL before WRAL, EWEN/EWDS write-protection state machine, and DO pin dual-role operation: serial data output during READ and Ready/Busy status indicator during programming. Clock frequency support scales with VCC (up to 3 MHz at 4.5–5.5 V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit), sufficient for firmware parameter tables or calibration data in microcontroller peripherals |
| Supply voltage | 1.8–5.5 V - supports direct interfacing with 1.8 V, 3.3 V, and 5 V logic domains without level shifters |
| Endurance | 1,000,000 erase/write cycles - enables reliable logging or field-updatable settings in industrial equipment |
| Data retention | >200 years at 25°C - ensures long-term validity of stored configuration across product lifecycle |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - minimal GPIO usage, compatible with legacy MCU SPI peripherals in 3-wire mode |
| Access time | TPD ≤ 400 ns (1.8 V), enabling sub-microsecond read response for real-time configuration fetch |
| Write cycle time | TWC = 6 ms (max) - deterministic programming latency for host software timeout handling |
Pinout & Package
8-lead MSOP (150 mil) package with exposed pad (optional VSS connection), footprint-compatible with SOIC-8 but 45% smaller area. Pin 1 marked by laser dot; no ORG pin present (fixed x8 organization).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable; must be held low ≥250 ns between instructions; initiates self-timed write on falling edge |
| CLK | Serial Clock | Synchronizes all data transfers; rising-edge sampling for DI/DO; stoppable mid-transfer without corruption |
| DI | Data Input | Accepts start bit, opcodes, addresses, and write data; tolerant of bus conflict if shared with DO (with series resistor) |
| DO | Data Output / Status | Outputs read data or Ready/Busy (low = busy); enters High-Z when CS low or during non-read operations |
| VSS | Ground | Reference for all I/O and internal circuitry; exposed pad may be tied to VSS for thermal/mechanical stability |
| NC | No Connection | Pin 7 is unconnected internally - must be left floating or tied to VSS per layout best practice |
| VCC | Power Supply | 1.8–5.5 V input; internal POR circuit triggers at ~1.5 V to prevent spurious writes during brown-out |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates need for external timing control or polling delays beyond TWC/TEC/TWL max values |
| Automatic ERAL before WRAL | Guarantees full-array readiness before bulk write, preventing partial-program corruption |
| EWEN/EWDS write protection | Hardware-enforced state machine prevents accidental writes - device powers up in EWDS mode |
| Ready/Busy via DO pin | Enables efficient polling instead of fixed delays; DO high = ready, DO low = active programming |
| Pb-free MSOP package | RoHS-compliant 3×3 mm body with 0.65 mm pitch - suitable for automated SMT assembly and compact PCB layouts |
Applications
| Industrial Sensor Calibration | Embedded System 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 store accessed at power-up and during field recalibration routines. Use Value: 1.8 V operation allows direct connection to low-power sensor ASICs; >200-year retention ensures calibration validity over equipment lifetime. | Use Scenario: Holding user-defined I/O mapping, communication protocol settings, and display brightness levels in human-machine interface panels. IC Role / Device Role / Timing Role: Serial configuration memory interfaced to MCU GPIOs using bit-banged Microwire protocol. Use Value: 6 ms max write time enables responsive UI updates; 1M endurance supports daily reconfiguration in maintenance workflows. |
| Medical Device Settings Backup | Automotive Body Control Module |
Use Scenario: Retaining alarm thresholds, dose limits, and audit log pointers in portable diagnostic instruments. IC Role / Device Role / Timing Role: Fail-safe storage element with power-loss protection activated below 1.5 V VCC threshold. Use Value: Power-on/off data protection prevents corruption during battery swaps or transient brownouts common in handheld devices. | Use Scenario: Saving seat position presets, mirror angles, and lighting profiles in automotive interior control units. IC Role / Device Role / Timing Role: Low-quiescent-current (1 µA standby) memory supporting always-on wake-up functionality. Use Value: 1 µA ICCS at industrial temp enables energy-efficient retention during vehicle sleep mode without draining battery. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66A-I/MS | Same 512×8 organization and MSOP package, but 2.5–5.5 V VCC range - lacks 1.8 V support | Not suitable for 1.8 V systems; otherwise identical instruction set and timing | Select 93LC66A-I/MS only if system VCC ≥2.5 V and 1.8 V operation is unnecessary |
| AT25040B-MAHL-T | 4 Kbit SPI EEPROM (8-bit), 1.8–5.5 V, but uses 4-wire SPI (with /CS, SCK, SI, SO) instead of Microwire | Requires separate /CS and SO pins; no DO status multiplexing - needs dedicated status polling method | Choose AT25040B-MAHL-T only when migrating to standard SPI infrastructure and accepting pin count increase |
Compared with 93LC66A-I/MS and AT25040B-MAHL-T, the 93AA66A-I/MS uniquely supports 1.8 V operation while retaining Microwire compatibility and DO-pin Ready/Busy signaling - critical for ultra-low-voltage, pin-constrained industrial designs.
Availability
93AA66A-I/MS is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded system configuration, and medical device settings backup requiring stable component supply, long-lifecycle availability, and RoHS-compliant packaging.
Supply support for 93AA66A-I/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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93XX66 family was designed specifically for cost-sensitive, low-power serial EEPROM applications in industrial, medical, and consumer systems where Microwire interface simplicity and robust nonvolatile storage are required.
FAQ
What is the memory organization of the 93AA66A-I/MS?
The 93AA66A-I/MS has a fixed 512 × 8-bit (4 Kbit) organization. Unlike 'C' variants, it does not feature an ORG pin - its word size is permanently configured for 8-bit communication. This eliminates external configuration logic and simplifies PCB layout for systems requiring byte-oriented access.
Does the 93AA66A-I/MS require an external pull-up resistor on the DO pin?
No, the 93AA66A-I/MS does not require an external pull-up on DO. The DO pin actively drives high/low during READ and Ready/Busy status reporting, and enters High-Z when inactive. However, if DI and DO are shorted (shared bus), a current-limiting resistor is recommended to prevent bus conflict during the dummy zero phase of READ.
How does write protection work on the 93AA66A-I/MS?
The 93AA66A-I/MS powers up in Erase/Write Disable (EWDS) mode. An Erase/Write Enable (EWEN) instruction must precede any ERASE or WRITE command. After programming, issuing EWDS restores protection. This two-instruction requirement prevents accidental writes due to noise or software glitches - a hardware-enforced safeguard independent of MCU firmware.
What is the minimum VCC required for reliable operation of the 93AA66A-I/MS?
The 93AA66A-I/MS requires VCC ≥1.8 V for functional operation, with internal power-on reset (POR) activating at ~1.5 V to inhibit commands during power ramp-up. Below 1.8 V, read/write operations are not guaranteed, and the device enters a high-impedance, write-protected state to preserve data integrity during brown-out conditions.
Can the 93AA66A-I/MS be used in place of the 93AA66B-I/MS?
No - the 93AA66A-I/MS and 93AA66B-I/MS are not interchangeable. The 'A' version is 512 × 8-bit; the 'B' version is 256 × 16-bit. They share the same pinout and voltage range, but differ in address depth, data width, instruction timing (20 vs. 27 clock cycles for READ/WRITE), and opcode compatibility. Substituting one for the other will cause data misalignment and communication failure.
93AA66A-I/MS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tube
- 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:
- 6ms
- Access Time:
- -
- Voltage - Supply:
- 1.8V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-MSOP
93AA66A-I/MS FAQ
1.How can I place an order for 93AA66A-I/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 93AA66A-I/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 93AA66A-I/MS reliable?
The price and inventory of 93AA66A-I/MS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93AA66A-I/MS is usually 5 days.
3.What payment methods are accepted for 93AA66A-I/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93AA66A-I/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93AA66A-I/MS?
93AA66A-I/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93AA66A-I/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 93AA66A-I/MS?
For technical support, including 93AA66A-I/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93AA66A-I/MS requirements.
6.How does Aetrix verify that 93AA66A-I/MS is sourced from the original manufacturer or authorized distributors?
All 93AA66A-I/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 93AA66A-I/MS meets industry standards.
7.What is the process for return or replacement of 93AA66A-I/MS?
All 93AA66A-I/MS units undergo pre-shipment inspection (PSI). If there is an issue with 93AA66A-I/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 93AA66A-I/MS part is unused and in its original packaging.
Return procedure for 93AA66A-I/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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