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Microchip Technology 93AA66AT-I/MS
- Part No.:
- 93AA66AT-I/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
93AA66AT-I/MS.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,892
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Product details
Overview
93AA66AT-I/MS from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, Microwire-compatible 3-wire interface (CS/CLK/DI/DO), and industrial temperature range (–40°C to +85°C). It features self-timed erase/write cycles, automatic ERAL before WRAL, power-on/off data protection, and 1,000,000 erase/write endurance - used in embedded system configuration storage and calibration data retention.
For engineers reviewing the 93AA66AT-I/MS datasheet, 93AA66AT-I/MS pinout, 93AA66AT-I/MS application, or 93AA66AT-I/MS equivalent, key selection considerations include VCC range (1.8–5.5 V), MSOP-8 package footprint, 8-bit fixed word size (no ORG pin), Ready/Busy status via DO, and compatibility with legacy Microwire controllers requiring no protocol translation.
Technical Context
This device implements a synchronous serial interface with start-bit detection, opcode-driven command set (READ/WRIT/ERASE/ERAL/WRAL/EWEN/EWDS), and internal auto-erase-before-write logic. All operations are initiated by CS falling edge (for 93AA versions) and monitored via DO pin's Ready/Busy state.
It uses CMOS EEPROM cell technology with on-chip charge pump for write/erase, supports sequential read, and enforces hardware-level data protection via VCC voltage detect (1.5 V threshold) and EWEN/EWDS lockout states - ensuring robustness against brown-out or spurious writes.
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 | 1.8 V to 5.5 V; enables direct interfacing with 1.8 V, 3.3 V, and 5 V microcontrollers without level shifters. |
| Clock Frequency | Up to 3 MHz at VCC ≥ 4.5 V; supports high-speed configuration loading in time-critical boot sequences. |
| Write Cycle Time | 6 ms typical (TWC); deterministic timing allows precise host-side polling or timeout-based status checking. |
| Data Retention | >200 years at 25°C; suitable for long-lifecycle industrial equipment where field recalibration data must persist across product generations. |
| Endurance | 1,000,000 erase/write cycles; sufficient for daily firmware parameter updates over 27+ years of continuous operation. |
| Interface Protocol | Microwire-compatible 3-wire serial (CS/CLK/DI/DO); interoperable with legacy PIC® MCU peripherals and widely supported in RTOS drivers. |
Pinout & Package
8-pin MSOP (Micro Small Outline Package), 3.0 mm × 3.0 mm body, 0.65 mm pitch, exposed pad optional (VSS or floating). Pin 1 marked by laser dot; pin 1 ID corner confirmed per Microchip DS21795E-page 24.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held low ≥250 ns between instructions; controls entry/exit from Standby mode and initiates all operations on falling edge. |
| 2 (CLK) | Serial Clock | Synchronizes all data transfers; rising edge clocks in opcodes, addresses, and data; stoppable mid-sequence without corruption. |
| 3 (DI) | Data Input | Receives start bit, instruction opcodes, memory addresses, and write data; requires stable setup/hold timing relative to CLK. |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); enters High-Z when CS low or during non-read phases. |
| 5 (VSS) | Ground | Reference return path for all I/O and internal circuitry; must be low-impedance for reliable erase/write margin. |
| 6 (NC) | No Connect | Internally unconnected; must be left floating or tied to VSS per design rules - no routing or loading allowed. |
| 7 (ORG) | Organization Select | Not present on 93AA66A devices; pin 7 is NC - confirms fixed 8-bit mode and eliminates external pull-up/down requirements. |
| 8 (VCC) | Power Supply | Core supply input; includes internal POR circuit triggering at 1.5 V - prevents invalid operation during power ramp. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates need for external timing control or wait-state insertion - host only polls DO or uses fixed 6 ms delay. |
| Automatic ERAL before WRAL | Guarantees full array erase prior to bulk write, preventing stale data remnants without separate erase command sequencing. |
| Power-On/Off Data Protection | VCC detect circuit blocks all write/erase below 1.5 V - prevents corruption during brown-out or hot-plug events. |
| Industry Standard 3-Wire Serial I/O | Reduces GPIO count vs. SPI/I²C; compatible with existing Microwire firmware stacks and debug tools without driver modification. |
| Device Status Signal (Ready/Busy) | DO pin doubles as status indicator - enables efficient polling instead of fixed delays, optimizing host CPU utilization. |
Applications
| Industrial Sensor Calibration Storage | Medical Device 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 configuration register accessed during power-up initialization and field recalibration routines. Use Value: 200-year data retention ensures calibration validity across equipment service life; 1M endurance supports periodic field updates without replacement. | Use Scenario: Holding user-selectable therapy parameters and safety thresholds in portable infusion pumps and diagnostic monitors. IC Role / Device Role / Timing Role: Secure, low-power memory for critical settings that must survive battery swaps and emergency shutdowns. Use Value: Power-on data protection prevents parameter loss during brown-out; 1.8 V operation enables direct connection to ultra-low-power MCUs. |
| Automotive Body Control Module (BCM) Settings | Consumer Appliance User Preference Storage |
Use Scenario: Saving seat/mirror position presets and lighting profiles in automotive BCMs operating across –40°C to +85°C. IC Role / Device Role / Timing Role: Dedicated configuration EEPROM interfaced via dedicated Microwire peripheral on 8-bit automotive MCUs. Use Value: Industrial temp grade meets AEC-Q100 stress requirements; MSOP-8 footprint fits tight PCB spaces near MCU. | Use Scenario: Retaining cooking modes, timer values, and language preferences in smart ovens and washing machines. IC Role / Device Role / Timing Role: Cost-optimized nonvolatile memory for consumer-grade microcontroller systems with limited GPIO resources. Use Value: 3-wire interface reduces BOM cost vs. SPI flash; RoHS-compliant matte tin finish ensures manufacturing compliance. |
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 | VCC range 2.5–5.5 V; same pinout, 512 × 8-bit, but lacks 1.8 V support - higher minimum VCC limits use with sub-2.5 V MCUs. | Not suitable for 1.8 V systems; otherwise identical function and timing - drop-in replacement where VCC ≥ 2.5 V. | Select when system VCC is guaranteed ≥2.5 V and extended low-voltage operation is unnecessary. |
| AT25040B-MAHL-T | SPI interface (4-wire), 512 × 8-bit, 1.8–5.5 V, 20 MHz clock - faster interface but requires additional CS and SO pins vs. Microwire's 3-wire simplicity. | Requires SPI-capable MCU and different driver stack; not protocol-compatible - board redesign needed for pin count and firmware. | Choose for higher throughput or when SPI infrastructure already exists; avoid if Microwire compatibility or minimal GPIO usage is mandatory. |
Compared with 93LC66AT-I/MS, the 93AA66AT-I/MS enables true 1.8 V operation and broader MCU compatibility, while the AT25040B-MAHL-T trades interface simplicity for speed and ecosystem alignment - making the 93AA66AT-I/MS optimal for resource-constrained, low-voltage embedded designs requiring proven Microwire integration.
Availability
93AA66AT-I/MS is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, and automotive body control module applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for 93AA66AT-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 microcontroller, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design, manufacturing, and sales operations.
The 93XX series EEPROMs were designed specifically for low-power, serially interfaced nonvolatile memory in space-constrained embedded systems - emphasizing reliability, wide VCC range, and protocol compatibility with legacy controllers.
FAQ
What is the memory organization of the 93AA66AT-I/MS?
The 93AA66AT-I/MS is a fixed 512 × 8-bit (4 Kbit) EEPROM with no ORG pin - confirming x8-only operation. Unlike C-versions, it does not support x16 configuration. This eliminates external ORG biasing and simplifies firmware addressing logic, as all read/write operations use 9-bit addresses (0x000–0x1FF).
Does the 93AA66AT-I/MS require an external pull-up resistor on the DO pin?
No, the 93AA66AT-I/MS does not require an external pull-up on DO. The DO pin actively drives high/low during read or Ready/Busy status reporting and enters High-Z when inactive. A pull-up may cause bus contention if DI and DO are shorted - Microchip recommends a series resistor if shared-line topology is used, per DS21795E Section 2.2.
What is the minimum VCC voltage required for reliable operation of the 93AA66AT-I/MS?
The 93AA66AT-I/MS requires VCC ≥ 1.5 V to exit power-on reset and enable functional operation, per its VCC voltage detect threshold. Below 1.5 V, all commands are inhibited - ensuring data integrity during power ramp-up or brown-out. Full specification compliance (including AC timing) begins at 1.8 V.
How is the Ready/Busy status monitored on the 93AA66AT-I/MS?
The Ready/Busy status is monitored on the DO pin: DO = low indicates ongoing erase/write, DO = high means operation complete. To sample status, CS must be brought high after ≥250 ns low time (TCSL); issuing a Start bit then lowering CS clears the status flag. No additional control signals or registers are needed.
Is the 93AA66AT-I/MS pin-compatible with other 93XX66 variants in MSOP-8 package?
Yes - the 93AA66AT-I/MS shares identical MSOP-8 pinout (CS/CLK/DI/DO/VSS/NC/ORG/VCC) with all 93XX66A/B/C variants in the same package, including 93LC66AT-I/MS and 93C66AT-I/MS. However, ORG is NC on A/B devices, and VCC ranges differ - electrical compatibility must be verified per target system voltage.
93AA66AT-I/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:
- 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
93AA66AT-I/MS FAQ
1.How can I place an order for 93AA66AT-I/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 93AA66AT-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 93AA66AT-I/MS reliable?
The price and inventory of 93AA66AT-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 93AA66AT-I/MS is usually 5 days.
3.What payment methods are accepted for 93AA66AT-I/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93AA66AT-I/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93AA66AT-I/MS?
93AA66AT-I/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93AA66AT-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 93AA66AT-I/MS?
For technical support, including 93AA66AT-I/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93AA66AT-I/MS requirements.
6.How does Aetrix verify that 93AA66AT-I/MS is sourced from the original manufacturer or authorized distributors?
All 93AA66AT-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 93AA66AT-I/MS meets industry standards.
7.What is the process for return or replacement of 93AA66AT-I/MS?
All 93AA66AT-I/MS units undergo pre-shipment inspection (PSI). If there is an issue with 93AA66AT-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 93AA66AT-I/MS part is unused and in its original packaging.
Return procedure for 93AA66AT-I/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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