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Microchip Technology 93AA66/P
- Part No.:
- 93AA66/P
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
93AA66/P.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,115
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Product details
Overview
93AA66/P from Microchip Technology Inc. is a 4K-bit (512 × 8 or 256 × 16) low-voltage serial EEPROM with Microwire interface, ORG-pin-selectable memory organization, and single-supply operation down to 1.8 V. It delivers 70 µA typical active read current at 1.8 V, 2 µA standby current, and ensures 1,000,000 erase/write cycles with >200-year data retention. It is used in embedded systems for parameter storage, calibration data logging, and configuration backup where space-constrained 8-pin PDIP packaging and robust power-on/off protection are required.
For engineers reviewing the 93AA66/P datasheet, 93AA66/P pinout, 93AA66/P application, or 93AA66/P equivalent, key selection criteria include its 1.8–5.5 V operating range, self-timed erase/write with automatic ERAL before WRAL, 3-wire serial I/O compatibility, and industrial temperature support (–40°C to +85°C) in PDIP package.
Technical Context
The 93AA66/P implements a synchronous 3-wire Microwire-compatible serial interface with CS, CLK, and bidirectional DI/DO lines. Its memory array supports dual x8/x16 organization selected via the ORG pin, enabling flexible byte- or word-oriented access without external logic.
Internal logic includes auto-erase-before-write (ERAL before WRAL), power-on/off data protection circuitry that inhibits programming below 1.4 V, and Ready/Busy status reporting via DO pin polling during erase/write cycles - all executed in self-timed fashion without external timing control.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8 or 256 × 16), configurable via ORG pin - enables compact firmware parameter storage with minimal address overhead |
| Supply voltage | 1.8 V to 5.5 V - supports direct interfacing with 1.8 V, 3.3 V, and 5 V microcontrollers without level shifters |
| Active read current | 70 µA typical at 1.8 V - minimizes system power budget in battery-powered sensor nodes and portable devices |
| Standby current | 2 µA typical at 1.8 V - ensures ultra-low quiescent draw during sleep modes in energy-sensitive applications |
| Erase/write endurance | 1,000,000 cycles - guarantees long-term reliability for frequently updated calibration or usage counters |
| Data retention | >200 years - eliminates need for periodic refresh or backup in mission-critical industrial controllers |
| Operating temperature | –40°C to +85°C (Industrial grade) - validated for deployment in automotive body electronics and factory automation environments |
Pinout & Package
8-pin Plastic Dual In-line Package (PDIP), 300 mil body (JEDEC MS-001), through-hole mount. Pin 1 marked by notch or dot; pin numbering follows standard counter-clockwise layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 CS | Chip Select | Active-high enable signal; must be held low ≥250 ns between instructions to reset internal state and prevent spurious commands |
| 2 CLK | Serial Clock | Synchronizes opcode/address/data transfer on rising edge; clock can pause mid-sequence without loss of state |
| 3 DI | Data Input | Receives Start bit, instruction opcodes, addresses, and write data; supports shared bus with DO when pull-up implemented |
| 4 DO | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); enters high-Z on CS falling edge to avoid bus contention |
| 5 VSS | Ground | Reference return path for all digital and analog functions; requires low-impedance connection to system ground plane |
| 6 ORG | Memory Organization | Selects x8 (VSS) or x16 (VCC) mode; floating only permitted ≤1 MHz in x16 mode per datasheet constraint |
| 7 NU | No Connect | Internally unconnected; must remain unconnected on PCB to avoid noise coupling or latch-up risk |
| 8 VCC | Power Supply | 1.8–5.5 V supply input; requires local 0.1 µF ceramic decoupling capacitor placed within 5 mm of pin |
Key Features
| Feature | Design Value |
|---|---|
| ORG-pin memory configuration | Enables runtime selection between 512×8 and 256×16 layouts - reduces need for multiple BOM variants in mixed-architecture designs |
| Self-timed erase/write | Eliminates external timing components and software delay loops - simplifies firmware integration and improves timing predictability |
| Automatic ERAL before WRAL | Guarantees full-array erase prior to bulk write - prevents partial writes and data corruption without host-side validation logic |
| Power-on/off data protection | Hardware-enforced lockout below 1.4 V - prevents inadvertent writes during brown-out or hot-plug events |
| Sequential read function | Allows continuous address incrementing while CS remains high - cuts command overhead by 75% vs. individual reads for block transfers |
Applications
| Smart Meter Calibration Storage | Industrial PLC Configuration Backup |
|---|---|
Use Scenario: Storing meter-specific calibration coefficients and tariff tables in electricity/water/gas meters deployed in field environments with wide temperature swings and intermittent power. IC Role / Device Role / Timing Role: Nonvolatile parameter register holding time-critical calibration data accessible via Microwire interface during boot or maintenance mode. Use Value: 2 µA standby current extends battery life in battery-backed meters; >200-year retention ensures data integrity over full product lifecycle without replacement. | Use Scenario: Preserving user-defined I/O mapping, PID loop parameters, and alarm thresholds in programmable logic controllers subjected to frequent power cycling and EMI-rich factory floors. IC Role / Device Role / Timing Role: Dedicated configuration EEPROM interfaced directly to PLC's MCU via 3-wire serial bus, isolated from main program flash. Use Value: 1M endurance supports daily parameter updates across 10+ years; industrial temperature rating (–40°C to +85°C) ensures reliable operation in unconditioned control cabinets. |
| Medical Device Usage Logging | Automotive Body Control Module Settings |
Use Scenario: Recording cumulative operational hours, error event timestamps, and sensor self-test results in portable diagnostic equipment requiring traceable usage history for regulatory compliance. IC Role / Device Role / Timing Role: Secure, tamper-resistant log storage element with hardware write-protection activated by EWDS after each write cycle. Use Value: Power-on protection prevents log corruption during unexpected shutdowns; 1.8 V minimum VCC allows direct connection to low-power medical SoCs. | Use Scenario: Storing seat position memory, mirror presets, and lighting profiles in automotive BCMs where EEPROM must survive load-dump transients and extended temperature exposure. IC Role / Device Role / Timing Role: Dedicated nonvolatile memory for user-customizable settings, accessed only during ignition-on initialization or button-press events. Use Value: 4 ms typical write time enables fast profile saves; PDIP package provides mechanical robustness for manual assembly in low-volume BCM variants. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93AA66C/P | Same 4K-bit Microwire EEPROM but with C-grade (0°C to +70°C) temperature range and updated process - not rated for industrial ambient extremes | Suitable for consumer electronics or lab equipment where ambient stays within commercial range | Select 93AA66C/P only if industrial temperature qualification is unnecessary and cost optimization is prioritized |
| 25LC040A-I/P | 4 Kbit SPI EEPROM (not Microwire), 2.5–5.5 V supply, 5 mA max active current - lacks ORG-pin configurability and has higher power consumption | Requires SPI-capable host; incompatible with legacy Microwire-only controllers without protocol translation | Choose only when migrating to SPI architecture or when existing design already uses SPI peripherals |
Compared with 93AA66C/P, the 93AA66/P offers guaranteed operation at –40°C to +85°C and maintains full backward compatibility with legacy Microwire firmware. Against 25LC040A-I/P, it preserves pin- and protocol-level compatibility with existing Microwire-based systems while delivering lower active and standby current.
Availability
93AA66/P is available at Aetrix Electronics and suitable for smart meter calibration storage, industrial PLC configuration backup, and medical device usage logging requiring stable component supply across extended product lifecycles.
Supply support for 93AA66/P 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, serving industrial, automotive, and consumer markets with high-reliability semiconductor products.
The 93AAxx family was designed specifically for low-voltage, low-power serial EEPROM applications in space-constrained embedded systems requiring robust nonvolatile storage with minimal external components.
FAQ
What is the maximum clock frequency supported by the 93AA66/P at 1.8 V?
The 93AA66/P supports a maximum clock frequency of 1 MHz when VCC is below 4.5 V, including at 1.8 V. This is specified in Table 1-1 under "Clock frequency" (FCLK), where FCLK = 1 MHz for VCC < 4.5 V. Exceeding this limit may result in unreliable instruction execution or data corruption.
How does the ORG pin affect memory addressing in the 93AA66/P?
When ORG is tied to VCC, the 93AA66/P configures as 256 × 16-bit (x16), using 8-bit addresses and outputting 16-bit words per READ. When ORG is tied to VSS, it configures as 512 × 8-bit (x8), using 9-bit addresses and outputting 8-bit bytes. The 93AA66/P instruction set tables (Tables 1-6 and 1-7) confirm distinct address widths and data widths per mode.
Can the 93AA66/P be used with a shared DI/DO bus line?
Yes, the 93AA66/P supports shared DI/DO bus configuration, but caution is required: a "bus conflict" may occur during the dummy zero preceding READ if A0 is high, causing undefined DO voltage. A pull-up resistor on DO is mandatory for reliable Ready/Busy polling, and proper timing (TCSL ≥250 ns) must be observed to avoid metastability.
What is the purpose of the NU pin on the 93AA66/P?
The NU (No Connect) pin on the 93AA66/P is internally unconnected and serves no electrical function. It must remain unconnected on the PCB - routing traces to or placing components near NU risks noise coupling or unintended parasitic paths that could degrade timing margins or increase EMI susceptibility in the 93AA66/P's serial interface.
Does the 93AA66/P require an external pull-up resistor on the DO pin?
Yes, an external pull-up resistor on the DO pin is required to reliably read the Ready signal (high state) after erase/write cycles. While DO drives low actively during Busy state, it enters high-Z upon completion - without a pull-up, the logic level is indeterminate. Microchip recommends a 4.7 kΩ resistor to VCC for stable status polling in the 93AA66/P datasheet Section 2.4 and Figure 2-1.
93AA66/P Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 4Kbit
- Memory Organization:
- 512 x 8, 256 x 16
- Memory Interface:
- Microwire
- Clock Frequency:
- 2 MHz
- Write Cycle Time - Word, Page:
- 10ms
- Access Time:
- -
- Voltage - Supply:
- 1.8V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
93AA66/P FAQ
1.How can I place an order for 93AA66/P through Aetrix?
Please submit a Request for Quotation (RFQ) for 93AA66/P 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 93AA66/P reliable?
The price and inventory of 93AA66/P are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93AA66/P is usually 5 days.
3.What payment methods are accepted for 93AA66/P?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93AA66/P transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93AA66/P?
93AA66/P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93AA66/P 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 93AA66/P?
For technical support, including 93AA66/P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93AA66/P requirements.
6.How does Aetrix verify that 93AA66/P is sourced from the original manufacturer or authorized distributors?
All 93AA66/P 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 93AA66/P meets industry standards.
7.What is the process for return or replacement of 93AA66/P?
All 93AA66/P units undergo pre-shipment inspection (PSI). If there is an issue with 93AA66/P, 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 93AA66/P part is unused and in its original packaging.
Return procedure for 93AA66/P:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93AA66/P Tags
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M24C02-WMN6TP
STMicroelectronics
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AT24C02C-XHM-T
Microchip Technology
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AT21CS01-STUM10-T
Microchip Technology
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AT24C02C-SSHM-T
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24LC01BT-I/OT
Microchip Technology
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M24C02-FMC6TG
STMicroelectronics
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AT24CS02-SSHM-T
Microchip Technology
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93LC46BT-I/OT
Microchip Technology
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AT24C04C-SSHM-T
Microchip Technology
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24LC01BT-I/SN
Microchip Technology
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24AA02UIDT-I/OT
Microchip Technology
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AT24C08C-STUM-T
Microchip Technology
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