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Microchip Technology 93AA66B-I/P
- Part No.:
- 93AA66B-I/P
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
93AA66B-I/P.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,206
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Product details
Overview
93AA66B-I/P from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with dedicated 16-bit organization, 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), supports self-timed erase/write cycles, and delivers >200 years data retention for nonvolatile configuration storage in embedded controllers.
For engineers reviewing the 93AA66B-I/P datasheet, 93AA66B-I/P pinout, 93AA66B-I/P application, or 93AA66B-I/P equivalent, key selection criteria include 256 × 16-bit memory mapping, Ready/Busy status signaling via DO, automatic ERAL/WRAL support, and compatibility with low-power microcontroller peripheral interfaces requiring deterministic timing at up to 3 MHz clock frequency.
Technical Context
The 93AA66B-I/P implements a synchronous serial Microwire interface with start-bit detection, opcode-driven instruction set (READ/WRITE/ERASE/ERAL/WRAL/EWEN/EWDS), and internal address counter enabling sequential read. It requires no external ORG pin control-its fixed 16-bit organization eliminates configuration dependency on external logic levels.
Internal power-on reset and voltage detect circuitry (1.5 V threshold) prevent spurious writes during brown-out conditions. Erase/write operations are fully self-timed (6 ms typical), with Ready/Busy status reported on DO pin after CS high pulse, enabling polling-based host synchronization without fixed delay loops.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (256 × 16-bit organization) |
| VCC range | 1.8 V to 5.5 V - enables direct interface with 1.8 V, 3.3 V, and 5 V microcontrollers |
| Clock frequency | Up to 3 MHz at VCC ≥ 4.5 V - supports high-speed configuration loading in real-time systems |
| Endurance | 1,000,000 erase/write cycles - suitable for field-updatable calibration or logging applications |
| Data retention | >200 years at 25°C - ensures long-term reliability in unattended equipment |
| Write cycle time | 6 ms typical - defines minimum inter-write interval for burst programming sequences |
| Standby current | 1 µA max at industrial temp - critical for battery-powered devices in sleep mode |
| Interface | 3-wire Microwire (CS/CLK/DI/DO) - minimal GPIO usage, no I²C pull-ups or UART overhead |
Pinout & Package
8-lead PDIP package (P suffix), 0.300" wide body, through-hole mounting. Pin 1 marked by notch or dot; pin 1 ID confirmed per Microchip DS21795E-page 18.
| 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 | Positive-edge synchronized I/O; supports stopped-clock operation; no clock required during write cycle |
| DI | Data Input | Accepts start bit, opcode, address, and data; tied to DO only with series resistor to avoid bus conflict |
| DO | Data Output / Status | Outputs read data or Ready/Busy (low = busy); enters High-Z on CS falling edge |
| VSS | Ground | Reference for all digital and analog functions; decoupling capacitor required near pin |
| 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 activates below 1.5 V to inhibit writes during power ramp |
| ORG | Organization Select | Not present on 93AA66B - fixed 16-bit mode; pin 6 is NC and must not be driven |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates need for host-controlled timing delays; 6 ms typical cycle completes autonomously |
| Automatic ERAL before WRAL | Ensures full-array write integrity without separate erase command - reduces firmware complexity |
| Ready/Busy status on DO | Enables efficient polling instead of fixed-delay waits; reduces CPU idle time during programming |
| Power-on/off data protection | Voltage detect circuit blocks writes below 1.5 V - prevents corruption during brown-out or power-up |
| 1,000,000 endurance cycles | Supports frequent field updates (e.g., sensor calibration, firmware patching) over product lifetime |
| Industry-standard 3-wire interface | Minimizes MCU pin count and PCB routing; compatible with legacy Microwire peripherals |
Applications
| Industrial Sensor Calibration | Medical Device Configuration |
|---|---|
Use Scenario: Storing factory-trimmed ADC offset/gain coefficients and user-adjusted alarm thresholds in portable blood glucose meters. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed at power-up and during service mode; 16-bit word size matches microcontroller data bus width. Use Value: Eliminates external trimming components and enables post-manufacture calibration updates via USB service port. | Use Scenario: Holding patient-specific therapy parameters (e.g., infusion rate limits, drug concentration tables) in ambulatory insulin pumps. IC Role / Device Role / Timing Role: Secure, tamper-resistant parameter store with write-protection via EWEN/EWDS commands. Use Value: Ensures therapy safety by preventing accidental overwrites during runtime; 1 µA standby current extends battery life between charges. |
| Automotive ECU Parameter Storage | Smart Energy Meter Firmware Patching |
Use Scenario: Retaining adaptive learning values (e.g., throttle position offset, idle air control adaptation) across ignition cycles in engine control units. IC Role / Device Role / Timing Role: High-reliability data logger interfaced to 16-bit automotive MCU via SPI-like Microwire bus. Use Value: Withstands –40°C to +85°C ambient and 1M-cycle endurance, meeting AEC-Q100 stress requirements for under-hood use. | Use Scenario: Storing delta patches applied to meter firmware during OTA updates, allowing rollback to prior version if validation fails. IC Role / Device Role / Timing Role: Dual-bank emulated flash using WRAL/ERAL for atomic sector updates; 6 ms write time enables sub-second patch application. Use Value: Enables secure, field-upgradable firmware without external NOR/NAND flash - reducing BOM cost and board area. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66B-I/P | Same 256 × 16-bit organization but wider VCC range (2.5–5.5 V); lacks 1.8 V operation | Not suitable for 1.8 V systems; otherwise identical instruction set and timing | Select when system VCC never drops below 2.5 V and extended voltage margin is preferred |
| AT25040B-MAU-5.0-T | 4 Kbit SPI EEPROM (256 × 16), 1.8–5.5 V, but uses 4-wire SPI (CS/SCK/MOSI/MISO) instead of Microwire | Requires additional MCU GPIO for MISO; incompatible opcode and status reporting (no DO Ready/Busy) | Choose only if migrating from SPI-based designs and willing to modify driver firmware |
Compared with 93LC66B-I/P, the 93AA66B-I/P adds 1.8 V operation for ultra-low-power systems; compared with AT25040B, it retains Microwire compatibility and hardware-ready/busy signaling-reducing software overhead in resource-constrained MCUs.
Availability
93AA66B-I/P is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, and automotive ECU parameter storage requiring stable component supply, long-life data retention, and RoHS-compliant packaging.
Supply support for 93AA66B-I/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, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93XX66 family was designed specifically for low-power, nonvolatile memory applications in space-constrained embedded systems requiring simple 3-wire serial configuration storage - emphasizing reliability, voltage flexibility, and ease of integration.
FAQ
What is the memory organization of the 93AA66B-I/P?
The 93AA66B-I/P has a fixed 256 × 16-bit organization - meaning it stores 256 words of 16 bits each, totaling 4 Kbit. Unlike 'C' variants, it does not use the ORG pin; its 16-bit word size is hardwired, eliminating external configuration logic and simplifying interface design for 16-bit microcontrollers.
Does the 93AA66B-I/P support 1.8 V operation?
Yes, the 93AA66B-I/P supports a VCC range of 1.8 V to 5.5 V, making it compatible with modern ultra-low-power microcontrollers and battery-operated systems. Its internal voltage detector activates at 1.5 V to prevent writes during brown-out, ensuring data integrity even during 1.8 V rail ramp-up.
How does the Ready/Busy status work on the 93AA66B-I/P?
The 93AA66B-I/P reports Ready/Busy status on the DO pin: DO = low indicates an erase or write operation is in progress; DO = high means the device is ready for the next command. This status is valid only after CS is brought high for ≥250 ns following the write initiation - enabling efficient polling without fixed delays.
What is the purpose of the EWEN and EWDS commands in the 93AA66B-I/P?
The 93AA66B-I/P powers up in EWDS (Erase/Write Disable) mode. An EWEN command must precede any ERASE or WRITE operation to enable programming; EWDS re-disables it afterward. This dual-command scheme prevents accidental writes during noise events or power transients - a critical safeguard for field-deployed equipment.
Can the 93AA66B-I/P be used in place of the 93AA66A-I/P?
No - the 93AA66B-I/P and 93AA66A-I/P are not interchangeable without firmware changes. The 93AA66A-I/P uses 512 × 8-bit organization (8-bit words), while the 93AA66B-I/P uses 256 × 16-bit organization (16-bit words). Addressing, data width, and instruction timing differ, requiring corresponding updates to the host MCU's EEPROM driver.
93AA66B-I/P Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 4Kbit
- Memory Organization:
- 256 x 16
- 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:
- Through Hole
- Supplier Device Package:
- 8-PDIP
93AA66B-I/P FAQ
1.How can I place an order for 93AA66B-I/P through Aetrix?
Please submit a Request for Quotation (RFQ) for 93AA66B-I/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 93AA66B-I/P reliable?
The price and inventory of 93AA66B-I/P are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93AA66B-I/P is usually 5 days.
3.What payment methods are accepted for 93AA66B-I/P?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93AA66B-I/P transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93AA66B-I/P?
93AA66B-I/P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93AA66B-I/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 93AA66B-I/P?
For technical support, including 93AA66B-I/P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93AA66B-I/P requirements.
6.How does Aetrix verify that 93AA66B-I/P is sourced from the original manufacturer or authorized distributors?
All 93AA66B-I/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 93AA66B-I/P meets industry standards.
7.What is the process for return or replacement of 93AA66B-I/P?
All 93AA66B-I/P units undergo pre-shipment inspection (PSI). If there is an issue with 93AA66B-I/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 93AA66B-I/P part is unused and in its original packaging.
Return procedure for 93AA66B-I/P:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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