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Microchip Technology 93AA66BT-I/MS
- Part No.:
- 93AA66BT-I/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
93AA66BT-I/MS.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,836
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Product details
Overview
93AA66BT-I/MS from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, industrial temperature range (−40°C to +85°C), 1.8–5.5 V supply, and Microwire-compatible 3-wire serial interface. It features self-timed erase/write cycles, automatic ERAL before WRAL, and power-on/off data protection - used in embedded system configuration storage, sensor calibration retention, and firmware parameter backup.
For engineers reviewing the 93AA66BT-I/MS datasheet, 93AA66BT-I/MS pinout, 93AA66BT-I/MS application, or 93AA66BT-I/MS equivalent, key selection criteria include voltage compatibility (1.8–5.5 V), MSOP-8 package footprint, 8-bit word organization (no ORG pin), industrial-grade reliability, and support for sequential read and Ready/Busy polling via DO.
Technical Context
This device implements a synchronous 3-wire Microwire interface with CS, CLK, and DI/DO signals. It uses internal auto-erase-before-write logic and supports full-array erase (ERAL) and full-array write (WRAL) with VCC ≥ 4.5 V. The absence of an ORG pin confirms fixed 8-bit word size and eliminates external configuration logic.
Operation relies on start-bit detection (CS high + DI high on first CLK rising edge), clock-synchronized instruction loading (12 CLK cycles for READ), and DO-driven status polling during programming. Standby current is ≤5 µA, and write endurance is rated at 1 million cycles with >200 years data retention.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8-bit), fixed x8 organization - no ORG pin required, simplifies PCB layout and firmware addressing. |
| Supply Voltage | 1.8–5.5 V - enables direct interfacing with 1.8 V, 3.3 V, and 5 V microcontrollers without level-shifting. |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - minimal GPIO usage, compatible with legacy PIC® and 8051 controllers. |
| Write Endurance | 1,000,000 erase/write cycles - supports frequent field-updatable parameters in industrial control systems. |
| Data Retention | >200 years at 25°C - ensures long-term calibration data integrity in unpowered equipment. |
| Operating Temp | −40°C to +85°C (Industrial grade) - qualified for deployment in factory automation, metering, and outdoor electronics. |
| Max Clock Frequency | 3 MHz at VCC ≥ 4.5 V - enables fast parameter reads during boot-up sequences. |
Pinout & Package
8-pin MSOP (Micro Small Outline Package), 3.0 mm × 4.9 mm body, 0.65 mm pitch, exposed pad optional (VSS or floating). Pin 1 marked by laser dot.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held low ≥250 ns between instructions; controls standby entry and Ready/Busy polling window. |
| 2 (CLK) | Serial Clock | Rising-edge synchronized I/O; stoppable mid-transfer; TCKH/TCKL timing varies with VCC (e.g., 200 ns min at 4.5–5.5 V). |
| 3 (DI) | Data Input | Accepts start bit, opcode, address, and write data; requires pull-up if shared with DO to prevent bus conflict. |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy (low = busy); enters High-Z on CS falling edge; status valid only after TCSL ≥250 ns. |
| 5 (VSS) | Ground | Reference for all I/O and internal logic; connect exposed pad to VSS for thermal performance in MSOP. |
| 6 (NC) | No Connection | Internally unconnected; must be left floating or tied to VSS per layout best practice - no routing required. |
| 7 (ORG) | Organization Select | Not present on 'A' devices - pin 7 is NC; confirms fixed 8-bit operation and eliminates external biasing components. |
| 8 (VCC) | Power Supply | 1.8–5.5 V input; includes on-chip POR at ~1.5 V; decoupling capacitor (0.1 µF) required near pin 8. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates external timing control - TWC = 6 ms typical for AA-series, enabling deterministic firmware delay handling. |
| Automatic ERAL before WRAL | Guarantees clean memory state prior to full-array write - removes need for separate erase command in bootloader routines. |
| Power-On/Off Data Protection | Hardware lockout below 1.5 V VCC - prevents corruption during brown-out or hot-plug events without software intervention. |
| Ready/Busy Polling via DO | Enables non-blocking writes - host MCU can execute other tasks while checking DO high/low instead of fixed delays. |
| Sequential Read Mode | Continuous data stream across addresses with CS held high - reduces transaction overhead for bulk parameter reads. |
Applications
| Industrial Sensor Calibration Storage | Embedded System Configuration Memory |
|---|---|
Use Scenario: Storing factory-calibrated offset/gain coefficients for analog sensor front-ends in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile parameter register accessed during power-up initialization and field recalibration routines. Use Value: 1.8 V operation allows direct connection to low-power ADC reference rails; 1M endurance supports lifetime recalibration cycles. | Use Scenario: Holding user-configurable settings (baud rate, I/O mapping, alarm thresholds) in HVAC controller HMI modules. IC Role / Device Role / Timing Role: Serial configuration store interfaced to 8-bit MCU GPIOs using minimal 3-wire lines. Use Value: MSOP-8 footprint saves board space vs. SOIC; sequential read accelerates boot-time config loading. |
| Firmware Parameter Backup | Smart Meter Tamper-Resistant Log |
Use Scenario: Retaining runtime-adjusted PID loop constants and fault history in motor drive inverters after power loss. IC Role / Device Role / Timing Role: Fail-safe parameter vault updated during normal operation and validated at startup. Use Value: >200-year data retention ensures integrity across product lifecycle; VCC brown-out protection prevents partial writes. | Use Scenario: Recording timestamped tamper events (cover removal, magnetic interference) in utility meters with legal audit requirements. IC Role / Device Role / Timing Role: Secure event log with write-protection enforced by EWEN/EWDS commands. Use Value: Hardware-based write disable (EWDS) prevents malicious overwrite; industrial temp rating ensures field reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66BT-I/MS | 2.5–5.5 V VCC range; identical pinout, timing, and instruction set; no functional difference for 3.3 V systems. | Requires minimum 2.5 V - unsuitable for 1.8 V-only designs but offers tighter VCC tolerance in noise-prone environments. | Select when operating exclusively at 3.3 V and higher immunity to supply ripple is needed. |
| AT25040B-MAHL-T | SPI interface (4-wire), 1 MHz max clock, 1.8–5.5 V, same 4 Kbit density; different command protocol and no ERAL/WRAL auto-erase. | Lacks Microwire compatibility - requires SPI peripheral and firmware rewrite; no built-in full-array erase automation. | Choose only if migrating to SPI architecture and accepting added firmware complexity for multi-vendor sourcing flexibility. |
Compared with 93LC66BT-I/MS, the 93AA66BT-I/MS supports lower-voltage operation (1.8 V) critical for battery-powered nodes, while the AT25040B demands SPI infrastructure and manual erase management - making the 93AA66BT-I/MS optimal for cost-sensitive, Microwire-based industrial control designs.
Availability
93AA66BT-I/MS is available at Aetrix Electronics and suitable for industrial sensor calibration storage, embedded system configuration memory, and firmware parameter backup requiring stable component supply across extended production lifecycles.
Supply support for 93AA66BT-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 and manufacturing operations.
The 93AAxx series targets low-power, cost-sensitive nonvolatile memory applications in industrial, automotive, and consumer systems - emphasizing voltage flexibility, robust data retention, and simple 3-wire integration.
FAQ
What is the memory organization of the 93AA66BT-I/MS?
The 93AA66BT-I/MS has a fixed 512 × 8-bit (4 Kbit) organization. As an 'A' variant, it lacks an ORG pin - confirming dedicated 8-bit word size without external configuration. This eliminates ambiguity in address decoding and simplifies firmware development compared to 'C' variants requiring ORG pin control.
Does the 93AA66BT-I/MS require an external pull-up resistor on the DO line?
Yes, when DI and DO are wired together (common bus configuration), a pull-up resistor is required on the DO line to prevent bus conflict during the dummy zero preceding read operations. The 93AA66BT-I/MS datasheet specifies this to avoid undefined voltage levels caused by competing drivers - especially when A0 is high.
What is the maximum clock frequency supported by the 93AA66BT-I/MS at 3.3 V?
At VCC = 3.3 V (within 2.5–5.5 V range), the 93AA66BT-I/MS supports a maximum clock frequency of 2 MHz. This is specified in Table 1-2 (A1) for 2.5 V ≤ VCC < 5.5 V. Exceeding this may cause setup/hold violations and read/write failures.
How does the 93AA66BT-I/MS protect against accidental writes during power transitions?
The 93AA66BT-I/MS incorporates hardware power-on/power-off protection that inhibits all operations when VCC falls below ~1.5 V. Additionally, it powers up in Erase/Write Disable (EWDS) mode, requiring an explicit EWEN command before any erase or write - preventing spurious writes during brown-out or reset conditions.
Is the 93AA66BT-I/MS pin-compatible with the 93LC66BT-I/MS?
Yes, the 93AA66BT-I/MS and 93LC66BT-I/MS share identical MSOP-8 pinouts, electrical characteristics, and instruction sets. The primary difference is VCC range: 93AA66BT-I/MS operates from 1.8 V, while 93LC66BT-I/MS requires minimum 2.5 V - making them drop-in replacements in 3.3 V systems but not in 1.8 V designs.
93AA66BT-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:
- 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:
- Surface Mount
- Supplier Device Package:
- 8-MSOP
93AA66BT-I/MS FAQ
1.How can I place an order for 93AA66BT-I/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 93AA66BT-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 93AA66BT-I/MS reliable?
The price and inventory of 93AA66BT-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 93AA66BT-I/MS is usually 5 days.
3.What payment methods are accepted for 93AA66BT-I/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93AA66BT-I/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93AA66BT-I/MS?
93AA66BT-I/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93AA66BT-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 93AA66BT-I/MS?
For technical support, including 93AA66BT-I/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93AA66BT-I/MS requirements.
6.How does Aetrix verify that 93AA66BT-I/MS is sourced from the original manufacturer or authorized distributors?
All 93AA66BT-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 93AA66BT-I/MS meets industry standards.
7.What is the process for return or replacement of 93AA66BT-I/MS?
All 93AA66BT-I/MS units undergo pre-shipment inspection (PSI). If there is an issue with 93AA66BT-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 93AA66BT-I/MS part is unused and in its original packaging.
Return procedure for 93AA66BT-I/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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