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Microchip Technology 93AA66B-I/ST
- Part No.:
- 93AA66B-I/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
93AA66B-I/ST.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,463
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Product details
Overview
93AA66B-I/ST from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with dedicated 16-bit organization, 1.8–5.5 V supply range, industrial temperature rating (–40°C to +85°C), and Microwire-compatible 3-wire serial interface. It provides nonvolatile storage for configuration data in embedded microcontroller systems requiring reliable, low-power memory with automatic erase-before-write.
For engineers reviewing the 93AA66B-I/ST datasheet, 93AA66B-I/ST pinout, 93AA66B-I/ST application, or 93AA66B-I/ST equivalent, key selection criteria include its fixed x16 word size (no ORG pin), 256 × 16-bit memory map, 6 ms typical write cycle time, Ready/Busy status via DO pin, and compatibility with 8-lead TSSOP packaging for space-constrained PCB layouts.
Technical Context
The 93AA66B-I/ST implements a synchronous Microwire-compatible serial interface using CS, CLK, DI, and DO signals - no ORG pin required due to fixed 16-bit organization. All instructions (READ, WRITE, ERASE, ERAL, WRAL, EWEN, EWDS) are initiated by a Start bit followed by opcode, address, and data bits clocked on CLK rising edges.
It features self-timed erase/write cycles with automatic pre-erase, power-on/off data protection, and hardware-based write disable (EWDS) default state. The DO pin serves dual function: serial data output during READ and Ready/Busy status indicator during programming - active-low during operation, high-Z when deselected or idle.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (256 × 16-bit organization) |
| Supply Voltage | 1.8 V to 5.5 V - supports single-supply operation across wide voltage rails including 3.3 V and 5 V systems |
| Write Cycle Time | 6 ms typical - determines minimum time between successive write operations; impacts firmware polling or interrupt-driven status handling |
| Endurance | 1,000,000 erase/write cycles - ensures long-term reliability in frequently updated configuration storage applications |
| Data Retention | 200 years at 25°C - guarantees nonvolatile data integrity over product lifetime without refresh |
| Interface | Microwire-compatible 3-wire serial (CS, CLK, DI/DO) - minimal GPIO usage; no I²C or SPI protocol overhead |
| Temperature Range | –40°C to +85°C (Industrial grade) - validated for use in commercial and industrial control environments |
Pinout & Package
93AA66B-I/ST is packaged in an 8-lead TSSOP (Thin Shrink Small Outline Package), lead-free, RoHS-compliant, with standard 0.65 mm pitch and exposed pad option not applicable for this variant. Pin 1 marked by laser dot or notch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable; device enters standby when low; must be held low ≥250 ns between commands |
| CLK | Serial Clock | Synchronizes all data transfers; rising edge clocks in/out bits; can be paused mid-transfer |
| DI | Data Input | Accepts Start bit, opcodes, addresses, and write data; must be stable before first CLK rising edge |
| DO | Data Output / Status | Outputs read data or Ready/Busy (low = busy); high-Z when CS low or during non-read states |
| VSS | Ground | Reference return path for all signals and internal circuitry; requires low-impedance connection |
| NC | No Connect | Internally unconnected; must be left floating or tied to VSS per layout best practice |
| VCC | Power Supply | 1.8–5.5 V input; includes internal POR detection at ~1.5 V to prevent spurious writes during power ramp |
| ORG | Organization Select | Not present on 93AA66B - fixed x16 mode; pin is NC and must not be connected |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates need for external timing control - firmware only polls DO or waits fixed 6 ms |
| Automatic Erase All before Write All | WRAL command internally executes ERAL then writes full array - simplifies bulk update sequences |
| Power-On/Off Data Protection | Hardware lockout below 1.5 V VCC prevents corruption during brown-out or power cycling |
| Ready/Busy Status on DO | Enables efficient polling without additional pins - reduces system resource overhead vs. interrupt-driven schemes |
| Sequential Read Mode | Continuous data stream across addresses while CS remains high - accelerates block reads |
Applications
| Motor Control Configuration | Industrial Sensor Calibration |
|---|---|
Use Scenario: Storing motor commutation tables, PID coefficients, and fault thresholds in BLDC drive firmware. IC Role / Device Role / Timing Role: Nonvolatile configuration store accessed at startup and during field updates via MCU's GPIO bit-banged Microwire interface. Use Value: Enables field-upgradable motor parameters without requiring reflash of main controller firmware or external programming hardware. | Use Scenario: Holding factory-trimmed offset/gain values and linearization coefficients for analog sensor front-ends. IC Role / Device Role / Timing Role: Dedicated calibration memory mapped to MCU's peripheral bus via software-controlled serial interface. Use Value: Maintains sensor accuracy across temperature and aging without recalibration hardware; supports multi-sensor module traceability. |
| Medical Device Settings | Smart Energy Metering |
Use Scenario: Securing user-prescribed therapy parameters and audit logs in portable infusion pumps. IC Role / Device Role / Timing Role: Tamper-resistant settings register accessed under secure boot flow with EWEN/EWDS sequence enforcement. Use Value: Meets IEC 62304 safety requirements for persistent critical data with write-protection and 200-year retention. | Use Scenario: Storing tariff schedules, demand-response profiles, and metering history in ANSI C12.19-compliant utility meters. IC Role / Device Role / Timing Role: High-endurance data logger buffer interfaced to metrology SoC via shared 3-wire bus with deterministic 6 ms write latency. Use Value: Survives >1M write cycles from daily billing updates while maintaining data integrity during grid transients. |
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/ST | Same 256 × 16-bit organization but wider VCC range (2.5–5.5 V); lacks 1.8 V support | Not suitable for 1.8 V logic domains; otherwise pin- and function-compatible | Select if system operates ≥2.5 V and requires higher noise immunity at VCC extremes |
| AT25040B-MAU-5A | 4 Kbit SPI interface (not Microwire); 1.8–5.5 V; 5 MHz max clock vs. 3 MHz for 93AA66B | Requires SPI peripheral instead of bit-banged Microwire; faster throughput but different protocol stack | Choose when MCU has dedicated SPI hardware and higher-speed serial memory access is prioritized |
Compared with 93LC66B-I/ST, the 93AA66B-I/ST enables lower-voltage operation down to 1.8 V, critical for battery-powered devices; versus AT25040B-MAU-5A, it retains Microwire simplicity and deterministic 6 ms write timing but trades off peak bandwidth for broader legacy MCU compatibility.
Availability
93AA66B-I/ST is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, and smart energy metering requiring stable component supply, long-term obsolescence management, and RoHS-compliant packaging.
Supply support for 93AA66B-I/ST 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 93AA66B-I/ST belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-power embedded systems needing simple, robust nonvolatile storage without complex protocol stacks.
FAQ
What is the memory organization of the 93AA66B-I/ST?
The 93AA66B-I/ST has a fixed 256 × 16-bit organization - meaning 256 words of 16 bits each, totaling 4 Kbit. Unlike 'C' variants, it does not feature an ORG pin; the x16 mode is hardwired. This eliminates external configuration logic and simplifies PCB layout compared to selectable-word-size alternatives.
Does the 93AA66B-I/ST require an external ORG pin connection?
No, the 93AA66B-I/ST does not require or support an ORG pin. As a 'B'-suffix device, it is permanently configured for 16-bit operation. The ORG pin position on the 8-lead TSSOP package is designated NC (No Connect) and must remain unconnected - tying it to any voltage risks undefined behavior.
What is the maximum clock frequency supported by the 93AA66B-I/ST?
The 93AA66B-I/ST supports up to 3 MHz clock frequency when VCC is 4.5 V to 5.5 V. At lower voltages (2.5–4.5 V), max frequency drops to 2 MHz; at 1.8–2.5 V, it is limited to 1 MHz. These limits ensure reliable setup/hold timing across voltage and temperature ranges per AC specification Table 1-2.
How does the Ready/Busy status work on the 93AA66B-I/ST?
The DO pin of the 93AA66B-I/ST outputs Ready/Busy status during erase or write cycles: logic low indicates ongoing operation; high indicates completion. To sample status, CS must be brought high for ≥250 ns after initiating the command. Issuing a new Start bit then lowering CS clears the status flag.
Is the 93AA66B-I/ST compatible with 1.8 V microcontroller I/O?
Yes, the 93AA66B-I/ST is fully compatible with 1.8 V logic systems. Its VIH1 threshold is 2.0 V minimum at VCC ≥ 2.7 V, but VIH2 drops to 0.7 × VCC - so at 1.8 V VCC, VIH2 = 1.26 V, safely within 1.8 V logic-high margins. Input leakage remains ≤±1 µA across voltage range, ensuring clean signal interpretation.
93AA66B-I/ST Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP (0.173", 4.40mm Width)
- 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:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
93AA66B-I/ST FAQ
1.How can I place an order for 93AA66B-I/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 93AA66B-I/ST 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/ST reliable?
The price and inventory of 93AA66B-I/ST 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/ST is usually 5 days.
3.What payment methods are accepted for 93AA66B-I/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93AA66B-I/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93AA66B-I/ST?
93AA66B-I/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93AA66B-I/ST 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/ST?
For technical support, including 93AA66B-I/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93AA66B-I/ST requirements.
6.How does Aetrix verify that 93AA66B-I/ST is sourced from the original manufacturer or authorized distributors?
All 93AA66B-I/ST 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/ST meets industry standards.
7.What is the process for return or replacement of 93AA66B-I/ST?
All 93AA66B-I/ST units undergo pre-shipment inspection (PSI). If there is an issue with 93AA66B-I/ST, 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/ST part is unused and in its original packaging.
Return procedure for 93AA66B-I/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93AA66B-I/ST Tags
-
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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