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Microchip Technology 93AA66AT-I/SN
- Part No.:
- 93AA66AT-I/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93AA66AT-I/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,439
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Product details
Overview
93AA66AT-I/SN 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 >200 years data retention. Used in embedded system configuration storage, sensor calibration memory, and firmware parameter backup.
For engineers reviewing the 93AA66AT-I/SN datasheet, 93AA66AT-I/SN pinout, 93AA66AT-I/SN application, or 93AA66AT-I/SN equivalent, key selection criteria include VCC range (1.8–5.5 V), 8-bit word organization (no ORG pin), standby current ≤5 µA, and compatibility with legacy Microwire controllers in space-constrained industrial designs.
Technical Context
The 93AA66AT-I/SN implements a synchronous serial interface with start-bit detection, opcode-driven command set (READ/WRITE/ERASE/ERAL/WRAL/EWEN/EWDS), and Ready/Busy status polling via DO pin. Its internal architecture includes address counter, mode decode logic, and output buffer, enabling sequential read and auto-erase-before-write operation without external timing control.
It operates across 1.8–5.5 V with guaranteed AC timing at 3 MHz (VCC ≥ 4.5 V), 2 MHz (2.5 V ≤ VCC < 4.5 V), and 1 MHz (1.8 V ≤ VCC < 2.5 V). The device powers up in EWDS mode and requires explicit EWEN before any programming cycle - a hardware-enforced write-protection mechanism independent of VCC monitoring.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit); fixed x8 organization with no ORG pin - eliminates external logic for word-size selection. |
| VCC range | 1.8 V to 5.5 V; supports single-supply operation across battery-powered, 3.3 V, and 5 V systems without level shifters. |
| Endurance | 1,000,000 erase/write cycles; enables frequent field updates in telemetry loggers and programmable I/O modules. |
| Data retention | >200 years at 25°C; ensures long-term reliability in unattended infrastructure monitoring equipment. |
| Write time | 6 ms typical per byte/page; self-timed with no host CPU wait-state overhead during programming. |
| Standby current | ≤5 µA at –40°C to +85°C; critical for always-on IoT edge nodes powered by coin cells or energy harvesters. |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO); interoperable with legacy microcontrollers lacking SPI hardware. |
Pinout & Package
8-pin SOIC (SN) package with 150-mil body width, Pb-free Matte Tin finish, and standard pin mapping: Pin 1 = CS, Pin 2 = CLK, Pin 3 = DI, Pin 4 = DO, Pin 5 = VSS, Pin 6 = NC (no internal connection), Pin 7 = NC, Pin 8 = VCC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable; must be held low ≥250 ns between instructions; deselects device into ultra-low-power standby. |
| CLK | Serial Clock | Synchronizes all data transfers on rising edge; stoppable at any point - simplifies timing-critical host firmware. |
| DI | Data Input | Accepts start bit, opcodes, addresses, and write data; tolerant of bus conflicts when shared with DO (with series resistor). |
| DO | Data Output / Status | Outputs read data or Ready/Busy flag (low = busy); high-Z when inactive - enables multi-drop bus sharing. |
| VSS | Ground | Reference for all I/O and internal logic; must be connected directly to PCB ground plane for noise immunity. |
| NC (Pins 6 & 7) | No internal connection | Unbonded pins; must remain floating - no pull-up/down or routing required. |
| VCC | Power Supply | Supplies core logic and memory array; internal POR circuit triggers at ~1.5 V to prevent partial writes during brownout. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates need for host-controlled timing delays - reduces firmware complexity and improves system robustness. |
| Automatic ERAL before WRAL | Guarantees full-array erase prior to bulk write, preventing stale data corruption without software intervention. |
| Power-on/off data protection | Hardware lockout below 1.5 V VCC prevents inadvertent writes during power ramp-up/down sequences. |
| Ready/Busy status via DO | Enables non-blocking polling instead of fixed delays - optimizes host CPU utilization in real-time applications. |
| Sequential read mode | Allows continuous address increment with CS held high - cuts transaction overhead by 40% vs. individual reads. |
Applications
| Industrial Sensor Calibration | Embedded System Configuration |
|---|---|
Use Scenario: Storing factory-trimmed ADC offset/gain coefficients and temperature compensation tables in pressure transmitters. IC Role / Device Role / Timing Role: Nonvolatile parameter store accessed at boot and during field recalibration; uses READ and WRITE with EWEN/EWDS for safety. Use Value: Enables one-time calibration in production and field updates without soldering - reducing service cost by 65%. | Use Scenario: Holding user-defined network settings (IP, subnet, gateway), display brightness, and language preference in HVAC controllers. IC Role / Device Role / Timing Role: Boot-time configuration loader and runtime parameter scratchpad; leverages sequential read for fast initialization. Use Value: Survives 10+ years of power cycles and retains settings through firmware upgrades - eliminating reconfiguration labor. |
| Firmware Parameter Backup | Telemetry Data Logging |
Use Scenario: Archiving last-known operational state (fan speed, valve position, error flags) before unexpected shutdown in medical infusion pumps. IC Role / Device Role / Timing Role: Crash-safe persistent memory; triggered by brownout detection circuitry to capture critical context before VCC collapse. Use Value: Reduces mean time to recovery (MTTR) by 90% - technicians restore function using saved state instead of full reset. | Use Scenario: Buffering timestamped sensor readings (temperature, humidity, vibration) in predictive maintenance gateways. IC Role / Device Role / Timing Role: Circular buffer with WRAL for fast bulk overwrite; endurance rating supports daily logging for >27 years. Use Value: Eliminates need for external FRAM or flash - cutting BOM cost by $0.32/unit while meeting 10-year field life. |
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/SN | VCC min = 2.5 V; identical pinout, timing, and instruction set; same 512 × 8-bit organization. | Not suitable for 1.8 V systems; requires higher supply voltage margin - limits use in ultra-low-power wearables. | Select when system VCC is stable ≥2.5 V and legacy 93LC-series qualification is required. |
| AT25040B-MAHL-T | SPI interface (4-wire), 4 Kbit (512 × 8), 1.8–5.5 V, 20 MHz max clock; no ERAL/WRAL commands. | Lacks Microwire compatibility and auto-erase-all functionality - requires host-managed erase sequencing. | Select when migrating to SPI-based platforms and firmware can handle discrete erase/write commands. |
Compared with 93LC66AT-I/SN and AT25040B-MAHL-T, the 93AA66AT-I/SN uniquely supports 1.8 V operation while retaining Microwire compatibility and hardware-assisted bulk operations (ERAL/WRAL), making it optimal for brownout-prone, legacy-controller-based industrial designs.
Availability
93AA66AT-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded system configuration, and firmware parameter backup requiring stable component supply across extended product lifecycles.
Supply support for 93AA66AT-I/SN 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, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93AA66AT-I/SN belongs to Microchip's legacy 93XX serial EEPROM product line, designed specifically for cost-sensitive, low-power, nonvolatile memory applications in industrial, automotive, and consumer electronics where Microwire interface compatibility and robust data integrity are essential.
FAQ
What is the memory organization of the 93AA66AT-I/SN?
The 93AA66AT-I/SN has a fixed 512 × 8-bit organization with no ORG pin. Unlike 'C' variants, it does not support word-size selection - it is dedicated to 8-bit communication only. This eliminates external logic for configuration and simplifies PCB layout in space-constrained designs where x8 interface suffices.
Does the 93AA66AT-I/SN require an external pull-up resistor on the DO pin?
No, the 93AA66AT-I/SN does not require an external pull-up on DO. The pin actively drives high/low during READ and Ready/Busy status reporting, and enters high-impedance (High-Z) state otherwise. However, if DI and DO are shorted (shared bus), a 1–10 kΩ series resistor is recommended to prevent bus conflict during dummy-zero read preamble.
How does the 93AA66AT-I/SN protect against accidental writes during power transitions?
The 93AA66AT-I/SN incorporates hardware-level protection: it powers up in Erase/Write Disable (EWDS) mode, and its internal POR circuit inhibits all programming when VCC falls below ~1.5 V. An explicit EWEN instruction is mandatory before any ERASE or WRITE - ensuring no unintended writes occur during brownout or startup.
What is the maximum clock frequency supported by the 93AA66AT-I/SN at 3.3 V VCC?
At VCC = 3.3 V (within 2.5–5.5 V range), the 93AA66AT-I/SN supports a maximum clock frequency of 2 MHz. This is specified in Table 1-2 (A1) for 2.5 V ≤ VCC < 4.5 V. Exceeding this frequency risks setup/hold violations and unreliable command execution.
Can the 93AA66AT-I/SN be used as a direct replacement for the 93C66AT-I/SN?
No, the 93AA66AT-I/SN is not a direct replacement for the 93C66AT-I/SN. While pin-compatible, they differ critically in VCC range (93AA: 1.8–5.5 V; 93C: 4.5–5.5 V), erase/write timing (6 ms vs. 2 ms), and POR threshold (1.5 V vs. 3.8 V). Substituting without verifying voltage margins and timing may cause functional failure or data corruption.
93AA66AT-I/SN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- 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-SOIC
93AA66AT-I/SN FAQ
1.How can I place an order for 93AA66AT-I/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93AA66AT-I/SN 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/SN reliable?
The price and inventory of 93AA66AT-I/SN 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/SN is usually 5 days.
3.What payment methods are accepted for 93AA66AT-I/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93AA66AT-I/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93AA66AT-I/SN?
93AA66AT-I/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93AA66AT-I/SN 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/SN?
For technical support, including 93AA66AT-I/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93AA66AT-I/SN requirements.
6.How does Aetrix verify that 93AA66AT-I/SN is sourced from the original manufacturer or authorized distributors?
All 93AA66AT-I/SN 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/SN meets industry standards.
7.What is the process for return or replacement of 93AA66AT-I/SN?
All 93AA66AT-I/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93AA66AT-I/SN, 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/SN part is unused and in its original packaging.
Return procedure for 93AA66AT-I/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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