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Microchip Technology 93LC66AXT-I/SN
- Part No.:
- 93LC66AXT-I/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93LC66AXT-I/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,398
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Product details
Overview
93LC66AXT-I/SN from Microchip Technology Inc. is a 4 Kbit (512 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, operating from 2.5V to 5.5V, rated for Industrial temperature range (–40°C to +85°C), and housed in an 8-lead SOIC package (SN). It features self-timed erase/write cycles, automatic ERAL before WRAL, and Ready/Busy status via DO pin - used for configuration storage in embedded microcontroller systems.
For engineers reviewing the 93LC66AXT-I/SN datasheet, 93LC66AXT-I/SN pinout, 93LC66AXT-I/SN application, or 93LC66AXT-I/SN equivalent, key selection criteria include VCC range (2.5–5.5 V), 8-bit x 512 organization, industrial temp rating, SOIC-8 packaging, and Microwire protocol compliance - critical for legacy MCU peripheral interfaces requiring nonvolatile parameter retention.
Technical Context
This device implements a synchronous serial Microwire interface with CS, CLK, DI, and DO pins - no ORG pin (dedicated 8-bit mode). Communication requires a Start bit followed by opcode, address, and data bits clocked on rising CLK edges; DO outputs data or Ready/Busy status depending on CS timing and operation state.
It uses self-timed internal erase-before-write architecture: falling edge of CS initiates auto-erase and programming for 93LC66A/B/C variants. Write cycle time is 6 ms typical at 25°C; endurance is 1 million erase/write cycles with >200-year data retention - validated under specified VCC and temperature conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 words × 8 bits) - fixed x8 organization; no ORG pin; supports sequential read and single-byte write. |
| VCC Range | 2.5 V to 5.5 V - compatible with 3.3 V and 5 V logic systems; POR threshold is 1.5 V for power-on data protection. |
| Interface | Microwire-compatible 3-wire serial (CS, CLK, DI/DO) - no I²C or SPI; requires Start bit detection and opcode-based command set. |
| Write Cycle Time | 6 ms max - self-timed erase-and-write; no external delay required; includes auto-erase prior to write. |
| Endurance & Retention | 1,000,000 erase/write cycles; >200 years data retention at 25°C - qualified per JEDEC JESD22-A117. |
| Temperature Range | Industrial: –40°C to +85°C - suitable for industrial control, metering, and automotive body electronics (non-safety-critical). |
| Package | 8-lead SOIC (SN) - 150-mil width, Pb-free Matte Tin finish; pin-compatible with industry-standard 8-pin SOIC footprints. |
Pinout & Package
8-lead SOIC (SN) package with standard 150-mil body width, RoHS-compliant Matte Tin plating, and exposed pad not present. Pin 1 marked by laser dot or notch; orientation follows standard SOIC convention.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - CS | Chip Select | Active-high enable; must be held high ≥250 ns between instructions; deselects device into standby when low. |
| 2 - CLK | Serial Clock | Rising-edge synchronized I/O; clock stops freely during transmission; no clock required during self-timed write. |
| 3 - DI | Data Input | Accepts Start bit, opcodes, addresses, and write data; tied to DO only with series resistor to avoid bus conflict. |
| 4 - DO | Data Output / Status | Outputs read data or Ready/Busy (low = busy); enters High-Z on CS falling edge; status valid after TCSL and TSV. |
| 5 - VSS | Ground | Reference for all I/O and internal circuitry; must be connected directly to system ground plane. |
| 6 - NC | No Connect | Internally unconnected; must remain floating or tied to VSS per layout best practice; not bonded in die. |
| 7 - NC | No Connect | Same as Pin 6; dual NC pins confirm absence of ORG functionality in 'A' version devices. |
| 8 - VCC | Power Supply | 2.5–5.5 V supply; internal voltage detector (VPOR = 1.5 V) blocks operations below threshold for data integrity. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates need for external timing control or polling delays - falling edge of CS triggers full auto-erase-and-program sequence. |
| Automatic ERAL before WRAL | Ensures full array is erased before bulk write; prevents partial writes or data corruption without host software intervention. |
| Ready/Busy via DO pin | Enables real-time status monitoring without dedicated status lines - reduces pin count and simplifies host firmware. |
| Power-On/Off Data Protection | Hardware-level lockout below 1.5 V VCC prevents inadvertent writes during brown-out or power ramp-up/down. |
| 1,000,000 Endurance Cycles | Supports frequent field updates (e.g., calibration, logging, firmware patch storage) over product lifetime without wear-out risk. |
Applications
| Industrial Sensor Calibration | Legacy MCU Configuration Storage |
|---|---|
|
Use Scenario: Storing factory-calibrated sensor offset/gain coefficients in programmable logic controllers (PLCs) and analog input modules. IC Role / Device Role / Timing Role: Nonvolatile parameter register accessed during boot or recalibration; Microwire interface matches legacy 8051/AVR peripherals. Use Value: Eliminates external NVRAM or battery-backed SRAM; retains calibration across power cycles with guaranteed 200-year data integrity. |
Use Scenario: Holding boot configuration flags, communication settings, and user preferences in embedded HVAC controllers and motor drives. IC Role / Device Role / Timing Role: Serial configuration EEPROM interfaced to MCU GPIO bit-banged Microwire; 6 ms write time fits within watchdog-safe intervals. Use Value: Reduces BOM cost vs. SPI Flash; avoids complex initialization sequences required by newer serial NOR/NAND devices. |
| Energy Meter Firmware Patch Log | Automotive Body Control Module Settings |
|
Use Scenario: Recording firmware update history and rollback metadata in ANSI C12.22-compliant smart meters. IC Role / Device Role / Timing Role: Tamper-resistant event log storage; write-protected via EWEN/EWDS commands during normal operation. Use Value: Supports regulatory audit trails with 1M-cycle endurance - enables 10+ years of daily patch logging at 300 cycles/year. |
Use Scenario: Storing seat position memory, mirror presets, and lighting profiles in automotive BCMs operating at –40°C to +85°C. IC Role / Device Role / Timing Role: Industrial-temp EEPROM integrated into CAN/LIN gateway subsystems; SOIC-8 eases rework and conforms to AEC-Q200 stress test requirements. Use Value: Qualified for extended temperature operation without derating; Pb-free SOIC meets automotive soldering profile and RoHS compliance mandates. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66BXT-I/SN | 256 × 16-bit organization; same VCC range, package, and timing; no ORG pin - fixed x16 mode. | Requires host firmware adapted for 16-bit word access; incompatible with existing 8-bit read/write routines. | Select only if system architecture mandates 16-bit data alignment and eliminates byte-level addressing overhead. |
| AT25040B-MAU-1.8 | SPI interface (4-wire), 512 × 8-bit, 1.8–5.5 V, SOIC-8; lacks Ready/Busy pin; uses WIP flag polled via STATUS register. | Requires SPI master peripheral or bit-banged GPIO; no hardware status signal - increases firmware polling burden. | Choose when migrating to SPI ecosystem or needing lower 1.8 V operation; verify timing compatibility with existing clock rates. |
Compared with 93LC66BXT-I/SN, the 93LC66AXT-I/SN provides native 8-bit word access without firmware rework; versus AT25040B-MAU-1.8, it delivers deterministic Ready/Busy signaling and Microwire protocol compatibility for legacy MCU designs.
Availability
93LC66AXT-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, legacy MCU configuration storage, and energy meter firmware patch logging requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for 93LC66AXT-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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93LC66A belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-power embedded systems requiring simple, robust, and long-life nonvolatile storage with minimal pin count and firmware overhead.
FAQ
What is the memory organization of the 93LC66AXT-I/SN?
93LC66AXT-I/SN has a fixed 512 × 8-bit (4 Kbit) organization. Unlike 'C' variants, it lacks an ORG pin and operates exclusively in x8 mode - no configuration required. This simplifies PCB layout and firmware development for systems expecting byte-addressable serial EEPROM.
Does the 93LC66AXT-I/SN support SPI or I²C interface?
No, 93LC66AXT-I/SN uses a Microwire-compatible 3-wire serial interface (CS, CLK, DI/DO) - not SPI or I²C. It requires Start-bit detection and specific opcode-based commands (e.g., 0x10 for READ, 0x01 for WRITE). Host MCU must implement Microwire timing, not generic SPI/I²C drivers.
How is write protection implemented on the 93LC66AXT-I/SN?
93LC66AXT-I/SN uses Erase/Write Enable (EWEN) and Disable (EWDS) instructions. It powers up in EWDS mode - all writes are blocked until EWEN is issued. After each write, executing EWDS restores protection. This prevents accidental overwrites during noise events or power transients.
What is the maximum clock frequency supported by the 93LC66AXT-I/SN?
93LC66AXT-I/SN supports up to 3 MHz clock frequency when VCC ≥ 4.5 V, 2 MHz at 2.5 V ≤ VCC < 4.5 V, and 1 MHz at 1.8 V ≤ VCC < 2.5 V. Since this part is rated for 2.5–5.5 V, its operational max is 3 MHz - verified across the full industrial temperature range.
Is the 93LC66AXT-I/SN pin-compatible with other 8-lead SOIC EEPROMs?
93LC66AXT-I/SN is pin-compatible with standard 8-lead SOIC footprints (e.g., 150-mil width, 0.050" pitch), but not functionally interchangeable with SPI or I²C EEPROMs due to its unique Microwire protocol and command set. Electrical pinout (CS/CLK/DI/DO/VSS/VCC/NC/NC) matches other 93XXA SOIC variants.
93LC66AXT-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:
- Not 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:
- 2.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
93LC66AXT-I/SN FAQ
1.How can I place an order for 93LC66AXT-I/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66AXT-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 93LC66AXT-I/SN reliable?
The price and inventory of 93LC66AXT-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 93LC66AXT-I/SN is usually 5 days.
3.What payment methods are accepted for 93LC66AXT-I/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66AXT-I/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66AXT-I/SN?
93LC66AXT-I/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66AXT-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 93LC66AXT-I/SN?
For technical support, including 93LC66AXT-I/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66AXT-I/SN requirements.
6.How does Aetrix verify that 93LC66AXT-I/SN is sourced from the original manufacturer or authorized distributors?
All 93LC66AXT-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 93LC66AXT-I/SN meets industry standards.
7.What is the process for return or replacement of 93LC66AXT-I/SN?
All 93LC66AXT-I/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66AXT-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 93LC66AXT-I/SN part is unused and in its original packaging.
Return procedure for 93LC66AXT-I/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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