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Microchip Technology 93LC66AT/SN
- Part No.:
- 93LC66AT/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93LC66AT/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:7,467
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Product details
Overview
93LC66AT/SN from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, operating across 2.5–5.5 V, supporting Industrial (−40°C to +85°C) and Automotive (−40°C to +125°C) temperature ranges, and featuring Microwire-compatible 3-wire serial interface for embedded system configuration storage.
For engineers reviewing the 93LC66AT/SN datasheet, 93LC66AT/SN pinout, 93LC66AT/SN application, or 93LC66AT/SN equivalent, key selection criteria include VCC range compatibility, 8-bit word size (no ORG pin), SOIC-8 package footprint, self-timed erase/write cycles, and Ready/Busy status signaling via DO pin.
Technical Context
This device implements a synchronous 3-wire Microwire-compatible serial interface with CS, CLK, and DI/DO lines. It uses internal auto-erase before write and supports ERAL (Erase All) and WRAL (Write All) commands - both requiring VCC ≥ 4.5 V for execution.
It operates in Standby mode when CS is low, enters active mode on CS high, and provides Ready/Busy status polling via DO pin after minimum TCSL (250 ns). The ORG pin is NC (no internal connection) on this 'A' variant, fixing memory organization to 512 × 8-bit.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8-bit organization) |
| VCC Range | 2.5 V to 5.5 V - supports dual-supply systems and brown-out tolerant operation |
| Interface | Microwire-compatible 3-wire serial (CS, CLK, DI/DO) - minimal pin count, no address bus required |
| Write Cycle Time | 6 ms max - self-timed; no external timing control needed during erase/write |
| Endurance | 1,000,000 erase/write cycles - suitable for frequent firmware parameter updates |
| Data Retention | 200 years at 25°C - ensures long-term nonvolatile storage without refresh |
| Temp Range | Industrial (−40°C to +85°C) and Automotive (−40°C to +125°C) - qualified for harsh environments |
Pinout & Package
93LC66AT/SN is supplied in an 8-lead SOIC (SN) package per JEDEC MS-012, with gull-wing leads, 1.27 mm pitch, and Pb-free Matte Tin finish. Pin 1 is marked by laser dot or bevelled corner.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable; device enters Standby when low; programming continues to completion if initiated before CS low |
| CLK | Serial Clock | Synchronizes all data transfers on rising edge; clock may pause mid-sequence without error |
| DI | Data Input | Accepts Start bit, opcode, address, and write data; must be stable before first CLK rising edge |
| DO | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); tri-states on CS falling edge |
| VSS | Ground | Reference for all I/O and internal logic; requires low-impedance connection to minimize noise |
| NC | No Internal Connection | Pin 7 is unconnected internally - must be left floating or tied to VSS per layout best practice |
| VCC | Power Supply | Supplies core and I/O circuitry; internal POR triggers at ~1.5 V; decoupling capacitor required |
| ORG | Organization Select | No internal connection on 'A' devices - memory fixed at 8-bit word size; not used |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates need for external timing control or watchdog timeout logic in host firmware |
| Auto-Erase Before Write | Guarantees clean write operation without separate erase command - reduces software complexity |
| Ready/Busy Status via DO | Enables polling-based host synchronization instead of fixed delays, improving system responsiveness |
| Power-On/Off Data Protection | Hardware-level write inhibition below VCC threshold (~1.5 V) prevents corruption during power ramp |
| 1,000,000 Endurance Cycles | Supports daily reconfiguration over 27+ years - suitable for field-upgradable calibration tables |
Applications
| Industrial Sensor Calibration | Automotive Body Control Module |
|---|---|
Use Scenario: Storing factory-trimmed sensor offset/gain coefficients and real-time compensation parameters in programmable industrial transmitters. IC Role / Device Role / Timing Role: Nonvolatile configuration storage with infrequent writes and frequent reads; accessed only during power-up or recalibration events. Use Value: Enables field-replaceable sensor heads without recalibration tools - coefficients persist across power cycles and firmware updates. | Use Scenario: Holding seat position memory, mirror angle presets, and lighting configuration in automotive door modules. IC Role / Device Role / Timing Role: Low-pin-count serial EEPROM interfaced directly to 8-bit microcontroller GPIO; accessed during ignition-on initialization. Use Value: Survives automotive temperature extremes and vibration; retains user preferences even after battery disconnect. |
| Medical Device Settings Storage | Consumer Appliance Configuration |
Use Scenario: Saving therapy parameters, alarm thresholds, and usage logs in portable infusion pumps and diagnostic monitors. IC Role / Device Role / Timing Role: Secure, tamper-resistant storage for FDA-regulated configuration data; accessed via isolated SPI bridge. Use Value: Meets 200-year data retention requirement for medical records; supports audit trail integrity via WRAL/ERAL commands. | Use Scenario: Storing user-selected wash cycles, spin speeds, and language preferences in smart washing machines and dishwashers. IC Role / Device Role / Timing Role: Cost-optimized serial EEPROM sharing MCU's limited GPIO resources; written once per user session. Use Value: Reduces BOM cost vs. flash-based alternatives while maintaining reliability under repeated thermal cycling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66B/SN | 16-bit word organization (256 × 16), same VCC range and package; ORG pin not present but functionally fixed | Requires host firmware to handle 16-bit addressing and data packing; incompatible with existing 8-bit read/write routines | Select only if system architecture mandates 16-bit data alignment and memory bandwidth optimization |
| 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 bulk erase/write; requires byte-by-byte or page-write management; higher pin count due to dedicated SI/SO pins | Prefer when migrating to SPI-standard peripherals or when leveraging existing SPI controller infrastructure |
Compared with 93LC66B/SN and AT25040B-MAHL-T, the 93LC66AT/SN offers optimal balance of Microwire simplicity, 8-bit native access, and hardware-accelerated bulk operations - reducing host CPU overhead in resource-constrained designs.
Availability
93LC66AT/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive body control modules, and medical device settings storage requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for 93LC66AT/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, and Flash-IP solutions, serving industrial, automotive, and consumer markets with high-reliability silicon and development tools.
The 93LC66A/B/C family was designed specifically for low-power, pin-efficient nonvolatile memory in space-constrained embedded systems - emphasizing robustness, wide VCC tolerance, and simplified firmware integration.
FAQ
What is the memory organization of the 93LC66AT/SN?
The 93LC66AT/SN features a fixed 512 × 8-bit organization. As an 'A' variant, it has no functional ORG pin (marked NC), so word size cannot be changed. This differs from 'C' variants where ORG selects between 8-bit and 16-bit modes. The 93LC66AT/SN delivers byte-aligned data access ideal for 8-bit microcontrollers without packing/unpacking overhead.
Does the 93LC66AT/SN support bulk erase or write operations?
Yes, the 93LC66AT/SN supports both ERAL (Erase All) and WRAL (Write All) commands. ERAL erases the entire 512-byte array to 0xFF; WRAL writes the same 8-bit value to all locations. Both require VCC ≥ 4.5 V and are self-timed - no external delay needed. These functions reduce host firmware complexity versus byte-by-byte operations.
How is Ready/Busy status monitored on the 93LC66AT/SN?
Ready/Busy status is signaled on the DO pin: logic low indicates ongoing erase/write, logic high means operation complete. To poll, hold CS low for ≥250 ns (TCSL), then drive CS high - DO becomes valid within TSV (max 500 ns). Issuing a new Start bit clears the status. No additional status register or command is required.
What is the role of the NC pin on the 93LC66AT/SN?
Pin 7 on the 93LC66AT/SN is designated NC (No Connection) - it has no internal bond wire or circuit connection. Per Microchip's layout guidance, it may be left floating or tied to VSS for mechanical stability or EMI reduction. It must never be driven high or used as a signal path, as doing so violates the device's electrical specification.
Is the 93LC66AT/SN compatible with 1.8 V systems?
No, the 93LC66AT/SN is not rated for 1.8 V operation. Its specified VCC range is 2.5 V to 5.5 V. For 1.8 V systems, consider the 93AA66A/SN (1.8–5.5 V, same 512 × 8-bit organization), which shares identical pinout and instruction set but includes lower-voltage design optimizations and different POR threshold (1.5 V).
93LC66AT/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:
- 2.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
93LC66AT/SN FAQ
1.How can I place an order for 93LC66AT/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66AT/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 93LC66AT/SN reliable?
The price and inventory of 93LC66AT/SN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66AT/SN is usually 5 days.
3.What payment methods are accepted for 93LC66AT/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66AT/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66AT/SN?
93LC66AT/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66AT/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 93LC66AT/SN?
For technical support, including 93LC66AT/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66AT/SN requirements.
6.How does Aetrix verify that 93LC66AT/SN is sourced from the original manufacturer or authorized distributors?
All 93LC66AT/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 93LC66AT/SN meets industry standards.
7.What is the process for return or replacement of 93LC66AT/SN?
All 93LC66AT/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66AT/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 93LC66AT/SN part is unused and in its original packaging.
Return procedure for 93LC66AT/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93LC66AT/SN Tags
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