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Microchip Technology 93LC66AT-I/MC
- Part No.:
- 93LC66AT-I/MC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-VFDFN Exposed Pad
- Datasheet:
-
93LC66AT-I/MC.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,244
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Product details
Overview
93LC66AT-I/MC 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 1,000,000 endurance cycles - used in microcontroller configuration storage and calibration data retention.
For engineers reviewing the 93LC66AT-I/MC datasheet, 93LC66AT-I/MC pinout, 93LC66AT-I/MC application, or 93LC66AT-I/MC equivalent, key selection criteria include VCC range (2.5–5.5 V), 8-bit fixed word size (no ORG pin), DFN-8 package (2×3 mm), Ready/Busy status via DO pin, and compatibility with legacy Microwire controllers in space-constrained embedded systems.
Technical Context
This device implements a synchronous serial interface with start-bit detection, opcode-driven command set (READ/WRITE/ERASE/ERAL/WRAL/EWEN/EWDS), and internal auto-erase-before-write logic. It operates without external timing components and supports sequential read mode when CS remains high.
Memory access uses rising-edge clocked serial protocol: 20 clock cycles for READ (including dummy zero), 20 for WRITE, and 12 for ERAL/WRAL. The DO pin serves dual function - data output during READ and Ready/Busy indicator during programming - with status valid after TSV (200–500 ns) following CS high.
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 vs. x8/x16 configurable variants. |
| VCC Range | 2.5 V to 5.5 V - supports direct interface with 3.3 V and 5 V microcontrollers without level-shifting. |
| Endurance | 1,000,000 erase/write cycles - enables frequent field updates in metering or sensor calibration applications. |
| Data Retention | 200 years at 25°C - ensures long-term reliability for firmware parameter storage in unattended equipment. |
| Write Cycle Time | 6 ms typical (TWC) - defines minimum inter-command delay; impacts real-time logging latency. |
| Max Clock Frequency | 3 MHz at VCC ≥ 4.5 V; 2 MHz at 2.5 V ≤ VCC < 4.5 V - sets maximum throughput for bulk data writes. |
| Standby Current | 1 µA (I-temp) - critical for battery-powered devices requiring ultra-low quiescent power. |
Pinout & Package
8-pin 2×3 mm DFN package (MC suffix), exposed pad (may be connected to VSS or left floating), Pb-free Matte Tin finish. Pin 1 marked by laser dot; pin 1 ID corner indicated on top marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held low ≥250 ns between commands; deselects device into standby but allows ongoing write completion. |
| 2 (CLK) | Serial Clock | Rising-edge synchronized I/O; clock can pause mid-transfer; no clocks needed during self-timed write cycle. |
| 3 (DI) | Data Input | Accepts start bit, opcode, address, and data; tied high with pull-up for start condition detection. |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy (low = busy); enters High-Z on CS falling edge; requires CS high ≥250 ns to sample status. |
| 5 (NC) | No Internal Connection | Unbonded pad; must be left floating or grounded per layout best practice - no electrical function. |
| 6 (ORG) | Organization Select | Not connected internally (NC) on 'A' and 'B' versions - this pin is unused and may be left floating or tied to VSS/VCC without effect. |
| 7 (VSS) | Ground | Reference for all I/O and internal circuitry; exposed pad recommended to connect to ground plane for thermal and EMI performance. |
| 8 (VCC) | Power Supply | 2.5–5.5 V supply; internal POR circuit triggers at ~1.5 V - prevents spurious writes during power ramp. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates need for external timing control or polling delays beyond Ready/Busy check - reduces firmware overhead. |
| Automatic ERAL before WRAL | Guarantees full array erase prior to bulk write - prevents data corruption if previous erase was skipped. |
| Power-On/Off Data Protection | Hardware-level lockout below VCC = 1.5 V - prevents inadvertent writes during brown-out or power-down sequences. |
| Industry Standard 3-Wire Serial I/O | Direct drop-in replacement for legacy Microwire EEPROMs - maintains compatibility with existing drivers and HAL layers. |
| Sequential Read Function | Enables continuous address increment with single CS assertion - improves read throughput for block data retrieval. |
Applications
| Industrial Sensor Calibration | Consumer Remote Control Memory |
|---|---|
Use Scenario: Storing factory-trimmed ADC offset/gain coefficients and user-adjusted thresholds in environmental monitoring nodes. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed infrequently during startup or maintenance mode; timing-critical only during write confirmation (Ready/Busy polling). Use Value: 200-year data retention ensures calibration validity across product lifetime without battery backup; 1M endurance supports field recalibration over 10+ years. | Use Scenario: Retaining user-programmed channel presets, volume levels, and IR learning codes in universal remotes. IC Role / Device Role / Timing Role: Low-power serial memory interfaced to 8-bit MCU via GPIO-banged Microwire; standby current <1 µA extends coin-cell life. Use Value: DFN-8 (2×3 mm) footprint saves board area in compact remote PCBs; 2.5 V operation enables direct connection to 3 V MCU I/O without voltage translation. |
| Automotive Body Control Module | Medical Infusion Pump Settings |
Use Scenario: Saving seat/mirror position memory, lighting profiles, and door lock preferences in 12 V automotive systems with local 5 V LDO. IC Role / Device Role / Timing Role: Configuration EEPROM accessed during ignition-on initialization; write operations occur only during service mode. Use Value: Industrial temp grade (–40°C to +85°C) meets under-hood ambient requirements; 5.5 V max VCC accommodates automotive load-dump transients. | Use Scenario: Storing drug library parameters, flow rate limits, and alarm thresholds in battery-powered portable infusion pumps. IC Role / Device Role / Timing Role: Safety-critical nonvolatile memory holding FDA-mandated configuration data; write-protection enforced via EWDS/EWEN protocol. Use Value: Hardware write disable (EWDS default on power-up) prevents accidental overwrite; 1M endurance supports >100,000 pump cycles with daily parameter updates. |
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/MC | 16-bit organization (256 × 16), same VCC/temp/package - requires ORG pin tied to VSS for x8 emulation, but not internally bonded. | Requires external ORG tie-off; incompatible with x8-only firmware unless recompiled for 16-bit addressing. | Select only if migrating to wider bus or consolidating memory map; not a drop-in replacement. |
| AT25040B-MAHL-T | SPI interface (4-wire), 512 × 8-bit, 1.8–5.5 V, SOIC-8/TSSOP-8 - lacks Ready/Busy pin; uses Write Enable (WREN) instead of EWEN/EWDS. | Requires SPI driver stack; no hardware status pin - mandates timeout-based write polling instead of active DO monitoring. | Choose for SPI-native designs or where pin count permits extra CS/WP/HOLD lines; not compatible with Microwire protocol. |
Compared with 93LC66B-I/MC and AT25040B-MAHL-T, the 93LC66AT-I/MC offers native Microwire compatibility with hardware Ready/Busy signaling in the smallest footprint (DFN-8), making it optimal for cost-sensitive, space-constrained 3-wire systems requiring deterministic write status feedback.
Availability
93LC66AT-I/MC is available at Aetrix Electronics and suitable for industrial sensor calibration, consumer remote control memory, and automotive body control modules requiring stable component supply across extended production lifecycles.
Supply support for 93LC66AT-I/MC 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 93LC66A/B/C family is part of Microchip's legacy serial EEPROM product line, designed specifically for low-power, Microwire-compatible nonvolatile storage in resource-constrained embedded systems.
FAQ
What is the memory organization of the 93LC66AT-I/MC?
The 93LC66AT-I/MC has a fixed 512 × 8-bit (4 Kbit) organization. It belongs to the 'A' variant group, meaning the ORG pin is not internally connected and the device operates exclusively in x8 mode - no external configuration is required to select word size.
Does the 93LC66AT-I/MC require an external pull-up resistor on the DO pin?
Yes, the 93LC66AT-I/MC requires an external pull-up resistor on the DO pin when used in shared-bus configurations (e.g., DI and DO tied together), to prevent bus conflict during the dummy-zero phase of READ operations. A typical value is 4.7 kΩ to VCC, as specified in Section 2.2 of the DS21795E datasheet.
What is the purpose of the NC pin (Pin 5) on the 93LC66AT-I/MC DFN package?
Pin 5 on the 93LC66AT-I/MC is labeled NC (No Internal Connection) - it is an unconnected die pad with no electrical function. It may be left floating or connected to ground for mechanical stability or thermal relief, but it must not be used as a signal or power path.
How does the 93LC66AT-I/MC handle power loss during a write cycle?
The 93LC66AT-I/MC incorporates power-loss protection: its internal POR circuit disables all write functions when VCC drops below ~1.5 V. This ensures that partial or corrupted writes cannot occur during brown-out conditions, preserving data integrity without requiring external supervision circuitry.
Can the 93LC66AT-I/MC be used in automotive applications requiring AEC-Q200 qualification?
No, the 93LC66AT-I/MC carries the 'I' (Industrial) temperature grade (–40°C to +85°C) and is not AEC-Q200 qualified. For automotive applications, Microchip offers the 'E' grade variants (e.g., 93LC66AT-E/MC) rated to –40°C to +125°C and qualified per AEC-Q200 - the 93LC66AT-I/MC is intended for industrial and commercial use only.
93LC66AT-I/MC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-VFDFN Exposed Pad
- 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN (2x3)
93LC66AT-I/MC FAQ
1.How can I place an order for 93LC66AT-I/MC through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66AT-I/MC 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-I/MC reliable?
The price and inventory of 93LC66AT-I/MC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66AT-I/MC is usually 5 days.
3.What payment methods are accepted for 93LC66AT-I/MC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66AT-I/MC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66AT-I/MC?
93LC66AT-I/MC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66AT-I/MC 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-I/MC?
For technical support, including 93LC66AT-I/MC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66AT-I/MC requirements.
6.How does Aetrix verify that 93LC66AT-I/MC is sourced from the original manufacturer or authorized distributors?
All 93LC66AT-I/MC 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-I/MC meets industry standards.
7.What is the process for return or replacement of 93LC66AT-I/MC?
All 93LC66AT-I/MC units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66AT-I/MC, 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-I/MC part is unused and in its original packaging.
Return procedure for 93LC66AT-I/MC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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