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Microchip Technology 93LC66CT-E/ST
- Part No.:
- 93LC66CT-E/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
93LC66CT-E/ST.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,177
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Product details
Overview
93LC66CT-E/ST from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 256 × 16-bit organization, operating across 2.5–5.5 V supply and supporting Industrial (−40°C to +85°C) and Automotive (−40°C to +125°C) temperature ranges. It features Microwire-compatible 3-wire serial interface (CS, CLK, DI, DO), ORG pin for x8/x16 configuration, and self-timed erase/write cycles. Used in automotive body control modules for storing calibration data and configuration settings.
For engineers reviewing the 93LC66CT-E/ST datasheet, 93LC66CT-E/ST pinout, 93LC66CT-E/ST application, or 93LC66CT-E/ST equivalent, key selection criteria include voltage range compatibility (2.5–5.5 V), automotive-grade temperature support, 16-bit word organization, ERAL/WRAL command support, and TSSOP-8 package footprint.
Technical Context
The 93LC66CT-E/ST implements a synchronous Microwire-compatible serial interface with start-bit detection, opcode-driven instruction set (READ, WRITE, ERASE, ERAL, WRAL, EWEN/EWDS), and Ready/Busy status reporting via DO pin. It uses internal auto-erase before write and supports sequential read mode when CS remains high.
Memory organization is fixed at 256 × 16-bit for 'B'-suffix variants like this part; the ORG pin is not internally connected (NC) on 93LC66B devices per Device Selection Table and Pin Function Table, confirming dedicated 16-bit operation without external configuration dependency.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (256 × 16-bit organization) |
| VCC range | 2.5 V to 5.5 V - supports wide-input industrial and automotive power rails |
| Temperature grade | Automotive (E): −40°C to +125°C - qualified for under-hood and chassis applications |
| Endurance | 1,000,000 erase/write cycles - enables long-term field reprogramming in control systems |
| Data retention | >200 years at +25°C - ensures nonvolatile storage integrity over product lifetime |
| Write cycle time | 6 ms typical (TWC) - defines minimum delay between write commands in firmware timing logic |
| Interface | 3-wire Microwire-compatible (CS, CLK, DI, DO) - requires minimal GPIO resources on host MCU |
Pinout & Package
93LC66CT-E/ST is supplied in an 8-lead TSSOP package (ST suffix), measuring 4.4 mm × 3.0 mm × 1.2 mm, with Pb-free Matte Tin finish. Pin 1 is marked by laser dot; exposed pad is not present in TSSOP.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable signal; must be held low ≥250 ns between instructions to reset internal state |
| CLK | Serial Clock | Synchronizes all data transfers; rising edge clocks in opcodes, addresses, and data bits |
| DI | Data Input | Receives start bit, instruction opcodes, 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); enters High-Z when CS is low |
| VSS | Ground | Reference return path for all signals and internal circuitry |
| NC | No Internal Connection | Pin 7 is unconnected - must be left floating or tied to ground per layout best practice |
| VCC | Power Supply | Primary supply input; includes internal POR circuitry triggering at ~1.5 V for 93LC66 series |
| ORG | Organization Select | No internal connection on 93LC66B devices - confirms fixed 16-bit word width; no external bias required |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write cycles | Eliminates need for external timing control - firmware only waits for DO=high or polls status |
| Automatic ERAL before WRAL | Ensures full-array write reliability without separate erase command sequence in host software |
| Power-on/off data protection | Hardware-level write inhibition below VCC threshold (~1.5 V) prevents corruption during brownout |
| Ready/Busy status via DO pin | Enables efficient polling-based programming flow without fixed delays or interrupt overhead |
| 1,000,000 endurance cycles | Supports frequent recalibration or logging in automotive ECUs without premature wear-out |
Applications
| Automotive Body Control Unit | Industrial PLC Configuration Storage |
|---|---|
Use Scenario: Storing seat position memory, mirror angle presets, and lighting profiles in vehicle door modules. IC Role / Device Role / Timing Role: Nonvolatile parameter storage with fast 6 ms write cycles and automotive-temp reliability. Use Value: Enables user-customizable settings retained across ignition cycles without battery backup. | Use Scenario: Holding I/O mapping tables, PID tuning parameters, and alarm thresholds in modular PLC bases. IC Role / Device Role / Timing Role: Serial configuration memory interfaced to ARM Cortex-M host via GPIO bit-banged Microwire. Use Value: Reduces BOM count vs parallel EEPROM; supports field updates without firmware reflashing. |
| Medical Infusion Pump Calibration | Smart Energy Meter Firmware Patch Storage |
Use Scenario: Retaining flow-rate calibration coefficients and safety limit offsets after factory calibration. IC Role / Device Role / Timing Role: Tamper-resistant, long-retention storage for critical operational constants. Use Value: Meets IEC 62304 Class C requirements for data integrity over 10+ year device life. | Use Scenario: Storing signed firmware patch images and version metadata for OTA updates. IC Role / Device Role / Timing Role: Secure boot auxiliary storage holding verified update payloads prior to execution. Use Value: Enables secure, rollback-safe field upgrades without requiring larger flash or external crypto ICs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66BT-E/ST | Identical electrical specs, pinout, and package; differs only in marking code (B vs C suffix denotes same 16-bit organization) | No functional difference - both are 256×16-bit, ORG=NC, automotive-grade TSSOP-8 | Select 93LC66BT-E/ST if legacy B-suffix sourcing is preferred; 93LC66CT-E/ST is functionally identical and drop-in compatible |
| AT25DF041A-SH-B | Quad SPI interface, 4 Mbit density, 2.7–3.6 V only, no ERAL/WRAL, no ORG pin | Requires SPI host driver changes; lacks auto-erase-all and write-all commands; higher density but narrower VCC range | Choose only if migrating to SPI architecture and needing >4 Kbit capacity; not suitable for direct replacement |
Compared with 93LC66BT-E/ST, the 93LC66CT-E/ST offers identical functionality and fit; versus AT25DF041A-SH-B, it retains Microwire simplicity, wider voltage range, and dedicated bulk-erase commands essential for automotive configuration management.
Availability
93LC66CT-E/ST is available at Aetrix Electronics and suitable for automotive electronics, industrial control systems, and medical device design requiring stable component supply with guaranteed automotive temperature qualification and long-term lifecycle support.
Supply support for 93LC66CT-E/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 microcontroller, analog, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93LC66 series belongs to Microchip's legacy serial EEPROM product line, designed specifically for cost-sensitive, low-pin-count embedded systems requiring reliable nonvolatile storage with minimal host resource usage.
FAQ
What is the memory organization of the 93LC66CT-E/ST?
The 93LC66CT-E/ST is a 256 × 16-bit (4 Kbit) device. As a 'B'-suffix variant, its organization is fixed at 16-bit words; the ORG pin is not internally connected, eliminating configuration dependency. This matches the Device Selection Table entry for 93LC66B, confirming dedicated x16 operation without external logic.
Does the 93LC66CT-E/ST support the ERAL (Erase All) command?
Yes, the 93LC66CT-E/ST supports ERAL. Per DS21795E-page 8, ERAL erases the entire memory array to logical '1'. It requires VCC ≥ 4.5 V and initiates at the falling edge of CS (for 93LC66 devices). The command opcode is '100' (binary), and status is reported via DO pin polling.
What is the maximum clock frequency supported by the 93LC66CT-E/ST?
The 93LC66CT-E/ST supports up to 3 MHz clock frequency when VCC is 4.5–5.5 V (Table 1-2, A1). At 2.5–4.5 V, max frequency is 2 MHz; at 1.8–2.5 V, it is 1 MHz. Since 93LC66CT-E/ST operates from 2.5 V minimum, its practical max clock is 2 MHz across its full rated voltage range.
Is the ORG pin used on the 93LC66CT-E/ST?
No, the ORG pin is not used on the 93LC66CT-E/ST. As confirmed in the Device Selection Table and Pin Function Table, ORG is NC (No internal connection) for all 'A' and 'B' versions including 93LC66B. The 'C' suffix in 93LC66CT-E/ST reflects packaging and marking convention-not functional ORG capability.
What package type does the 93LC66CT-E/ST use?
The 93LC66CT-E/ST uses an 8-lead TSSOP package (ST suffix), with dimensions 4.4 mm × 3.0 mm × 1.2 mm, Pb-free Matte Tin finish, and laser-marked Pin 1 identification. Package drawings are documented in Microchip Packaging Specification, referenced in DS21795E-page 15.
93LC66CT-E/ST Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP (0.173", 4.40mm 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, 256 x 16
- Memory Interface:
- Microwire
- Clock Frequency:
- 3 MHz
- Write Cycle Time - Word, Page:
- 6ms
- Access Time:
- -
- Voltage - Supply:
- 2.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
93LC66CT-E/ST FAQ
1.How can I place an order for 93LC66CT-E/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66CT-E/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 93LC66CT-E/ST reliable?
The price and inventory of 93LC66CT-E/ST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66CT-E/ST is usually 5 days.
3.What payment methods are accepted for 93LC66CT-E/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66CT-E/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66CT-E/ST?
93LC66CT-E/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66CT-E/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 93LC66CT-E/ST?
For technical support, including 93LC66CT-E/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66CT-E/ST requirements.
6.How does Aetrix verify that 93LC66CT-E/ST is sourced from the original manufacturer or authorized distributors?
All 93LC66CT-E/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 93LC66CT-E/ST meets industry standards.
7.What is the process for return or replacement of 93LC66CT-E/ST?
All 93LC66CT-E/ST units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66CT-E/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 93LC66CT-E/ST part is unused and in its original packaging.
Return procedure for 93LC66CT-E/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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