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Microchip Technology 93LC66BT/ST
- Part No.:
- 93LC66BT/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
93LC66BT/ST.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,480
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Product details
Overview
93LC66BT/ST from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 256 × 16-bit organization, operating over 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 configuration storage in microcontroller systems.
For engineers reviewing the 93LC66BT/ST datasheet, 93LC66BT/ST pinout, 93LC66BT/ST application, or 93LC66BT/ST equivalent, this page delivers verified electrical specs, package-confirmed pin functions, real-world use cases, and two validated alternative parts - all grounded in DS21795E and Microchip's official packaging documentation.
Technical Context
The 93LC66BT/ST implements a synchronous Microwire-compatible serial interface with CS, CLK, DI, and DO signals, requiring no external timing components. It supports dedicated 16-bit word access (no ORG pin), self-timed erase/write cycles (6 ms typical), and automatic ERAL before WRAL operations.
It integrates power-on/off data protection, Ready/Busy status via DO pin polling, sequential read capability, and Erase/Write Enable/Disable (EWEN/EWDS) logic to prevent accidental writes - all compliant with Pb-free and RoHS requirements.
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 | Industrial (−40°C to +85°C) and Automotive (−40°C to +125°C) - qualified for harsh environments |
| Endurance | 1,000,000 erase/write cycles - enables long-term field reconfiguration |
| Data retention | Greater than 200 years at 25°C - ensures nonvolatile integrity across product lifecycle |
| Interface | 3-wire Microwire-compatible serial (CS, CLK, DI, DO) - minimal GPIO usage on host MCU |
| Write cycle time | 6 ms max (TWC) - deterministic programming latency for real-time firmware updates |
Pinout & Package
93LC66BT/ST is supplied in an 8-lead TSSOP (ST) package per Microchip DS21795E, with pin 1 marked by laser, body dimensions 4.4 mm × 3.0 mm × 1.2 mm, and matte tin (Pb-free) finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable; must be held low ≥250 ns between instructions to reset internal logic |
| CLK | Serial Clock | Positive-edge synchronous clock; tolerates stopped clock during transmission |
| DI | Data Input | Accepts Start bit, opcode, address, and 16-bit write data; requires no pull-up when shared with DO |
| DO | Data Output / Status | Outputs 16-bit read data or Ready/Busy (low = busy); enters High-Z on CS falling edge |
| VSS | Ground | Reference for all I/O and internal circuitry; must be connected before VCC |
| NC | No Internal Connection | Pin 7 is unconnected - no routing or termination required |
| VCC | Power Supply | 2.5–5.5 V supply; powers internal charge pump for write/erase; POR threshold = 2.5 V |
| ORG | Organization Select | Not present on 93LC66B - fixed 16-bit mode; pin 6 is NC per Device Selection Table |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | 6 ms max cycle time eliminates need for external timing control or software delays |
| Automatic ERAL before WRAL | Ensures full-array readiness prior to bulk write - prevents partial-write corruption |
| Ready/Busy status via DO | Enables non-blocking polling instead of fixed-delay waits, improving system responsiveness |
| EWEN/EWDS command protection | Hardware-level write lock prevents unintended memory modification during noise events |
| Power-on/off data protection | Internal circuitry inhibits all operations below VCC = 2.5 V - guarantees safe power sequencing |
Applications
| Industrial Sensor Calibration | Automotive Body Control Module |
|---|---|
Use Scenario: Storing factory-trimmed sensor offset/gain coefficients and user-adjusted calibration values in programmable sensors. IC Role / Device Role / Timing Role: Nonvolatile configuration register holding 16-bit calibration parameters accessed during boot or runtime recalibration. Use Value: Enables field-updatable calibration without MCU firmware changes; 200-year retention ensures accuracy across equipment lifetime. |
Use Scenario: Retaining seat position memory, mirror angle settings, and lighting preferences in vehicle door modules. IC Role / Device Role / Timing Role: Dedicated 16-bit EEPROM storing user-configurable settings with Automotive-grade temperature operation. Use Value: Supports −40°C to +125°C ambient operation and withstands 1M+ write cycles for frequent user adjustments. |
| Medical Device Configuration | Consumer Appliance Settings |
Use Scenario: Saving therapy parameters, alarm thresholds, and device ID in portable infusion pumps and diagnostic monitors. IC Role / Device Role / Timing Role: Secure, low-power serial EEPROM interfacing directly with ARM Cortex-M host MCU via 3-wire bus. Use Value: Microwire compatibility reduces GPIO count; 2.5 V minimum VCC enables direct connection to battery-backed rails. |
Use Scenario: Preserving cooking presets, timer values, and language selection in smart ovens and washing machines. IC Role / Device Role / Timing Role: Cost-optimized nonvolatile memory for consumer-grade UI state persistence. Use Value: TSSOP-8 package allows compact PCB layout; RoHS/Pb-free compliance meets global regulatory requirements. |
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/ST | Same 256×16-bit organization, identical TSSOP-8 package, but rated only for Industrial (−40°C to +85°C) range | Lacks Automotive qualification - unsuitable for under-hood or safety-critical modules | Select when Automotive temp grade is not required and cost optimization is prioritized |
| AT25128B-SSHL-T | SPI interface (4-wire), 128 Kbit capacity, 1.8–5.5 V operation, 5 ms write cycle, SOIC-8 package | Higher density and SPI compatibility, but requires additional CS line and different command set | Choose for systems already using SPI peripherals and needing >4 Kbit storage; not drop-in compatible |
Compared with 93LC66B-I/ST, the 93LC66BT/ST adds Automotive qualification without changing pinout or timing; versus AT25128B-SSHL-T, it retains Microwire simplicity and lower gate count but trades off density and voltage flexibility.
Availability
93LC66BT/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive body control modules, and medical device configuration requiring stable component supply, long-term lifecycle support, and guaranteed Pb-free compliance.
Supply support for 93LC66BT/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 microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93LC66BT/ST belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for low-pin-count, low-power nonvolatile storage in space-constrained embedded systems where Microwire compatibility and robust write protection are essential.
FAQ
What is the memory organization of the 93LC66BT/ST?
The 93LC66BT/ST has a fixed 256 × 16-bit organization - it is a 'B' variant, meaning no ORG pin is used and word size is permanently configured for 16-bit access. This is confirmed in the Device Selection Table of DS21795E, where 93LC66B entries list "No" under ORG Pin and "16-bit" under Word Size.
Does the 93LC66BT/ST require an external pull-up resistor on the DO pin?
No, the 93LC66BT/ST does not require an external pull-up on DO. The DO pin actively drives high/low during read or Ready/Busy status reporting and enters High-Z when CS is low or during non-read states. Pull-ups may interfere with valid status signaling and are explicitly unnecessary per Section 2.2 and Figure 2-7 of DS21795E.
What is the maximum clock frequency supported by the 93LC66BT/ST?
The 93LC66BT/ST supports up to 3 MHz clock frequency when VCC is 4.5–5.5 V, 2 MHz at 2.5–4.5 V, and 1 MHz at 1.8–2.5 V. Since the 93LC66BT/ST operates from 2.5 V minimum, its usable maximum is 2 MHz - verified in Table 1-2 (A1) of DS21795E for '93LC' devices.
How is write protection implemented on the 93LC66BT/ST?
Write protection on the 93LC66BT/ST is enforced via EWEN (Erase/Write Enable) and EWDS (Erase/Write Disable) commands. The device powers up in EWDS mode; an EWEN instruction must precede any ERASE or WRITE. After each write, executing EWDS restores protection - a hardware-level safeguard independent of MCU firmware state.
Is the 93LC66BT/ST pin-compatible with the 93LC66A series?
No, the 93LC66BT/ST is not pin-compatible with 93LC66A variants. While both use TSSOP-8 (ST) packaging, the 93LC66A is 512 × 8-bit (x8) and lacks ORG functionality, whereas the 93LC66BT/ST is 256 × 16-bit (x16) with ORG pin designated as NC. Their instruction sets differ - e.g., READ requires 20 clocks for x16 vs. 27 for x8 - making direct substitution invalid.
93LC66BT/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:
- Obsolete
- Programmable:
- Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 4Kbit
- Memory Organization:
- 256 x 16
- 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-TSSOP
93LC66BT/ST FAQ
1.How can I place an order for 93LC66BT/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66BT/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 93LC66BT/ST reliable?
The price and inventory of 93LC66BT/ST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66BT/ST is usually 5 days.
3.What payment methods are accepted for 93LC66BT/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66BT/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66BT/ST?
93LC66BT/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66BT/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 93LC66BT/ST?
For technical support, including 93LC66BT/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66BT/ST requirements.
6.How does Aetrix verify that 93LC66BT/ST is sourced from the original manufacturer or authorized distributors?
All 93LC66BT/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 93LC66BT/ST meets industry standards.
7.What is the process for return or replacement of 93LC66BT/ST?
All 93LC66BT/ST units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66BT/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 93LC66BT/ST part is unused and in its original packaging.
Return procedure for 93LC66BT/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93LC66BT/ST Tags
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M24C02-WMN6TP
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AT24C02C-XHM-T
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AT21CS01-STUM10-T
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AT24C02C-SSHM-T
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24LC01BT-I/OT
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M24C02-FMC6TG
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AT24CS02-SSHM-T
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93LC46BT-I/OT
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AT24C04C-SSHM-T
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24LC01BT-I/SN
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24AA02UIDT-I/OT
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AT24C08C-STUM-T
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