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Microchip Technology 93LC66B-I/P
- Part No.:
- 93LC66B-I/P
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
93LC66B-I/P.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,119
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Product details
Overview
93LC66B-I/P from Microchip Technology Inc. is a 4 Kbit (256 × 16-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, operating from 2.5 V to 5.5 V, rated for industrial temperature (−40°C to +85°C), and housed in an 8-lead PDIP package. It features self-timed erase/write cycles, automatic ERAL before WRAL, and Ready/Busy status signaling via DO pin - used in embedded system configuration storage and calibration data retention.
For engineers reviewing the 93LC66B-I/P datasheet, 93LC66B-I/P pinout, 93LC66B-I/P application, or 93LC66B-I/P equivalent, key selection considerations include its fixed 16-bit word organization (no ORG pin), 6 ms typical write cycle time, industrial-grade temperature support, and compatibility with legacy Microwire controllers requiring strict timing compliance per DS21795E.
Technical Context
The 93LC66B-I/P implements a synchronous serial interface using CS, CLK, and DI/DO signals with start-bit detection and opcode-driven command execution. Its memory array is organized as 256 words × 16 bits, with no ORG pin - eliminating external configuration logic required by 'C' variants.
It supports full instruction set including READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS, all executed via rising-edge clocked serial bitstreams. Status polling is enabled through DO pin behavior during programming, and power-on data protection ensures integrity during brown-out conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (256 × 16-bit) - provides compact nonvolatile storage for firmware parameters or device-specific settings without external address decoding. |
| VCC range | 2.5 V to 5.5 V - supports direct interfacing with 3.3 V and 5 V microcontrollers without level-shifting. |
| Write cycle time | 6 ms max (TWC) - defines minimum inter-write interval; impacts real-time logging latency and firmware update sequencing. |
| Endurance | 1,000,000 erase/write cycles - enables long-term field deployment in systems requiring frequent calibration updates. |
| Data retention | 200 years at 25°C - guarantees data integrity over product lifetime without refresh mechanisms. |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - requires only four GPIOs and matches legacy controller peripherals like PIC® MSSP modules. |
| Temperature grade | Industrial (−40°C to +85°C) - validated for use in industrial control panels, metering equipment, and automotive body electronics. |
Pinout & Package
8-lead PDIP (Plastic Dual In-line Package), 0.3 inch body width, through-hole mounting. Pin 1 marked by notch or dot; pin 1 ID confirmed by laser mark per DS21795E-page 18.
| 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 and avoid spurious commands. |
| CLK | Serial Clock | Rising-edge synchronized timing source; supports up to 3 MHz (VCC ≥4.5 V); clock may pause mid-transfer without corruption. |
| DI | Data Input | Serial input for start bit, opcodes, addresses, and write data; shares no internal path with DO - avoids bus contention when externally wired together. |
| DO | Data Output / Status | Tri-state output delivering read data or Ready/Busy status (low = busy); enters High-Z on CS falling edge. |
| VSS | Ground | Reference return for all I/O and core logic; must be connected before VCC during power-up to ensure POR stability. |
| NC | No Connection | Pin 7 has no internal bond; must remain unconnected - floating or tied to VSS/VCC risks undefined behavior per DS21795E-page 12. |
| VCC | Power Supply | Core supply input; voltage detect threshold is 1.5 V - below which all operations are inhibited to prevent partial writes. |
| ORG | Organization Select | Not present on 93LC66B - permanently configured for 16-bit word mode; pin 6 is NC and must not be driven. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates need for external timing control or watchdog timeout logic - simplifies host firmware and reduces CPU overhead during memory updates. |
| Automatic ERAL before WRAL | Ensures full-array readiness prior to bulk write, preventing partial overwrite failures and guaranteeing deterministic WRAL completion. |
| Ready/Busy status on DO | Enables efficient polling-based operation without dedicated interrupt lines - critical for resource-constrained MCUs lacking hardware SPI status flags. |
| Power-on/off data protection | Hardware-level lockout below 1.5 V VCC prevents corruption during power ramp-up/down - removes requirement for software write-protection sequences. |
| 1,000,000 endurance cycles | Supports daily calibration updates for >2,700 years at one write per day - exceeds typical industrial equipment service life requirements. |
Applications
| Industrial Sensor Calibration | Embedded System Configuration |
|---|---|
Use Scenario: Storing factory-trimmed gain/offset coefficients and linearization tables in pressure or temperature transmitters. IC Role / Device Role / Timing Role: Nonvolatile parameter store accessed during power-up and field recalibration; uses READ/WRITE with 6 ms write latency managed via status polling. Use Value: Enables field-serviceable calibration without firmware reflash; 200-year data retention ensures accuracy across multi-decade deployments. | Use Scenario: Holding user-configurable settings (e.g., display brightness, communication baud rate, alarm thresholds) in HVAC controllers. IC Role / Device Role / Timing Role: Serial configuration memory interfaced directly to MCU GPIOs; leverages Microwire protocol for minimal pin count and deterministic timing. Use Value: Reduces BOM cost vs. I²C EEPROMs by eliminating pull-up resistors; industrial temp rating ensures reliability in uncontrolled cabinet environments. |
| Automotive Body Control Module | Medical Device Usage Logs |
Use Scenario: Recording seat position memory, mirror presets, and lighting profiles in 12 V automotive systems with local 3.3 V regulation. IC Role / Device Role / Timing Role: Low-power EEPROM storing user preferences; operates within 2.5–5.5 V range compatible with post-regulator rails. Use Value: Meets AEC-Q100 stress test requirements for industrial temp grade; 1M endurance supports lifetime seat adjustment cycles. | Use Scenario: Logging usage timestamps, battery cycles, and error events in portable diagnostic instruments with infrequent but critical data writes. IC Role / Device Role / Timing Role: Tamper-resistant event logger using WRAL for atomic full-memory updates after session completion. Use Value: Automatic ERAL before WRAL guarantees log consistency even after unexpected power loss; 200-year retention satisfies medical audit trail mandates. |
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/SN | Same 256×16-bit organization and electrical specs, but in 8-lead SOIC package (surface-mount, 150 mil width). | Requires PCB redesign for SMT assembly; better thermal performance and smaller footprint than PDIP. | Select for automated manufacturing or space-constrained designs where through-hole is not required. |
| 93LC66A-I/P | Identical PDIP package and industrial rating, but 512×8-bit organization - double byte count, half word width. | Suitable for byte-oriented protocols (e.g., legacy 8-bit MCUs); incompatible with 16-bit address/data handling logic. | Choose only if host firmware expects 8-bit word access or memory map alignment differs. |
Compared with 93LC66B-I/SN, the 93LC66B-I/P offers through-hole reliability for prototyping and high-vibration environments; compared with 93LC66A-I/P, it delivers higher data density per access cycle but requires 16-bit data path support in the host controller.
Availability
93LC66B-I/P is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded system configuration, and automotive body control modules requiring stable component supply across extended production lifecycles.
Supply support for 93LC66B-I/P 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, serving industrial, automotive, and consumer markets since 1989.
The 93LC66B belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-pin-count embedded systems needing reliable nonvolatile storage with Microwire compatibility and robust power-supply immunity.
FAQ
What is the memory organization of the 93LC66B-I/P?
The 93LC66B-I/P is a fixed 256 × 16-bit (4 Kbit) EEPROM with no ORG pin - it operates exclusively in 16-bit word mode. Unlike 'C' variants, it does not support runtime switching between 8-bit and 16-bit configurations. This simplifies hardware design by removing the need for external ORG logic, and ensures deterministic addressing behavior in all applications using the 93LC66B-I/P.
Does the 93LC66B-I/P require an external pull-up resistor on the DO line?
No, the 93LC66B-I/P does not require an external pull-up on DO. Its DO pin is actively driven high or low during READ or status polling, and enters High-Z when CS is low or during idle states. External pull-ups may cause contention or increased standby current. The 93LC66B-I/P datasheet specifies DO output drive strength per DC characteristics table D3/D4, confirming active push-pull capability without external biasing.
Can the 93LC66B-I/P be used with modern SPI controllers?
The 93LC66B-I/P is Microwire-compatible, not standard SPI - it uses a start-bit detection protocol and specific opcode framing that differs from SPI's continuous shift register model. While some SPI peripherals can emulate Microwire timing (e.g., certain PIC® MSSP modes), generic SPI master drivers will not function correctly with the 93LC66B-I/P without firmware-level protocol translation. Always verify controller support for Microwire mode before integration.
What is the purpose of the NC pin on the 93LC66B-I/P?
Pin 7 of the 93LC66B-I/P is designated NC (No Connection) - it has no internal bond wire or circuit connection. Per DS21795E-page 12, this pin must remain unconnected; tying it to VCC, VSS, or any signal risks undefined behavior or potential damage. The NC designation applies specifically to 'A' and 'B' variants like the 93LC66B-I/P; 'C' variants replace this pin with ORG functionality.
How does the 93LC66B-I/P handle power loss during a write cycle?
The 93LC66B-I/P incorporates hardware power-loss protection: its internal voltage detector disables all write operations when VCC falls below ~1.5 V (DS21795E-page 11). This prevents partial writes and data corruption. Additionally, the self-timed write architecture ensures that once initiated, the 6 ms erase/write cycle completes autonomously - no host intervention is needed. As long as VCC remains above threshold during the entire TWC window, the 93LC66B-I/P guarantees atomic update success.
93LC66B-I/P Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
93LC66B-I/P FAQ
1.How can I place an order for 93LC66B-I/P through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66B-I/P 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 93LC66B-I/P reliable?
The price and inventory of 93LC66B-I/P are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66B-I/P is usually 5 days.
3.What payment methods are accepted for 93LC66B-I/P?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66B-I/P transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66B-I/P?
93LC66B-I/P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66B-I/P 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 93LC66B-I/P?
For technical support, including 93LC66B-I/P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66B-I/P requirements.
6.How does Aetrix verify that 93LC66B-I/P is sourced from the original manufacturer or authorized distributors?
All 93LC66B-I/P 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 93LC66B-I/P meets industry standards.
7.What is the process for return or replacement of 93LC66B-I/P?
All 93LC66B-I/P units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66B-I/P, 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 93LC66B-I/P part is unused and in its original packaging.
Return procedure for 93LC66B-I/P:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93LC66B-I/P Tags
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AT24C02C-XHM-T
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