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Microchip Technology 93LC66B-E/P
- Part No.:
- 93LC66B-E/P
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
93LC66B-E/P.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,513
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Product details
Overview
93LC66B-E/P from Microchip Technology Inc. is a 4 Kbit (256 × 16-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 2.5–5.5 V supply range, and industrial/automotive temperature support (–40°C to +125°C). It features self-timed erase/write cycles, automatic ERAL before WRAL, Ready/Busy status signaling via DO pin, and 1,000,000 endurance cycles - deployed in automotive body control modules for calibration storage.
For engineers reviewing the 93LC66B-E/P datasheet, 93LC66B-E/P pinout, 93LC66B-E/P application, or 93LC66B-E/P equivalent, key selection criteria include guaranteed 16-bit word organization (no ORG pin), automotive-grade reliability, Pb-free PDIP packaging, and compatibility with legacy Microwire controllers requiring deterministic timing and hardware data protection.
Technical Context
This device implements a synchronous serial interface with CS, CLK, and DI/DO pins operating at up to 3 MHz (VCC ≥ 4.5 V), supporting READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS instructions. Its internal logic enforces power-on write protection and requires explicit EWEN before programming.
Memory architecture uses a fixed 256-word × 16-bit array with no ORG pin (dedicated x16 mode), eliminating external configuration logic. All erase/write operations are self-timed and include auto-erase; WRAL performs full-array write after implicit ERAL, requiring VCC ≥ 4.5 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (256 × 16-bit) - fixed word width eliminates software bit-packing for 16-bit microcontrollers. |
| VCC range | 2.5 V to 5.5 V - supports direct connection to 3.3 V or 5 V rails without level shifters. |
| Endurance | 1,000,000 erase/write cycles - enables frequent recalibration logging in automotive ECUs. |
| Data retention | > 200 years at 25°C - ensures firmware parameter persistence over vehicle lifetime. |
| Write cycle time | 6 ms typical - deterministic timing allows precise host CPU scheduling without polling overhead. |
| Temperature grade | Automotive (–40°C to +125°C) - qualified for under-hood and transmission control unit environments. |
| Interface | Microwire 3-wire serial (CS/CLK/DI/DO) - compatible with legacy PIC® MCU peripherals and minimal GPIO designs. |
Pinout & Package
8-lead PDIP package (P suffix), lead-free Matte Tin finish, through-hole mounting. Pin 1 marked by notch or dot; pin 1 ID confirmed per Microchip DS21795E-page 18.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held low ≥250 ns between commands; initiates self-timed write on falling edge for 93LC66B. |
| 2 (CLK) | Serial Clock | Synchronizes all data transfers; rising edge clocks in opcode/address/data; stoppable mid-sequence. |
| 3 (DI) | Data Input | Accepts Start bit, instruction opcodes, addresses, and write data; high-impedance when not selected. |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy (low = busy); enters High-Z on CS falling edge. |
| 5 (VSS) | Ground | Reference for all I/O and internal circuitry; decoupling capacitor required near pin. |
| 6 (NC) | No Connect | Internally unconnected; must be left floating or tied to VSS per design guidelines. |
| 7 (NC) | No Connect | Internally unconnected; no routing or loading required. |
| 8 (VCC) | Power Supply | 2.5–5.5 V input; internal POR triggers at 1.5 V; requires local 0.1 µF ceramic bypass. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | Eliminates external timing components and host wait-state management; 6 ms max cycle time. |
| Automatic ERAL before WRAL | Guarantees clean memory state before bulk write; removes need for separate erase command sequence. |
| Power-on/off data protection | Hardware lockout below 1.5 V VCC prevents corruption during brown-out or hot-swap events. |
| Ready/Busy status on DO | Enables efficient polling instead of fixed delays; reduces average write latency by >40% vs. worst-case timeout. |
| Pb-free RoHS-compliant PDIP | Meets automotive ELV directive; Matte Tin finish ensures solderability and long-term shelf life. |
Applications
| Automotive Body Control Module | Industrial PLC Configuration Storage |
|---|---|
Use Scenario: Storing seat position presets, mirror angles, and lighting profiles across vehicle ignition cycles. IC Role / Device Role / Timing Role: Nonvolatile parameter register accessed via SPI-like Microwire interface during boot and runtime updates. Use Value: 16-bit word organization matches ECU register map directly; automotive temp grade ensures operation in door modules exposed to cabin heat soak. | Use Scenario: Retaining I/O mapping, scaling coefficients, and alarm thresholds after power loss in factory automation controllers. IC Role / Device Role / Timing Role: Serial configuration EEPROM interfaced to ARM Cortex-M3 with bit-banged Microwire driver. Use Value: 1M endurance supports daily firmware updates; 2.5 V min VCC enables use with 3.3 V isolated power supplies. |
| Medical Infusion Pump Calibration | Smart Energy Meter Firmware Patch Storage |
Use Scenario: Holding flow-rate calibration constants and safety-critical dose limits updated during service calibration. IC Role / Device Role / Timing Role: Secure, tamper-resistant memory accessed only during authenticated service mode. Use Value: Hardware write protection (EWEN/EWDS) prevents accidental overwrite; 200-year data retention meets ISO 13485 long-term record requirements. | Use Scenario: Storing field-upgradable metering algorithm patches validated before activation in utility smart meters. IC Role / Device Role / Timing Role: Dual-bank patch storage where WRAL writes new firmware image atomically after ERAL. Use Value: 6 ms WRAL cycle enables sub-20 ms patch commits; automotive temp grade accommodates outdoor meter enclosures. |
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/P | Same 256×16-bit organization and PDIP package, but rated for industrial (–40°C to +85°C) only. | Lacks automotive qualification; unsuitable for under-hood or transmission control units. | Select only for cost-sensitive industrial controls where ambient temperature stays below 85°C. |
| AT25128B-MAHL-T | 128 Kbit SPI EEPROM (8K×16), 1.8–5.5 V, SOIC-8, no ERAL/WRAL; uses standard SPI protocol. | Requires different command set and lacks auto-ERAL; higher density but no hardware erase-all primitive. | Choose when migrating to SPI-based platforms or needing larger capacity; verify timing and protection logic compatibility. |
Compared with 93LC66B-I/P, the 93LC66B-E/P adds automotive qualification and extended high-temp operation; versus AT25128B-MAHL-T, it retains Microwire compatibility and integrated ERAL/WRAL but offers lower density and legacy interface constraints.
Availability
93LC66B-E/P is available at Aetrix Electronics and suitable for automotive body electronics, industrial programmable logic controllers, and medical device calibration storage requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for 93LC66B-E/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, with global manufacturing and support infrastructure.
The 93LC66B-E/P belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-power embedded systems requiring robust nonvolatile storage with minimal pin count and deterministic timing behavior.
FAQ
What is the memory organization of the 93LC66B-E/P?
The 93LC66B-E/P has a fixed 256 × 16-bit organization - meaning it stores 256 words of 16 bits each, totaling 4 Kbit. Unlike 'C' variants, it has no ORG pin; the x16 configuration is hardwired. This eliminates external logic and simplifies interface design for 16-bit microcontrollers. The 93LC66B-E/P does not support x8 mode.
Does the 93LC66B-E/P require an external pull-up resistor on the DO pin?
No, the 93LC66B-E/P does not require an external pull-up on DO. The DO pin actively drives high/low during READ and Ready/Busy status reporting, and enters High-Z when deselected or idle. However, if DI and DO are shorted (bus-sharing configuration), a current-limiting resistor is required to prevent bus conflict during the dummy zero phase of READ.
What is the minimum VCC required for reliable operation of the 93LC66B-E/P?
The 93LC66B-E/P requires a minimum VCC of 2.5 V for guaranteed operation across its full automotive temperature range (–40°C to +125°C). Below 2.5 V, internal voltage detection disables all programming functions to prevent data corruption. The device remains readable down to 1.5 V, but write/erase commands are inhibited.
Can the 93LC66B-E/P be used with modern SPI controllers?
The 93LC66B-E/P uses Microwire protocol - a subset of SPI with single-data-line (DI/DO multiplexed) and specific timing - and is not directly SPI-compatible. While bit-banged GPIO can emulate Microwire, standard SPI hardware peripherals typically cannot drive it without protocol translation. The 93LC66B-E/P requires dedicated Microwire support or software-controlled timing.
What is the purpose of the NC pins on the 93LC66B-E/P PDIP package?
Pins 6 and 7 on the 93LC66B-E/P PDIP package are No Connect (NC) - internally unconnected and electrically inactive. They must be left floating; tying them to VCC or VSS may cause unpredictable behavior. These pins exist for package compatibility across the 93XX family (e.g., to accommodate ORG on 'C' variants) but serve no function in the 93LC66B-E/P.
93LC66B-E/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 ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
93LC66B-E/P FAQ
1.How can I place an order for 93LC66B-E/P through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66B-E/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-E/P reliable?
The price and inventory of 93LC66B-E/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-E/P is usually 5 days.
3.What payment methods are accepted for 93LC66B-E/P?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66B-E/P transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66B-E/P?
93LC66B-E/P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66B-E/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-E/P?
For technical support, including 93LC66B-E/P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66B-E/P requirements.
6.How does Aetrix verify that 93LC66B-E/P is sourced from the original manufacturer or authorized distributors?
All 93LC66B-E/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-E/P meets industry standards.
7.What is the process for return or replacement of 93LC66B-E/P?
All 93LC66B-E/P units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66B-E/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-E/P part is unused and in its original packaging.
Return procedure for 93LC66B-E/P:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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