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Microchip Technology 93LC66B-E/SN
- Part No.:
- 93LC66B-E/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93LC66B-E/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:405
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Product details
Overview
93LC66B-E/SN from Microchip Technology Inc. is a 4 Kbit (256 × 16-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, operating from 2.5V to 5.5V, rated for automotive temperature range (–40°C to +125°C), and housed in an 8-lead SOIC package (SN). It features self-timed erase/write cycles, automatic ERAL before WRAL, and Ready/Busy status via DO pin - used for nonvolatile configuration storage in automotive control modules.
For engineers reviewing the 93LC66B-E/SN datasheet, 93LC66B-E/SN pinout, 93LC66B-E/SN application, or 93LC66B-E/SN equivalent, key selection considerations include its dedicated 16-bit organization (no ORG pin), automotive-grade reliability, 1 million erase/write cycles, 200-year data retention, and compatibility with legacy Microwire host controllers requiring minimal firmware changes.
Technical Context
This device implements a synchronous serial interface with CS, CLK, and DI/DO pins, supporting READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS instructions. Its memory array is organized as 256 words × 16 bits, with no ORG pin - fixed x16 operation. All programming operations are self-timed and include auto-erase.
Power-on/off data protection is enforced by internal voltage detection (VPOR = 2.5V typ.), and write enable/disable logic (EWEN/EWDS) prevents accidental writes. The DO pin serves dual function: serial data output during READ and Ready/Busy status indicator during erase/write - asserted low while busy, high when complete.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (256 × 16-bit) - provides compact nonvolatile storage for calibration tables or device IDs in space-constrained automotive PCBs. |
| VCC Range | 2.5V to 5.5V - supports direct connection to 3.3V or 5V rails without level-shifting in engine control units and body electronics. |
| Endurance | 1,000,000 erase/write cycles - ensures reliable field updates over full vehicle lifetime, including frequent reprogramming during diagnostics. |
| Data Retention | 200 years at +25°C - guarantees long-term integrity of safety-critical configuration data without refresh. |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - enables drop-in replacement for legacy 93LCxx designs with minimal driver modification. |
| Temp Range | –40°C to +125°C (Automotive E-grade) - qualified for under-hood and transmission control applications per AEC-Q100 stress requirements. |
| Write Cycle Time | 6 ms typical (TWC) - enables fast parameter updates during production line programming or over-the-air calibration uploads. |
Pinout & Package
8-lead SOIC package (SN), Pb-free Matte Tin finish, 150 mil width. Pin 1 marked by laser dot; pin 1 ID corner defined by beveled edge or notch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable: must be held ≥250 ns low between commands; deselects device into standby (ICC ≤ 5 µA) but allows ongoing write completion. |
| CLK | Serial Clock | Synchronizes all data transfers on rising edge; clock can be paused mid-sequence; TCKH/TCKL vary with VCC (e.g., 250 ns min at 2.5V). |
| DI | Data Input | Accepts Start bit, opcode, address, and data; requires setup/hold times (TDIS/TDIH) relative to CLK; shares bus with DO only with series resistor to prevent conflict. |
| DO | Data Output / Status | Outputs read data on rising CLK edge (TPD ≤ 400 ns); also signals Ready/Busy - low = busy, high = ready - when CS is reasserted post-write. |
| VSS | Ground | Reference for all I/O and internal logic; must be low-impedance connection to minimize noise coupling during write cycles. |
| NC | No Internal Connection | Pin 7 in SOIC/SN package - left unconnected; not bonded internally; must not be tied to any signal or power rail. |
| VCC | Power Supply | Supplies core and I/O circuitry; includes internal POR detection at ~2.5V; decoupling capacitor (0.1 µF) required within 10 mm of pin. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates external timing control - host only needs to issue command and poll DO; reduces firmware complexity and interrupt latency. |
| Automatic ERAL before WRAL | Ensures full array erase prior to bulk write - prevents stale data corruption without requiring separate ERAL command in application code. |
| Power-On/Off Data Protection | Hardware-enforced write inhibition below VPOR (~2.5V) - prevents partial writes during brown-out or hot-swap events in automotive power domains. |
| EWEN/EWDS Security | Explicit enable/disable sequence required before any write - blocks unintended writes from noise or software glitches; default power-up state is EWDS. |
| Sequential Read Mode | Continuous data stream across addresses with single CS assertion - accelerates bulk read of configuration blocks (e.g., sensor calibration maps). |
Applications
| Engine Control Unit (ECU) | Advanced Driver Assistance Systems (ADAS) |
|---|---|
Use Scenario: Storing adaptive fuel trim values, misfire counters, and diagnostic trouble codes (DTCs) that persist across ignition cycles. IC Role / Device Role / Timing Role: Nonvolatile configuration and event logging memory interfaced directly to MCU SPI/Microwire peripheral. Use Value: 1M endurance and 200-year retention ensure DTC history remains intact over 15+ year vehicle service life without battery backup. |
Use Scenario: Holding camera calibration offsets, radar beamforming coefficients, and sensor fusion parameters updated during factory calibration or OTA updates. IC Role / Device Role / Timing Role: Secure, automotive-qualified serial EEPROM for storing safety-critical configuration data in ISO 26262-compliant systems. Use Value: –40°C to +125°C rating and AEC-Q100 alignment allow direct placement near image sensors or radar MMICs without thermal derating. |
| Body Control Module (BCM) | Electric Power Steering (EPS) |
Use Scenario: Saving user preferences (mirror position, seat memory, lighting profiles) and door lock actuation history for anti-theft forensics. IC Role / Device Role / Timing Role: Low-power serial EEPROM accessed intermittently via microcontroller GPIO-banged or hardware Microwire interface. Use Value: 5 µA standby current extends battery life during vehicle sleep mode; 2.5V minimum VCC enables operation during start-stop battery dips. |
Use Scenario: Storing torque sensor zero-point compensation, motor phase resistance values, and fault log entries for ASIL-B functional safety compliance. IC Role / Device Role / Timing Role: Safety-relevant nonvolatile memory with deterministic 6 ms write time and hardware write protection (EWEN/EWDS). Use Value: Self-timed writes eliminate software timing dependencies; VPOR-based protection prevents corruption during EPS power cycling during steering maneuvers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66A-E/SN | 256 × 8-bit organization (x8), same VCC range, package, and temp grade. | Requires host software adaptation for byte-oriented access; less efficient for 16-bit parameter storage. | Select if system uses 8-bit data paths or legacy x8 firmware; not pin-compatible for x16 use cases. |
| AT25DF041A-SHN-T | 4 Mbit SPI NOR Flash (not EEPROM), quad I/O capable, 2.7–3.6V only, no built-in write protection logic. | Larger capacity but lacks EEPROM's byte-level erase; requires external wear leveling and error correction. | Choose only if >4 Kbit capacity is needed and host can manage flash-specific protocols; not a functional substitute for EEPROM behavior. |
Compared with 93LC66A-E/SN, the 93LC66B-E/SN delivers native 16-bit word access - reducing transaction count by 50% for multi-byte parameters. Versus AT25DF041A-SHN-T, it offers true EEPROM semantics (no erase-before-write, no block management), making it suitable for safety-critical, low-latency configuration storage where deterministic timing is mandatory.
Availability
93LC66B-E/SN is available at Aetrix Electronics and suitable for automotive control units, ADAS subsystems, and electric power steering modules requiring stable component supply with guaranteed long-term availability and traceable sourcing.
Supply support for 93LC66B-E/SN 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 93LC66B-E/SN belongs to Microchip's legacy 93LCxx serial EEPROM product line, designed specifically for cost-sensitive, low-power, nonvolatile memory applications in automotive, industrial, and consumer systems requiring proven reliability and long-lifecycle support.
FAQ
What is the memory organization of the 93LC66B-E/SN?
The 93LC66B-E/SN has a fixed 256 × 16-bit (4 Kbit) organization - no ORG pin is present, so it operates exclusively in x16 mode. This differs from 'C' variants which use the ORG pin to select between x8/x16; the 'B' suffix confirms dedicated 16-bit interface, simplifying host controller design for word-aligned data structures.
Does the 93LC66B-E/SN require an external pull-up resistor on the DO pin?
No external pull-up is required on the DO pin of the 93LC66B-E/SN - the device drives DO actively high or low during READ or Ready/Busy status reporting. However, if DI and DO are shorted (shared bus configuration), a series resistor (typically 1–10 kΩ) is mandatory to prevent bus contention during the dummy zero phase of READ operations.
What is the maximum clock frequency supported by the 93LC66B-E/SN at 3.3V?
At VCC = 3.3V (within 2.5V–5.5V range), the 93LC66B-E/SN supports a maximum clock frequency of 2 MHz. This is specified in Table 1-2 (A1) for 2.5V ≤ VCC < 5.5V; higher frequencies (up to 3 MHz) are only permitted at VCC ≥ 4.5V.
How does the 93LC66B-E/SN protect against inadvertent writes during power transitions?
The 93LC66B-E/SN incorporates hardware-level write protection: it powers up in EWDS (Erase/Write Disable) mode, and all writes require explicit EWEN instruction first. Additionally, internal voltage detection (VPOR ≈ 2.5V) inhibits all programming when VCC drops below threshold - preventing partial writes during brown-out or startup.
Is the 93LC66B-E/SN RoHS compliant and lead-free?
Yes, the 93LC66B-E/SN is Pb-free and RoHS compliant, with Matte Tin (Sn) finish on all leads. This is explicitly stated in the Features section of DS21795E and confirmed in Packaging Information - suitable for modern automotive and industrial assembly processes requiring lead-free soldering.
93LC66B-E/SN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- 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:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
93LC66B-E/SN FAQ
1.How can I place an order for 93LC66B-E/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66B-E/SN 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/SN reliable?
The price and inventory of 93LC66B-E/SN 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/SN is usually 5 days.
3.What payment methods are accepted for 93LC66B-E/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66B-E/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66B-E/SN?
93LC66B-E/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66B-E/SN 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/SN?
For technical support, including 93LC66B-E/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66B-E/SN requirements.
6.How does Aetrix verify that 93LC66B-E/SN is sourced from the original manufacturer or authorized distributors?
All 93LC66B-E/SN 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/SN meets industry standards.
7.What is the process for return or replacement of 93LC66B-E/SN?
All 93LC66B-E/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66B-E/SN, 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/SN part is unused and in its original packaging.
Return procedure for 93LC66B-E/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93LC66B-E/SN Tags
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M24C02-WMN6TP
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AT24C02C-XHM-T
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93LC46BT-I/OT
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AT24C04C-SSHM-T
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