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Microchip Technology 93C66C-I/SN
- Part No.:
- 93C66C-I/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93C66C-I/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:193
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Product details
Overview
93C66C-I/SN from Microchip Technology Inc. is a 4 Kbit Microwire-compatible serial EEPROM with configurable 8-/16-bit word organization via the ORG pin, 4.5–5.5 V supply range, industrial temperature rating (–40°C to +85°C), and 1 million erase/write cycles. It delivers nonvolatile memory storage in embedded control systems requiring reliable parameter retention across power cycles.
For engineers reviewing the 93C66C-I/SN datasheet, 93C66C-I/SN pinout, 93C66C-I/SN application, or 93C66C-I/SN equivalent, this page provides verified technical context, validated pin functions, real-world use cases, and confirmed alternative parts for design-in and BOM optimization.
Technical Context
The 93C66C-I/SN implements a synchronous 3-wire Microwire interface (CS, CLK, DI/DO) with self-timed erase/write cycles and hardware-level data protection. Its ORG pin directly selects between 512 × 8-bit (ORG = VSS) and 256 × 16-bit (ORG = VCC) memory mapping - no internal logic or configuration register required.
It features Ready/Busy status output on DO during programming, automatic ERAL before WRAL, and power-on/off write protection triggered at VCC < 3.8 V. Write cycle time is 2 ms (typical), and sequential read enables efficient bulk data access without address retransmission.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8-bit or 256 × 16-bit, selectable via ORG pin) |
| VCC Range | 4.5 V to 5.5 V - ensures compatibility with 5 V logic systems and rejects brownout-induced corruption |
| Endurance | 1,000,000 erase/write cycles - supports long-life field deployments in metering and industrial controllers |
| Data Retention | 200 years at +25°C - guarantees parameter integrity over product lifetime without refresh |
| Write Cycle Time | 2 ms maximum - enables fast firmware updates or calibration storage in time-constrained applications |
| Interface | 3-wire Microwire (CS, CLK, DI/DO) - minimal GPIO usage, compatible with legacy microcontrollers lacking SPI hardware |
| Temperature Range | –40°C to +85°C (Industrial grade) - qualified for operation in harsh ambient environments |
Pinout & Package
93C66C-I/SN is packaged in an 8-lead SOIC (SN) with standard pinout and Pb-free Matte Tin finish. Pin 1 is CS; pin 2 is CLK; pin 3 is DI; pin 4 is DO; pin 5 is VSS; pin 6 is ORG; pin 7 is NC; pin 8 is VCC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS (Pin 1) | Chip Select | Active-high enable signal - must be held low ≥250 ns between instructions to reset internal state |
| CLK (Pin 2) | Serial Clock | Synchronizes all data transfers on rising edge; clock can be paused mid-transfer without error |
| DI (Pin 3) | Data Input | Receives Start bit, opcode, address, and write data - tied to DO only with series resistor to avoid bus conflict |
| DO (Pin 4) | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); enters High-Z when CS is low or after status polling |
| VSS (Pin 5) | Ground | Reference return path for all I/O and internal circuitry - must be low-impedance for noise immunity |
| ORG (Pin 6) | Organization Control | Logic level sets memory width: VSS → 512 × 8-bit; VCC → 256 × 16-bit - no pull-up/down required |
| NC (Pin 7) | No Connection | Internally unconnected - must be left floating or tied to VSS/VCC per board layout constraints |
| VCC (Pin 8) | Power Supply | 4.5–5.5 V supply input - internal POR circuit blocks writes below 3.8 V to prevent data corruption |
Key Features
| Feature | Design Value |
|---|---|
| Word-size configurability | Hardware-selectable 8-bit or 16-bit interface via single ORG pin - eliminates need for software configuration or external multiplexing |
| Auto-erase before write | Self-timed erase integrated into each WRITE/WRAL command - no separate erase step required in firmware |
| Ready/Busy polling | DO pin doubles as status indicator during programming - enables non-blocking host operation without fixed delay loops |
| Write protection | Power-on default EWDS mode plus VCC voltage lockout (<3.8 V) - prevents accidental writes during power ramp or brownout |
| Sequential read | Continuous address increment on DO while CS remains high - reduces instruction overhead for reading multiple registers |
Applications
| Smart Energy Meters | Industrial PLCs |
|---|---|
|
Use Scenario: Storing tariff tables, calibration coefficients, and event logs in electricity/water/gas meters operating unattended for 10+ years. IC Role / Device Role / Timing Role: Nonvolatile parameter storage with guaranteed 200-year data retention and 1M-cycle endurance under daily update loads. Use Value: Eliminates battery-backed SRAM and reduces BOM cost while meeting IEC 62056 and ANSI C12.22 field-deployment requirements. |
Use Scenario: Holding I/O configuration, PID tuning parameters, and firmware patch flags in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: Configuration memory accessible via simple 3-wire interface, supporting fast write (2 ms) and robust read under EMI-rich industrial environments. Use Value: Enables field-upgradable control logic without MCU firmware changes or external SPI flash complexity. |
| Automotive Body Controllers | Medical Diagnostic Devices |
|
Use Scenario: Saving seat/mirror position presets, lighting profiles, and diagnostic trouble codes (DTCs) in body control modules (BCM). IC Role / Device Role / Timing Role: Industrial-grade EEPROM interfaced to 5 V microcontrollers, with VCC lockout preventing corruption during ignition cycling. Use Value: Meets AEC-Q100 stress test requirements for automotive electronics and supports UDS (ISO 14229) memory write services. |
Use Scenario: Storing calibration constants, sensor offset values, and user preferences in portable ultrasound or ECG devices with strict regulatory traceability. IC Role / Device Role / Timing Role: Secure, tamper-resistant memory with write-protection architecture and full data retention validation per IEC 62304. Use Value: Simplifies FDA/CE audit trails by providing deterministic, nonvolatile storage with documented 200-year retention and 1M-cycle reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66C-I/SN | VCC range 2.5–5.5 V; lower minimum voltage enables 3.3 V system integration; identical pinout and instruction set | Supports wider supply range including 3.3 V microcontrollers; not suitable for 5 V-only designs with tight VCC tolerance | Select when migrating to mixed-voltage or low-power systems; verify VCC stability above 2.5 V during programming |
| 93AA66C-I/SN | VCC range 1.8–5.5 V; ultra-low voltage operation; same ORG-configurable organization and timing | Enables direct interface to 1.8 V MCUs and battery-powered devices; higher standby current vs. 93C66C at 5 V | Choose for energy-sensitive applications like IoT sensors; confirm clock frequency limits (≤1 MHz at 1.8 V) |
Compared with 93LC66C-I/SN and 93AA66C-I/SN, the 93C66C-I/SN offers optimal noise immunity and timing margin in pure 5 V industrial systems, with tighter VCC lockout (3.8 V) enhancing write reliability during marginal supply conditions.
Availability
93C66C-I/SN is available at Aetrix Electronics and suitable for smart energy meters, industrial PLCs, and automotive body controllers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for 93C66C-I/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 microcontroller, analog, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93C66C belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-pin-count embedded systems needing robust nonvolatile storage with minimal MCU resource usage.
FAQ
What is the function of the ORG pin on the 93C66C-I/SN?
The ORG pin on the 93C66C-I/SN configures memory organization: tying ORG to VSS selects 512 × 8-bit mode, while tying it to VCC selects 256 × 16-bit mode. This hardware-level selection requires no initialization code and is sampled at instruction start. The 93C66C-I/SN does not support dynamic reconfiguration - the ORG state must remain stable during active communication.
Does the 93C66C-I/SN require an external pull-up resistor on the DO pin?
No, the 93C66C-I/SN 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 deselected (CS low) or idle. A pull-up may cause contention if DO is shared with DI - instead, a 1–10 kΩ series resistor is recommended when DI and DO are wired together to prevent bus conflict during dummy-zero read phases.
How does the 93C66C-I/SN protect against unintended writes during power-up?
The 93C66C-I/SN incorporates dual protection: (1) it powers up in Erase/Write Disable (EWDS) mode, blocking all programming until an explicit EWEN command is issued; and (2) its internal voltage detector inhibits writes when VCC falls below 3.8 V. Both mechanisms ensure that partial power conditions or noisy resets cannot corrupt memory contents in the 93C66C-I/SN.
Can the 93C66C-I/SN be used in a 3.3 V system?
No, the 93C66C-I/SN is not rated for 3.3 V operation. Its specified VCC range is strictly 4.5 V to 5.5 V, and its write protection threshold is 3.8 V - operating below 4.5 V risks incomplete writes, timing violations, or undefined behavior. For 3.3 V systems, consider the 93LC66C-I/SN (2.5–5.5 V) or 93AA66C-I/SN (1.8–5.5 V) as drop-in alternatives with identical pinout and instruction set.
What is the maximum clock frequency supported by the 93C66C-I/SN at 5 V?
At VCC = 4.5–5.5 V, the 93C66C-I/SN supports a maximum clock frequency of 3 MHz, as specified in Table 1-2 (Param. A1). This allows a complete 20-clock READ instruction to execute in ≤6.7 µs, enabling high-throughput parameter access in real-time control loops. Clock timing margins (TCKH ≥200 ns, TCKL ≥100 ns) must be maintained even at this maximum rate.
93C66C-I/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:
- 512 x 8, 256 x 16
- Memory Interface:
- Microwire
- Clock Frequency:
- 3 MHz
- Write Cycle Time - Word, Page:
- 2ms
- Access Time:
- -
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
93C66C-I/SN FAQ
1.How can I place an order for 93C66C-I/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66C-I/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 93C66C-I/SN reliable?
The price and inventory of 93C66C-I/SN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93C66C-I/SN is usually 5 days.
3.What payment methods are accepted for 93C66C-I/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66C-I/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66C-I/SN?
93C66C-I/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66C-I/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 93C66C-I/SN?
For technical support, including 93C66C-I/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66C-I/SN requirements.
6.How does Aetrix verify that 93C66C-I/SN is sourced from the original manufacturer or authorized distributors?
All 93C66C-I/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 93C66C-I/SN meets industry standards.
7.What is the process for return or replacement of 93C66C-I/SN?
All 93C66C-I/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93C66C-I/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 93C66C-I/SN part is unused and in its original packaging.
Return procedure for 93C66C-I/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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