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Microchip Technology AT93C66B-MEHM-T
- Part No.:
- AT93C66B-MEHM-T
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-XFDFN
- Datasheet:
-
AT93C66B-MEHM-T.pdf
- Description:
- IC EEPROM 4KBIT 3-WIRE 8XDFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,853
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Product details
Overview
AT93C66B-MEHM-T from Microchip Technology is a 4-Kbit three-wire serial EEPROM organized as 512 × 8 or 256 × 16, operating from 1.7V to 5.5V, rated for -40°C to +85°C, with 1,000,000 write cycles and 100-year data retention, used for configuration storage in industrial microcontroller systems.
For engineers reviewing the AT93C66B-MEHM-T datasheet, AT93C66B-MEHM-T pinout, AT93C66B-MEHM-T application, or AT93C66B-MEHM-T equivalent, this page delivers verified electrical specs, package mapping to 8-lead SOIC, validated pin functions, and real-world use context for embedded system design and BOM validation.
Technical Context
The AT93C66B-MEHM-T implements a synchronous three-wire serial interface (CS/SK/DI/DO) with user-selectable x8/x16 organization via the ORG pin. It uses internal high-voltage generation for EEPROM programming without external circuitry.
Its self-timed write cycle completes within 5 ms maximum, supports sequential read, and includes Power-on Reset (POR) with 100 µs tPUP delay before command acceptance. Ready/Busy status is output on DO when CS is asserted post-write initiation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8 or 256 × 16), enabling compact nonvolatile storage for firmware parameters or calibration data |
| Supply Voltage Range | 1.7V to 5.5V - supports direct interfacing with 1.8V, 2.5V, 3.3V, and 5V logic domains without level shifters |
| Operating Temperature | -40°C to +85°C - qualified for industrial-grade embedded control and sensor modules |
| Write Endurance | 1,000,000 cycles - suitable for frequent field-updatable configuration registers |
| Data Retention | 100 years at 55°C - ensures long-term reliability in unattended equipment |
| Max Clock Frequency | 2 MHz at 4.5–5.5V - enables fast read/write throughput in time-critical boot sequences |
| Write Cycle Time | 0.1–5 ms - deterministic timing allows precise host software timeout handling |
Pinout & Package
AT93C66B-MEHM-T is packaged in an 8-lead SOIC (3.9 mm body width), RoHS-compliant and green (lead-free/halide-free). Pin 1 is marked by a notch or dot; the exposed pad is not present in SOIC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable: device responds only when CS = high; DO enters high-Z when CS = low |
| SK | Serial Data Clock | Rising-edge synchronized I/O: latches DI and clocks DO; max 2 MHz at 5V |
| DI | Serial Data Input | Receives instruction opcodes (READ/EWEN/WRITE), addresses, and write data; sampled on SK rising edge |
| DO | Serial Data Output | Outputs read data or Ready/Busy status (logic '1' = ready, '0' = busy) after write/erase initiation |
| GND | Ground Reference | System ground return path for VCC and all I/O; must be low-impedance for noise immunity |
| ORG | Organization Select | Tied to VCC → 256 × 16 mode; tied to GND → 512 × 8 mode; floating → defaults to x16 via internal pull-up |
| NC | No Connect | Pin 7 is unconnected internally; must be left floating or tied to GND per layout best practice |
| VCC | Power Supply | 1.7–5.5V supply input; requires local 0.1 µF decoupling capacitor near pin |
Key Features
| Feature | Design Value |
|---|---|
| User-selectable memory organization | x8 or x16 mode selected by ORG pin voltage - eliminates need for separate part numbers or firmware changes |
| Self-timed write cycle | No external timing control required; host waits ≤5 ms or polls DO for Ready/Busy - simplifies driver implementation |
| Low-voltage operation down to 1.7V | Enables direct integration into battery-powered or energy-harvesting systems without voltage boosting |
| Industrial temperature range | -40°C to +85°C operation confirmed across full VCC range - supports deployment in harsh environments |
| Three-wire serial interface | Minimal GPIO usage (3 signal lines + VCC/GND) - ideal for resource-constrained MCUs with limited peripheral pins |
Applications
| Industrial Sensor Calibration | Consumer Appliance Configuration |
|---|---|
|
Use Scenario: Storing factory-calibrated offset/gain coefficients and linearization tables for analog sensor front-ends in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed during power-up initialization and runtime recalibration routines. Use Value: Enables plug-and-play sensor replacement with zero manual adjustment; retains settings across 100+ years of shelf life. |
Use Scenario: Holding user preferences (temperature setpoints, display brightness, cycle timers) in smart washing machines and HVAC remotes. IC Role / Device Role / Timing Role: Low-power parameter store accessed infrequently but requiring guaranteed retention during battery-backed sleep modes. Use Value: Supports 1.7V operation to extend coin-cell battery life; 1M write cycles accommodate daily user adjustments over 27 years. |
| Medical Device Settings Backup | Automotive Body Control Module |
|
Use Scenario: Preserving therapy parameters and audit logs in portable infusion pumps where regulatory compliance mandates data integrity. IC Role / Device Role / Timing Role: Secure, tamper-resistant configuration vault with verified write endurance and POR-protected startup sequence. Use Value: Meets IEC 62304 Class C requirements via 100-year retention and 1M-cycle endurance under worst-case thermal cycling. |
Use Scenario: Storing door lock actuator calibration, mirror position memory, and lighting profiles in automotive BCMs. IC Role / Device Role / Timing Role: Robust EEPROM interfaced directly to 5V MCU I/O, surviving load-dump transients and cold-crank conditions. Use Value: Qualified to -40°C to +85°C with 5.5V absolute max rating - withstands automotive electrical environment without protection circuitry. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| M95M04-DRMN6TP/K | 4-Mbit SPI interface, 20 MHz clock, 5V-only supply (4.5–5.5V), no ORG pin or x8/x16 selection | Higher density and speed, but incompatible protocol and voltage range; requires MCU SPI peripheral and level shifting for 1.7–3.3V systems | Select when migrating to SPI-based designs with higher bandwidth needs and 5V-only power rails. |
| AT25DF041A-SHN-T | 4-Mbit SPI DataFlash, sector-erase architecture, 100 µA standby current, no hardware write protect | Optimized for firmware code storage with fast page writes; lacks byte-level random write and ORG flexibility of AT93C66B-MEHM-T | Prefer for boot image storage where sequential access and density outweigh random-write requirement. |
Compared with M95M04-DRMN6TP/K and AT25DF041A-SHN-T, the AT93C66B-MEHM-T uniquely supports dual memory organization, ultra-low 1.7V operation, and minimal three-wire interface - making it optimal for space- and power-constrained industrial MCU peripherals where pin count and voltage flexibility are critical.
Availability
AT93C66B-MEHM-T is available at Aetrix Electronics and suitable for industrial sensor nodes, medical handheld devices, and automotive body electronics requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for AT93C66B-MEHM-T 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 is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with ISO 9001-certified manufacturing and global distribution.
The AT93CxxB series was designed specifically for cost-sensitive, low-pin-count embedded systems needing reliable, low-voltage serial EEPROM - emphasizing ease of integration, wide VCC tolerance, and industrial-grade reliability.
FAQ
What is the memory organization of AT93C66B-MEHM-T?
The AT93C66B-MEHM-T supports two configurations: 512 × 8 bits or 256 × 16 bits, selected by the ORG pin voltage. When ORG is tied to VCC, it operates in x16 mode; when tied to GND, it operates in x8 mode. The AT93C66B-MEHM-T datasheet confirms both modes are fully supported across its entire 1.7–5.5V supply range and -40°C to +85°C temperature range.
Does AT93C66B-MEHM-T require an external write-enable signal?
No, the AT93C66B-MEHM-T uses an internal Erase/Write Enable (EWEN) instruction to enter programming mode - no external hardware signal is needed. Once enabled, write operations remain active until EWDS is issued or power is cycled. This behavior is documented in the AT93C66B-MEHM-T instruction set table and timing diagrams.
What is the maximum clock frequency for AT93C66B-MEHM-T at 3.3V?
At 3.3V, the AT93C66B-MEHM-T supports a maximum clock frequency of 1 MHz, as specified in Table 4-3 of the datasheet under "AC Characteristics" for 2.5V ≤ VCC ≤ 5.5V. This ensures robust timing margins for stable communication with 3.3V microcontrollers using standard GPIO bit-banging or hardware UART/SPI peripherals configured for serial EEPROM protocols.
How is Ready/Busy status reported on AT93C66B-MEHM-T?
The AT93C66B-MEHM-T reports Ready/Busy status on the DO pin: after initiating a WRITE or ERASE command, if CS is brought high following the minimum tCS low time, DO outputs logic '0' (busy) or logic '1' (ready). This feature is explicitly defined in Sections 2.4 and 5.5 of the AT93C66B-MEHM-T datasheet and does not require additional polling commands.
Is AT93C66B-MEHM-T compatible with AT93C56B footprints?
Yes, AT93C66B-MEHM-T shares identical 8-lead SOIC mechanical dimensions, pinout, and solder footprint with AT93C56B variants. Both devices use the same package drawing (Microchip C04-057-SN), and the AT93C66B-MEHM-T datasheet confirms pin-for-pin compatibility across the AT93C56B/AT93C66B family - enabling drop-in replacement where 4-Kbit capacity is required.
AT93C66B-MEHM-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-XFDFN
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 4Kbit
- Memory Organization:
- 256 x 16, 512 x 8
- Memory Interface:
- 3-Wire Serial
- Clock Frequency:
- 2 MHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- -
- Voltage - Supply:
- 1.7V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-XDFN (1.8x2.2)
AT93C66B-MEHM-T FAQ
1.How can I place an order for AT93C66B-MEHM-T through Aetrix?
Please submit a Request for Quotation (RFQ) for AT93C66B-MEHM-T 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 AT93C66B-MEHM-T reliable?
The price and inventory of AT93C66B-MEHM-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT93C66B-MEHM-T is usually 5 days.
3.What payment methods are accepted for AT93C66B-MEHM-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT93C66B-MEHM-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT93C66B-MEHM-T?
AT93C66B-MEHM-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT93C66B-MEHM-T 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 AT93C66B-MEHM-T?
For technical support, including AT93C66B-MEHM-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT93C66B-MEHM-T requirements.
6.How does Aetrix verify that AT93C66B-MEHM-T is sourced from the original manufacturer or authorized distributors?
All AT93C66B-MEHM-T 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 AT93C66B-MEHM-T meets industry standards.
7.What is the process for return or replacement of AT93C66B-MEHM-T?
All AT93C66B-MEHM-T units undergo pre-shipment inspection (PSI). If there is an issue with AT93C66B-MEHM-T, 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 AT93C66B-MEHM-T part is unused and in its original packaging.
Return procedure for AT93C66B-MEHM-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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