My Inquiry
My Account
Microchip Technology AT93C66W-10SI
- Part No.:
- AT93C66W-10SI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
AT93C66W-10SI.pdf
- Description:
- IC EEPROM 4KBIT 3-WIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,452
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT93C66W-10SI from Microchip Technology (formerly Atmel) is a 4-kbit serial EEPROM with 3-wire interface, supporting user-selectable 512 × 8 or 256 × 16 organization via the ORG pin, operating from 2.7V to 5.5V, and rated for industrial temperature range (−40°C to +85°C). It delivers self-timed write cycles ≤10 ms, 1 million write endurance, and 100-year data retention - deployed in embedded system configuration storage, sensor calibration memory, and industrial controller parameter backup.
For engineers reviewing the AT93C66W-10SI datasheet, AT93C66W-10SI pinout, AT93C66W-10SI application, or AT93C66W-10SI equivalent, key selection criteria include low-voltage operation down to 2.7V, industrial-grade temperature tolerance, SOIC-8 (EIAJ) package compatibility, and support for both x8/x16 memory mapping without external logic.
Technical Context
The AT93C66W-10SI implements a synchronous 3-wire serial interface (CS, SK, DI/DO) with instruction-based command set including READ, WRITE, ERASE, EWEN, EWDS, ERAL, and WRAL. Its internal architecture enables dual-word-width addressing (9-bit address for x8, 8-bit for x16), with ORG pin determining organization at power-up.
Write operations require explicit Erase/Write Enable (EWEN) before programming; status feedback is provided via DO pin during CS high after tCS ≥250 ns. The device supports clock rates up to 2 MHz at 5V and scales down to 250 kHz at 1.8V, with timing parameters fully characterized across voltage and temperature ranges.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4096 bits (512 × 8 or 256 × 16) |
| Supply Voltage Range | 2.7V to 5.5V - enables direct interface with 3.3V and 5V microcontrollers without level shifting |
| Write Cycle Time | ≤10 ms max - ensures predictable firmware update latency in real-time systems |
| Endurance | 1 million write cycles - supports frequent recalibration or logging in field-deployed equipment |
| Data Retention | 100 years at 25°C - guarantees long-term reliability for unattended infrastructure devices |
| Operating Temperature | −40°C to +85°C - qualified for industrial control, automotive body electronics, and outdoor IoT nodes |
| Interface Protocol | 3-wire serial (CS/SK/DI/DO) - reduces PCB routing complexity vs. SPI/I²C, no dedicated chip select per device needed |
Pinout & Package
AT93C66W-10SI is housed in an 8-lead EIAJ SOIC package (8S2), 0.200" wide, with standard gull-wing lead form. Pin 1 is marked by notch or bevel; leads are tin-lead plated per JEDEC J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable; must be held low for entire instruction cycle; determines READY/BUSY status readout timing |
| SK | Serial Clock | Synchronous edge-triggered input; rising edge latches DI, falling edge clocks DO; max 2 MHz at 5V |
| DI | Data Input | Serial instruction and address/data input; accepts 7–9 bit addresses depending on ORG state and memory size |
| DO | Data Output | Open-drain output; provides read data, READY/BUSY status, or high-impedance when CS high |
| VCC | Power Supply | Primary supply rail; powers internal logic and charge pump; decoupling capacitor required near pin |
| GND | Ground | Reference return path for all signals and internal circuitry; must be low-impedance connection |
| ORG | Organization Select | Logic-high = 256 × 16 mode; logic-low = 512 × 8 mode; unconnected defaults to x16 via internal ~1 MΩ pull-up |
| DC | Don't Connect | No internal connection; must remain floating or tied to GND/VCC only if required by board layout constraints |
Key Features
| Feature | Design Value |
|---|---|
| User-selectable memory organization | Hardware-configurable 512 × 8 or 256 × 16 via ORG pin - eliminates need for software remapping or external address decoding |
| Low-voltage operation | 2.7V minimum VCC - interoperable with 3.3V systems and battery-backed applications without regulator overhead |
| Self-timed write cycle | No external timing control needed; internal state machine manages erase/write sequence - simplifies host firmware design |
| Industrial temperature rating | −40°C to +85°C operation - validated for use in motor drives, PLC modules, and factory automation hardware |
| ESD protection | >4000V HBM - enhances robustness during handling and in electrically noisy industrial environments |
Applications
| Industrial Sensor Calibration Storage | Embedded System Configuration Memory |
|---|---|
Use Scenario: Storing factory-trimmed offset/gain coefficients and linearization tables for analog sensor front-ends in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile configuration register holding calibration constants accessed at power-on reset and updated during maintenance mode. Use Value: Enables field-replaceable sensor modules without firmware reflash; ORG pin flexibility allows same part to serve 8-bit or 16-bit coefficient formats. |
Use Scenario: Retaining user-defined settings (network IP, display brightness, alarm thresholds) across power cycles in medical infusion pumps and diagnostic equipment. IC Role / Device Role / Timing Role: Serial parameter store interfaced directly to MCU GPIOs using minimal 3-wire protocol - no dedicated peripheral required. Use Value: Reduces BOM count vs. SPI flash; 100-year retention ensures settings persist over product lifetime without battery backup. |
| Automotive Body Control Module (BCM) | Smart Meter Firmware Parameter Backup |
Use Scenario: Saving seat/mirror position presets, door lock behavior, and lighting profiles in 12V automotive BCMs operating under cold-crank conditions. IC Role / Device Role / Timing Role: Low-voltage EEPROM tolerant of 2.7V brown-out events; accessed during MCU initialization after power stabilization. Use Value: 2.7V operation avoids reset during engine start; industrial temp grade supports under-hood placement near junction boxes. |
Use Scenario: Archiving tariff schedules, metering constants, and security keys in utility smart meters exposed to outdoor temperature extremes. IC Role / Device Role / Timing Role: Tamper-resistant nonvolatile memory storing critical operational parameters updated infrequently but requiring absolute persistence. Use Value: 1M write cycles accommodate decades of firmware updates; ESD >4kV withstands electrostatic discharge during field installation and servicing. |
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, 1.8–5.5V, 20 MHz clock, WLCSP package | Higher density, faster interface, but requires SPI peripheral and different command set | Select when migrating to higher-density storage with existing SPI infrastructure and board space constraints favor WLCSP |
| 25AA040A-I/P | 4-kbit SPI EEPROM, 1.8–5.5V, 10 MHz, PDIP-8 package | Same capacity and voltage range, but SPI protocol increases pin count and MCU resource usage | Prefer when legacy PDIP footprint is mandatory and SPI is already used elsewhere on the board |
Compared with M95M04-DRMN6TP/K and 25AA040A-I/P, the AT93C66W-10SI offers lower pin count (3-wire vs. 4-wire SPI), simpler firmware integration, and EIAJ SOIC packaging optimized for automated assembly - making it ideal for cost-sensitive, space-constrained industrial designs where moderate speed suffices.
Availability
AT93C66W-10SI is available at Aetrix Electronics and suitable for industrial sensor calibration storage, embedded system configuration memory, and automotive body control module applications requiring stable component supply across extended product lifecycles.
Supply support for AT93C66W-10SI 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 acquired Atmel in 2016 and maintains full support for the legacy AT93C family. The company specializes in microcontrollers, analog, and memory solutions for industrial, automotive, and consumer markets.
The AT93C66W-10SI belongs to Atmel's legacy serial EEPROM product line, designed specifically for low-pin-count, low-power, and industrial-temperature nonvolatile storage in resource-constrained embedded systems.
FAQ
What is the maximum clock frequency supported by the AT93C66W-10SI at 3.3V operation?
The AT93C66W-10SI supports up to 1 MHz SK clock frequency when VCC = 2.7V to 5.5V, as specified in the AC Characteristics table for the 2.7V ≤ VCC ≤ 5.5V condition. At 3.3V, this translates to a guaranteed 1 MHz operation with tSKH/tSKL ≥250 ns, enabling reliable communication with most 3.3V MCUs without timing margin concerns. The AT93C66W-10SI does not support 2 MHz at 3.3V - that rating applies only at VCC ≥4.5V.
Can the AT93C66W-10SI be used in x8 and x16 modes simultaneously on the same device?
No. The AT93C66W-10SI selects either 512 × 8 or 256 × 16 organization exclusively via the ORG pin state at power-up or reset - it cannot operate in both modes concurrently. The ORG pin must be statically tied to VCC (x16) or GND (x8); floating is allowed but defaults to x16 via internal pull-up. The AT93C66W-10SI does not support dynamic reconfiguration between modes during runtime.
Does the AT93C66W-10SI require an external pull-up resistor on the DO pin?
Yes. The DO pin is open-drain, so an external pull-up resistor (typically 4.7 kΩ to VCC) is required to establish valid logic-high levels during read and status reporting. This is explicitly stated in the "Pin Capacitance" and "DC Characteristics" sections of the AT93C66W-10SI datasheet, and omission will result in undefined or weak HIGH states on DO, causing communication failures.
Is the AT93C66W-10SI pin-compatible with the AT93C66-10SI?
Yes - the AT93C66W-10SI and AT93C66-10SI share identical pinout, package (8S2 SOIC), and electrical specifications. The "W" suffix denotes EIAJ SOIC (0.200" wide), while standard "AT93C66-10SI" uses JEDEC SOIC (0.150" wide); however, both variants use the same 8-lead SOIC footprint with matching pin assignments. Mechanical compatibility depends on board land pattern - verify against 8S1 vs. 8S2 dimensions before substitution.
What happens if the EWEN instruction is not issued before WRITE on the AT93C66W-10SI?
If the Erase/Write Enable (EWEN) instruction is omitted, all subsequent WRITE, ERASE, ERAL, and WRAL commands are ignored by the AT93C66W-10SI. The device remains in Erase/Write Disable (EWDS) state after power-up, and only READ instructions execute successfully. Attempting to program without prior EWEN results in no memory change and DO remains high-impedance or outputs invalid status - the AT93C66W-10SI enforces this security lock to prevent accidental writes.
AT93C66W-10SI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 4Kbit
- Memory Organization:
- 512 x 8, 256 x 16
- Memory Interface:
- 3-Wire Serial
- Clock Frequency:
- 2 MHz
- Write Cycle Time - Word, Page:
- 10ms
- 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
AT93C66W-10SI FAQ
1.How can I place an order for AT93C66W-10SI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT93C66W-10SI 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 AT93C66W-10SI reliable?
The price and inventory of AT93C66W-10SI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT93C66W-10SI is usually 5 days.
3.What payment methods are accepted for AT93C66W-10SI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT93C66W-10SI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT93C66W-10SI?
AT93C66W-10SI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT93C66W-10SI 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 AT93C66W-10SI?
For technical support, including AT93C66W-10SI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT93C66W-10SI requirements.
6.How does Aetrix verify that AT93C66W-10SI is sourced from the original manufacturer or authorized distributors?
All AT93C66W-10SI 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 AT93C66W-10SI meets industry standards.
7.What is the process for return or replacement of AT93C66W-10SI?
All AT93C66W-10SI units undergo pre-shipment inspection (PSI). If there is an issue with AT93C66W-10SI, 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 AT93C66W-10SI part is unused and in its original packaging.
Return procedure for AT93C66W-10SI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT93C66W-10SI Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
