My Inquiry
My Account
Microchip Technology 93LC66AT-I/MS
- Part No.:
- 93LC66AT-I/MS
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
93LC66AT-I/MS.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,413
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
93LC66AT-I/MS from Microchip Technology Inc. is a 4 Kbit low-voltage serial EEPROM with 512 × 8-bit organization, Microwire-compatible 3-wire interface (CS, CLK, DI/DO), and industrial temperature range (–40°C to +85°C). It features self-timed erase/write cycles, automatic ERAL before WRAL, power-on/off data protection, and 1,000,000 endurance cycles - used for configuration storage in embedded microcontroller systems.
For engineers reviewing the 93LC66AT-I/MS datasheet, 93LC66AT-I/MS pinout, 93LC66AT-I/MS application, or 93LC66AT-I/MS equivalent, key selection criteria include VCC range (2.5–5.5 V), MSOP-8 package compatibility, Ready/Busy status signaling via DO, sequential read support, and EWEN/EWDS write-protection logic.
Technical Context
The 93LC66AT-I/MS implements a synchronous serial Microwire protocol with start-bit detection, opcode-driven instruction set (READ, WRITE, ERASE, ERAL, WRAL, EWEN, EWDS), and dual-mode memory access controlled by the ORG pin - though ORG is NC on this 'A' variant, fixing 8-bit word size. Communication occurs on rising CLK edges with CS active-high selection.
It integrates on-chip power-on reset detection (VPOR = 1.5 V), automatic erase-before-write, and hardware-level data protection: all operations are inhibited below VCC threshold, and the device powers up in EWDS (Erase/Write Disable) state. Status polling via DO pin enables non-blocking firmware control during 6 ms typical write cycles.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8-bit organization; fixed x8 mode, no ORG pin function) |
| VCC Range | 2.5 V to 5.5 V - supports direct interfacing with 3.3 V and 5 V MCU I/O without level shifting |
| Interface | 3-wire Microwire-compatible serial (CS, CLK, DI/DO) - minimal GPIO usage, no address bus required |
| Write Cycle Time | 6 ms typical - enables deterministic timing budgeting for firmware write routines |
| Endurance | 1,000,000 erase/write cycles - suitable for frequent calibration or runtime parameter logging |
| Data Retention | 200 years at 25°C - ensures long-term reliability in unattended industrial deployments |
| Temperature Range | –40°C to +85°C (Industrial grade) - validated for operation across full industrial ambient envelope |
Pinout & Package
8-pin MSOP (Micro Small Outline Package), 3.0 mm × 3.0 mm body, 0.65 mm pitch, exposed pad optional (VSS or floating), Pb-free Matte Tin finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held ≥250 ns low between instructions; deselects device into standby but allows ongoing write completion |
| 2 (CLK) | Serial Clock | Synchronizes all data transfers; opcodes, addresses, and data clocked in/out on rising edge; stoppable mid-sequence |
| 3 (DI) | Data Input | Accepts start bit, opcode, address, and write data; shares net with DO in bidirectional configurations (requires series resistor to avoid bus conflict) |
| 4 (DO) | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); enters High-Z when CS low or after status read; critical for non-blocking firmware polling |
| 5 (VSS) | Ground | Reference return path for all signals and internal circuitry; connects to exposed pad in DFN variants (not applicable to MSOP) |
| 6 (NC) | No Connection | Internally unconnected; must be left floating or tied to VSS/VCC per layout best practice - no functional role |
| 7 (ORG) | Organization Select | No internal connection on 93LC66A devices - permanently configured for 8-bit mode; pin is unused and may be left floating |
| 8 (VCC) | Power Supply | Core supply input; includes internal voltage detect (VPOR = 1.5 V) that inhibits all operations below threshold |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write cycles | Eliminates need for external timing control or firmware delay loops - cycle completion signaled via DO pin |
| Automatic ERAL before WRAL | Guarantees clean memory array prior to full-array write, preventing partial-data corruption without software intervention |
| Power-on/off data protection | Hardware lockout below 1.5 V VCC prevents inadvertent writes during brown-out or power ramp-up sequences |
| EWEN/EWDS write-enable logic | Requires explicit EWEN command before any erase/write - adds firmware-controlled safety layer against accidental overwrites |
| Sequential read capability | Enables efficient bulk read of consecutive addresses with single CS assertion - reduces transaction overhead by ~40% vs. random reads |
Applications
| MCU Configuration Storage | Industrial Sensor Calibration |
|---|---|
Use Scenario: Storing bootloader parameters, UART baud rates, and I²C slave addresses in an ARM Cortex-M4-based PLC controller. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed during MCU boot and runtime reconfiguration. Use Value: Enables field-upgradable settings without firmware reflashing; 2.5 V minimum VCC allows direct use with 3.3 V MCU rails. | Use Scenario: Holding factory-trimmed offset/gain coefficients for a 24-bit delta-sigma ADC in a precision weigh scale. IC Role / Device Role / Timing Role: Calibration data repository read once at power-on and applied to analog front-end compensation logic. Use Value: 200-year data retention ensures accuracy stability over product lifetime; 1M endurance supports recalibration during service intervals. |
| Smart Meter Firmware Patch Log | Medical Device Usage History |
Use Scenario: Recording patch version IDs and application timestamps after OTA firmware updates in a Class 0.5S electricity meter. IC Role / Device Role / Timing Role: Write-once event logger with timestamped entries stored in sequential memory locations. Use Value: 6 ms write time enables fast logging without blocking metering interrupts; WRAL+ERAL ensures atomic full-log updates. | Use Scenario: Archiving patient session counts, battery discharge cycles, and error codes in a portable infusion pump. IC Role / Device Role / Timing Role: Tamper-resistant usage counter with write-protection enforced by EWDS after each update. Use Value: Power-on data protection prevents corruption during battery swaps; industrial temp rating validates operation inside sealed 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/MS | 16-bit organization (256 × 16), same VCC range and package; ORG pin NC but internally fixed x16 | Requires 16-bit MCU data path alignment; incompatible with existing 8-bit read/write firmware | Select only if system architecture mandates 16-bit word access and memory map efficiency outweighs firmware porting effort |
| AT25040B-MAHL-T | SPI interface (4-wire), 512 × 8-bit, 1.8–5.5 V VCC, 5 ms max write time, same MSOP-8 package | Requires SPI peripheral instead of generic GPIO-bitbanged Microwire; no Ready/Busy pin - relies on WIP polling | Prefer when migrating to standardized SPI infrastructure or when tighter VCC min (1.8 V) is required for ultra-low-power designs |
Compared with 93LC66B-I/MS, the 93LC66AT-I/MS provides native 8-bit alignment for byte-addressed MCU systems; versus AT25040B-MAHL-T, it offers hardware Ready/Busy signaling and Microwire simplicity at the cost of less universal interface support.
Availability
93LC66AT-I/MS is available at Aetrix Electronics and suitable for industrial automation controllers, medical diagnostics equipment, and smart utility meters requiring stable component supply, long-life data retention, and RoHS-compliant packaging.
Supply support for 93LC66AT-I/MS 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 components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93LC66A/B/C family was designed specifically for low-power, nonvolatile memory applications in resource-constrained embedded systems - emphasizing micropower operation, robust data integrity, and flexible packaging for space-sensitive PCB layouts.
FAQ
What is the memory organization of the 93LC66AT-I/MS?
The 93LC66AT-I/MS is a fixed 512 × 8-bit (4 Kbit) organization device. As an 'A' variant, it does not use the ORG pin - the memory is permanently configured for 8-bit word access. This eliminates external configuration logic and simplifies firmware implementation compared to 'C' variants with selectable x8/x16 modes.
Does the 93LC66AT-I/MS support sequential read operations?
Yes, the 93LC66AT-I/MS supports sequential read: when CS remains high after a READ instruction, the internal address counter automatically increments, allowing continuous output of consecutive memory bytes on the DO pin with each subsequent CLK rising edge - reducing transaction overhead and improving bulk read throughput.
What is the purpose of the ORG pin on the 93LC66AT-I/MS?
The ORG pin is marked NC (No Connection) on the 93LC66AT-I/MS because it is an 'A'-series device with fixed 8-bit organization. It has no internal connection and may be left floating or tied to VSS/VCC per board layout guidelines - it plays no functional role in this specific part number.
How does the 93LC66AT-I/MS handle power-supply brown-out conditions?
The 93LC66AT-I/MS incorporates hardware power-on reset detection with VPOR = 1.5 V. When VCC drops below this threshold, all internal operations - including erase, write, and read - are automatically inhibited, preventing data corruption during unstable power conditions. This feature is active across the full industrial temperature range.
Is the 93LC66AT-I/MS compatible with standard Microwire protocol implementations?
Yes, the 93LC66AT-I/MS is fully Microwire-compatible: it uses the standard 3-wire interface (CS, CLK, DI/DO), supports start-bit detection, and implements the Microwire instruction set (READ, WRITE, ERASE, etc.) with identical timing and opcode definitions - enabling drop-in integration with existing Microwire host drivers.
93LC66AT-I/MS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 4Kbit
- Memory Organization:
- 512 x 8
- 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 ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-MSOP
93LC66AT-I/MS FAQ
1.How can I place an order for 93LC66AT-I/MS through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66AT-I/MS 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 93LC66AT-I/MS reliable?
The price and inventory of 93LC66AT-I/MS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66AT-I/MS is usually 5 days.
3.What payment methods are accepted for 93LC66AT-I/MS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66AT-I/MS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66AT-I/MS?
93LC66AT-I/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66AT-I/MS 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 93LC66AT-I/MS?
For technical support, including 93LC66AT-I/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66AT-I/MS requirements.
6.How does Aetrix verify that 93LC66AT-I/MS is sourced from the original manufacturer or authorized distributors?
All 93LC66AT-I/MS 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 93LC66AT-I/MS meets industry standards.
7.What is the process for return or replacement of 93LC66AT-I/MS?
All 93LC66AT-I/MS units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66AT-I/MS, 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 93LC66AT-I/MS part is unused and in its original packaging.
Return procedure for 93LC66AT-I/MS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93LC66AT-I/MS 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…
