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Microchip Technology 93LC66A/SN
- Part No.:
- 93LC66A/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
93LC66A/SN.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:13,138
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Product details
Overview
93LC66A/SN from Microchip Technology Inc. is a 4 Kbit (512 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 2.5–5.5 V supply range, and industrial/automotive temperature support (−40°C to +125°C). It features self-timed erase/write cycles, automatic ERAL before WRAL, power-on/off data protection, and Ready/Busy status via DO pin - used in embedded system configuration storage, sensor calibration retention, and firmware parameter backup.
For engineers reviewing the 93LC66A/SN datasheet, 93LC66A/SN pinout, 93LC66A/SN application, or 93LC66A/SN equivalent, key selection criteria include voltage compatibility (2.5–5.5 V), 8-bit fixed word size (no ORG pin), 1 million erase/write endurance, 200-year data retention, and SOIC-8 package footprint suitability for space-constrained industrial control modules.
Technical Context
The 93LC66A/SN implements a synchronous serial Microwire protocol with CS, CLK, and DI/DO signals - no ORG pin (fixed 8-bit organization). Communication requires a Start bit followed by opcode, address (A8–A0), and data (8 bits), with all operations synchronized to CLK rising edges.
It uses internal auto-erase-before-write logic and supports full-array ERAL and WRAL commands (VCC ≥ 4.5 V required). Ready/Busy status is polled on DO while CS is high after TCSL ≥ 250 ns; DO returns High-Z when CS falls, and device enters Standby mode when CS is low.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8-bit); provides compact nonvolatile storage for boot parameters or device IDs in resource-limited microcontrollers. |
| VCC Range | 2.5 V to 5.5 V; compatible with both 3.3 V and 5 V systems without level-shifting. |
| Endurance | 1,000,000 erase/write cycles; supports frequent field-updatable calibration or logging in industrial sensors. |
| Data Retention | > 200 years at 25°C; ensures long-term reliability for unattended equipment like utility meters or remote telemetry nodes. |
| Interface | 3-wire Microwire-compatible serial (CS, CLK, DI/DO); reduces PCB routing complexity vs. SPI or I²C. |
| Access Time | TPD ≤ 400 ns (1.8 V), ≤ 250 ns (2.5–4.5 V), ≤ 200 ns (4.5–5.5 V); enables fast read response in real-time control loops. |
| Write Cycle Time | TWC = 6 ms (erase+write); deterministic timing allows precise host software timeout handling. |
Pinout & Package
93LC66A/SN is supplied in an 8-pin SOIC (SN) package per JEDEC MS-012, with gull-wing leads, 1.27 mm pitch, and Pb-free Matte Tin finish. Pin 1 is marked by laser dot or notch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-high enable; must be held low ≥250 ns between instructions; deselects device into Standby mode. |
| CLK | Serial Clock | Synchronizes all data transfers on rising edge; clock can pause mid-transfer without state loss. |
| DI | Data Input | Receives Start bit, opcodes, addresses, and write data; shares bidirectional bus with DO only if external resistor limits bus conflict. |
| DO | Data Output / Status | Outputs read data or Ready/Busy (low = busy); enters High-Z on CS falling edge; requires CS high ≥250 ns to sample status. |
| VSS | Ground | Reference return path for all I/O and core logic; must be low-impedance to ensure noise immunity during write cycles. |
| NC | No Internal Connection | Pin 7 is unconnected; must be left floating or tied to VSS per layout best practice - no functional role. |
| VCC | Power Supply | Supplies core logic and memory array; internal POR triggers below 1.5 V; WRAL/ERAL require ≥4.5 V. |
| ORG | Organization Select | Not present on 93LC66A - permanently configured for 8-bit operation; pin 6 is NC (no internal connection). |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed Erase/Write | Eliminates need for external timing control - host only waits for DO status or fixed 6 ms timeout. |
| Automatic ERAL before WRAL | Guarantees clean memory state before bulk write; prevents partial writes due to prior corruption or incomplete erase. |
| Power-On/Off Data Protection | Hardware-level lockout below 1.5 V VCC prevents inadvertent writes during brown-out or power ramp. |
| Ready/Busy Status Signal | Enables polling-based firmware design without interrupts or complex state machines - simplifies integration with low-end MCUs. |
| Sequential Read Function | Allows continuous address incrementing with CS held high - reduces command overhead for reading multi-byte records. |
Applications
| Industrial Sensor Calibration Storage | Embedded System Boot Configuration |
|---|---|
Use Scenario: Storing factory-calibrated gain/offset coefficients and temperature compensation tables in pressure or current sensors deployed in harsh environments. IC Role / Device Role / Timing Role: Nonvolatile parameter register accessed at power-up and during field recalibration; retains values across 10+ year deployments. Use Value: Enables plug-and-play sensor replacement without manual reconfiguration; eliminates need for external programming fixtures in production test. | Use Scenario: Holding bootloader settings, network MAC address, and hardware revision ID in programmable logic controllers (PLCs) and motor drives. IC Role / Device Role / Timing Role: Early-boot configuration store read before main MCU firmware initializes peripherals. Use Value: Supports field firmware updates with persistent identity and secure boot policy flags - critical for IIoT security compliance. |
| Automotive Body Control Module (BCM) | Medical Device Usage Logging |
Use Scenario: Recording seat position memory, mirror angle presets, and lighting profiles in automotive BCMs operating across −40°C to +125°C ambient. IC Role / Device Role / Timing Role: Automotive-grade EEPROM interfaced directly to 8-bit/16-bit MCU via Microwire; withstands thermal cycling and ESD events. Use Value: Meets AEC-Q100 Grade 1 requirements; eliminates battery-backed SRAM and associated leakage/power concerns. | Use Scenario: Capturing usage hours, sterilization cycle counts, and error logs in portable diagnostic devices requiring traceability and regulatory audit trails. IC Role / Device Role / Timing Role: Tamper-resistant event logger with guaranteed write integrity - each log entry verified via DO status before next write. Use Value: Satisfies FDA 21 CFR Part 11 electronic record requirements through deterministic write completion signaling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66B/SN | 16-bit organization (256 × 16), same VCC range and package; requires different address/data framing in host firmware. | Used where wider data path reduces transaction count (e.g., storing 16-bit ADC calibration slopes). | Select only if host MCU supports 16-bit serial framing and memory map alignment matches 256-word boundary. |
| AT25040B-MAHL-T | SPI interface (4-wire), 4 Kbit (512 × 8), 1.8–5.5 V, same endurance and retention; lacks Ready/Busy pin - relies on WIP flag polling. | Preferred in designs already using SPI peripherals; avoids Microwire-specific driver development. | Choose when SPI bus is available and firmware already implements SPI EEPROM drivers; verify timing margins for WIP polling loop. |
Compared with 93LC66B/SN, the 93LC66A/SN offers simpler 8-bit addressing and direct compatibility with legacy Microwire firmware; versus AT25040B-MAHL-T, it provides deterministic Ready/Busy signaling instead of status-register polling - reducing CPU load in interrupt-constrained real-time systems.
Availability
93LC66A/SN is available at Aetrix Electronics and suitable for industrial automation, automotive electronics, and medical device manufacturing requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.
Supply support for 93LC66A/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 Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93LC66A belongs to Microchip's legacy 93XX serial EEPROM product line, designed specifically for cost-sensitive, low-power embedded systems needing reliable, pin-efficient nonvolatile storage with minimal external components.
FAQ
What is the maximum clock frequency supported by the 93LC66A/SN?
The 93LC66A/SN supports up to 3 MHz clock frequency at VCC ≥ 4.5 V, 2 MHz at 2.5 V ≤ VCC < 4.5 V, and 1 MHz at 1.8 V ≤ VCC < 2.5 V. These limits are defined in Table 1-2 (AC Characteristics) of DS21795E and ensure reliable setup/hold timing for DI and DO signals across voltage and temperature ranges. The 93LC66A/SN does not operate above these frequencies even with ideal signal integrity.
Does the 93LC66A/SN have an ORG pin, and how is memory organization determined?
No, the 93LC66A/SN does not have a functional ORG pin - it is permanently configured for 8-bit organization (512 × 8-bit). Per the Device Selection Table and Pin Function Table in DS21795E, 'A' versions like 93LC66A omit ORG functionality; pin 6 is labeled NC (No internal connection). This eliminates external configuration logic and simplifies PCB layout compared to 'C' variants.
How does the Ready/Busy status work on the 93LC66A/SN DO pin?
The DO pin of the 93LC66A/SN outputs Ready/Busy status only when CS is brought high after being low for ≥250 ns (TCSL). During erase/write, DO = low indicates ongoing operation; DO = high means completion. If CS remains low, DO stays in High-Z. Issuing a Start bit then lowering CS clears the status. This behavior is confirmed in Sections 2.4–2.9 and Figure 2-1 of DS21795E.
What are the voltage requirements for ERAL and WRAL commands on the 93LC66A/SN?
Both ERAL (Erase All) and WRAL (Write All) commands on the 93LC66A/SN require VCC ≥ 4.5 V for proper operation, as explicitly stated in Figures 2-3, 2-4, 2-10, and 2-11 of DS21795E. Attempting these commands below 4.5 V may result in incomplete erasure or corrupted data - the device will not assert Ready/Busy correctly, and no error flag is provided.
Is the 93LC66A/SN RoHS compliant and what packaging does the /SN suffix indicate?
Yes, the 93LC66A/SN is Pb-free and RoHS compliant per DS21795E-page 1. The /SN suffix denotes the 8-pin SOIC (Small Outline Integrated Circuit) package per JEDEC MS-012, with gull-wing leads, 1.27 mm pitch, and Matte Tin (Sn) finish - verified in Section 4.0 and Package Types diagrams on pages 2–3 of the datasheet.
93LC66A/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
- Memory Interface:
- Microwire
- Clock Frequency:
- 2 MHz
- Write Cycle Time - Word, Page:
- 6ms
- Access Time:
- -
- Voltage - Supply:
- 2.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
93LC66A/SN FAQ
1.How can I place an order for 93LC66A/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66A/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 93LC66A/SN reliable?
The price and inventory of 93LC66A/SN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66A/SN is usually 5 days.
3.What payment methods are accepted for 93LC66A/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66A/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66A/SN?
93LC66A/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66A/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 93LC66A/SN?
For technical support, including 93LC66A/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66A/SN requirements.
6.How does Aetrix verify that 93LC66A/SN is sourced from the original manufacturer or authorized distributors?
All 93LC66A/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 93LC66A/SN meets industry standards.
7.What is the process for return or replacement of 93LC66A/SN?
All 93LC66A/SN units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66A/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 93LC66A/SN part is unused and in its original packaging.
Return procedure for 93LC66A/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93LC66A/SN Tags
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M24C02-WMN6TP
STMicroelectronics
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AT24C02C-XHM-T
Microchip Technology
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AT21CS01-STUM10-T
Microchip Technology
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AT24C02C-SSHM-T
Microchip Technology
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24LC01BT-I/OT
Microchip Technology
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M24C02-FMC6TG
STMicroelectronics
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AT24CS02-SSHM-T
Microchip Technology
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93LC46BT-I/OT
Microchip Technology
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AT24C04C-SSHM-T
Microchip Technology
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24LC01BT-I/SN
Microchip Technology
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24AA02UIDT-I/OT
Microchip Technology
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AT24C08C-STUM-T
Microchip Technology
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