My Inquiry
My Account
Microchip Technology 93LC66/P
- Part No.:
- 93LC66/P
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
93LC66/P.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:489
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
93LC66/P from Microchip Technology Inc. is a 4K-bit (512 × 8 or 256 × 16) low-voltage serial EEPROM with Microwire™ interface, operating down to 2.5V and featuring ORG-pin-selectable memory organization, self-timed erase/write cycles, and industrial temperature range (–40°C to +85°C). It serves as nonvolatile configuration storage in microcontroller-based systems requiring reliable parameter retention.
For engineers reviewing the 93LC66/P datasheet, 93LC66/P pinout, 93LC66/P application, or 93LC66/P equivalent, key selection considerations include its 3-wire serial interface timing (max 2 MHz at VCC < 4.5V), 1M endurance cycles, >200-year data retention, and PDIP-8 package compatibility with legacy through-hole designs.
Technical Context
The 93LC66/P implements a synchronous 3-wire Microwire-compatible interface with CS, CLK, and bidirectional DI/DO lines. Its internal logic decodes 10-bit addresses (x8 mode) or 8-bit addresses (x16 mode) based on ORG pin state, supporting READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS instructions with clocked opcode/address/data sequences.
It features power-on/off data protection that inhibits programming below 1.4V, automatic ERAL before WRAL execution, and device status signaling via DO pin during erase/write operations - enabling polling-based readiness detection without external timers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8 or 256 × 16 organization selectable via ORG pin) |
| Supply voltage | 2.5V to 5.5V - enables direct interfacing with 2.5V, 3.3V, and 5V logic systems |
| Interface | Microwire™ 3-wire serial (CS, CLK, DI/DO) - requires no I²C pull-ups or SPI SS management |
| Endurance | 1,000,000 erase/write cycles - supports frequent firmware or calibration updates |
| Data retention | Greater than 200 years at 25°C - ensures long-term reliability in unpowered storage |
| Operating temperature | –40°C to +85°C (Industrial grade) - validated for embedded control and instrumentation environments |
| Write cycle time | 4 ms typical per word - deterministic timing simplifies host software delay handling |
Pinout & Package
93LC66/P is housed in an 8-lead Plastic Dual In-line Package (PDIP), 300 mil body width, JEDEC MS-001 compliant, with through-hole mounting and standard lead pitch of 2.54 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 CS | Chip Select | Active-high enable signal; must be held low ≥250 ns between instructions to reset internal logic |
| 2 CLK | Serial Clock | Positive-edge-triggered clock for synchronizing opcode, address, and data bits |
| 3 DI | Data Input | Accepts Start bit, instruction opcodes, addresses, and write data; high-impedance when not clocking |
| 4 DO | Data Output / Status | Outputs read data or Ready/Busy status (low = busy); high-Z when CS is low or during non-read states |
| 5 VSS | Ground | Reference return path for all digital and power circuitry |
| 6 ORG | Memory Organization | Logic-high selects 256 × 16-bit mode; logic-low selects 512 × 8-bit mode; must be fixed (not floated) above 1 MHz |
| 7 NU | No Connect | Internally unused pin - must remain unconnected per datasheet |
| 8 VCC | Power Supply | Accepts 2.5V–5.5V; includes on-chip power-on reset and voltage threshold protection |
Key Features
| Feature | Design Value |
|---|---|
| ORG-pin memory configuration | Enables single BOM support for both x8 and x16 data-width applications via external strap |
| Self-timed erase/write | Eliminates need for external timing components or host-controlled delays during programming |
| Power-on/off data protection | Hardware-enforced lockout below 1.4V prevents corruption during brown-out or hot-plug events |
| RDY/BSY status polling | Allows host MCU to verify completion without fixed timeouts - improves system responsiveness |
| Sequential read mode | Enables burst reads across consecutive addresses with single CS assertion - reduces bus overhead |
Applications
| Industrial Sensor Calibration | Consumer Remote Control Memory |
|---|---|
|
Use Scenario: Storing factory-trimmed sensor offset/gain coefficients and user-adjusted calibration points in pressure or temperature transmitters. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed infrequently during setup or field recalibration; operates at ≤1 MHz clock rate. Use Value: Ensures consistent measurement accuracy across power cycles and product lifetime without battery backup. |
Use Scenario: Retaining user-programmed channel presets, volume levels, and IR code learning history in universal remote controls. IC Role / Device Role / Timing Role: Low-power serial configuration store interfaced directly to 8-bit microcontroller GPIO pins. Use Value: Delivers 100 µA active read current at 2.5V - extends alkaline battery life beyond 12 months. |
| Embedded System Boot Configuration | Legacy Industrial PLC Parameter Storage |
|
Use Scenario: Holding boot-time hardware configuration flags (e.g., UART baud rate, ADC resolution, watchdog timeout) in microcontroller-based edge nodes. IC Role / Device Role / Timing Role: Early-boot initialization resource accessed once per power-up using minimal GPIO resources. Use Value: Supports 2.5V operation - eliminates level-shifting when paired with modern low-voltage MCUs. |
Use Scenario: Preserving machine-specific operational parameters (e.g., motor ramp rates, I/O mapping, alarm thresholds) in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Robust, long-life nonvolatile memory compatible with existing PDIP socket footprints and 5V backplane supplies. Use Value: 8-pin PDIP package enables drop-in replacement in legacy PCBs without layout revision. |
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/P | Enhanced version with improved ESD rating (≥6 kV), tighter AC timing specs, and updated process technology | Same pinout and instruction set; preferred for new designs requiring higher robustness | Select 93LC66C-I/P when designing new products - it supersedes 93LC66/P per Microchip's notice |
| AT25040B-PU | SPI interface (4-wire), 4 Kbit capacity, 1.8–5.5V supply, 20 MHz max clock, different command set and status reporting | Requires SPI master peripheral instead of bit-banged Microwire; no ORG pin for x8/x16 reconfiguration | Choose AT25040B-PU only if migrating to SPI infrastructure and accepting loss of dual-organization flexibility |
Compared with 93LC66C-I/P, the 93LC66/P lacks enhanced ESD protection and has looser AC timing margins; compared with AT25040B-PU, it uses a simpler 3-wire protocol but requires dedicated ORG routing and offers no SPI compatibility.
Availability
93LC66/P is available at Aetrix Electronics and suitable for industrial sensor calibration, consumer remote control memory, embedded system boot configuration, and legacy PLC parameter storage requiring stable component supply and long-term obsolescence support.
Supply support for 93LC66/P 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 devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93LC66/P belongs to Microchip's legacy 93LC serial EEPROM family, designed specifically for cost-sensitive, low-power, and space-constrained embedded systems requiring simple, reliable nonvolatile storage with minimal external components.
FAQ
What is the memory organization of the 93LC66/P and how is it selected?
The 93LC66/P supports two memory organizations: 512 × 8-bit or 256 × 16-bit. Selection is controlled by the ORG pin - tied to VCC for x16 mode, or to VSS for x8 mode. This configuration is latched at power-up and remains fixed during operation. The 93LC66/P datasheet confirms this behavior in Section 2.0 and Table 1-5/1-6 instruction sets.
Does the 93LC66/P require external pull-up resistors on its DI or DO lines?
The 93LC66/P does not require external pull-ups on DI, but a pull-up resistor on DO is necessary when polling Ready/Busy status after an erase or write cycle - because DO enters high-impedance state when CS is low, and the "Ready" signal (logic high) needs a defined voltage level. This requirement is explicitly stated in Section 3.4 of the 93LC66/P datasheet.
What is the maximum clock frequency supported by the 93LC66/P at 2.5V supply?
At VCC = 2.5V, the 93LC66/P supports a maximum clock frequency of 1 MHz, as specified in the AC Characteristics table (Param No. 1, FCLK). This limit increases to 2 MHz when VCC ≥ 4.5V. These values are measured under industrial temperature conditions and are guaranteed across the full –40°C to +85°C range per DS21712C-page 3.
How does the 93LC66/P protect against accidental writes during power transitions?
The 93LC66/P incorporates hardware-level power-on/power-off protection that disables all programming functions (ERASE, WRITE, EWEN) until VCC rises above 1.4V, and re-enables protection when VCC falls below that threshold. Additionally, it powers up in EWDS (Erase/Write Disable) mode, requiring an explicit EWEN command before any programming - ensuring data integrity during brown-out or hot-swap events as described in Sections 2.3 and 2.5 of the 93LC66/P datasheet.
Is the 93LC66/P pin-compatible with the 93LC66C-I/P?
Yes, the 93LC66/P and 93LC66C-I/P share identical pinout, package (PDIP-8), and electrical interface - making them mechanically and electrically interchangeable. However, the 93LC66C-I/P features improved ESD performance and tighter AC timing, and Microchip explicitly recommends it for new designs. This compatibility is confirmed in Microchip's Product Identification System documentation (DS21712C-page 17).
93LC66/P Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- 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:
- 2 MHz
- Write Cycle Time - Word, Page:
- 10ms
- Access Time:
- -
- Voltage - Supply:
- 2.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
93LC66/P FAQ
1.How can I place an order for 93LC66/P through Aetrix?
Please submit a Request for Quotation (RFQ) for 93LC66/P 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 93LC66/P reliable?
The price and inventory of 93LC66/P are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93LC66/P is usually 5 days.
3.What payment methods are accepted for 93LC66/P?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93LC66/P transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93LC66/P?
93LC66/P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93LC66/P 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 93LC66/P?
For technical support, including 93LC66/P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93LC66/P requirements.
6.How does Aetrix verify that 93LC66/P is sourced from the original manufacturer or authorized distributors?
All 93LC66/P 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 93LC66/P meets industry standards.
7.What is the process for return or replacement of 93LC66/P?
All 93LC66/P units undergo pre-shipment inspection (PSI). If there is an issue with 93LC66/P, 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 93LC66/P part is unused and in its original packaging.
Return procedure for 93LC66/P:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93LC66/P 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…
