My Inquiry
My Account
Microchip Technology 93C66B-I/P
- Part No.:
- 93C66B-I/P
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
93C66B-I/P.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,491
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
93C66B-I/P from Microchip Technology Inc. is a 4Kbit, 256 x 16-bit organization serial EEPROM with Microwire-compatible 3-wire interface, operating at 4.5–5.5V, rated for -40°C to +85°C industrial temperature range, and housed in an 8-lead PDIP package. It delivers self-timed erase/write cycles, automatic ERAL/WRAL support, and Ready/Busy status signaling for embedded configuration storage in microcontroller systems.
For engineers reviewing the 93C66B-I/P datasheet, 93C66B-I/P pinout, 93C66B-I/P application, or 93C66B-I/P equivalent, key selection criteria include its fixed 16-bit word width (no ORG pin), 2 ms write cycle time, 1M endurance rating, 200-year data retention, and compatibility with legacy Microwire controllers requiring strict timing compliance at 5V operation.
Technical Context
The 93C66B-I/P implements a synchronous serial Microwire interface with dedicated CS, CLK, DI, and DO lines - no ORG pin present - enforcing fixed 16-bit word access. Its internal architecture includes auto-erase-before-write logic, hardware-based EWEN/EWDS protection, and status polling via DO pin during programming.
Timing is strictly defined: max 3 MHz clock frequency at 4.5–5.5V, 250 ns minimum CS low time between instructions, and 2 ms typical erase/write cycle duration. Power-on reset detection triggers at 3.8V, disabling all operations below that threshold to prevent corruption.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (256 × 16-bit words) - supports compact nonvolatile storage of calibration data or firmware parameters without external address decoding. |
| VCC Range | 4.5 V to 5.5 V - designed for stable 5V system rails; operation disabled below 3.8V for robust power-fail protection. |
| Interface | Microwire 3-wire serial (CS/CLK/DI/DO) - compatible with legacy microcontrollers lacking SPI hardware but supporting bit-banged Microwire protocols. |
| Write Cycle Time | 2 ms (typical) - enables fast field updates while maintaining deterministic timing for real-time host software polling. |
| Endurance | 1,000,000 erase/write cycles - suitable for applications requiring frequent reconfiguration, such as industrial sensor calibration tables. |
| Data Retention | 200 years at 25°C - ensures long-term reliability in unattended equipment like utility meters or building automation nodes. |
| Temperature Range | -40°C to +85°C (Industrial grade) - validated for deployment in extended-temperature industrial control cabinets and automotive under-hood modules. |
Pinout & Package
8-lead PDIP (Plastic Dual In-line Package), 0.3 inch body width, through-hole mounting. Pin 1 marked by notch or dot; pin 1 ID confirmed per Microchip DS21795E-page 18.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held low ≥250 ns between commands to reset internal state and avoid spurious instruction latching. |
| 2 (CLK) | Serial Clock | Rising-edge synchronized I/O; clocking stops safely mid-transfer; no requirement for continuous clock during self-timed write. |
| 3 (DI) | Data Input | Accepts Start bit, opcode, address, and 16-bit data; high-impedance when not selected; requires pull-down if unused. |
| 4 (DO) | Data Output / Status | Outputs read data on rising CLK edge; signals Ready/Busy (low = busy) during erase/write when CS is reasserted after TCSL. |
| 5 (VSS) | Ground | System reference return path; must be low-inductance connection to minimize noise coupling into sensitive serial timing. |
| 6 (NC) | No Connect | Internally unconnected; must remain floating - no external tie or routing to avoid parasitic coupling or ESD risk. |
| 7 (NC) | No Connect | Same as Pin 6; dual NC pins reflect package pinout compatibility across A/B/C variants; both must be left unconnected. |
| 8 (VCC) | Power Supply | 4.5–5.5V supply input; requires local 0.1 µF ceramic decoupling placed within 5 mm of pin for stable 3 MHz operation. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 16-bit word organization | Eliminates need for external ORG pin control logic - simplifies PCB layout and firmware driver design for dedicated 16-bit systems. |
| Self-timed erase/write with auto-erase | Removes host timing dependency; host only waits for DO status or fixed 2 ms timeout - reduces CPU overhead and interrupt latency. |
| Hardware write protection (EWEN/EWDS) | Prevents accidental overwrites during power transients or firmware bugs; EWDS is default power-up state for fail-safe initialization. |
| Ready/Busy status on DO pin | Enables efficient polling without additional GPIO lines - critical for resource-constrained MCUs with limited I/O count. |
| Industry-standard Microwire protocol | Ensures drop-in compatibility with existing 8051, PIC, and legacy ARM designs using Microwire peripherals or bit-banged drivers. |
Applications
| Industrial Sensor Calibration | Legacy MCU Configuration Storage |
|---|---|
Use Scenario: Storing temperature-compensation coefficients and sensor offset values in factory-calibrated pressure transmitters. IC Role / Device Role / Timing Role: Nonvolatile parameter register accessed during boot and periodic recalibration; uses sequential read and single-word write. Use Value: 256 × 16-bit capacity holds full calibration matrix; 1M endurance supports >10 years of daily recalibration; 200-year retention ensures lifetime data integrity without battery backup. | Use Scenario: Holding bootloader configuration flags, communication baud rates, and device ID in 8-bit microcontroller-based HVAC controllers. IC Role / Device Role / Timing Role: Microwire-compatible configuration memory interfaced directly to bit-banged GPIO pins on legacy 8051 derivatives. Use Value: Fixed 16-bit word width matches common 16-bit register fields; 5V-only operation aligns with industrial 5V bus standards; PDIP package enables easy prototyping and socket-based field replacement. |
| Automotive Body Control Module (BCM) | Point-of-Sale Terminal Security Keys |
Use Scenario: Storing seat position presets, mirror angles, and lighting profiles in automotive BCMs operating across -40°C to +85°C. IC Role / Device Role / Timing Role: Industrial-grade EEPROM retaining user preferences across ignition cycles; accessed via discrete GPIO-driven Microwire interface. Use Value: -40°C to +85°C rating meets AEC-Q100 Grade 2 requirements; 3.8V POR prevents writes during brown-out; 2 ms write time allows fast profile saves without blocking main control loop. | Use Scenario: Securing cryptographic keys and terminal-specific identifiers in PCI-compliant payment terminals where tamper resistance is required. IC Role / Device Role / Timing Role: Tamper-evident nonvolatile storage isolated from main processor; accessed only during secure boot and key loading sequences. Use Value: Hardware EWEN/EWDS enables lock-after-programming; 1M endurance supports secure key rotation policies; Pb-free RoHS compliance satisfies global regulatory mandates. |
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/P | 2.5–5.5V VCC range; same 256×16 organization; identical pinout and timing; includes POR at 2.5V instead of 3.8V. | Supports wider voltage range including 3.3V systems; suitable for mixed-voltage boards where 5V and 3.3V domains coexist. | Select 93LC66B-I/P when operating from 3.3V supplies or requiring lower POR threshold; retains full software and hardware compatibility. |
| AT25040B-PU | SPI interface (4-wire), 512×8 organization, 1.8–5.5V, 5 ms write time, same PDIP-8 package. | Requires SPI master instead of Microwire; smaller capacity; slower write; different instruction set and status reporting mechanism. | Choose AT25040B-PU only if migrating to SPI infrastructure; not a drop-in replacement due to protocol and timing differences. |
Compared with 93LC66B-I/P, the 93C66B-I/P offers tighter 5V-only timing margins and higher immunity to undervoltage corruption, while AT25040B-PU trades Microwire simplicity for SPI ubiquity at the cost of longer write latency and reduced endurance headroom.
Availability
93C66B-I/P is available at Aetrix Electronics and suitable for industrial sensor calibration, legacy MCU configuration storage, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for 93C66B-I/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 components, and memory solutions, headquartered in Chandler, Arizona, serving industrial, automotive, and consumer markets globally.
The 93Cxx series was engineered specifically for cost-sensitive, low-pin-count embedded systems needing reliable, low-power serial EEPROM with Microwire compatibility and robust data integrity under voltage and temperature stress.
FAQ
What is the memory organization of the 93C66B-I/P?
The 93C66B-I/P has a fixed 256 × 16-bit organization - 4,096 total bits arranged as 256 words of 16 bits each. Unlike 'C' variants, it lacks an ORG pin and does not support runtime switching between 8-bit and 16-bit modes. This fixed width simplifies firmware development and eliminates external configuration logic.
Does the 93C66B-I/P require an external ORG pin connection?
No, the 93C66B-I/P does not have an ORG pin. Pin 6 and Pin 7 are both marked NC (No Connect) in the PDIP package. The device is hardwired for 16-bit operation, making it electrically and functionally distinct from 93C66C variants that use ORG for word-size selection.
What is the maximum clock frequency supported by the 93C66B-I/P?
The 93C66B-I/P supports up to 3 MHz clock frequency when operated within its specified 4.5–5.5V VCC range. This timing is validated per DS21795E Table 1-2 (A1), and exceeds the 2 MHz limit of broader-voltage variants like 93LC66B, enabling faster data throughput in 5V systems.
How does write protection work on the 93C66B-I/P?
The 93C66B-I/P powers up in Erase/Write Disable (EWDS) mode. Before any ERASE or WRITE command executes, an Erase/Write Enable (EWEN) instruction must be issued. After programming, issuing EWDS relocks the memory - a mandatory step to prevent corruption during power glitches or firmware errors.
Is the 93C66B-I/P compatible with SPI interfaces?
No, the 93C66B-I/P is not SPI-compatible. It implements the Microwire protocol - a 3-wire subset of SPI with distinct instruction opcodes, timing requirements (e.g., TCSL = 250 ns), and status reporting via DO pin. Direct connection to an SPI master will not function without protocol translation firmware or hardware bridging.
93C66B-I/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:
- 256 x 16
- Memory Interface:
- Microwire
- Clock Frequency:
- 2 MHz
- Write Cycle Time - Word, Page:
- 2ms
- Access Time:
- -
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
93C66B-I/P FAQ
1.How can I place an order for 93C66B-I/P through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66B-I/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 93C66B-I/P reliable?
The price and inventory of 93C66B-I/P are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93C66B-I/P is usually 5 days.
3.What payment methods are accepted for 93C66B-I/P?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66B-I/P transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66B-I/P?
93C66B-I/P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66B-I/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 93C66B-I/P?
For technical support, including 93C66B-I/P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66B-I/P requirements.
6.How does Aetrix verify that 93C66B-I/P is sourced from the original manufacturer or authorized distributors?
All 93C66B-I/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 93C66B-I/P meets industry standards.
7.What is the process for return or replacement of 93C66B-I/P?
All 93C66B-I/P units undergo pre-shipment inspection (PSI). If there is an issue with 93C66B-I/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 93C66B-I/P part is unused and in its original packaging.
Return procedure for 93C66B-I/P:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93C66B-I/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…
