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Microchip Technology 93C66B-E/ST
- Part No.:
- 93C66B-E/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
93C66B-E/ST.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,666
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Product details
Overview
93C66B-E/ST from Microchip Technology Inc. is a 4 Kbit (256 x 16-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 4.5–5.5 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 93C66B-E/ST datasheet, 93C66B-E/ST pinout, 93C66B-E/ST application, or 93C66B-E/ST equivalent, key selection criteria include its fixed 16-bit organization (no ORG pin), automotive-grade reliability, 2 ms typical write cycle time, and compatibility with legacy Microwire controllers in space-constrained industrial modules.
Technical Context
The 93C66B-E/ST implements a synchronous serial interface with CS, CLK, and DI/DO pins, requiring no external timing components. Its command set includes READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS - all executed via rising-edge clocked 12-bit instruction sequences for x16 mode.
Unlike C-variant parts, the 93C66B has no ORG pin (NC), permanently configured for 256 × 16-bit memory mapping. Write initiation occurs on the rising edge of CLK at the final data bit, and VCC must be ≥4.5 V for ERAL and WRAL operations - distinguishing it from 93AA/93LC variants with wider voltage ranges.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (256 words × 16 bits) - supports compact firmware parameter tables without byte-level addressing overhead |
| VCC range | 4.5 V to 5.5 V - compatible with 5 V logic systems; excludes low-voltage operation below 4.5 V |
| Write cycle time | 2 ms typical - enables fast field updates without blocking host MCU for extended periods |
| Endurance | 1,000,000 erase/write cycles - suitable for applications requiring frequent recalibration or logging |
| Data retention | 200 years at +25°C - ensures long-term integrity of stored calibration coefficients or security keys |
| Temperature range | –40°C to +125°C (Automotive E-grade) - qualified for under-hood and motor control environments |
| Interface | Microwire-compatible 3-wire serial (CS/CLK/DI/DO) - interoperable with legacy microcontrollers lacking SPI hardware |
Pinout & Package
Package: 8-lead SOIC (ST suffix per Microchip marking convention, JEDEC MS-012).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must be held low ≥250 ns between instructions to reset internal state |
| 2 (CLK) | Serial Clock | Rising-edge synchronized I/O; clocking stops during self-timed write; no minimum duty cycle required |
| 3 (DI) | Data Input | Accepts Start bit, opcodes, addresses, and 16-bit data; high-impedance when CS low |
| 4 (DO) | Data Output / Status | Outputs 16-bit read data or Ready/Busy (low = busy); enters High-Z on CS falling edge |
| 5 (VSS) | Ground | Reference for all I/O and internal logic; requires low-impedance connection to minimize noise coupling |
| 6 (NC) | No Connect | Internally unconnected; must be left floating or tied to VSS per layout best practice |
| 7 (NC) | No Connect | Same as Pin 6 - not bonded; no routing or termination required |
| 8 (VCC) | Power Supply | 4.5–5.5 V only; POR threshold at 3.8 V ensures reliable initialization during brown-out conditions |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 16-bit organization | Eliminates need for ORG pin control logic; simplifies PCB design and firmware driver implementation |
| Self-timed erase/write | Removes requirement for external timeout management; host MCU can poll DO for completion |
| Automatic ERAL before WRAL | Guarantees full-array readiness prior to bulk write - prevents partial-write corruption on power loss |
| Power-on/off data protection | Hardware-enforced write inhibition below 3.8 V VCC - prevents inadvertent writes during power ramp |
| Ready/Busy status on DO | Enables non-blocking host operation; eliminates need for fixed delay loops or external timers |
Applications
| Industrial Motor Control | Automotive Body Controller |
|---|---|
Use Scenario: Storing motor pole-pair count, current limits, and encoder offset calibration across power cycles. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed during boot; read once per startup, written only during commissioning or field update. Use Value: Ensures consistent motor behavior after power loss; eliminates manual re-calibration in production or service. | Use Scenario: Retaining door lock timeout settings, mirror position memory, and lighting dimming profiles in body control modules. IC Role / Device Role / Timing Role: Parameter store interfaced via legacy 8051-based MCU with Microwire peripheral; accessed asynchronously during user interaction. Use Value: Maintains personalized settings across ignition cycles without battery drain; meets AEC-Q100 Grade 1 thermal requirements. |
| Medical Infusion Pump | Smart Energy Meter |
Use Scenario: Securing delivery rate presets, alarm thresholds, and maintenance logs subject to regulatory audit trails. IC Role / Device Role / Timing Role: Tamper-resistant configuration vault; write-protected via EWDS/EWEN sequence; accessed only by authenticated firmware. Use Value: Supports FDA 21 CFR Part 11 compliance through deterministic write endurance and data retention guarantees. | Use Scenario: Storing tariff schedules, meter calibration constants, and tamper-event timestamps in ANSI C12.22-compliant meters. IC Role / Device Role / Timing Role: High-reliability parameter storage operating continuously at +85°C ambient; accessed during daily firmware sync. Use Value: Delivers 200-year data retention at elevated temperature - exceeds ANSI C12.22 lifetime requirements for 20+ year deployments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93LC66B-E/ST | Wider VCC range (2.5–5.5 V); same 256 × 16-bit organization and pinout | Supports mixed-voltage systems (e.g., 3.3 V MCU + 5 V peripherals); lower VCC min enables battery-backed operation | Select if system operates below 4.5 V or requires dual-supply flexibility; otherwise 93C66B-E/ST offers tighter voltage tolerance for pure 5 V rails |
| AT25DF041A-SH-B | SPI interface (4-wire), 4 Mbit density, 2.7–3.6 V only; no Ready/Busy pin | Higher density for firmware storage; requires SPI controller and software polling instead of hardware status signal | Choose for cost-sensitive designs needing >4 Kbit capacity and 3.3 V compatibility; avoid if Microwire legacy support or DO status signal is mandatory |
Compared with 93LC66B-E/ST, the 93C66B-E/ST trades voltage flexibility for stricter 5 V rail stability and enhanced noise immunity; versus AT25DF041A-SH-B, it provides deterministic timing, smaller footprint, and hardware-ready signaling at lower density - making it optimal for resource-constrained automotive and industrial control nodes.
Availability
93C66B-E/ST is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, medical infusion pumps, and smart energy metering requiring stable component supply, long-term lifecycle assurance, and AEC-Q100-compliant nonvolatile memory.
Supply support for 93C66B-E/ST 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 93C66B-E/ST belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, space-constrained embedded systems requiring robust nonvolatile storage with minimal external components and proven automotive qualification.
FAQ
What is the memory organization of the 93C66B-E/ST?
The 93C66B-E/ST has a fixed 256 × 16-bit organization (4 Kbit total), with no ORG pin - unlike C-variant parts. This means it always operates in 16-bit word mode, eliminating external configuration logic and simplifying firmware address handling. The absence of ORG confirms dedicated x16 functionality per Microchip DS21795E-page 1.
Does the 93C66B-E/ST support 3.3 V operation?
No, the 93C66B-E/ST requires 4.5 V to 5.5 V supply voltage and is not rated for 3.3 V operation. Its power-on reset threshold is 3.8 V, and electrical characteristics (e.g., VOL, VOH, FCLK) are specified only within the 4.5–5.5 V range. For 3.3 V systems, consider the 93LC66B-E/ST instead.
How does the Ready/Busy status work on the 93C66B-E/ST?
The 93C66B-E/ST asserts Ready/Busy status on the DO pin: DO = low indicates ongoing erase/write, DO = high signals completion. To read status, CS must be brought high for ≥250 ns after TCSL; DO returns to High-Z on CS falling edge. This hardware signal eliminates need for fixed delays in host firmware.
What is the write endurance and data retention of the 93C66B-E/ST?
The 93C66B-E/ST guarantees 1,000,000 erase/write cycles and 200 years of data retention at +25°C. Endurance is characterized at 5.0 V and 25°C per DS21795E-page 4 (Note 2); retention degrades predictably at higher temperatures but remains compliant with automotive and industrial lifetime requirements.
Is the 93C66B-E/ST pin-compatible with other 93XX66 packages?
Yes, the 93C66B-E/ST in SOIC-8 (ST) shares identical pinout and footprint with all 93XX66A/B/C variants in ST package, including 93AA66B-E/ST and 93LC66B-E/ST. Pins 1–8 map identically to CS, CLK, DI, DO, VSS, NC, NC, VCC - enabling direct substitution where voltage and timing requirements align.
93C66B-E/ST Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not 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 ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
93C66B-E/ST FAQ
1.How can I place an order for 93C66B-E/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66B-E/ST 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-E/ST reliable?
The price and inventory of 93C66B-E/ST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 93C66B-E/ST is usually 5 days.
3.What payment methods are accepted for 93C66B-E/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66B-E/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66B-E/ST?
93C66B-E/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66B-E/ST 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-E/ST?
For technical support, including 93C66B-E/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66B-E/ST requirements.
6.How does Aetrix verify that 93C66B-E/ST is sourced from the original manufacturer or authorized distributors?
All 93C66B-E/ST 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-E/ST meets industry standards.
7.What is the process for return or replacement of 93C66B-E/ST?
All 93C66B-E/ST units undergo pre-shipment inspection (PSI). If there is an issue with 93C66B-E/ST, 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-E/ST part is unused and in its original packaging.
Return procedure for 93C66B-E/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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