My Inquiry
My Account
Microchip Technology 93C66BT-E/ST
- Part No.:
- 93C66BT-E/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
93C66BT-E/ST.pdf
- Description:
- IC EEPROM 4KBIT MICROWIRE 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,085
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
The 93C66BT-E/ST from Microchip Technology Inc. is a 4 Kbit serial EEPROM with 8-bit organization, operating in the 4.5–5.5 V supply range and rated for automotive temperature (−40°C to +125°C). It uses Microwire-compatible 3-wire serial interface (CS, CLK, DI, DO), supports self-timed erase/write cycles (2 ms typical), and provides Ready/Busy status via DO pin. It is used in automotive body control modules for storing calibration data and configuration parameters.
For engineers reviewing the 93C66BT-E/ST datasheet, 93C66BT-E/ST pinout, 93C66BT-E/ST application, or 93C66BT-E/ST equivalent, key selection considerations include its automotive-grade temperature rating, 4.5–5.5 V VCC range, 8-bit x 512 organization, 2 ms write cycle time, and TSSOP-8 package with exposed pad compatibility.
Technical Context
The 93C66BT-E/ST implements a synchronous serial Microwire interface with start-bit detection, opcode-driven command set (READ, WRITE, ERASE, ERAL, WRAL), and hardware-based data protection including power-on/off lockout and EWEN/EWDS enable/disable logic. Its internal architecture includes an address decoder, mode decode logic, and output buffer with high-impedance DO during standby.
It features dedicated 8-bit organization (no ORG pin functionality), requires VCC ≥ 4.5 V for ERAL and WRAL operations, and initiates write cycles on the rising edge of CLK at the final data bit - a timing behavior distinct from 93AA/93LC variants that use CS falling edge. The device enters Standby mode when CS is low, but completes ongoing programming before entering sleep.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit organization; fixed, no ORG pin) |
| VCC range | 4.5 V to 5.5 V - mandates external regulator stability above 4.5 V for reliable ERAL/WRAL execution |
| Temp grade | Automotive (−40°C to +125°C) - qualified for under-hood and powertrain ECU environments |
| Write cycle time | 2 ms typical - enables fast firmware parameter updates without blocking host MCU for extended periods |
| Endurance | 1,000,000 erase/write cycles - supports frequent recalibration logging in adaptive systems |
| Data retention | 200 years at +25°C - ensures long-term validity of stored calibration maps over vehicle lifetime |
| Interface | Microwire 3-wire serial (CS, CLK, DI, DO) - minimal GPIO usage; compatible with legacy microcontrollers lacking SPI hardware |
Pinout & Package
Package: 8-lead TSSOP (ST), Pb-free Matte Tin finish, exposed pad (may be connected to VSS or left floating per Microchip Packaging Spec).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CS) | Chip Select | Active-high enable; must remain low ≥250 ns between instructions; deselects device into Standby but allows ongoing write completion |
| 2 (CLK) | Serial Clock | Synchronizes all data transfers; rising edge clocks in opcodes, addresses, and data; rising edge of final CLK initiates write cycle |
| 3 (DI) | Data Input | Accepts start bit, instruction opcodes, address bits, and write data; must be stable before first CLK rising edge after CS high |
| 4 (DO) | Data Output / Status | Outputs read data on rising CLK edges; indicates Ready/Busy during programming (low = busy, high = ready); high-impedance when CS low or not reading |
| 5 (VSS) | Ground | Reference return path for all signals and power; exposed pad connection recommended for thermal performance |
| 6 (NC) | No Connection | Internally unconnected; must be left floating or tied to VSS per layout guidelines - no functional role |
| 7 (VCC) | Power Supply | 4.5–5.5 V supply input; voltage detect threshold is 3.8 V - below this, all operations are inhibited |
| 8 (ORG) | Organization select | Not applicable - NC on 93C66A/B devices; pin is unused and must be left floating or tied to VSS per datasheet guidance |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed erase/write | 2 ms typical cycle eliminates need for host MCU polling delay loops or timer interrupts |
| Ready/Busy status on DO | Enables non-blocking host operation - MCU can perform other tasks while waiting for write completion |
| Automatic ERAL before WRAL | Ensures full memory array is erased prior to bulk write, preventing stale data corruption without separate erase command |
| Power-on/off data protection | Hardware lockout below 3.8 V VCC prevents partial writes during brown-out or power ramp-up |
| EWEN/EWDS security | Prevents accidental writes: device powers up in EWDS state; explicit EWEN required before any programming |
Applications
| Instrument Cluster Calibration Storage | Engine Control Unit Trim Parameters |
|---|---|
Use Scenario: Storing factory-set display offsets, backlight brightness curves, and odometer correction factors in automotive instrument clusters. IC Role / Device Role / Timing Role: Nonvolatile configuration memory interfaced directly to cluster MCU via Microwire; accessed during boot and infrequently during service mode. Use Value: Ensures consistent UI behavior across vehicle lifetime; 200-year data retention guarantees calibration integrity beyond warranty period. | Use Scenario: Holding air-fuel ratio trim values, idle speed corrections, and knock sensor adaptation tables in gasoline engine ECUs. IC Role / Device Role / Timing Role: Dedicated 8-bit serial EEPROM providing robust, low-pin-count storage for adaptive learning parameters updated every drive cycle. Use Value: 1M endurance supports daily recalibration; automotive temp rating ensures reliability near hot engine compartments. |
| Body Control Module Configuration | Advanced Driver Assistance System (ADAS) Sensor Offset Tables |
Use Scenario: Retaining door lock logic states, window auto-up/down thresholds, and lighting timeout settings in BCMs. IC Role / Device Role / Timing Role: Low-power serial EEPROM used during BCM initialization and configuration changes; accessed only during setup or reprogramming. Use Value: 5 µA standby current minimizes battery drain in parked vehicles; 4.5–5.5 V range matches 12 V system regulation. | Use Scenario: Storing camera lens distortion coefficients and radar beam alignment offsets calibrated during vehicle assembly or dealer service. IC Role / Device Role / Timing Role: Automotive-grade nonvolatile memory holding precision sensor compensation data, written once per vehicle lifecycle. Use Value: −40°C to +125°C rating ensures data integrity during extreme environmental testing and real-world operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 93C66B-E/ST | 16-bit organization (256 × 16), same VCC/temp/package - requires host software to handle 16-bit word access | Used where MCU has native 16-bit data paths or legacy 16-bit firmware stack exists | Select only if system firmware already supports 16-bit addressing and data transfer protocol |
| AT25DF041A-SH-B | 4 Mbit SPI NOR Flash, 2.7–3.6 V, no built-in erase/write protection logic, sector-based erase | Higher density for firmware storage; lacks microwire compatibility and automatic ERAL/WRAL | Choose for code storage or larger data logs; not drop-in - requires SPI driver and wear-leveling management |
Compared with 93C66B-E/ST and AT25DF041A-SH-B, the 93C66BT-E/ST offers optimal balance of automotive qualification, simple 8-bit Microwire interface, and hardware-enforced data integrity - making it ideal for safety-critical calibration storage where minimal firmware overhead and guaranteed write atomicity are essential.
Availability
The 93C66BT-E/ST is available at Aetrix Electronics and suitable for automotive electronics, engine control units, and body control modules requiring stable component supply across extended production lifecycles.
Supply support for 93C66BT-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 microcontroller, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 93C66BT-E/ST belongs to Microchip's legacy 93Cxx serial EEPROM product line, designed specifically for cost-sensitive, space-constrained automotive and industrial applications requiring proven reliability, low-voltage operation, and simple 3-wire interface compatibility.
FAQ
What is the function of the ORG pin on the 93C66BT-E/ST?
The ORG pin is not functional on the 93C66BT-E/ST. As a '93C66A'-type device, it has fixed 8-bit organization and no ORG pin capability. Per datasheet DS21795E-page 12, ORG is marked "NC" (No Connection) for 93C66A/B variants. On the 93C66BT-E/ST in TSSOP-8 package, Pin 8 is internally unconnected and must be left floating or tied to VSS per layout guidelines - it plays no role in memory configuration or operation.
Does the 93C66BT-E/ST support 16-bit word access?
No, the 93C66BT-E/ST does not support 16-bit word access. It is a dedicated 8-bit organization device (512 × 8-bit), as confirmed by the 'A' suffix in its part number and the Device Selection Table in DS21795E-page 1. Unlike 93C66B or 93C66C variants, it lacks ORG pin functionality and executes only x8 instruction sets (e.g., 20-clock READ/WRITE cycles per DS21795E-page 5). Attempting 16-bit transfers will result in incorrect addressing or data corruption.
What is the minimum VCC required for reliable operation of the 93C66BT-E/ST?
The minimum VCC for reliable operation of the 93C66BT-E/ST is 4.5 V. Per DS21795E-page 3, Table 1-1 D11, its VCC voltage detect threshold is 3.8 V - below which all operations are inhibited. However, ERAL and WRAL commands require VCC ≥ 4.5 V (DS21795E-page 8 and page 11), and AC timing specs (e.g., FCLK = 3 MHz) are specified only for 4.5 V ≤ VCC < 5.5 V (DS21795E-page 4, A1). Operating below 4.5 V risks failed bulk operations and marginal timing compliance.
How does the 93C66BT-E/ST indicate Ready/Busy status during a write cycle?
The 93C66BT-E/ST indicates Ready/Busy status on the DO pin. After initiating a WRITE, ERASE, ERAL, or WRAL command, bring CS high for ≥250 ns (TCSL), then monitor DO: logic low means programming is still in progress; logic high means the operation completed successfully and the device is ready for the next instruction. Per DS21795E-page 7 and page 12, DO returns to high-impedance when CS is low, and issuing a Start bit followed by CS low clears the status flag.
Is the 93C66BT-E/ST pin-compatible with other 93C66x variants in TSSOP-8 package?
Yes, the 93C66BT-E/ST is pin-compatible with all 93C66x variants (e.g., 93C66A-E/ST, 93C66B-E/ST, 93C66C-E/ST) in the TSSOP-8 (ST) package per DS21795E-page 12 Pin Function Table. All share identical pinout: CS(1), CLK(2), DI(3), DO(4), VSS(5), NC(6), VCC(7), ORG/NC(8). However, functional compatibility depends on organization (8-bit vs. 16-bit) and ORG pin usage - 93C66BT-E/ST behaves as a fixed 8-bit device regardless of ORG pin state.
93C66BT-E/ST Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP (0.173", 4.40mm 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:
- 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
93C66BT-E/ST FAQ
1.How can I place an order for 93C66BT-E/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 93C66BT-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 93C66BT-E/ST reliable?
The price and inventory of 93C66BT-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 93C66BT-E/ST is usually 5 days.
3.What payment methods are accepted for 93C66BT-E/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 93C66BT-E/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 93C66BT-E/ST?
93C66BT-E/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 93C66BT-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 93C66BT-E/ST?
For technical support, including 93C66BT-E/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 93C66BT-E/ST requirements.
6.How does Aetrix verify that 93C66BT-E/ST is sourced from the original manufacturer or authorized distributors?
All 93C66BT-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 93C66BT-E/ST meets industry standards.
7.What is the process for return or replacement of 93C66BT-E/ST?
All 93C66BT-E/ST units undergo pre-shipment inspection (PSI). If there is an issue with 93C66BT-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 93C66BT-E/ST part is unused and in its original packaging.
Return procedure for 93C66BT-E/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
93C66BT-E/ST 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…
