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Microchip Technology AT28HC64B-90TU-T
- Part No.:
- AT28HC64B-90TU-T
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-TSSOP (0.465", 11.80mm Width)
- Datasheet:
-
AT28HC64B-90TU-T.pdf
- Description:
- IC EEPROM 64KBIT PARALLEL 28TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,460
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Product details
Overview
AT28HC64B-90TU-T from Atmel is a 64 Kbit (8K × 8) parallel EEPROM with JEDEC-standard byte-wide pinout, 90 ns read access time, hardware/software data protection, and 100,000 write endurance - used in industrial control firmware storage, embedded configuration memory, and boot code retention.
For engineers reviewing the AT28HC64B-90TU-T datasheet, AT28HC64B-90TU-T pinout, AT28HC64B-90TU-T application, or AT28HC64B-90TU-T equivalent, key selection factors include page write capability (1–64 bytes), CMOS/TTL compatibility, 5 V ±10% single-supply operation, DATA polling/toggle bit write completion detection, and industrial temperature range (−40°C to +85°C).
Technical Context
The AT28HC64B-90TU-T implements a parallel interface with static RAM-like read/write timing, eliminating external address latches. Its internal 64-byte page register enables burst writes without bus hold, while automatic internal write timing eliminates external delay logic.
Write completion is verified via dual methods: DATA polling on I/O7 (complement-to-data during write, true data after completion) and toggle-bit behavior on I/O6 (toggling during write, stable after completion). Hardware protection includes VCC sense (<3.8 V inhibit), 5 ms power-on delay, and noise filtering on WE/CE inputs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8,192 × 8), sufficient for firmware patches or device calibration tables |
| Read Access Time | 90 ns maximum - meets real-time boot and configuration fetch timing budgets |
| Page Write Cycle | 10 ms max - enables efficient multi-byte updates without per-byte overhead |
| Endurance | 100,000 write/erase cycles - supports field-upgradable systems over product lifetime |
| Data Retention | 10 years at 85°C - ensures long-term reliability in unpowered industrial environments |
| Supply Voltage | 5 V ±10% - compatible with legacy 5 V logic rails and mixed-voltage system backplanes |
| Standby Current | 100 µA CMOS - minimizes quiescent power in always-on monitoring subsystems |
Pinout & Package
AT28HC64B-90TU-T is packaged in a 28-lead Thin Small Outline Package (TSOP), JEDEC MO-183 compliant, 8 mm × 13.4 mm footprint, green (Pb/halide-free) construction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A12 | Address Inputs | 13-bit address bus selecting one of 8,192 memory locations |
| I/O0–I/O7 | Bidirectional Data Bus | Byte-wide parallel interface compatible with 8-bit microcontrollers and FPGAs |
| CE | Chip Enable | Active-low chip select enabling memory access; high disables outputs and reduces current |
| OE | Output Enable | Active-low output gate controlling data bus drive; used with CE for bus contention management |
| WE | Write Enable | Active-low signal initiating byte or page write; combined with CE for robust write control |
| VCC | Power Supply | +5 V ±10% supply; powers core logic and I/O buffers |
| GND | Ground Reference | Common return path for all signals and power |
| NC | No Connect | Unbonded pins (TSOP pins 1, 14, 27, 28); must remain floating |
Key Features
| Feature | Design Value |
|---|---|
| Page Write Operation | Writes 1–64 bytes in a single 10 ms cycle, reducing host CPU overhead vs. byte-by-byte writes |
| DATA Polling & Toggle Bit | Dual asynchronous write completion detection - eliminates fixed delays and improves system responsiveness |
| Software Data Protection (SDP) | User-configurable lock/unlock via 3-byte command sequence - prevents accidental writes during power transitions |
| Hardware Write Inhibit | VCC sense, 5 ms power-on delay, and 15 ns noise filtering prevent spurious writes in noisy industrial environments |
| Device Identification Area | 64-byte reserved EEPROM block (1FC0H–1FFFH) accessible at 12 V - enables unique device serialization and traceability |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Memory |
|---|---|
Use Scenario: Storing user-defined I/O mapping, PID tuning parameters, and alarm thresholds in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile configuration store accessed at power-up and during runtime parameter updates. Use Value: 100,000-cycle endurance and 10-year data retention ensure reliable operation across decades of factory automation use. | Use Scenario: Holding calibrated sensor offsets, gain coefficients, and safety-critical operational limits in diagnostic imaging equipment. IC Role / Device Role / Timing Role: Secure, tamper-resistant memory for FDA-regulated calibration data requiring audit trail integrity. Use Value: Software Data Protection (SDP) prevents unauthorized modification, while 90 ns read speed supports real-time calibration lookups. |
| Telecom Base Station Boot Code | Automotive Body Control Module (BCM) Settings |
Use Scenario: Storing bootloader images and FPGA configuration bitstreams in remote radio units operating in wide-temperature outdoor enclosures. IC Role / Device Role / Timing Role: Primary boot memory interfaced directly to ARM Cortex-M or RISC-V processors via parallel bus. Use Value: Industrial temperature range (−40°C to +85°C) and 5 V tolerance ensure robust startup under extreme thermal cycling. | Use Scenario: Retaining seat position presets, mirror angles, and lighting profiles across ignition cycles in premium vehicle BCMs. IC Role / Device Role / Timing Role: Low-power nonvolatile storage accessed only during initialization or user input events. Use Value: 100 µA standby current extends battery life during vehicle sleep mode without compromising recall accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ST M28W640ECB90N6 | 64 Mbit (8M × 8), 90 ns access, 3.3 V supply only - not 5 V compatible | Requires level-shifting in 5 V systems; higher density suits larger firmware images | Select only if migrating to 3.3 V architecture and needing >64 Kbit capacity |
| Microchip 28C64B-25J | 64 Kbit, 250 ns access, PLCC-32 package - slower and larger footprint than TSOP | Limited to legacy designs with PLCC sockets; no software data protection feature | Consider only for backward-compatible replacements where timing budget allows 250 ns latency |
Compared with ST M28W640ECB90N6 and Microchip 28C64B-25J, the AT28HC64B-90TU-T uniquely combines 5 V operation, 90 ns speed, TSOP-28 compactness, and integrated SDP - making it optimal for space-constrained, legacy 5 V industrial systems requiring secure, fast configuration storage.
Availability
AT28HC64B-90TU-T is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics equipment, telecom base stations, and automotive body control modules requiring stable component supply and long-term lifecycle support.
Supply support for AT28HC64B-90TU-T 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
Atmel Corporation (now part of Microchip Technology) is a semiconductor manufacturer specializing in microcontrollers, nonvolatile memory, and security ICs for industrial, automotive, and consumer applications.
The AT28HC64B belongs to Atmel's parallel EEPROM product line, designed for systems requiring direct bus interfacing, fast read/write performance, and robust data integrity in harsh environments.
FAQ
What is the maximum page write size supported by the AT28HC64B-90TU-T?
The AT28HC64B-90TU-T supports up to 64 bytes per page write operation. This is implemented using an internal 64-byte page register that latches addresses and data simultaneously, allowing burst programming without external buffering. Each byte must be loaded within 150 µs of the previous one (tBLC), and all bytes must reside on the same page defined by A6–A12. The AT28HC64B-90TU-T completes the full page write in ≤10 ms.
Does the AT28HC64B-90TU-T require a 12 V supply for any operation?
The AT28HC64B-90TU-T operates from a single 5 V ±10% supply for standard read/write functions. A 12 V ±0.5 V supply is required only for accessing the 64-byte device identification area (addresses 1FC0H–1FFFH) - this is optional and not needed for normal memory operations. All other features, including software data protection enable/disable sequences, function at 5 V.
How does the AT28HC64B-90TU-T detect write completion without polling the status register?
The AT28HC64B-90TU-T provides two hardware-based write completion indicators: DATA polling on I/O7 (returns complement of written data during write, true data after completion) and toggle-bit behavior on I/O6 (toggles between 0 and 1 during write, stabilizes after completion). Neither requires a status register - both operate directly on the data bus using standard read cycles, simplifying host firmware design.
Is the AT28HC64B-90TU-T pin-compatible with earlier AT28HC64A variants?
Yes, the AT28HC64B-90TU-T maintains identical pinout, timing, and electrical specifications with the AT28HC64A series across all packages (TSOP, SOIC, PLCC). Key improvements - including enhanced endurance (100,000 vs. 10,000 cycles), improved data retention, and added software data protection - are implemented without altering interface compatibility. Migration requires no PCB changes.
What is the purpose of the NC pins on the AT28HC64B-90TU-T TSOP package?
The AT28HC64B-90TU-T TSOP package has four NC (No Connect) pins: pins 1, 14, 27, and 28. These pins are physically present but internally unbonded and electrically isolated. They must remain unconnected - neither tied to VCC nor GND - to avoid unintended coupling or EMI. Their presence accommodates die pad layout constraints and ensures mechanical compatibility across Atmel's parallel EEPROM family.
AT28HC64B-90TU-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-TSSOP (0.465", 11.80mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 64Kbit
- Memory Organization:
- 8K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 10ms
- Access Time:
- 90 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-TSOP
AT28HC64B-90TU-T FAQ
1.How can I place an order for AT28HC64B-90TU-T through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC64B-90TU-T 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 AT28HC64B-90TU-T reliable?
The price and inventory of AT28HC64B-90TU-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28HC64B-90TU-T is usually 5 days.
3.What payment methods are accepted for AT28HC64B-90TU-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC64B-90TU-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC64B-90TU-T?
AT28HC64B-90TU-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC64B-90TU-T 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 AT28HC64B-90TU-T?
For technical support, including AT28HC64B-90TU-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC64B-90TU-T requirements.
6.How does Aetrix verify that AT28HC64B-90TU-T is sourced from the original manufacturer or authorized distributors?
All AT28HC64B-90TU-T 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 AT28HC64B-90TU-T meets industry standards.
7.What is the process for return or replacement of AT28HC64B-90TU-T?
All AT28HC64B-90TU-T units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC64B-90TU-T, 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 AT28HC64B-90TU-T part is unused and in its original packaging.
Return procedure for AT28HC64B-90TU-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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