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Microchip Technology AT28HC64BF-90SU
- Part No.:
- AT28HC64BF-90SU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
AT28HC64BF-90SU.pdf
- Description:
- IC EEPROM 64KBIT PARALLEL 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,731
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Product details
Overview
AT28HC64BF-90SU from Atmel is a 64 Kbit (8K × 8) parallel EEPROM with JEDEC-standard byte-wide pinout, 90 ns read access time, 2 ms maximum page write cycle, and industrial temperature range (−40°C to +85°C). It supports hardware/software data protection, DATA polling, and toggle-bit write completion detection for embedded control and firmware storage applications.
For engineers reviewing the AT28HC64BF-90SU datasheet, AT28HC64BF-90SU pinout, AT28HC64BF-90SU application, or AT28HC64BF-90SU equivalent, key selection considerations include page-write timing (≤2 ms), CMOS/TTL compatibility, 5 V ±10% single-supply operation, and green (Pb/halide-free) SOIC-28 packaging.
Technical Context
The AT28HC64BF-90SU operates as a static RAM-compatible nonvolatile memory: reads require CE and OE low with WE high; writes initiate on WE or CE low pulse while OE is high. Its internal 64-byte page register latches up to 64 bytes simultaneously, freeing the address/data bus during internal programming.
Write completion is verified via I/O7 DATA polling (complement-to-true transition) or I/O6 toggle-bit behavior. Hardware protection includes VCC sense (<3.8 V inhibits write), 5 ms power-on delay, and noise filtering (<15 ns pulses ignored); software protection uses a three-byte command sequence at addresses 1555H/0AAAH/1555H.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8,192 × 8 bits) - sufficient for boot code, calibration tables, or device configuration in microcontroller systems. |
| Read Access Time | 90 ns max - enables direct replacement of SRAM in legacy 8-bit bus systems without timing redesign. |
| Page Write Cycle | 2 ms max - allows efficient bulk updates (1–64 bytes/page) without per-byte overhead, reducing firmware update latency. |
| Supply Voltage | 5 V ±10% - compatible with standard TTL/CMOS logic rails and eliminates need for auxiliary voltage regulators. |
| Standby Current | 100 µA CMOS - supports low-power modes in battery-backed or energy-sensitive industrial controllers. |
| Endurance | 100,000 write cycles - ensures reliable field reprogramming over product lifetime in telemetry or sensor nodes. |
| Data Retention | 10 years - maintains stored parameters across extended shelf life or unpowered deployment intervals. |
Pinout & Package
AT28HC64BF-90SU is supplied in a 28-lead, 0.300" wide plastic gull-wing small outline (SOIC) package compliant with JEDEC MS-013, RoHS-compliant and Pb/halide-free.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A12 | Address Inputs | 13-bit address bus selecting one of 8,192 memory locations; A6–A12 define page boundaries for 64-byte page writes. |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel interface for read/write operations; supports DATA polling on I/O7 and toggle-bit detection on I/O6. |
| CE | Chip Enable | Active-low chip select; must be low for read/write access; high state forces outputs to high-impedance and disables writes. |
| OE | Output Enable | Active-low output control; used with CE to manage bus contention; high state disables output drivers. |
| WE | Write Enable | Active-low write strobe; initiates byte or page write when CE is low and OE is high; supports WE- or CE-controlled write modes. |
| VCC | Power Supply | +5 V ±10% supply; powers core logic and memory array; internal VCC sense prevents writes below 3.8 V. |
| GND | Ground Reference | Signal and power return path; decoupling capacitor required near VCC pin for stable read/write timing. |
| NC | No Connect | Unbonded pins (e.g., Pin 1, Pin 14 in SOIC top view); must remain unconnected to avoid signal integrity issues. |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC Byte-wide Pinout | Direct drop-in replacement for industry-standard 28-pin parallel EEPROMs and SRAMs without PCB layout changes. |
| 64-byte Page Write | Reduces firmware update time by up to 64× vs. byte-write mode; internal latching frees host bus for concurrent tasks. |
| Hardware + Software Protection | VCC sensing, 5 ms power-up delay, and programmable SDP prevent accidental writes during brown-out or reset sequences. |
| DATA Polling & Toggle Bit | Two independent, pin-level methods (I/O7 complement, I/O6 toggle) enable robust write-status monitoring without external timers or interrupts. |
| Industrial Temperature Range | −40°C to +85°C operation validated across full voltage and timing specs - suitable for factory automation and outdoor metering. |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Data |
|---|---|
Use Scenario: Storing I/O mapping, PID tuning parameters, and alarm thresholds in programmable logic controllers deployed in harsh factory environments. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed via 8-bit parallel bus; 90 ns read speed supports real-time scan-cycle execution. Use Value: 100,000 write cycles and 10-year data retention ensure parameter integrity across decades of maintenance-free operation. | Use Scenario: Holding patient-specific calibration coefficients and safety-critical operational limits in portable diagnostic equipment. IC Role / Device Role / Timing Role: Secure firmware parameter store with hardware/software write protection preventing corruption during power transitions. Use Value: Dual write-completion detection (DATA polling + toggle bit) guarantees deterministic update confirmation for FDA-regulated validation protocols. |
| Automotive Body Control Module | Telecom Base Station Settings |
Use Scenario: Retaining window position, mirror angle, and lighting profiles in vehicle body control units subject to frequent ignition cycling. IC Role / Device Role / Timing Role: Low-power (100 µA standby) EEPROM interfaced to 8051-class MCUs; 5 V supply matches legacy automotive MCU rails. Use Value: VCC-sense and 5 ms power-on delay eliminate spurious writes during cold-cranking voltage sag (down to 3.8 V). | Use Scenario: Storing RF channel plans, gain settings, and regulatory compliance flags in outdoor telecom infrastructure with wide ambient temperature swings. IC Role / Device Role / Timing Role: Industrial-grade (−40°C to +85°C) parallel EEPROM supporting hot-swap configuration reloads via backplane bus. Use Value: Green (Pb/halide-free) SOIC-28 packaging meets RoHS requirements for global telecom deployments without derating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ST M28W640ECT-90N6T | 64 Mbit (8M × 8), 90 ns access, 3.3 V supply only - not 5 V compatible. | Requires level-shifting or voltage rail redesign; unsuitable for legacy 5 V systems. | Select only if migrating to 3.3 V architecture and higher density is needed. |
| Microchip 25LC640-I/P | 64 Kbit SPI interface, 5 V tolerant, 5 MHz max clock - serial, not parallel. | Needs MCU SPI peripheral and software driver; slower effective throughput than parallel 90 ns reads. | Choose for space-constrained designs where pin count reduction outweighs speed penalty. |
Compared with ST M28W640ECT-90N6T and Microchip 25LC640-I/P, the AT28HC64BF-90SU delivers pin-compatible 5 V parallel EEPROM functionality without voltage translation or interface protocol conversion - preserving legacy system timing and minimizing firmware changes.
Availability
AT28HC64BF-90SU is available at Aetrix Electronics and suitable for industrial PLC configuration storage, medical device calibration data retention, and automotive body control module parameter backup requiring stable component supply across extended production lifecycles.
Supply support for AT28HC64BF-90SU 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) designed high-reliability nonvolatile memory and microcontroller solutions for industrial, automotive, and communications markets before its 2016 acquisition.
The AT28HC64BF product line targets legacy 8-bit parallel bus systems requiring drop-in EEPROM replacements with enhanced endurance, write protection, and industrial temperature support - especially where SRAM compatibility and JEDEC pinout are mandatory.
FAQ
What is the maximum page write cycle time for AT28HC64BF-90SU?
The AT28HC64BF-90SU has a maximum page write cycle time of 2 ms, as specified in the AC characteristics table. This applies to all 1–64 byte writes within a single 64-byte page (defined by A6–A12). The timing is internally controlled and does not require external wait-state generation. AT28HC64BF-90SU achieves this performance using Atmel's advanced CMOS process with integrated charge-pump programming circuitry.
Does AT28HC64BF-90SU support both hardware and software write protection?
Yes, AT28HC64BF-90SU implements dual-layer protection: hardware features include VCC sensing (<3.8 V inhibits writes), 5 ms power-on delay, and noise filtering on WE/CE inputs; software protection uses a user-configurable three-byte command sequence (AAH/55H/A0H) to enable/disable write lock. AT28HC64BF-90SU ships with software data protection disabled but retains full hardware safeguards active at all times.
What package type is used for AT28HC64BF-90SU?
AT28HC64BF-90SU is packaged in a 28-lead, 0.300" wide plastic gull-wing small outline (SOIC) package, designated as 28S per Atmel's ordering guide. It complies with JEDEC MS-013, features Pb/halide-free construction, and measures 17.7–18.1 mm × 7.4–7.6 mm × 2.35–2.65 mm (L × W × H). This SOIC variant is pin-compatible with other 28-pin parallel EEPROMs in PDIP and TSOP footprints.
Can AT28HC64BF-90SU be used as a direct replacement for standard SRAM in existing designs?
Yes, AT28HC64BF-90SU is accessed like Static RAM for reads and writes - CE and OE low with WE high for reads; WE or CE low with OE high for writes - requiring no external timing logic. Its 90 ns read access and JEDEC byte-wide pinout allow drop-in replacement in many 8-bit bus systems. However, write cycles take up to 2 ms, so AT28HC64BF-90SU requires host software to poll I/O7 or monitor I/O6 to detect completion before initiating subsequent accesses.
What is the purpose of the extra 64 bytes of EEPROM in AT28HC64BF-90SU?
The AT28HC64BF-90SU includes an additional 64 bytes of EEPROM (addresses 1FC0H–1FFFH) accessible by raising A9 to 12.0 V ±0.5 V. These bytes are intended for device identification, manufacturing traceability, or customer-specific metadata storage. They operate identically to main array bytes but require elevated voltage on A9 for access - a feature distinct from the main 64 Kbit array and not activated during normal 5 V operation.
AT28HC64BF-90SU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- 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-SOIC
AT28HC64BF-90SU FAQ
1.How can I place an order for AT28HC64BF-90SU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC64BF-90SU 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 AT28HC64BF-90SU reliable?
The price and inventory of AT28HC64BF-90SU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28HC64BF-90SU is usually 5 days.
3.What payment methods are accepted for AT28HC64BF-90SU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC64BF-90SU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC64BF-90SU?
AT28HC64BF-90SU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC64BF-90SU 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 AT28HC64BF-90SU?
For technical support, including AT28HC64BF-90SU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC64BF-90SU requirements.
6.How does Aetrix verify that AT28HC64BF-90SU is sourced from the original manufacturer or authorized distributors?
All AT28HC64BF-90SU 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 AT28HC64BF-90SU meets industry standards.
7.What is the process for return or replacement of AT28HC64BF-90SU?
All AT28HC64BF-90SU units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC64BF-90SU, 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 AT28HC64BF-90SU part is unused and in its original packaging.
Return procedure for AT28HC64BF-90SU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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