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Microchip Technology AT28HC64BF-70JU
- Part No.:
- AT28HC64BF-70JU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT28HC64BF-70JU.pdf
- Description:
- IC EEPROM 64KBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:1,769
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Product details
Overview
AT28HC64BF-70JU from Microchip Technology (formerly Atmel) is a 64 Kbit (8K × 8) parallel EEPROM with JEDEC-standard byte-wide pinout, 70 ns read access time, single 5 V ±10% supply, and industrial temperature range (–40°C to +85°C). It supports automatic page write of up to 64 bytes, hardware/software data protection, and DATA polling/toggle bit for write completion detection - used in embedded system configuration storage, firmware parameter retention, and industrial controller nonvolatile memory.
For engineers reviewing the AT28HC64BF-70JU datasheet, AT28HC64BF-70JU pinout, AT28HC64BF-70JU application, or AT28HC64BF-70JU equivalent, key selection criteria include verified 70 ns read timing, 2 ms max page write cycle, CMOS/TTL-compatible I/O, 100 µA standby current, and green PLCC-32 packaging with A9 high-voltage device identification capability.
Technical Context
The AT28HC64BF-70JU operates as a parallel-access EEPROM with static RAM-like read/write interface - no external timing components required. Its internal 64-byte page register latches addresses and data during page writes, freeing the bus for concurrent operations while an internal timer manages programming.
Write completion is confirmed via dual methods: DATA polling on I/O7 (complement-to-data during write, true data after completion) and toggle-bit behavior on I/O6. Hardware protection includes VCC sense (<3.8 V inhibit), 5 ms power-on delay, and noise filtering on WE/CE inputs; software protection uses a three-step 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 flags, calibration tables, or device ID storage in resource-constrained systems. |
| Read Access Time | 70 ns maximum - enables direct replacement of SRAM in legacy 5 MHz bus systems without timing redesign. |
| Page Write Cycle | 2 ms maximum - allows efficient bulk updates (e.g., logging 64 sensor samples) with minimal CPU intervention. |
| Supply Voltage | 5 V ±10% - compatible with standard TTL/CMOS logic rails; eliminates need for dedicated EEPROM voltage regulators. |
| Standby Current | 100 µA (CMOS mode) - supports low-power operation in battery-backed industrial controllers and metering devices. |
| Endurance | 100,000 write/erase cycles - ensures reliable field updates over 10+ years in programmable logic controllers and test equipment. |
| Data Retention | 10 years at 85°C - validated for long-term storage in automotive under-hood modules and industrial automation panels. |
Pinout & Package
AT28HC64BF-70JU is packaged in a 32-lead Plastic J-Leaded Chip Carrier (PLCC), JEDEC MS-016 compliant, with lead coplanarity ≤0.102 mm and green (Pb/halide-free) finish. Pin 1 identifier located at corner with 45° chamfer.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A12 | Address Inputs | 13-bit address bus supporting full 8K-word addressing; A6–A12 define page boundaries for 64-byte writes. |
| I/O0–I/O7 | Bidirectional Data Bus | Byte-wide parallel interface; I/O7 used for DATA polling, I/O6 for toggle-bit write status indication. |
| CE | Chip Enable | Active-low chip select; must be low with OE low and WE high for read; inhibits writes when high. |
| OE | Output Enable | Active-low output control; places I/O pins in high-Z state when high, preventing bus contention. |
| WE | Write Enable | Active-low write strobe; initiates byte or page write on falling edge; combined with CE for dual-control write safety. |
| VCC / GND | Power Supply | Single 5 V ±10% supply; GND referenced for all I/O and internal logic; no separate VPP required for normal operation. |
| A9 (with 12 V) | Device ID Access | When raised to 12.0 V ±0.5 V, enables access to dedicated 64-byte ID region (1FC0H–1FFFH) for serialization or firmware binding. |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC Byte-Wide Pinout | Direct drop-in compatibility with legacy SRAM and EPROM sockets in industrial control backplanes and telecom line cards. |
| Page Write (1–64 bytes) | Reduces firmware update latency by >30× vs. byte-by-byte writes - critical for real-time recalibration in motor drives. |
| Hardware + Software Data Protection | Prevents corruption during brown-out or reset: VCC sense blocks writes below 3.8 V; SDP command sequence locks memory until re-enabled. |
| DATA Polling & Toggle Bit | Eliminates need for fixed write delays - host CPU polls I/O7 or monitors I/O6 toggling to synchronize next access, improving throughput. |
| Industrial Temperature Range | Validated operation from –40°C to +85°C - suitable for deployment in outdoor base stations, factory-floor PLCs, and railway signaling units. |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Data Retention |
|---|---|
Use Scenario: Storing I/O mapping, PID tuning parameters, and alarm thresholds in programmable logic controllers deployed in manufacturing cells. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed during power-up and runtime parameter updates via parallel bus. Use Value: 70 ns read speed ensures deterministic boot within 100 µs; 100,000-cycle endurance supports daily field recalibration over 10-year product life. |
Use Scenario: Holding factory-calibrated sensor offsets and gain coefficients in portable ultrasound and ECG monitors. IC Role / Device Role / Timing Role: Secure parameter store with software data protection enabled to prevent accidental overwrite during battery swaps or firmware upgrades. Use Value: 100 µA standby current extends battery life between calibrations; 10-year data retention meets FDA Class II device archival requirements. |
| Telecom Line Card Bootloader Storage | Automotive Body Control Module Settings |
Use Scenario: Storing bootloader code and hardware revision identifiers on telecom DSLAM and ONU line cards operating in central office environments. IC Role / Device Role / Timing Role: Parallel EEPROM interfaced directly to microcontroller's external memory bus for fast, deterministic boot execution. Use Value: JEDEC pinout allows reuse of existing PCB footprints; 2 ms page write enables rapid field-upgrade of bootloader images without service interruption. |
Use Scenario: Saving user preferences (seat position, mirror angle, lighting profiles) and diagnostic trouble codes in automotive BCMs. IC Role / Device Role / Timing Role: Low-power nonvolatile memory accessed during ignition-on initialization and periodic DTC logging. Use Value: 5 V ±10% supply tolerance accommodates vehicle battery fluctuations; industrial temp rating covers under-dash mounting locations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ST M48T02-70F1 | Real-time clock + 2 Kbit NV SRAM integrated; no page write; 70 ns access but 10 mA active current. | Used where time-stamped logging is required; not suitable for pure configuration storage due to smaller capacity and higher power. | Select when RTC functionality is mandatory and 64 Kbit capacity is unnecessary. |
| ON Semiconductor CAT28C64B-70JI | Same 64 Kbit size, 70 ns access, and PLCC-32 package; identical pinout and software protection algorithm; 50 µA lower standby current (50 µA). | Drop-in replacement with improved power efficiency; same industrial temp range and page write timing. | Preferred for new designs targeting lowest possible standby power without changing layout or firmware. |
Compared with ST M48T02-70F1, AT28HC64BF-70JU provides 32× more memory and lower active power, but lacks RTC; versus CAT28C64B-70JI, it offers identical functionality with slightly higher standby current, making CAT28C64B-70JI optimal for ultra-low-power deployments.
Availability
AT28HC64BF-70JU is available at Aetrix Electronics and suitable for industrial PLC configuration storage, medical device calibration data retention, and telecom line card bootloader storage requiring stable component supply across extended production lifecycles.
Supply support for AT28HC64BF-70JU 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 acquired Atmel in 2016 and maintains its legacy parallel EEPROM portfolio with full datasheet, reliability, and packaging continuity.
The AT28HC64BF series was designed for industrial and telecom applications requiring robust, pin-compatible EEPROM replacements for aging EPROM/SRAM-based systems with minimal redesign effort.
FAQ
What is the maximum page write cycle time for AT28HC64BF-70JU?
The AT28HC64BF-70JU 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 the same page (defined by A6–A12). The timing is internally controlled and does not require external wait-state generation - the host detects completion via DATA polling on I/O7 or toggle-bit monitoring on I/O6. This value is guaranteed across the full industrial temperature range.
Does AT28HC64BF-70JU require a high-voltage supply for normal operation?
No, AT28HC64BF-70JU operates from a single 5 V ±10% supply for all standard read and write functions. A 12.0 V ±0.5 V supply is required only for accessing the dedicated 64-byte device identification memory region (addresses 1FC0H–1FFFH) by raising A9 to that voltage level. Normal configuration storage, firmware parameter retention, and page writes use only VCC = 5 V.
How is software data protection enabled on AT28HC64BF-70JU?
Software data protection (SDP) on AT28HC64BF-70JU is enabled by writing three specific bytes - 0xAA to address 0x1555, 0x55 to address 0x0AAA, then 0xA0 to address 0x1555 - followed by a standard write to any address. After the write cycle completes, the entire memory array becomes protected. Subsequent writes require repeating this 3-byte sequence before each data byte or page. AT28HC64BF-70JU ships with SDP disabled.
What package type does AT28HC64BF-70JU use, and is it RoHS compliant?
AT28HC64BF-70JU uses a 32-lead Plastic J-Leaded Chip Carrier (PLCC) package, designated "JU" in the ordering code. It conforms to JEDEC MS-016, Variation AE, and features green (Pb/halide-free) construction per RoHS Directive 2011/65/EU. Lead coplanarity is guaranteed ≤0.102 mm, and mold protrusion complies with JEDEC limits.
Can AT28HC64BF-70JU be used as a direct replacement for older EPROMs like 27C64?
No, AT28HC64BF-70JU is not a pin-compatible or functional replacement for UV-erasable EPROMs such as the 27C64. While both are 64 Kbit parallel memories, the AT28HC64BF-70JU is an electrically erasable EEPROM with different timing (e.g., WE/CE dual-control write), no VPP pin, and built-in write protection. It replaces battery-backed SRAM or earlier EEPROMs (e.g., AT28C64B), not EPROMs requiring UV erasure and 12.5 V programming.
AT28HC64BF-70JU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- 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:
- 70 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (13.97x11.43)
AT28HC64BF-70JU FAQ
1.How can I place an order for AT28HC64BF-70JU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC64BF-70JU 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-70JU reliable?
The price and inventory of AT28HC64BF-70JU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28HC64BF-70JU is usually 5 days.
3.What payment methods are accepted for AT28HC64BF-70JU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC64BF-70JU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC64BF-70JU?
AT28HC64BF-70JU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC64BF-70JU 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-70JU?
For technical support, including AT28HC64BF-70JU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC64BF-70JU requirements.
6.How does Aetrix verify that AT28HC64BF-70JU is sourced from the original manufacturer or authorized distributors?
All AT28HC64BF-70JU 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-70JU meets industry standards.
7.What is the process for return or replacement of AT28HC64BF-70JU?
All AT28HC64BF-70JU units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC64BF-70JU, 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-70JU part is unused and in its original packaging.
Return procedure for AT28HC64BF-70JU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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