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Microchip Technology AT28HC64B-70JI
- Part No.:
- AT28HC64B-70JI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT28HC64B-70JI.pdf
- Description:
- IC EEPROM 64KBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:1,765
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Product details
Overview
AT28HC64B-70JI from Atmel is a 64 Kbit (8K × 8) parallel EEPROM with 70 ns read access time, JEDEC-standard byte-wide pinout, and industrial temperature range (–40°C to +85°C). It supports hardware/software data protection, 64-byte page write, DATA polling, and toggle-bit write completion detection. Used in embedded systems for firmware storage, configuration retention, and calibration data logging.
For engineers reviewing the AT28HC64B-70JI datasheet, AT28HC64B-70JI pinout, AT28HC64B-70JI application, or AT28HC64B-70JI equivalent, key selection criteria include its 70 ns access time, 10 ms page write cycle, CMOS/TTL compatibility, 5 V ±10% supply, and dual write-detection methods (I/O7 polling & I/O6 toggle).
Technical Context
The AT28HC64B-70JI operates as a parallel-access nonvolatile memory with static RAM-like read/write interface-no external timing components required. Its internal 64-byte page register latches address and data during page writes, freeing the bus for concurrent operations while an internal timer manages programming.
Write completion is verified via two independent mechanisms: DATA polling on I/O7 (complement-to-data during write, true data after completion) and toggle-bit behavior on I/O6 (toggling until write ends). 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 boot code, device ID, or parameter tables in microcontroller-based systems |
| Read Access Time | 70 ns maximum - enables direct interfacing with 10–14 MHz microcontrollers without wait states |
| Page Write Cycle | 10 ms maximum - allows burst programming of up to 64 bytes per operation, reducing host CPU overhead |
| Supply Voltage | 5 V ±10% - compatible with legacy 5 V logic families and mixed-voltage system backplanes |
| Standby Current | 100 µA CMOS - supports low-power modes in battery-backed or energy-constrained applications |
| Endurance | 100,000 write/erase cycles - suitable for field-updatable firmware or frequently modified configuration registers |
| Data Retention | 10 years at 85°C - ensures long-term reliability in industrial control and automotive under-hood modules |
Pinout & Package
AT28HC64B-70JI is supplied in a 32-lead Plastic J-Leaded Chip Carrier (PLCC) package with gull-wing leads, compliant with JEDEC MS-016 (Variation AE), and rated for industrial temperature operation (–40°C to +85°C).
| 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 writes |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel interface for read/write; I/O7 used for DATA polling, I/O6 for toggle-bit write status |
| CE | Chip Enable | Active-low chip select; must be low with OE low and WE high for read; low with OE high and WE low for write |
| OE | Output Enable | Active-low output control; disables outputs (high-Z) when high, preventing bus contention during writes |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; rising edge initiates internal programming |
| VCC | Power Supply | +5 V ±10% supply; powers core logic and I/O buffers; VCC sense circuitry inhibits writes below ~3.8 V |
| GND | Ground Reference | Signal and power return path; decoupling capacitor required near VCC pin for stable operation |
| NC | No Connect | Pins 1 and 17 are unconnected - must remain floating per PLCC package specification |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC Byte-Wide Pinout | Direct drop-in replacement for SRAM and older EPROMs in existing 28-pin or 32-pin sockets, minimizing PCB redesign |
| 64-Byte Page Write | Reduces host-side write transaction count by up to 64× versus byte-write mode, accelerating firmware updates and parameter saves |
| Hardware + Software Data Protection | VCC sensing, noise filtering, and user-configurable software lock prevent accidental writes during power transitions or noise events |
| Dual Write Completion Detection | Simultaneous support for I/O7 DATA polling and I/O6 toggle-bit enables robust, interrupt-driven write synchronization |
| Industrial Temperature Range | Guaranteed operation from –40°C to +85°C supports deployment in motor drives, PLCs, and outdoor telecom equipment |
| Green (Pb/Halide-Free) Option | JU suffix variant available - meets RoHS Directive 2011/65/EU and JEDEC J-STD-609A Class 2 moisture sensitivity |
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 factory automation. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed during power-up and runtime reconfiguration; 70 ns read speed ensures real-time parameter retrieval. Use Value: Eliminates need for battery-backed SRAM; 100,000-cycle endurance supports field recalibration over 10+ years of service life. |
Use Scenario: Retaining sensor calibration coefficients, patient history flags, and safety-critical settings in portable diagnostic instruments. IC Role / Device Role / Timing Role: Secure, tamper-resistant storage with software data protection enabled to prevent unauthorized parameter modification. Use Value: Ensures regulatory compliance (IEC 62304) via guaranteed 10-year data retention and write-protection during power brownouts. |
| Automotive Body Control Module (BCM) | Networking Equipment Bootloader Storage |
Use Scenario: Holding door lock logic, lighting profiles, and seat position presets in automotive BCMs operating across extended temperature ranges. IC Role / Device Role / Timing Role: Industrial-grade EEPROM interfaced directly to 8-bit MCU data bus; withstands thermal cycling and ESD per ISO 10605. Use Value: Meets AEC-Q100 stress test requirements for Grade 3 (–40°C to +85°C); green packaging aligns with OEM environmental mandates. |
Use Scenario: Storing bootloader images and network stack configuration in enterprise switches and routers requiring field firmware upgrades. IC Role / Device Role / Timing Role: Parallel-boot memory mapped into MCU address space; 64-byte page writes accelerate OTA update verification and commit phases. Use Value: Reduces upgrade time by >90% vs. byte-write; DATA polling enables deterministic recovery from partial write failures. |
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 | 64 Mbit (8M × 8), 120 ns access, 3.3 V core with 5 V I/O tolerance; no software data protection | Higher density for larger boot images; lacks SDP and toggle-bit detection | Choose when migrating to 3.3 V systems and needing greater capacity, but accept reduced write-safety features |
| Microchip 25LC640A-I/P | 64 Kbit SPI EEPROM, 5 MHz interface, 5 ms write cycle, 2.5–5.5 V supply; no parallel bus or page write | Reduced pin count (8-pin PDIP), lower power, but serial interface adds MCU overhead | Prefer for space-constrained designs where board area or wiring complexity outweighs parallel-speed advantage |
Compared with ST M28W640ECT and Microchip 25LC640A-I/P, the AT28HC64B-70JI uniquely balances 70 ns parallel access, integrated software/hardware write protection, and JEDEC-compatible pinout - making it optimal for legacy 5 V embedded systems requiring field-upgradable, tamper-resistant configuration storage without architecture change.
Availability
AT28HC64B-70JI is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics equipment, automotive body control modules, and networking bootloaders requiring stable component supply across extended lifecycle programs.
Supply support for AT28HC64B-70JI 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 fabless semiconductor company specializing in microcontrollers, nonvolatile memory, and secure authentication ICs for industrial, automotive, and consumer markets.
The AT28HC64B product line was designed for high-reliability, pin-compatible replacement of EPROM and battery-backed SRAM in 5 V embedded systems - emphasizing write safety, industrial temperature operation, and seamless integration into legacy parallel bus architectures.
FAQ
What is the maximum page write cycle time for AT28HC64B-70JI?
The AT28HC64B-70JI has a maximum page write cycle time of 10 ms under standard conditions. This value is specified in the AC Write Characteristics table and applies to all 1–64 byte writes within a single page. The faster 2 ms option requires the AT28HC64BF variant, not the AT28HC64B-70JI.
Does AT28HC64B-70JI support both hardware and software data protection?
Yes, AT28HC64B-70JI implements dual-layer protection: hardware features include VCC sensing (<3.8 V inhibit), 5 ms power-on delay, and noise filtering on WE/CE inputs; software data protection (SDP) is user-enabled via a three-byte command sequence to addresses 1555H, 0AAAH, and 1555H - and remains active through power cycles.
Which package type does AT28HC64B-70JI use?
AT28HC64B-70JI uses a 32-lead Plastic J-Leaded Chip Carrier (PLCC) package, designated as "32J" in Atmel's ordering information. It conforms to JEDEC MS-016, Variation AE, with pins 1 and 17 designated as No Connect (NC).
Can AT28HC64B-70JI be used in place of standard SRAM for read operations?
Yes, AT28HC64B-70JI is accessed like Static RAM during reads: with CE and OE low and WE high, valid data appears on I/O0–I/O7 within 70 ns. Its TTL/CMOS-compatible inputs and outputs allow direct connection to 8-bit microcontrollers without level-shifting or glue logic.
How is write completion detected on AT28HC64B-70JI?
AT28HC64B-70JI provides two independent methods: DATA polling monitors I/O7 (complement of written data during write, true data after completion), and the toggle bit monitors I/O6 (toggles between 0/1 until write ends, then stabilizes). Both can be polled at any time during the write cycle.
AT28HC64B-70JI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- 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)
AT28HC64B-70JI FAQ
1.How can I place an order for AT28HC64B-70JI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC64B-70JI 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-70JI reliable?
The price and inventory of AT28HC64B-70JI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28HC64B-70JI is usually 5 days.
3.What payment methods are accepted for AT28HC64B-70JI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC64B-70JI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC64B-70JI?
AT28HC64B-70JI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC64B-70JI 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-70JI?
For technical support, including AT28HC64B-70JI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC64B-70JI requirements.
6.How does Aetrix verify that AT28HC64B-70JI is sourced from the original manufacturer or authorized distributors?
All AT28HC64B-70JI 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-70JI meets industry standards.
7.What is the process for return or replacement of AT28HC64B-70JI?
All AT28HC64B-70JI units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC64B-70JI, 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-70JI part is unused and in its original packaging.
Return procedure for AT28HC64B-70JI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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