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Microchip Technology AT28HC256F-12JC
- Part No.:
- AT28HC256F-12JC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT28HC256F-12JC.pdf
- Description:
- IC EEPROM 256KBIT PAR 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:4,404
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Product details
Overview
AT28HC256F-12JC from Atmel is a 256 Kbit (32K × 8) parallel EEPROM with JEDEC-standard byte-wide pinout, 120 ns maximum access time, 3 ms fast page write cycle, and industrial temperature range (–40°C to +85°C). It operates from a single 5V ±10% supply and supports hardware/software data protection for embedded control and firmware storage applications.
For engineers reviewing the AT28HC256F-12JC datasheet, AT28HC256F-12JC pinout, AT28HC256F-12JC application, or AT28HC256F-12JC equivalent, key selection criteria include verified 3 ms page write timing, 10⁴/10⁵ endurance rating, DATA Polling/Toggle Bit write completion detection, and compatibility with legacy SRAM-based memory interfaces in industrial controllers and instrumentation systems.
Technical Context
The AT28HC256F-12JC implements a CMOS-based parallel EEPROM architecture with internal 64-byte page latching and autonomous internal control timer for self-timed write operations. Its dual-line chip enable (CE) and output enable (OE) logic enables bus contention avoidance in multi-device systems.
It supports three distinct write modes-byte, page, and software chip erase-with page write requiring A6–A14 stable across successive WE transitions and tBLC ≤150 µs between bytes. DATA Polling on I/O7 and Toggle Bit on I/O6 provide deterministic end-of-write detection without external timing dependencies.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8), directly replaceable for SRAM-based boot code storage |
| Access Time | 120 ns max - meets timing budget for 8-bit microcontroller address/data bus cycles |
| Page Write Cycle | 3 ms max - reduces firmware update latency vs. standard 10 ms variant |
| Endurance | 10⁴ or 10⁵ write/erase cycles - validated for field-upgradable device configuration tables |
| Data Retention | 10 years at 85°C - ensures long-term reliability in unattended industrial deployments |
| Supply Voltage | 5 V ±10% - interoperable with legacy 5V TTL/CMOS logic families without level shifting |
| Operating Temp | –40°C to +85°C - qualified for industrial control cabinets and outdoor telemetry units |
Pinout & Package
AT28HC256F-12JC is packaged in a 28-lead plastic gull-wing small outline (SOIC) package (28S), 0.300" body width, JEDEC MS-013 compliant, with lead finish Pb/Halide-free per green packaging option.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K-word addressing; A6–A14 define page boundaries for 64-byte writes |
| I/O0–I/O7 | Bidirectional Data Bus | Byte-wide parallel interface compatible with 8-bit microcontrollers; supports true read/write without external latches |
| CE | Chip Enable | Active-low global select; when high, places outputs in high-impedance state and inhibits all writes |
| OE | Output Enable | Active-low read control; used with CE for bus contention management during mixed read/write operations |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; rising edge initiates internal programming timer |
| VCC, GND | Power Supply | Single 5V supply with <3 mA standby current; VCC sense circuitry disables writes below 3.8V |
Key Features
| Feature | Design Value |
|---|---|
| Fast Page Write (3 ms) | Reduces firmware update time by 70% vs. 10 ms standard variant, critical for field-deployed devices with limited maintenance windows |
| DATA Polling & Toggle Bit | Enables real-time write status monitoring via I/O7 complement or I/O6 toggling - eliminates need for fixed delay timers in host firmware |
| Hardware + Software Data Protection | VCC sense, noise filtering, and 3-byte SDP command sequence prevent accidental writes during power transitions or EMI events |
| 64-byte Page Register | Allows burst loading of up to 64 bytes before internal write begins - frees address/data bus for concurrent system tasks |
| Extra 64-byte ID EEPROM | Dedicated user-accessible memory block (7FC0H–7FFFH) for device serialization, calibration data, or revision tracking |
Applications
| Industrial PLC Firmware Storage | Medical Device Configuration Memory |
|---|---|
Use Scenario: Storing ladder logic programs and I/O mapping tables in programmable logic controllers deployed in factory automation lines. IC Role / Device Role / Timing Role: Nonvolatile program memory accessed as SRAM-equivalent during boot and runtime reconfiguration. Use Value: 120 ns access time ensures no CPU wait states; 3 ms page write enables rapid firmware patching during scheduled maintenance windows. | Use Scenario: Holding calibrated sensor offsets, alarm thresholds, and user preferences in portable diagnostic equipment subject to frequent battery cycling. IC Role / Device Role / Timing Role: Parameter retention memory with guaranteed 10-year data integrity at 85°C ambient. Use Value: Hardware write inhibit and VCC-sense protection prevent corruption during brown-out conditions common in battery-powered operation. |
| Avionics Data Logging Buffer | Test Equipment Calibration Storage |
Use Scenario: Capturing flight-critical sensor snapshots in airborne data acquisition modules operating across –40°C to +85°C thermal profiles. IC Role / Device Role / Timing Role: High-reliability nonvolatile buffer supporting periodic timestamped writes under vibration and EMI stress. Use Value: Toggle Bit detection allows deterministic write completion verification without adding external watchdog or timeout logic. | Use Scenario: Storing NIST-traceable calibration coefficients and date stamps in benchtop multimeters and signal generators. IC Role / Device Role / Timing Role: Secure, tamper-resistant memory with software data protection enabled to prevent unauthorized parameter modification. Use Value: 3-byte SDP enable/disable sequence ensures only authenticated service tools can alter calibration data. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28HC256-12JC | 10 ms page write cycle; same pinout, voltage, and temperature rating | Suitable where firmware update speed is non-critical and cost optimization is prioritized | Select AT28HC256F-12JC when sub-5 ms write latency is required; otherwise AT28HC256-12JC offers identical functionality at lower unit cost |
| MN5Q25612J | 120 ns access, 5 ms page write, 3.3V/5V dual-supply support, different pinout (28-pin TSOP) | Requires PCB layout change; adds flexibility for future 3.3V system migration | Choose MN5Q25612J only if 3.3V compatibility or smaller TSOP footprint is mandatory; not drop-in compatible |
Compared with AT28HC256-12JC and MN5Q25612J, the AT28HC256F-12JC uniquely delivers the fastest verified 3 ms page write within the JEDEC-standard SOIC-28 footprint, making it optimal for time-constrained field updates while maintaining full backward compatibility with legacy 5V designs.
Availability
AT28HC256F-12JC is available at Aetrix Electronics and suitable for industrial control, medical instrumentation, avionics data logging, and test equipment calibration requiring stable component supply across extended product lifecycles.
Supply support for AT28HC256F-12JC 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 secure authentication ICs.
The AT28HC256 product line was designed for high-reliability, pin-compatible replacement of EPROM and battery-backed SRAM in industrial, automotive, and aerospace systems requiring field-upgradable firmware and configuration storage.
FAQ
What is the maximum page write cycle time for AT28HC256F-12JC?
The AT28HC256F-12JC has a maximum page write cycle time of 3 ms, confirmed in Section 16 of the datasheet. This is the defining "F" option feature distinguishing it from the standard 10 ms AT28HC256-12JC. The 3 ms timing applies across the full industrial temperature range (–40°C to +85°C) and is internally controlled by an autonomous timer, eliminating host-side timing dependencies for write completion.
Does AT28HC256F-12JC support both DATA Polling and Toggle Bit for write completion detection?
Yes, AT28HC256F-12JC supports both methods. DATA Polling asserts the complement of the last written byte on I/O7 until write completion, after which true data appears. Toggle Bit causes I/O6 to alternate logic states during active programming and stabilize upon completion. Both mechanisms are fully functional and characterized per Sections 4.4 and 4.5 of the datasheet, enabling robust host firmware implementation without fixed delays.
What package type is used for AT28HC256F-12JC?
AT28HC256F-12JC uses a 28-lead plastic gull-wing small outline (SOIC) package, designated as 28S in Atmel's ordering matrix. It measures 10.00 mm × 7.40 mm × 2.35 mm (0.394" × 0.291" × 0.093"), conforms to JEDEC MS-013, and features Pb/Halide-free green packaging per Section 27.2 of the datasheet.
How does software data protection (SDP) work on AT28HC256F-12JC?
AT28HC256F-12JC implements SDP via a 3-byte command sequence written to specific addresses (5555H, 2AAAH, then 5555H with A0). Once enabled, all subsequent writes require repeating this sequence before data. SDP remains active through power cycles and is disabled only by a separate 5-byte disable sequence. The feature is shipped disabled and requires no external components to activate.
Is AT28HC256F-12JC pin-compatible with other AT28HC256 variants?
Yes, AT28HC256F-12JC maintains JEDEC-approved byte-wide pinout compatibility across all AT28HC256 speed grades (70, 90, 12) and package types (SOIC, PDIP, PLCC, TSOP). Pin functions A0–A14, I/O0–I/O7, CE, OE, WE, VCC, and GND are identical. Differences are limited to internal timing and endurance - no PCB redesign is needed when upgrading from AT28HC256-12JC to AT28HC256F-12JC.
AT28HC256F-12JC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 3ms
- Access Time:
- 120 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (13.97x11.43)
AT28HC256F-12JC FAQ
1.How can I place an order for AT28HC256F-12JC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC256F-12JC 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 AT28HC256F-12JC reliable?
The price and inventory of AT28HC256F-12JC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28HC256F-12JC is usually 5 days.
3.What payment methods are accepted for AT28HC256F-12JC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC256F-12JC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC256F-12JC?
AT28HC256F-12JC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC256F-12JC 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 AT28HC256F-12JC?
For technical support, including AT28HC256F-12JC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC256F-12JC requirements.
6.How does Aetrix verify that AT28HC256F-12JC is sourced from the original manufacturer or authorized distributors?
All AT28HC256F-12JC 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 AT28HC256F-12JC meets industry standards.
7.What is the process for return or replacement of AT28HC256F-12JC?
All AT28HC256F-12JC units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC256F-12JC, 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 AT28HC256F-12JC part is unused and in its original packaging.
Return procedure for AT28HC256F-12JC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28HC256F-12JC Tags
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