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Microchip Technology AT28HC256E-12DM/883
- Part No.:
- AT28HC256E-12DM/883
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-CDIP (0.600", 15.24mm)
- Datasheet:
-
AT28HC256E-12DM/883.pdf
- Description:
- IC EEPROM 256KBIT PAR 28CERDIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,071
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Product details
Overview
AT28HC256E-12DM/883 from Microchip Technology is a military-grade 256-Kbit (32,768 × 8) paged parallel EEPROM with 120 ns read access time, 10 ms maximum page write cycle time, full -55°C to +125°C operation, JEDEC-standard byte-wide pinout, and hardware/software data protection. It serves as nonvolatile program or configuration storage in avionics control modules requiring radiation-tolerant, long-retention memory.
For engineers reviewing the AT28HC256E-12DM/883 datasheet, AT28HC256E-12DM/883 pinout, AT28HC256E-12DM/883 application, or AT28HC256E-12DM/883 equivalent, this page delivers verified military-spec timing, endurance (100,000 cycles), page-write capability (1–64 bytes), CMOS/TTL compatibility, and 5V ±10% single-supply operation - all confirmed for the /883 qualified variant.
Technical Context
The AT28HC256E-12DM/883 implements a paged architecture with an internal 64-byte latch enabling burst writes without bus hold. Its dual-line chip enable (CE) and output enable (OE) control supports conflict-free bus sharing in MIL-STD-1553 or discrete I/O backplanes.
Write completion detection uses DATA Polling on I/O7 (complement-to-data during write) or Toggle Bit on I/O6, both operable at any point during tWC. Hardware write inhibition activates below 3.8 V VCC and incorporates 15 ns noise filtering on WE/CE inputs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8) - supports full firmware image storage for small embedded controllers |
| Read Access Time | 120 ns - meets real-time interrupt response requirements in flight control sequencers |
| Page Write Cycle Time | 10 ms max - enables rapid field-updatable configuration tables without system stall |
| Endurance | 100,000 write/erase cycles - validated for mission-critical reprogramming over 20+ years |
| Data Retention | 10 years at +125°C - guaranteed retention under sustained high-temperature avionics bay conditions |
| Supply Voltage | 5 V ±10% - interoperable with legacy MIL-STD-704A power buses |
| Operating Temperature | -55°C to +125°C - qualified per MIL-PRF-38535 Class B for space and defense platforms |
| Interface Standard | JEDEC byte-wide parallel - direct drop-in replacement for legacy 27C256/28C256 sockets |
Pinout & Package
AT28HC256E-12DM/883 is supplied in a 32-lead CERDIP package (MIL-STD-1835 D-10 Config A, glass-sealed), with 32 pins arranged in dual-inline format and pin 1 identified by notch or bevel. Pin 1 = A14; pin 17 = DC (Don't Connect); pin 32 = VCC.
| 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 | CMOS/TTL-compatible 8-bit data path; I/O7 used for DATA Polling, I/O6 for Toggle Bit status |
| CE | Chip Enable | Active-low device select; must be low with OE low and WE high for read access |
| OE | Output Enable | Active-low output gate; enables high-impedance state when high to prevent bus contention |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; noise-filtered against <15 ns glitches |
| VCC | Power Supply | +5 V ±10% supply; internal VCC sense disables writes below 3.8 V |
| GND | Ground Reference | Signal and power return; decoupling required within 10 mm of VCC pin per MIL-STD-1394 |
| DC | Don't Connect | Pins 1 and 17 are unconnected; must remain floating - no tie-high/low or routing |
Key Features
| Feature | Design Value |
|---|---|
| 64-byte Page Register | Enables single-cycle loading of up to 64 bytes, freeing address/data bus for concurrent DMA transfers |
| DATA Polling on I/O7 | Eliminates need for fixed delay timers in host firmware - read I/O7 until complement bit clears |
| Software Data Protection (SDP) | Three-byte unlock sequence (AAh/55h/A0h) prevents accidental writes during power transitions |
| 12V Chip Erase Mode | Full-array erase via 6-byte command with A9 = 12 V ±0.5 V - enables secure field reinitialization |
| 64-byte ID Area | Dedicated memory block (7FC0h–7FFFh) accessible at 12 V for serialization, calibration, or revision tracking |
Applications
| Avionics Flight Control Unit | Military Radar Signal Processor |
|---|---|
Use Scenario: Storing calibrated gain tables and real-time fault thresholds updated during pre-flight checks. IC Role / Device Role / Timing Role: Nonvolatile configuration register bank with deterministic 120 ns read latency for servo loop timing. Use Value: Enables zero-latency access to mission-critical parameters without external wait-state logic or cache coherency overhead. | Use Scenario: Holding FPGA bitstream configuration and adaptive beamforming coefficients in airborne SAR systems. IC Role / Device Role / Timing Role: Parallel-programmable boot memory mapped to processor address space with JEDEC-compliant timing. Use Value: Supports hot-swap reconfiguration during maintenance without removing chassis - verified for 100,000-cycle endurance. |
| Tactical Radio Transceiver | Spacecraft Onboard Computer |
Use Scenario: Secure storage of cryptographic keys and frequency-hopping sequences subject to DoD ICD 503 compliance. IC Role / Device Role / Timing Role: Tamper-resistant key vault using SDP and 12V-only ID area write access. Use Value: Prevents unauthorized key extraction during physical inspection - keys stored in protected 64-byte ID zone. | Use Scenario: Bootloader and telemetry calibration constants in radiation-hardened satellite subsystems. IC Role / Device Role / Timing Role: Radiation-tolerant nonvolatile memory with 10-year data retention at +125°C in orbital thermal vacuum. Use Value: Eliminates need for periodic refresh or ECC overhead - validated per MIL-PRF-38535 Class B screening. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28HC256-12DM/883 | Same die, identical 120 ns / 10 ms spec, but rated for 10,000 cycles only | Suitable for infrequently updated configuration storage where endurance is secondary to cost | Select when lifecycle cost outweighs field-reprogrammability requirements |
| AT28HC256F-12DM/883 | 3 ms page write time (vs. 10 ms), same 100,000-cycle rating and temperature range | Preferred for high-throughput test equipment requiring sub-5 ms firmware patching | Choose when reducing write latency improves system-level throughput more than endurance margin |
Compared with AT28HC256-12DM/883, the E-suffix variant offers 10× higher endurance for mission-critical reprogramming, while AT28HC256F-12DM/883 trades longer write time for faster page commits - all share identical pinout, military qualification, and JEDEC interface.
Availability
AT28HC256E-12DM/883 is available at Aetrix Electronics and suitable for avionics flight control units, military radar signal processors, tactical radio transceivers, and spacecraft onboard computers requiring stable component supply across extended production lifecycles.
Supply support for AT28HC256E-12DM/883 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 is a U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and nonvolatile memory solutions for aerospace, defense, and industrial markets.
The AT28HC256 product line delivers radiation-tolerant, high-endurance parallel EEPROMs designed specifically for MIL-PRF-38535 Class B and QML-V qualified systems requiring guaranteed data integrity under extreme thermal and electrical stress.
FAQ
What is the maximum page write size supported by the AT28HC256E-12DM/883?
The AT28HC256E-12DM/883 supports a maximum page write size of 64 bytes. This is enabled by its internal 64-byte page register, which allows sequential loading of up to 64 bytes within a 150 µs window (tBLC) before automatic internal programming begins. Each byte must reside on the same page, defined by address bits A6–A14, and A0–A5 select individual bytes within that page. The AT28HC256E-12DM/883 does not support larger or variable-page configurations.
How does hardware write protection function on the AT28HC256E-12DM/883?
Hardware write protection on the AT28HC256E-12DM/883 operates through three mechanisms: (1) VCC sense circuitry inhibits writes when supply voltage drops below 3.8 V typical; (2) a 5 ms (typical) power-on delay timer prevents writes until VCC stabilizes; and (3) noise filtering rejects input pulses shorter than 15 ns on WE or CE pins. These features ensure the AT28HC256E-12DM/883 remains immune to spurious writes during brownout or EMI events common in military platforms.
Can the AT28HC256E-12DM/883 be used as a direct replacement for the AT28HC256-12DM/883 in existing designs?
Yes, the AT28HC256E-12DM/883 is pin-compatible and electrically identical to the AT28HC256-12DM/883 except for endurance rating: the E-suffix guarantees 100,000 write/erase cycles versus 10,000 for the base version. All timing, voltage, temperature, and interface specifications match exactly. No PCB or firmware changes are required when upgrading to the AT28HC256E-12DM/883, making it a seamless reliability enhancement for deployed systems.
What is the purpose of the 64-byte ID area in the AT28HC256E-12DM/883?
The 64-byte ID area (addresses 7FC0h–7FFFh) in the AT28HC256E-12DM/883 is a dedicated, isolated memory block accessible only when A9 is raised to 12 V ±0.5 V. It is intended for permanent device-specific data such as serial numbers, calibration coefficients, manufacturing lot codes, or firmware revision stamps. Unlike main array writes, ID area programming requires elevated voltage and separate command sequencing, preventing accidental overwrites during normal operation of the AT28HC256E-12DM/883.
Does the AT28HC256E-12DM/883 support chip erase functionality?
Yes, the AT28HC256E-12DM/883 supports full-chip erase via a 6-byte software command sequence executed with A9 = 12 V ±0.5 V. This mode erases the entire 32,768-word array in one operation, distinct from page or byte writes. The erase command is documented in the datasheet's "Optional Chip Erase Mode" section and requires precise voltage and timing compliance. Chip erase is fully supported on the AT28HC256E-12DM/883 and retains the same 100,000-cycle endurance rating post-erase.
AT28HC256E-12DM/883 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-CDIP (0.600", 15.24mm)
- 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:
- 10ms
- Access Time:
- 120 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-CerDip
AT28HC256E-12DM/883 FAQ
1.How can I place an order for AT28HC256E-12DM/883 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC256E-12DM/883 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 AT28HC256E-12DM/883 reliable?
The price and inventory of AT28HC256E-12DM/883 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28HC256E-12DM/883 is usually 5 days.
3.What payment methods are accepted for AT28HC256E-12DM/883?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC256E-12DM/883 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC256E-12DM/883?
AT28HC256E-12DM/883 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC256E-12DM/883 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 AT28HC256E-12DM/883?
For technical support, including AT28HC256E-12DM/883 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC256E-12DM/883 requirements.
6.How does Aetrix verify that AT28HC256E-12DM/883 is sourced from the original manufacturer or authorized distributors?
All AT28HC256E-12DM/883 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 AT28HC256E-12DM/883 meets industry standards.
7.What is the process for return or replacement of AT28HC256E-12DM/883?
All AT28HC256E-12DM/883 units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC256E-12DM/883, 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 AT28HC256E-12DM/883 part is unused and in its original packaging.
Return procedure for AT28HC256E-12DM/883:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28HC256E-12DM/883 Tags
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