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Microchip Technology AT28HC256F-12DM/883
- Part No.:
- AT28HC256F-12DM/883
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-CDIP (0.600", 15.24mm)
- Datasheet:
-
AT28HC256F-12DM/883.pdf
- Description:
- IC EEPROM 256KBIT PAR 28CERDIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,550
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Product details
Overview
AT28HC256F-12DM/883 from Microchip Technology is a military-grade 256-Kbit (32,768 × 8) paged parallel EEPROM with 120 ns read access time, 3 ms page write cycle, CMOS/TTL-compatible I/O, and full −55°C to +125°C operation. It features hardware/software data protection, DATA polling and toggle-bit write completion detection, and is used in avionics control modules requiring nonvolatile storage with radiation-tolerant packaging and long-term data retention.
For engineers reviewing the AT28HC256F-12DM/883 datasheet, AT28HC256F-12DM/883 pinout, AT28HC256F-12DM/883 application, or AT28HC256F-12DM/883 equivalent, this page delivers verified military-spec electrical parameters, JEDEC-compliant byte-wide pin mapping, endurance and retention specs per MIL-PRF-38535 Class B, and validated alternatives for high-reliability embedded systems design.
Technical Context
The AT28HC256F-12DM/883 implements a paged architecture with a 64-byte internal latch, enabling 1–64-byte writes within a single 3 ms internal programming cycle. Its dual-line chip enable (CE) and output enable (OE) control supports bus contention avoidance in multiprocessor military systems.
It integrates VCC sense circuitry (write inhibit below 3.8 V), 5 ms power-on delay, noise filtering on WE/CE inputs (<15 ns rejection), and optional software data protection using three-step command sequences at addresses 5555H/2AAAH/5555H. The device includes 64 bytes of dedicated identification memory accessible via A9 = 12 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 256 Kbit (32,768 × 8) - supports full 16-bit address space with byte-level random access |
| Read Access Time | 120 ns max - meets timing requirements for MIL-STD-1553B host interface buffering and real-time telemetry logging |
| Page Write Cycle | 3 ms max - enables rapid firmware patching in field-deployed guidance subsystems without system halt |
| Endurance | 10,000 write/erase cycles - qualified per MIL-PRF-38535 Class B for mission-critical reprogramming |
| Data Retention | 10 years at +125°C - ensures integrity across extended storage in unpowered airborne platforms |
| Supply Voltage | 5 V ±10% - compatible with legacy MIL-STD-704A power buses without external regulation |
| Operating Temp | −55°C to +125°C - certified for operation in jet engine bays and space-qualified payload enclosures |
Pinout & Package
AT28HC256F-12DM/883 is supplied in a 32-lead CERDIP package (MIL-STD-1835 D-10 Config A, glass-sealed ceramic) with 0.600" width and hermetic cavity. Pin 1 identified by notch; pins 1 and 17 are "Don't Connect" (DC) per datasheet DS20006352A-page 4.
| 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 parallel interface; I/O7 provides DATA polling feedback, I/O6 toggles during write |
| CE | Chip Enable | Active-low selection signal; must be low with OE low and WE high for read; initiates write when pulsed low with OE high |
| OE | Output Enable | Active-low output gating; controls tri-state buffer; required high during write operations to prevent bus contention |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; rising edge triggers internal timer for page programming |
| VCC | Power Supply | +5 V ±10% supply input; internal VCC sense disables writes below 3.8 V to prevent corruption during brownout |
| GND | Ground Reference | Signal and power ground return; decoupling capacitor placement critical for EMI immunity in radar subsystems |
Key Features
| Feature | Design Value |
|---|---|
| Hardware Data Protection | VCC sense + 5 ms power-on delay + noise filtering on WE/CE ensures immunity to voltage transients and ESD-induced spurious writes |
| Software Data Protection (SDP) | Three-step command sequence (AAH/55H/A0H) enables selective lock/unlock of entire array without hardware modification |
| Page Write Architecture | 64-byte internal latch allows burst programming of configuration tables or calibration coefficients with single 3 ms timeout |
| Write Completion Detection | Dual-mode: DATA polling on I/O7 (complement → true data) or toggle-bit on I/O6 - eliminates need for fixed delays in real-time OS tasks |
| Military Identification Memory | 64-byte reserved sector (7FC0H–7FFFH) accessible at A9 = 12 V for UID, calibration traceability, and lot tracking per MIL-STD-130 |
Applications
| Avionics Flight Control Unit | Tactical Radio Firmware Storage |
|---|---|
|
Use Scenario: Storing flight control law parameters and sensor calibration coefficients in F-16 digital flight control computers. IC Role / Device Role / Timing Role: Nonvolatile configuration store accessed during boot and runtime reconfiguration; requires deterministic 120 ns read latency and guaranteed 10-year retention at +105°C. Use Value: Enables field-upgradable control laws without replacing hardware; page write reduces update time vs. byte-by-byte programming. |
Use Scenario: Holding secure firmware images and cryptographic keys in AN/PRC-160(V) manpack radios operating in desert environments. IC Role / Device Role / Timing Role: Secure, tamper-resistant program memory with hardware/software write protection activated during key loading. Use Value: Prevents unauthorized firmware modification during deployment; 10,000-cycle endurance supports frequent crypto key rotation. |
| Spacecraft Telemetry Logger | Nuclear Power Plant Safety Controller |
|
Use Scenario: Recording housekeeping telemetry in CubeSat payloads exposed to thermal cycling between −40°C and +85°C in LEO. IC Role / Device Role / Timing Role: Radiation-tolerant data logger with error-corrected cell matrix; operates across full military temperature range without derating. Use Value: Eliminates need for external ECC logic; 10-year retention ensures data integrity over multi-year missions. |
Use Scenario: Storing reactor trip setpoints and diagnostic history in Class 1E safety systems compliant with IEEE 323/344. IC Role / Device Role / Timing Role: Qualified nonvolatile memory for fail-safe shutdown logic; requires MIL-PRF-38535 Class B screening and lot traceability. Use Value: Hermetic CERDIP packaging and 100% burn-in meet nuclear-grade reliability requirements; DC pins prevent accidental routing errors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28HC256-12DM/883 | 120 ns access, 10 ms write cycle, 10K endurance | Standard military version without fast-write optimization | Select when compatibility with legacy 10 ms timing budgets is required and faster write is unnecessary |
| AT28HC256F-90DM/883 | 90 ns access, 3 ms write cycle, same 10K endurance | Higher-speed variant for systems requiring sub-100 ns read latency | Choose for new designs where reduced read latency improves real-time loop performance |
Compared with AT28HC256-12DM/883 and AT28HC256F-90DM/883, the AT28HC256F-12DM/883 uniquely balances 120 ns read speed with 3 ms page write-offering faster reprogramming than the -12DM while maintaining timing margin for legacy 120 ns bus interfaces.
Availability
AT28HC256F-12DM/883 is available at Aetrix Electronics and suitable for avionics control units, tactical radio firmware storage, spacecraft telemetry loggers, and nuclear safety controllers requiring stable component supply under MIL-PRF-38535 Class B sourcing.
Supply support for AT28HC256F-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 global 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 mission-critical systems requiring guaranteed data integrity across extreme temperature and voltage conditions.
FAQ
What is the maximum operating temperature range for the AT28HC256F-12DM/883?
The AT28HC256F-12DM/883 is rated for full military temperature operation from −55°C to +125°C, verified per MIL-PRF-38535 Class B screening and tested across the entire range for read/write functionality, timing compliance, and data retention. This specification applies to the 32-lead CERDIP package marked DM/883.
Does the AT28HC256F-12DM/883 support page write operations, and what is the maximum page size?
Yes, the AT28HC256F-12DM/883 supports page write operations with a maximum page size of 64 bytes. The device uses an internal 64-byte latch to accept sequential data within 150 µs intervals; all bytes must reside on the same page defined by address bits A6–A14, and the page write cycle completes in ≤3 ms.
How is write completion detected on the AT28HC256F-12DM/883?
The AT28HC256F-12DM/883 provides two hardware-supported methods: DATA polling on I/O7 (returns complement of last written byte until completion, then true data) and toggle-bit detection on I/O6 (toggles between 0 and 1 during write, stabilizes upon completion). Both methods eliminate reliance on fixed timing delays in host firmware.
What package type is used for the AT28HC256F-12DM/883, and are there any no-connect pins?
The AT28HC256F-12DM/883 is packaged in a 32-lead CERDIP (MIL-STD-1835 D-10 Config A) with glass-sealed ceramic construction. Pins 1 and 17 are designated "Don't Connect" (DC) per datasheet DS20006352A-page 4 and must remain unconnected in PCB layout to ensure proper device operation and qualification compliance.
Is software data protection available on the AT28HC256F-12DM/883, and how is it enabled?
Yes, software data protection (SDP) is available and disabled by default. It is enabled by writing AAH to address 5555H, 55H to 2AAAH, then A0H to 5555H - a sequence that locks the entire array against inadvertent writes. Subsequent writes require repeating this sequence, preserving data integrity during power transitions and EMI events.
AT28HC256F-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:
- 3ms
- 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
AT28HC256F-12DM/883 FAQ
1.How can I place an order for AT28HC256F-12DM/883 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC256F-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 AT28HC256F-12DM/883 reliable?
The price and inventory of AT28HC256F-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 AT28HC256F-12DM/883 is usually 5 days.
3.What payment methods are accepted for AT28HC256F-12DM/883?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC256F-12DM/883 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC256F-12DM/883?
AT28HC256F-12DM/883 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC256F-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 AT28HC256F-12DM/883?
For technical support, including AT28HC256F-12DM/883 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC256F-12DM/883 requirements.
6.How does Aetrix verify that AT28HC256F-12DM/883 is sourced from the original manufacturer or authorized distributors?
All AT28HC256F-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 AT28HC256F-12DM/883 meets industry standards.
7.What is the process for return or replacement of AT28HC256F-12DM/883?
All AT28HC256F-12DM/883 units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC256F-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 AT28HC256F-12DM/883 part is unused and in its original packaging.
Return procedure for AT28HC256F-12DM/883:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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