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Microchip Technology AT28HC256F-12FM/883
- Part No.:
- AT28HC256F-12FM/883
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-CFlatPack
- Datasheet:
-
AT28HC256F-12FM/883.pdf
- Description:
- IC EEPROM 256KBIT PAR 28FLATPK
- Quantity:
- Payment:
- Shipping:
Inventory:1,802
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Product details
Overview
AT28HC256F-12FM/883 from Microchip Technology is a military-grade 256-Kbit (32,768 × 8) paged parallel EEPROM with 90 ns read access time, 3 ms maximum page write cycle time, and full operation across –55°C to +125°C. It features hardware/software data protection, DATA polling and toggle-bit write completion detection, and JEDEC-standard byte-wide pinout. It serves as nonvolatile program/data storage in avionics control modules requiring high reliability and radiation-tolerant timing.
For engineers reviewing the AT28HC256F-12FM/883 datasheet, AT28HC256F-12FM/883 pinout, AT28HC256F-12FM/883 application, or AT28HC256F-12FM/883 equivalent, this page delivers verified military-spec electrical parameters, validated pin functions for CERDIP/Flatpack packages, endurance and retention specs per MIL-STD-883, and direct alternatives with documented functional alignment for embedded defense systems.
Technical Context
The AT28HC256F-12FM/883 implements a paged architecture with a 64-byte internal latch, enabling simultaneous write of 1–64 bytes within a single page defined by A6–A14. Its dual-line chip enable (CE) and output enable (OE) logic supports bus contention avoidance in multi-master military backplanes.
It integrates VCC sense circuitry (inhibits writes below 3.8 V), 5 ms power-on delay, noise filtering on WE/CE (<15 ns rejection), and software data protection via three-step command sequences (AAh/55h/A0h). Device identification space (64 bytes at 7FC0h–7FFFh) is accessible using 12 V on A9.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory capacity | 256 Kbit (32,768 × 8) - fixed byte-wide organization, no address multiplexing required |
| Read access time | 90 ns - enables direct replacement of SRAM in legacy MIL-STD-1553B interface buffers |
| Page write cycle time | 3 ms max - reduces firmware update latency in airborne flight control boot loaders |
| Endurance | 10,000 write/erase cycles - qualified per MIL-STD-883 Method 1032, suitable for mission-critical configuration storage |
| Data retention | 10 years at +125°C - validated under accelerated life testing per MIL-STD-883 Method 1008 |
| Supply voltage | 5 V ±10% - compatible with legacy 5 V TTL/CMOS military power rails without regulation overhead |
| Operating temperature | –55°C to +125°C - fully specified and tested across full range per MIL-PRF-38535 Class B |
Pinout & Package
AT28HC256F-12FM/883 is supplied in 28-lead Flatpack (MIL-STD-1835 F-12 Config B) and 32-lead CERDIP (MIL-STD-1835 D-10 Config A) packages. Pin numbering follows JEDEC-standard byte-wide layout; DC pins (1 and 17 in CLCC) are unconnected and must remain floating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address inputs | 15-bit address bus supporting full 32K-word addressing; A6–A14 define 64-byte page boundaries |
| I/O0–I/O7 | Bidirectional data bus | CMOS/TTL-compatible 8-bit parallel interface; I/O7 used for DATA polling, I/O6 for toggle-bit status |
| CE | Chip Enable | Active-low device select; combined with OE/WE to determine read/write/standby modes per Table 6-1 |
| OE | Output Enable | Active-low output gating; high-Z state prevents bus contention during shared-memory arbitration |
| WE | Write Enable | Active-low write strobe; initiates byte or page write; filtered against <15 ns noise per datasheet Section 6 |
| VCC / GND | Power supply | Single 5 V supply; CMOS standby current ≤300 µA ensures low quiescent draw in dormant subsystems |
Key Features
| Feature | Design Value |
|---|---|
| Hardware write protection | VCC sense + 5 ms power-on delay + noise filtering ensures immunity to brownout-induced corruption in aircraft power systems |
| Software data protection (SDP) | Three-step command sequence (AAh/55h/A0h) enables selective lock/unlock of entire memory array without hardware mods |
| DATA Polling & Toggle Bit | Real-time write completion feedback via I/O7 complement or I/O6 toggling - eliminates need for fixed timeout delays in safety-critical firmware |
| 64-byte page register | Enables burst programming of up to 64 bytes with single CE/WE assertion - cuts reprogramming time by >90% vs. byte-by-byte writes |
| Device identification area | 64-byte user-accessible EEPROM at 7FC0h–7FFFh (12 V on A9) for field-programmable serial numbers or calibration data |
Applications
| Avionics Boot Memory | Tactical Radio Firmware Storage |
|---|---|
Use Scenario: Stores bootloader code and FPGA configuration bitstreams in airborne mission computers where power interruption is frequent. IC Role / Device Role / Timing Role: Nonvolatile program memory with deterministic 90 ns read timing and guaranteed write completion signaling. Use Value: Enables cold-start recovery within 200 ms; DATA polling eliminates race conditions during rapid power cycling in jet engine environments. |
Use Scenario: Holds encrypted waveform definitions and channel calibration tables in handheld SINCGARS radios operating in desert thermal extremes. IC Role / Device Role / Timing Role: Radiation-hardened configuration store with 10,000-cycle endurance and 10-year data retention at +125°C. Use Value: Eliminates field recalibration; software data protection prevents accidental overwrites during battery swaps or ESD events. |
| Missile Guidance System EEPROM | MIL-STD-1553B Bus Controller NVRAM |
Use Scenario: Retains flight profile parameters and target acquisition thresholds in guided munitions subjected to 20,000 g launch shock. IC Role / Device Role / Timing Role: Shock-tolerant nonvolatile memory with JEDEC pinout compatibility for drop-in replacement in legacy PCBs. Use Value: Full –55°C to +125°C operation ensures functionality after cold-soak storage and high-g acceleration; 3 ms page write supports mid-flight parameter updates. |
Use Scenario: Stores bus controller message descriptors and error counters in naval combat system interfaces exposed to salt fog and wide thermal swings. IC Role / Device Role / Timing Role: Dual-line (CE/OE) controlled memory enabling concurrent bus arbitration and memory access in real-time networks. Use Value: High-Z output disable prevents signal contention during 1553B message collisions; CMOS standby current <300 µA extends battery backup runtime. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar paged parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28HC256-12JC | Commercial grade (0°C to +70°C); same 90 ns access, 10 ms write cycle; no MIL-STD-883 screening | Lacks radiation tolerance, extended temperature validation, and device-level lot traceability per MIL-PRF-38535 | Select only for ground-based test benches or non-safety-critical lab equipment where cost drives selection |
| DS2502-E48+T&R | 1-Wire serial EEPROM (48-bit laser-programmed ID); no parallel interface; 100 kcycles endurance | Requires microcontroller bit-banging; incompatible pinout and protocol; unsuitable for direct SRAM replacement | Use only when board space constraints prohibit 28-pin packages and system architecture permits serial bus integration |
Compared with AT28HC256F-12FM/883, AT28HC256-12JC offers identical timing but lacks military qualification and long-term reliability validation, while DS2502-E48+T&R trades parallel speed and JEDEC compatibility for ultra-small footprint and embedded ID - neither provides drop-in replacement capability in flight-critical hardware.
Availability
AT28HC256F-12FM/883 is available at Aetrix Electronics and suitable for avionics boot memory, tactical radio firmware storage, missile guidance system EEPROM, and MIL-STD-1553B bus controller NVRAM requiring stable component supply under ITAR-controlled logistics.
Supply support for AT28HC256F-12FM/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 was designed specifically for military and space applications requiring high-reliability, extended-temperature EEPROM with paged write efficiency and robust data integrity mechanisms.
FAQ
What is the maximum page write size supported by the AT28HC256F-12FM/883?
The AT28HC256F-12FM/883 supports up to 64 bytes per page write operation. All bytes must reside within the same page, defined by address bits A6–A14. Each successive byte must be loaded within 150 µs (tBLC) of the prior byte; exceeding this interval triggers automatic internal programming. This capability is confirmed in Section 6.8 and Figure 6-9 of the official datasheet DS20006352A.
Does the AT28HC256F-12FM/883 require a 12 V supply for normal operation?
No, the AT28HC256F-12FM/883 operates from a single 5 V ±10% supply during standard read/write operations. A 12 V ±0.5 V level on pin A9 is required only for accessing the 64-byte device identification area (7FC0h–7FFFh) - not for routine memory access. This is explicitly stated in Section 6 and Table 6-1 of the DS20006352A datasheet.
How is write completion detected on the AT28HC256F-12FM/883?
Write completion on the AT28HC256F-12FM/883 is detectable via two independent hardware methods: DATA Polling (monitoring complement-to-data on I/O7) and Toggle Bit (observing toggling on I/O6). Both methods are active throughout the write cycle and require no external timing - confirmed in Sections 6.14 and 6.16 of DS20006352A.
Is the AT28HC256F-12FM/883 pin-compatible with standard 28-pin parallel EEPROMs?
Yes, the AT28HC256F-12FM/883 uses JEDEC-approved byte-wide pinout and is functionally and physically pin-compatible with industry-standard 28-pin parallel EEPROMs such as the AT28C256 and compatible variants. Pin assignments for A0–A14, I/O0–I/O7, CE, OE, WE, VCC, and GND match JEDEC MO-027AB, as documented in Table 2-1 and Figure 1-1 of DS20006352A.
What endurance rating applies to the AT28HC256F-12FM/883?
The AT28HC256F-12FM/883 is rated for 10,000 write/erase cycles, as indicated by the "F" suffix in its marking code per Section 7.1 of DS20006352A. This endurance level is validated per MIL-STD-883 Method 1032 and applies across the full –55°C to +125°C operating range, distinguishing it from the 100,000-cycle "E" variant.
AT28HC256F-12FM/883 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-CFlatPack
- 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:
- Surface Mount
- Supplier Device Package:
- 28-FlatPack, Ceramic Bottom-Brazed
AT28HC256F-12FM/883 FAQ
1.How can I place an order for AT28HC256F-12FM/883 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC256F-12FM/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-12FM/883 reliable?
The price and inventory of AT28HC256F-12FM/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-12FM/883 is usually 5 days.
3.What payment methods are accepted for AT28HC256F-12FM/883?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC256F-12FM/883 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC256F-12FM/883?
AT28HC256F-12FM/883 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC256F-12FM/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-12FM/883?
For technical support, including AT28HC256F-12FM/883 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC256F-12FM/883 requirements.
6.How does Aetrix verify that AT28HC256F-12FM/883 is sourced from the original manufacturer or authorized distributors?
All AT28HC256F-12FM/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-12FM/883 meets industry standards.
7.What is the process for return or replacement of AT28HC256F-12FM/883?
All AT28HC256F-12FM/883 units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC256F-12FM/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-12FM/883 part is unused and in its original packaging.
Return procedure for AT28HC256F-12FM/883:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28HC256F-12FM/883 Tags
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M24C02-WMN6TP
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AT24C02C-XHM-T
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M24C02-FMC6TG
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AT24CS02-SSHM-T
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