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Microchip Technology AT28C256F-15UM/883-815
- Part No.:
- AT28C256F-15UM/883-815
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-BCPGA
- Datasheet:
-
AT28C256F-15UM/883-815.pdf
- Description:
- IC EEPROM 256KBIT PAR 28CPGA
- Quantity:
- Payment:
- Shipping:
Inventory:1,468
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Product details
Overview
AT28C256F-15UM/883-815 from Microchip Technology (formerly Atmel) is a 256 Kbit (32K × 8) paged parallel EEPROM IC used for nonvolatile program/data storage in military-grade embedded systems. It delivers 150 ns read access time, 3 ms page write cycle time, 5 V ±10% single-supply operation, and operates across –55°C to +125°C. It serves as firmware storage or configuration memory in avionics control units requiring radiation-tolerant, long-retention data retention.
For engineers reviewing the AT28C256F-15UM/883-815 datasheet, AT28C256F-15UM/883-815 pinout, AT28C256F-15UM/883-815 application, or AT28C256F-15UM/883-815 equivalent, this page provides verified military-spec timing, JEDEC byte-wide pin compatibility, hardware/software write protection implementation, and full MIL-STD-883 Class B compliance details - critical for DO-254, MIL-HDBK-217F, and space-qualified design reviews.
Technical Context
The AT28C256F-15UM/883-815 implements a CMOS-based paged architecture with a 64-byte internal page register, enabling simultaneous latching of up to 64 bytes during write operations. Its internal control timer automates programming after address/data latch, eliminating external timing logic.
It supports dual write detection methods - DATA Polling on I/O7 and Toggle Bit on I/O6 - and integrates VCC sense, power-on delay, noise filtering, and software data protection (SDP) to prevent inadvertent writes during power transitions. The device includes 64 bytes of dedicated identification EEPROM accessible via A9 = 12 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8), organized as byte-addressable nonvolatile storage for firmware or calibration tables |
| Read Access Time | 150 ns maximum - enables direct replacement of SRAM in legacy MIL-STD-1553B bus controllers without wait-state insertion |
| Page Write Cycle Time | 3 ms maximum - 3× faster than standard AT28C256 variants, reducing system boot/configuration latency |
| Endurance | 10,000 write/erase cycles - validated per MIL-STD-883 Method 1037, sufficient for field-updatable mission profiles |
| Data Retention | 10 years at +125°C - meets MIL-PRF-38535 Class B requirements for long-term deployment in sealed avionics enclosures |
| Supply Voltage | 5 V ±10% - compatible with legacy 5 V TTL/CMOS logic families and MIL-STD-704A aircraft power buses |
| Operating Temperature | –55°C to +125°C case temperature - qualified per MIL-STD-883 Test Method 1010.8 for extended thermal cycling |
Pinout & Package
AT28C256F-15UM/883-815 uses a 28-pin Ceramic Pin Grid Array (PGA) package (package code 28U), compliant with MIL-STD-1835 and suitable for hermetic sealing in high-reliability modules.
| 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 page writes |
| I/O0–I/O7 | Bidirectional Data Bus | Byte-wide data path; I/O7 used for DATA Polling, I/O6 for Toggle Bit write completion signaling |
| CE | Chip Enable | Active-low chip select; must be low with OE low and WE high for read; inhibits write when high |
| OE | Output Enable | Active-low output control; places I/O pins in high-impedance state when high to prevent bus contention |
| WE | Write Enable | Active-low write strobe; falling edge latches address; rising edge latches data; controls byte/page write initiation |
| VCC | Power Supply | +5 V ±10% supply; internal VCC sense circuit disables writes below ~3.8 V to prevent partial programming |
| GND | Ground Reference | Signal and power return; decoupling capacitor placement near pin critical for noise immunity in EMI-prone platforms |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC Byte-wide Pinout | Ensures drop-in compatibility with industry-standard 28-pin EPROM/EEPROM sockets and legacy PCB layouts |
| Hardware Write Protection | VCC sense, 5 ms power-on delay, and 15 ns input noise filtering eliminate need for external reset supervisors or RC timers |
| Software Data Protection (SDP) | Three-byte unlock sequence (AAh→55h→A0h) enables/disables write access - prevents accidental reprogramming during field updates |
| 64-byte Page Register | Reduces host processor overhead by allowing burst loading of up to 64 bytes before internal programming begins |
| Dual Write Completion Detection | DATA Polling (I/O7 complement) and Toggle Bit (I/O6 toggling) provide redundant, real-time write status without polling delays |
Applications
| Avionics Boot Memory | MIL-STD-1553B Remote Terminal Storage |
|---|---|
Use Scenario: Stores boot firmware and configuration parameters for flight control computers operating in sealed, conduction-cooled chassis. IC Role / Device Role / Timing Role: Nonvolatile program memory providing deterministic 150 ns read access to initialize FPGAs and microcontrollers at power-on. Use Value: Eliminates external wait-state generators and supports hot-swap recovery via guaranteed 10-year data retention at +125°C. |
Use Scenario: Holds message descriptor tables and subsystem-specific protocol parameters in military vehicle data buses. IC Role / Device Role / Timing Role: Configuration EEPROM interfaced directly to 1553B protocol ASICs using standard 5 V TTL timing margins. Use Value: Enables field reconfiguration of remote terminal behavior without hardware modification or re-spinning PCBs. |
| Satellite Payload Calibration Storage | Nuclear Instrumentation Control |
Use Scenario: Retains sensor calibration coefficients and radiation-hardened lookup tables in low-earth orbit payloads. IC Role / Device Role / Timing Role: Radiation-tolerant nonvolatile memory with 64-byte page write capability for infrequent but critical parameter updates. Use Value: Meets MIL-PRF-38535 Class B screening and provides 10,000-cycle endurance for lifetime mission recalibration events. |
Use Scenario: Stores safety-critical trip thresholds and diagnostic history logs in reactor monitoring systems with strict qualification requirements. IC Role / Device Role / Timing Role: Secure, tamper-resistant configuration store with hardware/software write lockout active during power transients. Use Value: Prevents unauthorized or spurious writes during grid instability events via VCC sense and SDP enforcement. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar paged parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C256-15UM/883 | 10 ms page write cycle; 10K endurance; no Fast Write option | Lacks 3 ms write speed - unsuitable for time-critical configuration updates | Select only if legacy system timing budgets allow longer write latency and cost sensitivity outweighs performance gain |
| DS2502-E48+T&R | 1-Wire serial interface; 1 Kbit capacity; no parallel bus support | Requires microcontroller bit-banging or dedicated 1-Wire master; incompatible with existing address/data bus designs | Consider only for new designs where board space, wiring count, or single-wire diagnostics justify architectural change |
Compared with AT28C256-15UM/883 and DS2502-E48+T&R, the AT28C256F-15UM/883-815 uniquely delivers MIL-qualified 3 ms page writes in a JEDEC-standard 28-pin PGA footprint - enabling performance upgrades without PCB redesign or bus protocol changes.
Availability
AT28C256F-15UM/883-815 is available at Aetrix Electronics and suitable for avionics boot memory, MIL-STD-1553B remote terminal storage, and satellite payload calibration storage requiring stable component supply under extended temperature and radiation-exposed conditions.
Supply support for AT28C256F-15UM/883-815 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 acquired Atmel in 2016 and maintains full support for legacy Atmel military-grade EEPROMs, including qualification, testing, and documentation for MIL-STD-883 and MIL-PRF-38535 compliance.
The AT28C256F-15UM/883-815 belongs to Atmel's high-reliability parallel EEPROM product line, designed specifically for defense, aerospace, and nuclear instrumentation applications demanding guaranteed data integrity across extreme thermal and electrical stress conditions.
FAQ
What is the write cycle time specification for AT28C256F-15UM/883-815?
The AT28C256F-15UM/883-815 has a maximum page write cycle time of 3 ms, as confirmed in Section 16 "Page Mode Characteristics" and Ordering Information Table 27.1.3. This distinguishes it from standard AT28C256 variants (e.g., AT28C256-15UM/883), which require up to 10 ms. The 3 ms specification applies to all 1–64 byte page writes within the same page boundary (A6–A14 constant) and is validated per MIL-STD-883.
Does AT28C256F-15UM/883-815 support both hardware and software write protection?
Yes, AT28C256F-15UM/883-815 implements dual-layer write protection: hardware features include VCC sense (~3.8 V threshold), 5 ms power-on delay, WE/CE noise filtering (<15 ns), and CE/OE/WE logic inhibition; software protection uses a three-byte unlock sequence (AAh→55h→A0h) to enable/disable writes. Both mechanisms are fully functional and tested per MIL-STD-883 in the AT28C256F-15UM/883-815.
What package type does AT28C256F-15UM/883-815 use, and is it hermetically sealed?
AT28C256F-15UM/883-815 uses a 28-pin Ceramic Pin Grid Array (PGA) package (drawing 28U), specified in Section 29.8. It is hermetically sealed per MIL-STD-1835 and qualified for Class B operation under MIL-STD-883, making it suitable for high-reliability applications requiring moisture and particle ingress protection.
How is write completion detected on AT28C256F-15UM/883-815?
AT28C256F-15UM/883-815 supports two independent, real-time write completion detection methods: DATA Polling (reading I/O7 returns complement of last written byte until completion, then true data) and Toggle Bit (I/O6 toggles between 0 and 1 during write, then stabilizes). Both are usable at any point during the write cycle and are characterized per Sections 4.4, 4.5, 22, and 24.
Is AT28C256F-15UM/883-815 compliant with MIL-STD-883 Class B requirements?
Yes, AT28C256F-15UM/883-815 is fully compliant with MIL-STD-883 Class B, as indicated by the "/883" suffix and documented in Ordering Information Table 27.1.3. It undergoes screening including temperature cycling, steady-state life test, and burn-in per MIL-STD-883 Methods 1010.8, 1005.8, and 1015.8, and carries dual DESC number marking per SL815 requirement.
AT28C256F-15UM/883-815 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-BCPGA
- Packaging:
- Tray
- Product Status:
- Obsolete
- 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:
- 150 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-CPGA (13.97x16.51)
AT28C256F-15UM/883-815 FAQ
1.How can I place an order for AT28C256F-15UM/883-815 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C256F-15UM/883-815 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 AT28C256F-15UM/883-815 reliable?
The price and inventory of AT28C256F-15UM/883-815 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28C256F-15UM/883-815 is usually 5 days.
3.What payment methods are accepted for AT28C256F-15UM/883-815?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C256F-15UM/883-815 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C256F-15UM/883-815?
AT28C256F-15UM/883-815 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C256F-15UM/883-815 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 AT28C256F-15UM/883-815?
For technical support, including AT28C256F-15UM/883-815 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C256F-15UM/883-815 requirements.
6.How does Aetrix verify that AT28C256F-15UM/883-815 is sourced from the original manufacturer or authorized distributors?
All AT28C256F-15UM/883-815 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 AT28C256F-15UM/883-815 meets industry standards.
7.What is the process for return or replacement of AT28C256F-15UM/883-815?
All AT28C256F-15UM/883-815 units undergo pre-shipment inspection (PSI). If there is an issue with AT28C256F-15UM/883-815, 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 AT28C256F-15UM/883-815 part is unused and in its original packaging.
Return procedure for AT28C256F-15UM/883-815:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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