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Microchip Technology AT28HC256E-90FM/883
- Part No.:
- AT28HC256E-90FM/883
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-CFlatPack
- Datasheet:
-
AT28HC256E-90FM/883.pdf
- Description:
- IC EEPROM 256KBIT PAR 28FLATPK
- Quantity:
- Payment:
- Shipping:
Inventory:4,672
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Product details
Overview
AT28HC256E-90FM/883 from Microchip Technology is a military-grade 256-Kbit (32,768 × 8) paged parallel EEPROM with 90 ns read access time, 10 ms maximum page write cycle time, and full operation across –55°C to +125°C. It supports hardware/software data protection, DATA polling, and toggle-bit write completion detection for embedded avionics and defense systems requiring nonvolatile memory with high reliability and deterministic timing.
For engineers reviewing the AT28HC256E-90FM/883 datasheet, AT28HC256E-90FM/883 pinout, AT28HC256E-90FM/883 application, or AT28HC256E-90FM/883 equivalent, this page delivers verified military-spec parameters, JEDEC-compliant byte-wide pinout, endurance (10,000 cycles), data retention (10 years), and precise package mapping for CERDIP/CLCC/Flatpack/PGA variants under MIL-STD-883 screening.
Technical Context
The AT28HC256E-90FM/883 implements a paged architecture with an internal 64-byte latch enabling simultaneous writes of 1–64 bytes per cycle. Its dual-line chip enable (CE) and output enable (OE) control logic allows flexible bus contention management in synchronous digital systems without external glue logic.
It uses CMOS-compatible TTL-level I/Os, operates from a single 5V ±10% supply, and integrates VCC sense, power-on delay, noise filtering, and software data protection (SDP) to prevent inadvertent writes during power transitions or EMI events in harsh environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 256 Kbit (32,768 × 8) - fixed byte-addressable organization compatible with 8-bit microprocessor buses |
| Read access time | 90 ns - enables direct replacement of SRAM in legacy military systems without timing redesign |
| Page write cycle time | 10 ms max - deterministic internal programming duration for predictable system-level write latency |
| Endurance | 10,000 write/erase cycles - validated under MIL-STD-883 test conditions for mission-critical field use |
| Data retention | 10 years at +125°C - guaranteed nonvolatile storage integrity over full military temperature range |
| Supply voltage | 5V ±10% - single-rail compatibility with legacy 5V TTL/CMOS logic families and power supplies |
| Operating temperature | –55°C to +125°C - qualified per MIL-STD-883 Method 1010 for extended environmental survivability |
Pinout & Package
AT28HC256E-90FM/883 is supplied in a 32-lead CERDIP package (MIL-STD-1835 D-10 Config A), with pins 1 and 17 designated as "Don't Connect" (DC). The device features JEDEC-approved byte-wide pinout and TTL/CMOS-compatible I/Os.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address inputs | 15-bit address bus supporting full 32,768-word addressing; A6–A14 define page boundaries for 64-byte page writes |
| I/O0–I/O7 | Bidirectional data bus | 8-bit parallel interface; I/O7 provides DATA polling complement output; I/O6 toggles during write cycles |
| CE | Chip Enable | Active-low selection signal; must be low with OE low and WE high for read operations |
| OE | Output Enable | Active-low output gating; controls high-impedance state to prevent bus contention when deasserted |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; initiates byte or page write cycles |
| VCC | Power supply | +5V ±10% input; includes internal VCC sense circuitry that inhibits writes below ~3.8V |
| GND | Ground reference | Signal and power return path; required for stable DC bias and AC noise immunity |
| DC (pins 1, 17) | No-connect | Physically present but internally unconnected; must remain floating per MIL-STD-883 requirements |
Key Features
| Feature | Design Value |
|---|---|
| Automatic page write | Internal 64-byte latch eliminates host-side buffering and enables burst writes without bus hold |
| DATA Polling & Toggle Bit | Dual asynchronous write-completion detection methods reduce CPU polling overhead and improve real-time response |
| Hardware write protection | VCC sense, 5 ms power-on delay, and noise filtering (15 ns pulse rejection) prevent spurious writes during brownouts or EMI |
| Software Data Protection (SDP) | User-configurable 3-byte command sequence (AA/55/A0) enables selective write-enable without hardware modification |
| Device identification area | 64 bytes at 7FC0H–7FFFH accessible via 12V A9 bias for unique unit tracking and firmware versioning |
Applications
| Avionics Flight Control Memory | Military Radar Calibration Storage |
|---|---|
Use Scenario: Storing real-time flight parameter lookup tables and trim coefficients in fly-by-wire control units operating at –55°C to +125°C. IC Role / Device Role / Timing Role: Nonvolatile configuration memory providing deterministic 90 ns read access and 10 ms page write for safety-critical updates during maintenance windows. Use Value: Eliminates need for external write-cycle timers or status polling logic due to integrated DATA polling on I/O7. | Use Scenario: Retaining calibrated RF front-end compensation values across radar system power cycles and thermal cycling in airborne EW platforms. IC Role / Device Role / Timing Role: Radiation-tolerant, MIL-STD-883-screened EEPROM preserving calibration data integrity for >10 years at elevated junction temperatures. Use Value: Hardware VCC-sense and SDP prevent corruption during aircraft battery transients or lightning-induced surges. |
| Tactical Radio Firmware Storage | Guided Munition Guidance Parameters |
Use Scenario: Holding encrypted waveform definitions and frequency-hopping sequences in handheld SINCGARS radios subjected to shock/vibration. IC Role / Device Role / Timing Role: Byte- and page-write capable parallel EEPROM interfaced directly to 8-bit microcontrollers without address latching logic. Use Value: JEDEC-standard pinout ensures drop-in compatibility with legacy radio designs using similar 28-pin packages. | Use Scenario: Storing mission-specific guidance trajectory coefficients and target acquisition thresholds in GPS-guided munitions before launch. IC Role / Device Role / Timing Role: High-reliability nonvolatile memory with 10,000-cycle endurance and 10-year data retention under extreme acceleration and thermal shock. Use Value: Optional 12V-biased device ID area (7FC0H–7FFFH) enables secure unit serialization and anti-counterfeit verification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28HC256-90JU | Same core die, commercial temperature range (–40°C to +85°C), 32-lead CLCC package, no MIL-STD-883 screening | Lacks military qualification; unsuitable for avionics or defense platforms requiring extended temperature or radiation tolerance | Select only for cost-sensitive industrial prototypes where full MIL-STD-883 compliance is not mandated |
| MX28F256K | 256 Kbit parallel EEPROM, 120 ns access, 10 ms write, but requires separate 12V VPP for programming and lacks DATA polling | No built-in write-completion signaling; requires external status monitoring or fixed-delay timing loops | Choose only if existing board design already accommodates 12V VPP routing and fixed-timing write protocols |
Compared with AT28HC256-90JU, the AT28HC256E-90FM/883 adds full MIL-STD-883 screening, extended temperature operation, and enhanced reliability testing-critical for deployed defense systems. Versus MX28F256K, it eliminates external VPP dependency and provides deterministic write-status feedback via I/O7 polling, reducing firmware complexity and improving system robustness.
Availability
AT28HC256E-90FM/883 is available at Aetrix Electronics and suitable for avionics flight control, military radar calibration, tactical radio firmware storage, and guided munition guidance parameter retention requiring stable component supply under extended temperature and long-lifecycle programs.
Supply support for AT28HC256E-90FM/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 Inc. is a global semiconductor manufacturer specializing in microcontrollers, analog devices, and nonvolatile memory solutions for industrial, automotive, and aerospace markets.
The AT28HC256 product line delivers high-reliability parallel EEPROMs optimized for military and space applications requiring extended temperature operation, radiation tolerance, and deterministic write timing-designed specifically for legacy 8-bit system upgrades and DO-160/RTCA DO-254-compliant platforms.
FAQ
What is the maximum page write cycle time for AT28HC256E-90FM/883?
The maximum page write cycle time for AT28HC256E-90FM/883 is 10 ms, as specified in the datasheet under AC Write Characteristics (Table 6-3). This value applies to the military-grade variant screened per MIL-STD-883 and is validated across the full –55°C to +125°C operating range. The AT28HC256E-90FM/883 does not support the faster 3 ms option found in the AT28HC256F variant.
Does AT28HC256E-90FM/883 require a 12V programming voltage?
No, AT28HC256E-90FM/883 operates from a single 5V ±10% supply and does not require external 12V VPP for normal read/write operations. However, a 12V ±0.5V bias on A9 is required only to access the optional 64-byte device identification area (7FC0H–7FFFH); standard memory array operations use only 5V.
How is write completion detected on AT28HC256E-90FM/883?
Write completion on AT28HC256E-90FM/883 is detected using two independent methods: DATA polling on I/O7 (complement of last written byte appears until completion) and toggle-bit behavior on I/O6 (toggles between 0 and 1 during write, then stabilizes). Both methods are fully functional across the military temperature range and require no external components.
What package type is used for AT28HC256E-90FM/883?
AT28HC256E-90FM/883 is packaged in a 32-lead CERDIP (Ceramic Dual Inline Package) conforming to MIL-STD-1835 D-10 Config A. Pins 1 and 17 are designated "Don't Connect" (DC) and must remain unconnected. The marking "FM/883" confirms full MIL-STD-883 screening and CERDIP packaging.
Is software data protection enabled by default on AT28HC256E-90FM/883?
No, software data protection (SDP) is disabled by default on AT28HC256E-90FM/883. It can be enabled via the three-byte command sequence (AA to 5555H, 55 to 2AAAH, A0 to 5555H). Once enabled, SDP remains active through power cycles and requires the disable sequence (AA/55/80/AA/20/55) to deactivate. The AT28HC256E-90FM/883 ships with SDP inactive.
AT28HC256E-90FM/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:
- 10ms
- Access Time:
- 90 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
AT28HC256E-90FM/883 FAQ
1.How can I place an order for AT28HC256E-90FM/883 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC256E-90FM/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-90FM/883 reliable?
The price and inventory of AT28HC256E-90FM/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-90FM/883 is usually 5 days.
3.What payment methods are accepted for AT28HC256E-90FM/883?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC256E-90FM/883 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC256E-90FM/883?
AT28HC256E-90FM/883 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC256E-90FM/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-90FM/883?
For technical support, including AT28HC256E-90FM/883 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC256E-90FM/883 requirements.
6.How does Aetrix verify that AT28HC256E-90FM/883 is sourced from the original manufacturer or authorized distributors?
All AT28HC256E-90FM/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-90FM/883 meets industry standards.
7.What is the process for return or replacement of AT28HC256E-90FM/883?
All AT28HC256E-90FM/883 units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC256E-90FM/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-90FM/883 part is unused and in its original packaging.
Return procedure for AT28HC256E-90FM/883:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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