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Microchip Technology AT28C256E-15UM/883
- Part No.:
- AT28C256E-15UM/883
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-BCPGA
- Datasheet:
-
AT28C256E-15UM/883.pdf
- Description:
- IC EEPROM 256KBIT PAR 28CPGA
- Quantity:
- Payment:
- Shipping:
Inventory:4,497
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Product details
Overview
AT28C256E-15UM/883 from Microchip Technology is a military-grade paged parallel EEPROM with 256-Kbit (32,768 × 8) organization, 150 ns read access time, single 5V ±10% supply, and JEDEC-approved byte-wide pinout. It operates across −55°C to +125°C and supports page write cycles of up to 64 bytes in ≤10 ms for avionics data logging and embedded system configuration storage.
For engineers reviewing the AT28C256E-15UM/883 datasheet, AT28C256E-15UM/883 pinout, AT28C256E-15UM/883 application, or AT28C256E-15UM/883 equivalent, this page delivers verified military-spec electrical parameters, validated pin functions for 30-pin PGA packaging, endurance and retention specs per MIL-PRF-38535 Class B, and direct alternatives with documented timing and protection feature alignment.
Technical Context
The AT28C256E-15UM/883 implements a paged architecture with an internal 64-byte latch and autonomous control timer, enabling simultaneous write of 1–64 bytes without external address/data bus hold. Its dual-line chip enable (CE) and output enable (OE) logic ensures bus contention avoidance in multiprocessor memory-mapped systems.
It integrates hardware write inhibition via VCC sense (<3.8 V), 5 ms power-on delay, and noise filtering (<15 ns pulses), plus optional software data protection (SDP) using a three-byte command sequence at fixed addresses (5555H/2AAAH). Data polling on I/O7 and toggle-bit detection on I/O6 provide deterministic end-of-write signaling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 256 Kbit (32,768 × 8) - supports full-system configuration storage without external decoding |
| Read access time | 150 ns max - enables direct replacement of SRAM in legacy MIL-STD-1553 or 80C86-based designs |
| Page write cycle time | ≤10 ms - allows burst programming of calibration tables or firmware patches with minimal CPU overhead |
| Endurance | 100,000 write/erase cycles - qualified per MIL-PRF-38535 Class B for mission-critical field updates |
| Data retention | 10 years at +125°C - meets extended-life requirements for sealed aerospace electronics |
| Supply voltage | 5 V ±10% - compatible with legacy 5 V TTL/CMOS logic rails without level-shifting |
| Operating temperature | −55°C to +125°C - fully specified across military temperature range per MIL-STD-883 Method 1010 |
Pinout & Package
AT28C256E-15UM/883 is supplied in a 30-pin Ceramic Pin Grid Array (PGA) package compliant with MIL-STD-1835 U-28 configuration. Pin 1 is index-marked; pins are arranged in two staggered rows with 0.100" pitch.
| 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 indication |
| CE | Chip Enable | Active-low primary selection signal; must be low for read/write; high-Z output when asserted high |
| OE | Output Enable | Active-low output gate; controls data bus drive during reads; required high during writes |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; initiates byte or page programming |
| VCC | Power supply | +5 V ±10% main supply; internally monitored for write inhibition below 3.8 V |
| GND | Ground reference | Signal and power return; decoupling required within 0.5" of VCC pin per MIL-STD-1537 |
| DC (pins 1, 17) | Don't Connect | No internal connection; must remain unconnected per datasheet DS20006344A-page 4 |
Key Features
| Feature | Design Value |
|---|---|
| Page write with internal 64-byte latch | Eliminates need for external address/data latches and reduces host processor intervention during multi-byte writes |
| DATA Polling on I/O7 | Enables real-time, non-blocking write completion detection without dedicated status registers or interrupts |
| Hardware + software data protection | Prevents spurious writes during power-up/down transients and accidental firmware overwrites via configurable SDP |
| JEDEC byte-wide pinout | Ensures drop-in compatibility with legacy 27C256 EPROM and 62256 SRAM sockets in existing PCB layouts |
| 12 V chip erase mode | Permits full-device erasure via software command sequence (6-byte code), avoiding UV erasers or rework |
Applications
| Avionics Configuration Storage | Tactical Radio Firmware Patching |
|---|---|
Use Scenario: Storing flight control parameter sets, sensor calibration coefficients, and mission profiles in MIL-STD-1553B-equipped aircraft subsystems. IC Role / Device Role / Timing Role: Nonvolatile configuration register providing deterministic 150 ns read access and 10 ms page write for runtime parameter loading. Use Value: Eliminates boot-time EEPROM initialization delays and supports in-field updates without system reset. |
Use Scenario: Field-upgrading encryption keys and waveform definitions in handheld HF/VHF radios operating under extreme thermal cycling. IC Role / Device Role / Timing Role: Secure firmware repository with 100K-cycle endurance and software data protection enabled during OTA updates. Use Value: Prevents corruption during brown-out conditions and enables authenticated patch validation prior to write commit. |
| Spacecraft Onboard Telemetry Logging | Military Vehicle Health Monitoring |
Use Scenario: Capturing radiation-hardened telemetry snapshots (voltage, temperature, attitude) during orbital passes where power is intermittent. IC Role / Device Role / Timing Role: Radiation-tolerant nonvolatile buffer with 10-year data retention at +125°C and automatic page write recovery after power interruption. Use Value: Guarantees data integrity across multiple power cycles without host-level wear leveling or checksum management. |
Use Scenario: Recording engine diagnostics, CAN bus error logs, and maintenance history in armored ground vehicles exposed to shock/vibration. IC Role / Device Role / Timing Role: Ruggedized memory node interfacing directly to 80C32 microcontroller buses with CMOS/TTL compatibility. Use Value: Reduces BOM count by eliminating level shifters and supports hot-swap logging during vehicle operation. |
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 | Same die, identical 150 ns timing and 100K endurance; marked "E" denotes extended endurance grade | Qualified to same MIL-PRF-38535 Class B screening but lacks explicit "E" marking in part number | Select AT28C256E-15UM/883 when guaranteed 100K-cycle endurance and traceable lot documentation are contractually required. |
| DS2502-E48+T&R | 1-Wire interface, 1024-bit EEPROM; no parallel bus, no page write, 10K endurance, +85°C max | Used in identification/authentication tokens-not suitable for memory-mapped configuration storage | Choose only for secure serial ID tagging; not a functional or pinout alternative for AT28C256E-15UM/883. |
Compared with AT28C256E-15UM/883, the AT28C256-15UM/883 offers identical performance but lacks extended endurance certification, while DS2502-E48+T&R provides serial security features at the cost of parallel interface compatibility and temperature rating-making neither a drop-in replacement.
Availability
AT28C256E-15UM/883 is available at Aetrix Electronics and suitable for avionics configuration storage, tactical radio firmware patching, spacecraft telemetry logging, and military vehicle health monitoring requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for AT28C256E-15UM/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 company specializing in microcontrollers, analog devices, and nonvolatile memory solutions, with design centers and manufacturing facilities certified to ISO 9001 and AS9100 standards.
The AT28C256E-15UM/883 belongs to Microchip's military-grade parallel EEPROM product line, engineered for high-reliability applications in aerospace, defense, and industrial control where data integrity, long-term retention, and extreme environmental resilience are mandatory.
FAQ
What is the maximum page write size supported by the AT28C256E-15UM/883?
The AT28C256E-15UM/883 supports page write operations of 1 to 64 bytes per cycle. All bytes must reside within the same 64-byte page boundary defined by address bits A6–A14. Each successive byte must be loaded within 150 µs (tBLC) of the previous one; exceeding this window triggers automatic internal programming. This capability is confirmed in Section 6.8 and Figure 6-9 of datasheet DS20006344A.
Does the AT28C256E-15UM/883 require a 12 V supply for any operation?
The AT28C256E-15UM/883 operates from a single 5 V ±10% supply for all standard read and write functions. A 12 V ±0.5 V supply is required only for the optional Chip Erase mode (applied to OE pin), as specified in Table 6-1 and Section 6.10. Normal operation-including software data protection enable/disable-uses only 5 V.
How is write completion detected on the AT28C256E-15UM/883?
Write completion on the AT28C256E-15UM/883 is detected via two hardware methods: DATA Polling on I/O7 (complement of written data appears until completion) and Toggle Bit detection on I/O6 (bit toggles during write, stabilizes afterward). Both are characterized in Tables 6-5 and 6-6 and require no external components-confirmed in Sections 6.14 and 6.16 of DS20006344A.
What packaging and screening level does the AT28C256E-15UM/883 meet?
The AT28C256E-15UM/883 is packaged in a 30-pin Ceramic PGA (MIL-STD-1835 U-28) and screened to MIL-PRF-38535 Class B requirements, including temperature cycling, hermeticity, and burn-in. The "/883" suffix denotes compliance with the full MIL-STD-883 test suite, and "E" indicates extended 100,000-cycle endurance grading per datasheet revision history and Package Marking section.
Can the AT28C256E-15UM/883 be used as a direct replacement for the AT28C256-15UM/883?
Yes-the AT28C256E-15UM/883 is functionally and pin-compatible with the AT28C256-15UM/883, sharing identical timing, DC characteristics, and package. The "E" denotes extended endurance (100K vs. 10K cycles), making it a superior drop-in replacement where higher write-cycle reliability is required. Both comply with MIL-PRF-38535 Class B and use the same 30-pin PGA footprint.
AT28C256E-15UM/883 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-BCPGA
- Packaging:
- Box
- 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:
- 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)
AT28C256E-15UM/883 FAQ
1.How can I place an order for AT28C256E-15UM/883 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C256E-15UM/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 AT28C256E-15UM/883 reliable?
The price and inventory of AT28C256E-15UM/883 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28C256E-15UM/883 is usually 5 days.
3.What payment methods are accepted for AT28C256E-15UM/883?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C256E-15UM/883 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C256E-15UM/883?
AT28C256E-15UM/883 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C256E-15UM/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 AT28C256E-15UM/883?
For technical support, including AT28C256E-15UM/883 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C256E-15UM/883 requirements.
6.How does Aetrix verify that AT28C256E-15UM/883 is sourced from the original manufacturer or authorized distributors?
All AT28C256E-15UM/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 AT28C256E-15UM/883 meets industry standards.
7.What is the process for return or replacement of AT28C256E-15UM/883?
All AT28C256E-15UM/883 units undergo pre-shipment inspection (PSI). If there is an issue with AT28C256E-15UM/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 AT28C256E-15UM/883 part is unused and in its original packaging.
Return procedure for AT28C256E-15UM/883:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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