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Microchip Technology AT28C256E-25UM/883-815
- Part No.:
- AT28C256E-25UM/883-815
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-BCPGA
- Datasheet:
-
AT28C256E-25UM/883-815.pdf
- Description:
- IC EEPROM 256KBIT PAR 28CPGA
- Quantity:
- Payment:
- Shipping:
Inventory:2,348
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Product details
Overview
AT28C256E-25UM/883-815 from Microchip Technology is a military-grade paged parallel EEPROM with 256-Kbit (32,768 × 8) organization, 250 ns read access time, single 5V ±10% supply, and JEDEC-approved byte-wide pinout. It supports 1–64-byte page writes with automatic internal timing and operates across –55°C to +125°C for avionics and hardened embedded control systems.
For engineers reviewing the AT28C256E-25UM/883-815 datasheet, AT28C256E-25UM/883-815 pinout, AT28C256E-25UM/883-815 application, or AT28C256E-25UM/883-815 equivalent, key selection criteria include military temperature range compliance, page write endurance (10,000 cycles), CMOS/TTL compatibility, hardware/software data protection, and 30-pin PGA packaging per MIL-STD-1835.
Technical Context
The AT28C256E-25UM/883-815 implements a paged architecture with a 64-byte internal latch, enabling burst writes without external address/data bus hold. Its dual-line chip enable (CE) and output enable (OE) control prevents bus contention during read operations.
Write completion detection uses DATA Polling on I/O7 (complement-to-data during programming) and Toggle Bit on I/O6, both operable at any point in the write cycle. Hardware protection includes VCC sense (<3.8V inhibit), 5 ms power-on delay, and noise filtering on WE/CE inputs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8) - fixed byte-wide organization compatible with legacy 8-bit microprocessor buses |
| Read Access Time | 250 ns max - meets MIL-STD-883 Class B timing for real-time deterministic memory access |
| Page Write Cycle | 10 ms max - enables high-throughput firmware updates without CPU polling overhead |
| Endurance | 10,000 write/erase cycles - validated for mission-critical field reprogramming in aerospace systems |
| Data Retention | 10 years at +125°C - guaranteed nonvolatile storage under extended high-temperature operation |
| Supply Voltage | 5V ±10% - single-rail operation eliminates need for auxiliary voltage regulators |
| Operating Temp | –55°C to +125°C - qualified per MIL-PRF-38535 for space-qualified and defense electronics |
Pinout & Package
AT28C256E-25UM/883-815 is supplied in a 30-pin Ceramic Pin Grid Array (PGA) package per MIL-STD-1835 U-configuration, with pins 1–28 assigned to address, data, and control signals, and pins 29–30 designated as VCC and GND.
| 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 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 reporting |
| CE | Chip Enable | Active-low device select; must be low with OE low for read, or with WE low for write - enables bus arbitration |
| OE | Output Enable | Active-low output gate; high-Z state when asserted high, preventing bus contention during shared-memory access |
| WE | Write Enable | Active-low write strobe; initiates byte or page write; combined with CE for dual-signal write protection |
| VCC | Power Supply | +5V ±10% main supply; internal VCC sense disables writes below 3.8V to prevent corruption during brownout |
| GND | Ground Reference | Signal and power return; decoupling required within 10 mm of VCC pin per MIL-STD-1378 design rules |
Key Features
| Feature | Design Value |
|---|---|
| 64-byte Page Register | Reduces firmware update time by 63× vs. byte-write mode; eliminates external address latching logic |
| DATA Polling (I/O7) | Enables interrupt-driven write completion detection without dedicated status registers or timers |
| Software Data Protection | Three-byte unlock sequence (AAh/55h/A0h) prevents accidental writes during power transitions or EMI events |
| Hardware Write Inhibit | VCC sense + 5 ms power-on delay ensures reliable boot-time write blocking without external supervisor ICs |
| Device Identification Area | 64-byte reserved EEPROM block (7FC0h–7FFFh) accessible at 12V for serialization, calibration, or revision tracking |
Applications
| Avionics Flight Control | Military Radio Firmware Storage |
|---|---|
Use Scenario: Storing flight control law parameters and sensor calibration tables in F-16 digital flight computers. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed via MIL-STD-1553B host processor during power-up and in-flight reconfiguration. Use Value: 10-year data retention at +125°C ensures parameter integrity across aircraft service life without battery backup. | Use Scenario: Holding encrypted waveform definitions and channel maps in AN/PRC-160 tactical radios. IC Role / Device Role / Timing Role: Secure firmware repository with software data protection enabled to prevent tampering during field deployment. Use Value: Page write capability reduces over-the-air update time by >95% compared to byte-write alternatives. |
| Satellite Onboard Computer | Nuclear Power Plant Safety Controller |
Use Scenario: Storing fault-tolerant boot code and watchdog configuration in CubeSat OBCs operating in LEO radiation environment. IC Role / Device Role / Timing Role: Radiation-hardened (RHA) nonvolatile memory interfaced directly to LEON3 SPARC processor via 8-bit data bus. Use Value: –55°C to +125°C operation supports thermal cycling in unheated satellite bays without derating. | Use Scenario: Maintaining trip setpoints and diagnostic logs in Class 1E safety-related instrumentation and control systems. IC Role / Device Role / Timing Role: Qualified EEPROM for IEEE 323/344 seismic and environmental testing, used in redundant controller modules. Use Value: MIL-PRF-38535 Class B qualification ensures traceability, lot control, and failure analysis support for nuclear QA requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar paged parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C256-25JU | Commercial-grade 32-pin CLCC; 250 ns access; no MIL-STD-883 screening or temperature rating | Lacks radiation tolerance, burn-in, and extended temperature validation - unsuitable for defense/aerospace | Select only for cost-sensitive industrial prototypes where military qualification is not required |
| MX28F256K | 256-Kbit flash memory; 12V programming; no page write; erase-block architecture | Requires full-sector erase before rewrite; incompatible timing and command protocol with AT28C256E-25UM/883-815 | Use only if system redesign accommodates flash-specific erase/write sequencing and voltage generation |
Compared with AT28C256-25JU and MX28F256K, the AT28C256E-25UM/883-815 delivers guaranteed military temperature operation, built-in page write acceleration, and hardware/software dual-protection - critical for fielded systems requiring zero-failure firmware persistence.
Availability
AT28C256E-25UM/883-815 is available at Aetrix Electronics and suitable for avionics, military communications, satellite onboard computing, and nuclear safety systems requiring stable component supply across extended product lifecycles.
Supply support for AT28C256E-25UM/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 is a global semiconductor company specializing in microcontrollers, analog devices, and nonvolatile memory solutions for industrial, automotive, and aerospace markets.
The AT28C256 product line was designed for high-reliability, pin-compatible replacement of obsolete EPROMs and early EEPROMs in legacy military and spaceborne systems requiring long-term obsolescence mitigation.
FAQ
What is the maximum page write cycle time for AT28C256E-25UM/883-815?
The AT28C256E-25UM/883-815 has a maximum page write cycle time of 10 ms, as specified in the AC Electrical Characteristics table (tWC). This value applies to the -25 speed grade and is validated under MIL-STD-883 test conditions across the full –55°C to +125°C operating range. The AT28C256E-25UM/883-815 achieves this using an internal control timer that automatically manages the programming sequence after data latching.
Does AT28C256E-25UM/883-815 support both hardware and software data protection?
Yes, AT28C256E-25UM/883-815 implements dual-layer data protection. Hardware protection includes VCC sensing (inhibits writes below 3.8V), 5 ms power-on delay, and noise filtering on WE/CE inputs. Software protection uses a three-byte unlock sequence (AAh/55h/A0h) to enable/disable write blocking. Both mechanisms operate independently and are fully functional in the AT28C256E-25UM/883-815.
What package type is used for AT28C256E-25UM/883-815?
AT28C256E-25UM/883-815 is packaged in a 30-pin Ceramic Pin Grid Array (PGA) per MIL-STD-1835 U-configuration. This package features ceramic body construction, gold-plated pins, and hermetic sealing to meet MIL-PRF-38535 Class B reliability requirements. Pin 1 is marked with a Δ symbol, and the top-side marking includes "AT28C256@25UM/883" per Microchip's military marking standard.
How is write completion detected on AT28C256E-25UM/883-815?
AT28C256E-25UM/883-815 supports two independent write completion detection methods: DATA Polling on I/O7 (returns complement of written data until complete) and Toggle Bit on I/O6 (toggles between 0 and 1 during programming). Both methods are operational at any time during the write cycle and require no additional hardware - the AT28C256E-25UM/883-815 handles all timing internally.
What is the endurance rating for AT28C256E-25UM/883-815?
The AT28C256E-25UM/883-815 is rated for 10,000 write/erase cycles, as confirmed in the DC Characteristics table (endurance specification) and validated per MIL-STD-883 Method 1006. This endurance level is guaranteed across the full military temperature range and applies to both byte and page write operations. The device also includes internal error correction to extend effective field lifetime beyond the rated cycle count.
AT28C256E-25UM/883-815 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:
- 250 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-25UM/883-815 FAQ
1.How can I place an order for AT28C256E-25UM/883-815 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C256E-25UM/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 AT28C256E-25UM/883-815 reliable?
The price and inventory of AT28C256E-25UM/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 AT28C256E-25UM/883-815 is usually 5 days.
3.What payment methods are accepted for AT28C256E-25UM/883-815?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C256E-25UM/883-815 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C256E-25UM/883-815?
AT28C256E-25UM/883-815 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C256E-25UM/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 AT28C256E-25UM/883-815?
For technical support, including AT28C256E-25UM/883-815 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C256E-25UM/883-815 requirements.
6.How does Aetrix verify that AT28C256E-25UM/883-815 is sourced from the original manufacturer or authorized distributors?
All AT28C256E-25UM/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 AT28C256E-25UM/883-815 meets industry standards.
7.What is the process for return or replacement of AT28C256E-25UM/883-815?
All AT28C256E-25UM/883-815 units undergo pre-shipment inspection (PSI). If there is an issue with AT28C256E-25UM/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 AT28C256E-25UM/883-815 part is unused and in its original packaging.
Return procedure for AT28C256E-25UM/883-815:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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