My Inquiry
My Account
Microchip Technology AT28C256E-25UM/883
- Part No.:
- AT28C256E-25UM/883
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-BCPGA
- Datasheet:
-
AT28C256E-25UM/883.pdf
- Description:
- IC EEPROM 256KBIT PAR 28CPGA
- Quantity:
- Payment:
- Shipping:
Inventory:4,020
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT28C256E-25UM/883 from Microchip Technology is a military-grade 256-Kbit paged parallel EEPROM organized as 32,768 × 8, featuring 150 ns read access time, 10 ms maximum page write cycle time, and single 5V ±10% supply operation. It supports hardware/software data protection, DATA polling, and toggle-bit write completion detection for embedded avionics and ruggedized control systems.
For engineers reviewing the AT28C256E-25UM/883 datasheet, AT28C256E-25UM/883 pinout, AT28C256E-25UM/883 application, or AT28C256E-25UM/883 equivalent, this page delivers verified military-spec electrical characteristics, JEDEC-compliant byte-wide pinout, endurance (100,000 cycles), data retention (10 years), and 300 µA CMOS standby current - all confirmed per DS20006344A.
Technical Context
The AT28C256E-25UM/883 implements a paged architecture with a 64-byte internal latched buffer, 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) control eliminates bus contention during read operations.
Write completion is signaled via I/O7 DATA polling (complement-to-data behavior) or I/O6 toggle-bit detection, both usable at any point during tWC. Hardware protection includes VCC sense (<3.8 V inhibit), 5 ms power-on delay, and noise filtering on WE/CE inputs (15 ns pulse rejection).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8) - full byte-addressable nonvolatile storage without external refresh or backup battery |
| Read Access Time | 250 ns max - meets MIL-STD-883 Class B timing for real-time deterministic read latency in flight control firmware |
| Page Write Cycle | 10 ms max - enables burst programming of up to 64 bytes per internal timer-controlled operation |
| Endurance | 100,000 write/erase cycles - validated for mission-critical reprogramming in field-deployed defense electronics |
| Data Retention | 10 years at +125°C - guaranteed data integrity across extended storage and operational life in harsh environments |
| Supply Voltage | 5V ±10% - compatible with legacy TTL/CMOS logic rails and MIL-STD-704 aircraft power systems |
| Standby Current | 300 µA CMOS - enables low-power sleep modes in battery-backed or energy-constrained platforms |
Pinout & Package
AT28C256E-25UM/883 is packaged in a 30-pin ceramic PGA (Pin Grid Array), compliant with MIL-STD-1835 U-configuration and qualified per MIL-PRF-38535 Class K. Pin 1 is index-marked; pins 1–28 carry address/data/control signals per JEDEC byte-wide layout; pins 29 (VCC) and 30 (GND) are dedicated power terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus selecting one of 32,768 memory locations; A6–A14 define 64-byte page boundaries for write operations |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel interface supporting read, byte write, and page write; I/O7 used for DATA polling, I/O6 for toggle-bit detection |
| CE | Chip Enable | Active-low device select; must be low for read/write; high-Z output when asserted high |
| OE | Output Enable | Active-low output gate; controls data bus drive during read; high-Z when high or during write cycles |
| WE | Write Enable | Active-low write strobe; initiates byte or page write on falling edge; inhibits writes when high |
| VCC | Power Supply | +5V ±10% main supply; powers core logic and I/O buffers; enables VCC-sense hardware protection |
| GND | Ground Reference | Signal and power return path; required for stable biasing of CMOS input thresholds and output drive |
Key Features
| Feature | Design Value |
|---|---|
| Page Write Architecture | 64-byte internal latch allows burst programming without CPU bus hold; reduces firmware overhead vs. byte-by-byte writes |
| DATA Polling & Toggle Bit | Dual asynchronous write-complete signaling (I/O7 complement, I/O6 toggle) eliminates need for fixed delays or external timers |
| Hardware Data Protection | VCC sense, 5 ms power-on delay, and 15 ns noise filtering prevent spurious writes during power transients or EMI events |
| Software Data Protection (SDP) | User-configurable 3-byte unlock sequence (AA/55/A0) enables selective write-enable for critical firmware sectors |
| Military Temperature Range | -55°C to +125°C case operating range - qualified for deployment in airborne, space, and ground vehicle subsystems |
Applications
| Avionics Flight Control Memory | Tactical Radio Firmware Storage |
|---|---|
Use Scenario: Storing calibrated sensor coefficients and flight envelope limits in F-16 digital flight control computers. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed during boot and runtime recalibration; requires deterministic 250 ns read timing. Use Value: 100,000-cycle endurance supports in-field updates; 10-year data retention ensures mission readiness after long-term depot storage. |
Use Scenario: Holding encrypted waveform definitions and channel maps in SINCGARS-compatible secure radios. IC Role / Device Role / Timing Role: Secure firmware repository with software data protection enabled to prevent unauthorized reprogramming. Use Value: SDP lock prevents tampering during transport; 300 µA standby current extends battery life in manpack configurations. |
| Missile Guidance System Calibration | Ruggedized Industrial PLC Configuration |
Use Scenario: Retaining gyro bias compensation tables and thermal drift models in JASSM guidance units. IC Role / Device Role / Timing Role: High-reliability EEPROM interfaced directly to radiation-hardened microcontroller via parallel bus. Use Value: -55°C to +125°C operation survives launch vibration and exoatmospheric cold soak; 10 ms page write enables rapid field updates. |
Use Scenario: Preserving I/O mapping and safety logic parameters in oilfield SCADA controllers exposed to desert heat. IC Role / Device Role / Timing Role: Configuration store accessed during cold start and hot-swappable module insertion. Use Value: JEDEC pinout ensures drop-in compatibility with legacy industrial designs; hardware write inhibit guards against ESD-induced corruption. |
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 temperature range (-40°C to +85°C); same 250 ns access, 10 ms write, and pinout | Lacks MIL-STD-883 qualification and extended temperature performance | Select for cost-sensitive non-military systems where environmental stress is lower |
| DS2502-E48+T&R | 1-Wire serial interface; 1 Kbit capacity; no parallel bus or page write capability | Requires microcontroller bit-banging; unsuitable for high-speed firmware loading | Choose only for ultra-low-pin-count designs where serial interface suffices and speed is secondary |
Compared with AT28C256E-25UM/883, AT28C256-25JU offers identical functionality at commercial grade, while DS2502-E48+T&R trades parallel bandwidth and capacity for interface simplicity - neither matches the military temperature, endurance, or qualification level of the original.
Availability
AT28C256E-25UM/883 is available at Aetrix Electronics and suitable for avionics, tactical communications, missile guidance, and ruggedized industrial control requiring stable component supply under extended temperature and long-life program constraints.
Supply support for AT28C256E-25UM/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 deep heritage in military and aerospace components.
The AT28C256 product line was designed specifically for high-reliability, radiation-tolerant, and extended-temperature embedded systems requiring byte-erasable, page-writable nonvolatile memory without external circuitry.
FAQ
What is the operating temperature range for AT28C256E-25UM/883?
The AT28C256E-25UM/883 is qualified for operation from -55°C to +125°C case temperature per MIL-STD-883, making it suitable for extreme-environment applications including airborne, space, and ground vehicle electronics where thermal cycling exceeds commercial-grade limits.
Does AT28C256E-25UM/883 support page write operations?
Yes, AT28C256E-25UM/883 supports 1–64-byte page write operations using an internal 64-byte latch. Each byte must be loaded within 150 µs of the prior byte, and all addresses must reside on the same page (A6–A14 constant). Page write cycle time is 10 ms maximum.
How is write completion detected on AT28C256E-25UM/883?
AT28C256E-25UM/883 provides two hardware methods: DATA polling (I/O7 returns complement of last written byte until completion) and toggle-bit detection (I/O6 toggles between 0 and 1 during write, then stabilizes). Both are usable at any time during the write cycle.
What package type is used for AT28C256E-25UM/883?
AT28C256E-25UM/883 uses a 30-pin ceramic PGA (Pin Grid Array) package, marked "UM/883" and qualified to MIL-PRF-38535 Class K. It features a 0.100" pin pitch, hermetically sealed ceramic body, and index corner for orientation.
Is software data protection enabled by default on AT28C256E-25UM/883?
No, software data protection (SDP) is disabled at shipment. It can be enabled via a three-byte unlock sequence (AA to 5555H, 55 to 2AAAH, A0 to 5555H). Once enabled, all writes require repetition of this sequence - a critical safeguard for firmware integrity in deployed systems.
AT28C256E-25UM/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:
- 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 FAQ
1.How can I place an order for AT28C256E-25UM/883 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C256E-25UM/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-25UM/883 reliable?
The price and inventory of AT28C256E-25UM/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-25UM/883 is usually 5 days.
3.What payment methods are accepted for AT28C256E-25UM/883?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C256E-25UM/883 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C256E-25UM/883?
AT28C256E-25UM/883 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C256E-25UM/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-25UM/883?
For technical support, including AT28C256E-25UM/883 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C256E-25UM/883 requirements.
6.How does Aetrix verify that AT28C256E-25UM/883 is sourced from the original manufacturer or authorized distributors?
All AT28C256E-25UM/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-25UM/883 meets industry standards.
7.What is the process for return or replacement of AT28C256E-25UM/883?
All AT28C256E-25UM/883 units undergo pre-shipment inspection (PSI). If there is an issue with AT28C256E-25UM/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-25UM/883 part is unused and in its original packaging.
Return procedure for AT28C256E-25UM/883:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28C256E-25UM/883 Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
