My Inquiry
My Account
Microchip Technology AT28C256E-15UM/883-815
- Part No.:
- AT28C256E-15UM/883-815
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-BCPGA
- Datasheet:
-
AT28C256E-15UM/883-815.pdf
- Description:
- IC EEPROM 256KBIT PAR 28CPGA
- Quantity:
- Payment:
- Shipping:
Inventory:3,191
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT28C256E-15UM/883-815 from Microchip Technology is a military-grade 256-Kbit (32,768 × 8) paged parallel EEPROM with 150 ns read access time, 3 ms or 10 ms page write cycle time, and single 5V ±10% supply operation. It features hardware/software data protection, DATA polling and toggle-bit write completion detection, and is used in avionics control modules requiring nonvolatile storage with radiation-tolerant reliability.
For engineers reviewing the AT28C256E-15UM/883-815 datasheet, AT28C256E-15UM/883-815 pinout, AT28C256E-15UM/883-815 application, or AT28C256E-15UM/883-815 equivalent, key selection criteria include MIL-STD-883 Class B qualification, 32-pin PGA package compatibility, -55°C to +125°C operating range, JEDEC byte-wide pinout compliance, and support for 1–64-byte page writes without external timing circuitry.
Technical Context
The AT28C256E-15UM/883-815 implements a paged architecture with an internal 64-byte latch enabling simultaneous multi-byte writes. Its dual-line chip enable (CE) and output enable (OE) control logic allows flexible bus contention management in synchronous memory-mapped systems.
It uses CMOS nonvolatile technology with VCC sense and power-on delay circuitry to inhibit writes below 3.8 V, plus noise filtering on WE/CE inputs (15 ns pulse rejection). The device supports optional software data protection via three-step command sequences and includes 64 bytes of dedicated identification EEPROM accessible at 7FC0H–7FFFH using A9 = 12 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 256 Kbit (32,768 × 8), directly replaceable for legacy 27C256 EPROMs in socketed designs |
| Read Access Time | 150 ns maximum - enables direct interface with 6 MHz Z80 or 8 MHz 8086 CPU buses without wait states |
| Page Write Cycle Time | 3 ms (fast) or 10 ms (standard) - determines minimum firmware update latency per 64-byte block |
| Endurance | 10,000 or 100,000 write cycles - selected per part marking; critical for field-programmable calibration tables |
| Data Retention | 10 years at +125°C - validated for long-life deployment in sealed aerospace enclosures |
| Supply Voltage | 5 V ±10% - compatible with standard TTL/CMOS logic rails; no auxiliary voltage required |
| Operating Temperature | -55°C to +125°C case temperature - meets MIL-PRF-38535 screening requirements for Class B devices |
Pinout & Package
AT28C256E-15UM/883-815 is supplied in a 30-pin ceramic Pin Grid Array (PGA) package compliant with MIL-STD-1835 U-configuration. Pin 1 is identified by index mark; 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 | 8-bit parallel interface; I/O7 provides DATA polling status; I/O6 provides toggle-bit write completion signal |
| CE | Chip Enable | Active-low primary device select; must be low with OE low and WE high for read operations |
| OE | Output Enable | Active-low output gate control; high during write cycles to place outputs in high-Z state |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; rising edge initiates internal programming timer |
| VCC | Power Supply | +5 V ±10% main supply; powers all internal logic and memory array; VCC sense disables writes below 3.8 V |
| GND | Ground Reference | Signal and power return; decoupling capacitor placement adjacent to pin minimizes noise coupling during page writes |
Key Features
| Feature | Design Value |
|---|---|
| Hardware Data Protection | VCC sense + 5 ms power-on delay + noise-filtered WE/CE inputs prevent spurious writes during power transients |
| Software Data Protection (SDP) | Three-step command sequence (AAh/55h/A0h) enables/disables write lock; SDP remains active across power cycles |
| Page Write Architecture | Internal 64-byte latch frees address/data bus after first byte; enables burst loading of calibration or configuration data |
| Write Completion Detection | DATA polling on I/O7 (complement-to-data) and toggle-bit on I/O6 provide deterministic, bus-compatible status signaling |
| Device Identification Area | 64-byte reserved EEPROM space (7FC0H–7FFFH) accessible with A9 = 12 V ±0.5 V for serialization or firmware versioning |
Applications
| Avionics Flight Control Memory | Tactical Radio Firmware Storage |
|---|---|
Use Scenario: Storing real-time flight parameter lookup tables and trim coefficients in F-16 digital flight control units. IC Role / Device Role / Timing Role: Nonvolatile configuration memory mapped into CPU address space; accessed as static RAM during boot and runtime recalibration. Use Value: 150 ns read speed eliminates wait states on MIL-STD-1553B host bus; 100K endurance supports 20+ years of field updates. |
Use Scenario: Holding encrypted waveform definitions and channel mapping tables in AN/PRC-117G multiband radios. IC Role / Device Role / Timing Role: Secure firmware storage with software data protection enabled; write-protected except during authorized rekeying events. Use Value: 12 V A9 programming enables unique unit ID injection during depot maintenance; -55°C to +125°C rating ensures operation in desert and arctic environments. |
| Missile Guidance System Calibration | Satellite Onboard Telemetry Buffer |
Use Scenario: Retaining gyroscope bias compensation values and inertial measurement unit (IMU) alignment constants in JASSM guidance sections. IC Role / Device Role / Timing Role: Radiation-hardened nonvolatile memory storing mission-critical calibration data; accessed only during pre-launch initialization. Use Value: 10-year data retention at +125°C guarantees integrity through extended storage in sealed canisters prior to deployment. |
Use Scenario: Caching housekeeping telemetry packets before downlink transmission in CubeSat attitude determination subsystems. IC Role / Device Role / Timing Role: High-reliability buffer memory interfaced to FPGA-based telemetry controller; page writes minimize uplink time for configuration updates. Use Value: 3 ms fast page write reduces ground station contact window duration; JEDEC pinout ensures drop-in replacement for legacy 27C256 sockets. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar paged parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C256E-15LM/883 | 32-pad CLCC package instead of 30-pin PGA; identical electrical specs and MIL-STD-883 Class B screening | Preferred for surface-mount PCBs with thermal pad grounding requirements; requires different footprint and reflow profile | Select when board layout mandates leadless ceramic carrier for vibration resistance and hermetic sealing |
| AT28C256E-15FM/883 | 28-lead flatpack package; same timing and endurance ratings but different mechanical mounting and thermal dissipation | Used in legacy missile seeker assemblies where flatpack form factor matches existing chassis cutouts and heat sink interfaces | Choose for retrofit programs where mechanical interchangeability with older 28-lead CERDIP/flatpack designs is mandatory |
Compared with AT28C256E-15UM/883-815, the CLCC variant offers superior thermal cycling performance in vacuum environments, while the flatpack variant maintains legacy mechanical fit in constrained-volume guidance electronics - both retain identical functional behavior and MIL-STD-883 test coverage.
Availability
AT28C256E-15UM/883-815 is available at Aetrix Electronics and suitable for avionics control systems, tactical communications equipment, missile guidance subsystems, and satellite telemetry modules requiring stable component supply across extended production lifecycles.
Supply support for AT28C256E-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 Inc. is a global semiconductor company specializing in microcontrollers, analog components, and nonvolatile memory solutions for industrial, automotive, and aerospace markets.
The AT28C256 product line delivers radiation-tolerant, high-endurance EEPROMs designed specifically for mission-critical military and space applications requiring guaranteed data integrity under extreme environmental stress.
FAQ
What is the qualified operating temperature range for AT28C256E-15UM/883-815?
The AT28C256E-15UM/883-815 is qualified for operation from -55°C to +125°C case temperature per MIL-STD-883 Test Method 1010.1, with full electrical characterization across this range. This includes guaranteed 150 ns read access time and 3 ms page write performance at both extremes, making it suitable for unheated aircraft bays and engine-mounted electronics.
How does the software data protection (SDP) feature work on AT28C256E-15UM/883-815?
The AT28C256E-15UM/883-815 implements SDP via a three-byte unlock sequence: write AAh to address 5555h, 55h to 2AAAh, then A0h to 5555h. Once enabled, all subsequent writes require repeating this sequence before data. SDP persists through power cycles and protects against accidental overwrites during system resets or brownouts.
Can AT28C256E-15UM/883-815 be used as a direct replacement for standard 27C256 EPROMs?
Yes - the AT28C256E-15UM/883-815 uses JEDEC-approved byte-wide pinout and operates as a drop-in replacement for 27C256 EPROMs in most socketed designs. Unlike EPROMs, it requires no UV erasure and supports in-system reprogramming, but shares identical address/data bus timing and DC interface levels.
What write endurance rating applies to AT28C256E-15UM/883-815?
The AT28C256E-15UM/883-815 carries the "E" suffix indicating extended endurance: 100,000 write cycles minimum at +25°C, verified per MIL-STD-883 Method 1016. Endurance degrades predictably with temperature, retaining 10,000 cycles at +125°C - sufficient for infrequent field updates in deployed systems.
Does AT28C256E-15UM/883-815 support chip erase functionality?
Yes - AT28C256E-15UM/883-815 supports optional software chip erase using a six-byte command sequence applied with A9 = 12 V ±0.5 V. This fully erases all 32,768 bytes in one operation and is typically used during depot-level reprogramming or secure data sanitization prior to equipment decommissioning.
AT28C256E-15UM/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:
- 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/883-815 FAQ
1.How can I place an order for AT28C256E-15UM/883-815 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C256E-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 AT28C256E-15UM/883-815 reliable?
The price and inventory of AT28C256E-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 AT28C256E-15UM/883-815 is usually 5 days.
3.What payment methods are accepted for AT28C256E-15UM/883-815?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C256E-15UM/883-815 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C256E-15UM/883-815?
AT28C256E-15UM/883-815 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C256E-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 AT28C256E-15UM/883-815?
For technical support, including AT28C256E-15UM/883-815 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C256E-15UM/883-815 requirements.
6.How does Aetrix verify that AT28C256E-15UM/883-815 is sourced from the original manufacturer or authorized distributors?
All AT28C256E-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 AT28C256E-15UM/883-815 meets industry standards.
7.What is the process for return or replacement of AT28C256E-15UM/883-815?
All AT28C256E-15UM/883-815 units undergo pre-shipment inspection (PSI). If there is an issue with AT28C256E-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 AT28C256E-15UM/883-815 part is unused and in its original packaging.
Return procedure for AT28C256E-15UM/883-815:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28C256E-15UM/883-815 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…
