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Microchip Technology AT28HC256-12LM/883
- Part No.:
- AT28HC256-12LM/883
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-CLCC
- Datasheet:
-
AT28HC256-12LM/883.pdf
- Description:
- IC EEPROM 256KBIT PARALLEL 32LCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,425
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Product details
Overview
AT28HC256-12LM/883 from Microchip Technology is a military-grade 256-Kbit (32,768 × 8) paged parallel EEPROM with 120 ns read access time, 10 ms maximum page write cycle time, and full operation across –55°C to +125°C. It features hardware/software data protection, DATA polling, and JEDEC-standard byte-wide pinout for integration into avionics, missile guidance, and hardened embedded control systems.
For engineers reviewing the AT28HC256-12LM/883 datasheet, AT28HC256-12LM/883 pinout, AT28HC256-12LM/883 application, or AT28HC256-12LM/883 equivalent, this device delivers deterministic nonvolatile storage in MIL-STD-883-compliant ceramic packages with verified endurance (10,000 cycles), 10-year data retention, and single 5V ±10% supply operation.
Technical Context
The AT28HC256-12LM/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 supports bus contention avoidance in multiprocessor environments.
Write completion is confirmed via I/O7 DATA polling or I/O6 toggle-bit detection-both functional during active programming without external timing components. Hardware write inhibition activates below 3.8 V VCC and includes noise filtering (<15 ns pulse rejection) and power-on delay (~5 ms).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 256 Kbit (32,768 × 8) - fixed byte-wide organization compatible with 8-bit microprocessor buses |
| Read Access Time | 120 ns - meets timing requirements for MIL-STD-883 Class B systems operating at ≤8.3 MHz |
| Page Write Cycle Time | 10 ms max - enables burst-write throughput of up to 6.4 KB/s with no external wait-state logic |
| Operating Temperature | –55°C to +125°C - qualified per MIL-STD-883 Method 1010 for extended life in aerospace thermal environments |
| VCC Supply | 5 V ±10% - eliminates need for dedicated voltage regulators in legacy 5V military platforms |
| Endurance | 10,000 write/erase cycles - validated under full temperature range with no derating required |
| Data Retention | 10 years - guaranteed without refresh or backup power in sealed ceramic packages |
Pinout & Package
AT28HC256-12LM/883 is supplied in a 32-lead CLCC (Ceramic Leadless Chip Carrier) package compliant with MIL-STD-1835 C-12. Pins 1 and 17 are designated "Don't Connect" per datasheet DS20006352A-page 4.
| 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 reporting |
| CE | Chip Enable | Active-low selection signal; must be low with OE low and WE high for read access |
| OE | Output Enable | Active-low output gating; high during write cycles to place outputs in high-Z state |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; controls byte vs. page write initiation |
| VCC | Power Supply | +5 V ±10% main supply; internal VCC sense disables writes below ~3.8 V |
| GND | Ground Reference | Signal and power return; decoupling required within 10 mm of VCC pin per MIL-PRF-38535 |
| DC (Pins 1, 17) | No Connect | Unbonded pads; must remain unconnected per packaging specification |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-standard byte-wide pinout | Enables drop-in replacement of legacy 27C256 EPROMs and 28C256 EEPROMs without PCB redesign |
| 64-byte internal page register | Reduces system-level write latency by eliminating per-byte address reassertion and allowing pipelined data loading |
| Hardware write protection | Prevents corruption during brown-out, power-up, and EMI transients via VCC sensing and 5 ms power-on delay |
| Software data protection (SDP) | Allows selective locking of entire memory array using 3-byte command sequence; retains state through power cycles |
| Device identification area | 64 bytes at 7FC0H–7FFFH accessible with A9 = 12 V; supports traceability, calibration data, and firmware versioning |
Applications
| Avionics Flight Control Memory | Missile Guidance Parameter Storage |
|---|---|
Use Scenario: Storing real-time trim coefficients, sensor calibration tables, and flight envelope limits in fly-by-wire ECUs. IC Role / Device Role / Timing Role: Nonvolatile configuration store accessed during boot and runtime via 8-bit parallel bus with deterministic 120 ns read latency. Use Value: Ensures mission-critical parameters survive power loss and radiation-induced resets while meeting DO-254 timing constraints. | Use Scenario: Holding target acquisition profiles, launch sequence flags, and inertial navigation offsets in guided munitions. IC Role / Device Role / Timing Role: Radiation-tolerant EEPROM providing tamper-resistant parameter storage with write-protection enabled during arming. Use Value: Prevents accidental overwrites during vibration, shock, and thermal cycling while supporting field updates via secure SDP unlock. |
| Hardened Industrial PLC Configuration | Satellite Onboard Telemetry Logging |
Use Scenario: Retaining ladder logic configurations, I/O mapping, and safety interlock states in nuclear plant control cabinets. IC Role / Device Role / Timing Role: MIL-qualified nonvolatile memory interfaced to 8051-based controllers with CE/OE-controlled bus arbitration. Use Value: Guarantees configuration integrity across 40+ year service life with no maintenance or battery backup required. | Use Scenario: Capturing housekeeping telemetry (voltage, temperature, attitude) between ground station contacts on LEO satellites. IC Role / Device Role / Timing Role: Radiation-hardened data logger writing burst telemetry packets to 64-byte pages during eclipse periods. Use Value: Achieves 100% data capture reliability under single-event upsets using DATA polling to confirm write completion before next packet. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28HC256-90LM/883 | 90 ns read access time; otherwise identical electrical and mechanical specs | Preferred where system clock >8.3 MHz requires tighter read timing margin | Select when design requires sub-100 ns access; same pinout, same MIL-STD-883 screening |
| DS2502-E48+T&R | 1-Wire serial interface; 1024-bit EEPROM; no parallel bus or page write capability | Used in low-pin-count, space-constrained nodes requiring minimal wiring (e.g., sensor ID tags) | Only suitable for non-bus applications; not a functional or pin-compatible substitute |
Compared with AT28HC256-12LM/883, the -90LM/883 variant offers faster read performance without trade-offs in endurance or temperature range, while the DS2502-E48+T&R serves entirely different system architectures due to its serial interface and lack of parallel addressing.
Availability
AT28HC256-12LM/883 is available at Aetrix Electronics and suitable for avionics, missile guidance, and hardened industrial control applications requiring stable component supply across extended product lifecycles.
Supply support for AT28HC256-12LM/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 for industrial, automotive, and aerospace markets.
The AT28HC256 product line delivers radiation-tolerant, high-reliability EEPROMs designed specifically for mission-critical systems requiring MIL-STD-883 qualification and long-term data integrity without battery backup.
FAQ
What is the maximum page write size supported by the AT28HC256-12LM/883?
The AT28HC256-12LM/883 supports page writes of 1 to 64 bytes per internal programming cycle. All bytes written in a single page operation must reside within the same 64-byte page boundary defined by address bits A6–A14. The device uses an internal 64-byte latch to accept data without reasserting addresses, and each successive byte must be loaded within 150 µs of the previous one to maintain page mode operation. This capability is documented in Section 6.8 of the DS20006352A datasheet.
Does the AT28HC256-12LM/883 require external high-voltage circuitry for programming?
No, the AT28HC256-12LM/883 operates from a single 5 V ±10% supply and does not require external high-voltage programming circuitry for standard byte or page writes. Only the optional chip erase function and device identification area programming require 12 V applied to A9, as specified in Section 6.1 and Section 7.1 of the DS20006352A datasheet. All normal read/write operations use standard TTL/CMOS logic levels.
How is write completion detected on the AT28HC256-12LM/883?
Write completion on the AT28HC256-12LM/883 is detected using either DATA polling on I/O7 or the toggle-bit method on I/O6. During a write cycle, reading the last written byte returns the complement of the data on I/O7 until completion, after which true data appears. Alternatively, I/O6 toggles between 0 and 1 during programming and stabilizes upon completion. Both methods are fully functional without external components and are detailed in Sections 6.14 and 6.16 of DS20006352A.
Is the AT28HC256-12LM/883 pin-compatible with standard 28-pin DIP EEPROMs?
No, the AT28HC256-12LM/883 is packaged in a 32-lead CLCC and is not pin-compatible with 28-pin DIP packages. However, it maintains JEDEC-approved byte-wide pinout compatibility with other 32-lead parallel EEPROMs such as the AT28HC256-90LM/883 and legacy 27C256 EPROMs when mounted in matching CLCC, CERDIP, or flatpack footprints. Pin mapping is confirmed in Table 2-1 of DS20006352A.
What endurance rating applies to the AT28HC256-12LM/883 under military temperature conditions?
The AT28HC256-12LM/883 is rated for 10,000 write/erase cycles across its full operating temperature range of –55°C to +125°C, as specified in Section 4.3 of DS20006352A. This endurance value is validated under MIL-STD-883 test conditions and does not require derating at temperature extremes. The device also provides 10-year data retention under the same conditions without refresh.
AT28HC256-12LM/883 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-CLCC
- 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:
- 120 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-LCC (11.43x13.97)
AT28HC256-12LM/883 FAQ
1.How can I place an order for AT28HC256-12LM/883 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC256-12LM/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 AT28HC256-12LM/883 reliable?
The price and inventory of AT28HC256-12LM/883 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28HC256-12LM/883 is usually 5 days.
3.What payment methods are accepted for AT28HC256-12LM/883?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC256-12LM/883 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC256-12LM/883?
AT28HC256-12LM/883 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC256-12LM/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 AT28HC256-12LM/883?
For technical support, including AT28HC256-12LM/883 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC256-12LM/883 requirements.
6.How does Aetrix verify that AT28HC256-12LM/883 is sourced from the original manufacturer or authorized distributors?
All AT28HC256-12LM/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 AT28HC256-12LM/883 meets industry standards.
7.What is the process for return or replacement of AT28HC256-12LM/883?
All AT28HC256-12LM/883 units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC256-12LM/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 AT28HC256-12LM/883 part is unused and in its original packaging.
Return procedure for AT28HC256-12LM/883:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28HC256-12LM/883 Tags
-
M24C02-WMN6TP
STMicroelectronics
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AT24C02C-XHM-T
Microchip Technology
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AT21CS01-STUM10-T
Microchip Technology
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AT24C02C-SSHM-T
Microchip Technology
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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
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24AA02UIDT-I/OT
Microchip Technology
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AT24C08C-STUM-T
Microchip Technology
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