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Microchip Technology AT28C256-15JU-323
- Part No.:
- AT28C256-15JU-323
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT28C256-15JU-323.pdf
- Description:
- IC EEPROM 256KBIT PAR 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:1,735
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Product details
Overview
AT28C256-15JU-323 from Microchip Technology is an industrial-grade 256-Kbit paged parallel EEPROM organized as 32,768 × 8, featuring 150 ns read access time, 3 ms or 10 ms 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 system configuration storage.
For engineers reviewing the AT28C256-15JU-323 datasheet, AT28C256-15JU-323 pinout, AT28C256-15JU-323 application, or AT28C256-15JU-323 equivalent, this device serves as a drop-in replacement for legacy byte-wide EEPROMs in industrial control, instrumentation, and firmware parameter retention where JEDEC-compliant pinout and CMOS/TTL compatibility are required.
Technical Context
The AT28C256-15JU-323 implements a paged architecture with a 64-byte internal page register, enabling simultaneous write of 1–64 bytes within a single page (A6–A14 fixed). Its dual-line chip enable (CE) and output enable (OE) control allows bus contention avoidance in shared-memory systems.
Write operations are managed by an internal control timer; completion is signaled via DATA polling on I/O7 or toggle-bit behavior on I/O6. 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) - provides nonvolatile storage for firmware parameters, calibration data, or device configuration without external refresh. |
| Read Access Time | 150 ns - enables direct interface with 5–8 MHz microcontrollers without wait states in read-heavy applications. |
| Page Write Cycle Time | 3 ms (AT28C256F variant) or 10 ms (standard) - determines minimum latency between successive page writes; critical for real-time logging throughput. |
| Supply Voltage | 5V ±10% - ensures compatibility with legacy 5V logic families and eliminates need for level-shifting circuitry. |
| Endurance | 10,000 or 100,000 write cycles - defines maximum field-replaceable configuration updates before wear-out; variant-dependent per marking code. |
| Data Retention | 10 years at +85°C - guarantees long-term integrity of stored settings in industrial environments without battery backup. |
| Standby Current | 200 µA (CMOS) - minimizes quiescent power draw in always-on systems such as smart sensors or remote monitors. |
Pinout & Package
AT28C256-15JU-323 is supplied in a 32-lead PLCC (Plastic Leaded Chip Carrier) package with JEDEC-approved byte-wide pinout and no internal connection to pins 1 (DC) and 12 (NC).
| 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 page writes. |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel interface compatible with standard microcontroller data buses; I/O7 used for DATA polling, I/O6 for toggle-bit status. |
| CE | Chip Enable | Active-low global enable; must be low with OE low and WE high for read access; initiates write when low with OE high and WE low. |
| OE | Output Enable | Active-low output gate; controls tri-state buffer to prevent bus contention during shared-memory operation. |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; combined with CE and OE to select operating mode per Table 6-1. |
| VCC / GND | Power Supply | Single 5V supply with CMOS-compatible standby current; ground reference for all digital and analog timing thresholds. |
Key Features
| Feature | Design Value |
|---|---|
| 64-byte Page Register | Enables burst programming of up to 64 bytes per write cycle, reducing host CPU overhead and improving configuration update efficiency. |
| DATA Polling on I/O7 | Allows host to detect write completion without fixed delays or external timers-read returns complemented data until write finishes. |
| Software Data Protection (SDP) | Three-step command sequence (AAh/55h/A0h) enables/disables write lock, preventing accidental writes during power transitions or firmware bugs. |
| Hardware Write Inhibit | VCC sense, 5 ms power-on delay, and 15 ns noise filtering on WE/CE eliminate spurious writes caused by supply glitches or EMI. |
| Device Identification Area | 64-byte reserved EEPROM region (7FC0h–7FFFh) accessible at 12V on A9 for unique serialization or manufacturing traceability. |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Data Retention |
|---|---|
Use Scenario: Storing user-defined I/O mapping, scaling factors, and alarm thresholds in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed during boot and runtime via parallel bus; requires guaranteed 10-year data retention at +70°C ambient. Use Value: Eliminates need for battery-backed SRAM while maintaining JEDEC pin compatibility with legacy designs and supporting field-upgradable parameters without firmware reflash. | Use Scenario: Holding sensor calibration coefficients, patient history flags, and regulatory compliance logs in portable diagnostic equipment. IC Role / Device Role / Timing Role: Secure parameter store with software/hardware write protection to prevent corruption during unexpected power loss or ESD events. Use Value: Ensures FDA-required data integrity through 10,000+ write cycles and 10-year retention, with DATA polling enabling deterministic firmware update sequencing. |
| Automotive Body Control Module Settings | Test Equipment Firmware Patch Storage |
Use Scenario: Retaining seat/mirror position presets, lighting profiles, and CAN node configuration in automotive BCMs operating across -40°C to +85°C. IC Role / Device Role / Timing Role: Industrial-grade EEPROM interfaced directly to 8-bit MCU parallel bus; withstands automotive thermal cycling and voltage transients. Use Value: Provides reliable, low-power (200 µA standby) storage with hardware VCC-sense write inhibition to survive load-dump conditions and cold-cranking voltage drops. | Use Scenario: Storing field-deployed firmware patches and instrument-specific calibration offsets in benchtop oscilloscopes and signal generators. IC Role / Device Role / Timing Role: Paged write-capable memory allowing rapid patch loading (≤3 ms/page) without disrupting main application execution via background polling. Use Value: Enables zero-downtime firmware updates using 64-byte page writes and toggle-bit status checking, reducing service technician time and minimizing test equipment downtime. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C256-15PU | Same electrical specs and pinout, but in 28-lead PDIP package instead of 32-lead PLCC; lacks DC pins and has different mechanical footprint. | Suitable for through-hole prototyping or legacy PCBs with 28-pin DIP sockets; not interchangeable without board redesign. | Select when mechanical compatibility with existing DIP layouts is required and surface-mount constraints do not apply. |
| M95256-DWDW | 256-Kbit SPI EEPROM (not parallel); 5V-tolerant but serial interface; 5 ms write time; no page register or DATA polling. | Requires MCU SPI peripheral and software driver; lower pin count but higher latency per byte written; no JEDEC pinout compatibility. | Choose for space-constrained designs where board real estate is limited and serial interface overhead is acceptable. |
Compared with AT28C256-15PU, the AT28C256-15JU-323 offers superior thermal performance and smaller footprint in surface-mount form, while M95256-DWDW trades parallel speed and pin compatibility for reduced I/O count and simpler routing-making it viable only when redesigning for serial architecture.
Availability
AT28C256-15JU-323 is available at Aetrix Electronics and suitable for industrial control, medical instrumentation, and automotive body electronics requiring stable component supply, long-life data retention, and JEDEC-standard parallel EEPROM compatibility.
Supply support for AT28C256-15JU-323 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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and nonvolatile memory solutions, with ISO 9001-certified manufacturing and global distribution.
The AT28C256 product line delivers industrial-grade parallel EEPROMs optimized for robustness in harsh environments, targeting applications demanding proven reliability, long data retention, and seamless integration into legacy 5V microcontroller systems.
FAQ
What is the maximum page write size supported by the AT28C256-15JU-323?
The AT28C256-15JU-323 supports a maximum page write size of 64 bytes. This is enabled by its internal 64-byte page register, which latches address and data during a single write initiation. All bytes in a page write must reside on the same page defined by address bits A6–A14, and each subsequent byte must be loaded within 150 µs of the prior one to avoid premature internal programming.
Does the AT28C256-15JU-323 require a 12V supply for any operation?
The AT28C256-15JU-323 operates from a single 5V ±10% supply for normal read/write functions. A 12V ±0.5V supply on pin A9 is required only for accessing the optional 64-byte device identification area (7FC0h–7FFFh) or executing the software chip erase command-not for standard memory operations.
How does DATA polling work on the AT28C256-15JU-323?
During a write cycle, reading the last written byte from the AT28C256-15JU-323 returns the complement of that data on I/O7. Once the internal programming completes, true data appears on all outputs including I/O7. This allows the host MCU to poll I/O7 in a loop without fixed timing delays, detecting write completion deterministically.
Is the AT28C256-15JU-323 pin-compatible with other 28-pin parallel EEPROMs?
No-the AT28C256-15JU-323 uses a 32-lead PLCC package with JEDEC-approved byte-wide pinout, including dedicated DC and NC pins not present in 28-pin variants like AT28C256-15PU. While functionally identical, mechanical and pin-count differences prevent direct socket replacement without PCB modification.
What endurance rating applies to the AT28C256-15JU-323?
The AT28C256-15JU-323 is rated for 10,000 write cycles under standard conditions (10 ms write time), as indicated by the absence of an 'E' or 'F' suffix in its marking code. The 'F' variant (e.g., AT28C256F) offers 10,000 cycles at 3 ms write time, while 'E' denotes 100,000 cycles at 10 ms-neither applies to this specific part number.
AT28C256-15JU-323 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- Packaging:
- Tape & Reel (TR)
- 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:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (13.97x11.43)
AT28C256-15JU-323 FAQ
1.How can I place an order for AT28C256-15JU-323 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C256-15JU-323 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 AT28C256-15JU-323 reliable?
The price and inventory of AT28C256-15JU-323 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28C256-15JU-323 is usually 5 days.
3.What payment methods are accepted for AT28C256-15JU-323?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C256-15JU-323 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C256-15JU-323?
AT28C256-15JU-323 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C256-15JU-323 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 AT28C256-15JU-323?
For technical support, including AT28C256-15JU-323 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C256-15JU-323 requirements.
6.How does Aetrix verify that AT28C256-15JU-323 is sourced from the original manufacturer or authorized distributors?
All AT28C256-15JU-323 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 AT28C256-15JU-323 meets industry standards.
7.What is the process for return or replacement of AT28C256-15JU-323?
All AT28C256-15JU-323 units undergo pre-shipment inspection (PSI). If there is an issue with AT28C256-15JU-323, 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 AT28C256-15JU-323 part is unused and in its original packaging.
Return procedure for AT28C256-15JU-323:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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