My Inquiry
My Account
Microchip Technology AT28C256E-15TU
- Part No.:
- AT28C256E-15TU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-TSSOP (0.465", 11.80mm Width)
- Datasheet:
-
AT28C256E-15TU.pdf
- Description:
- IC EEPROM 256KBIT PAR 28TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,981
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT28C256E-15TU from Microchip Technology is an industrial-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 control and firmware storage in programmable logic controllers and industrial HMIs.
For engineers reviewing the AT28C256E-15TU datasheet, AT28C256E-15TU pinout, AT28C256E-15TU application, or AT28C256E-15TU equivalent, key selection criteria include JEDEC byte-wide pinout compatibility, 100,000 write endurance, industrial temperature range (–40°C to +85°C), CMOS/TTL I/O compatibility, and 64-byte page register architecture enabling efficient firmware updates.
Technical Context
The AT28C256E-15TU implements a paged write architecture with internal 64-byte latches and an autonomous control timer, allowing up to 64 bytes to be loaded within 150 µs per byte before initiating internal programming. Its dual-line chip enable (CE) and output enable (OE) logic enables bus contention avoidance in shared-memory systems.
Write completion is verified via DATA polling on I/O7 (complement-to-data during write, true data after completion) or toggle-bit behavior on I/O6, both usable at any point during tWC. 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) - supports full firmware image storage for 8-bit microcontrollers |
| Read Access Time | 150 ns - enables direct replacement of SRAM in legacy 8051/68K-based systems without timing redesign |
| Page Write Cycle | ≤10 ms - guarantees deterministic firmware update latency for safety-critical bootloaders |
| Write Endurance | 100,000 cycles - validated for field-upgradable calibration tables in industrial sensors |
| Operating Voltage | 5V ±10% - compatible with standard TTL/CMOS logic rails without level-shifting |
| Temperature Range | –40°C to +85°C - qualified for deployment in factory-floor PLCs and motor drives |
| Standby Current | 200 µA - enables low-power retention in battery-backed configuration memory |
Pinout & Package
AT28C256E-15TU is supplied in a 28-lead SOIC package with JEDEC-standard byte-wide pinout and 300 mil body width. Pin functions are electrically identical across PDIP, SOIC, and PLCC variants per datasheet DS20006386B.
| 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 | Byte-wide data path; I/O7 used for DATA polling, I/O6 for toggle-bit status indication |
| CE | Chip Enable | Active-low device select; must be low with OE low and WE high for read access |
| OE | Output Enable | Active-low output gate; high-Z state when asserted high or CE high prevents bus contention |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; initiates byte or page programming |
| VCC | Power Supply | +5V ±10% supply; internal VCC sense disables writes below ~3.8V |
| GND | Ground Reference | Signal and power return; decoupling capacitor required within 10 mm of VCC pin |
Key Features
| Feature | Design Value |
|---|---|
| 64-byte Page Register | Enables burst loading of configuration data without repeated address setup, reducing MCU overhead by >70% vs. byte-write |
| DATA Polling on I/O7 | Eliminates need for fixed-delay wait states; allows real-time system response during firmware update |
| Software Data Protection | Three-byte unlock sequence (AAh/55h/A0h) prevents accidental writes during power transitions or ESD events |
| Hardware Write Inhibit | VCC monitoring and 5 ms power-on delay ensure reliable initialization before first write command |
| Device Identification Area | 64-byte reserved space (7FC0h–7FFFh) accessible at 12V on A9 for unique serialization or calibration storage |
Applications
| Industrial PLC Configuration Storage | Legacy System Firmware Backup |
|---|---|
Use Scenario: Storing ladder logic parameters and I/O mapping tables in DIN-rail mounted programmable logic controllers operating in ambient temperatures up to 70°C. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed via 8-bit parallel bus; provides deterministic 150 ns read timing for scan-cycle execution. Use Value: 100,000 write cycles support daily parameter updates over 27 years; software protection prevents corruption during brown-out conditions. | Use Scenario: Retaining BIOS or bootloader code in discontinued 80286/68000-based test equipment where flash replacement is incompatible with existing PCB layout. IC Role / Device Role / Timing Role: Drop-in SRAM replacement with identical JEDEC pinout and timing; operates as memory-mapped device at 5 MHz bus speed. Use Value: 150 ns access time matches original SRAM spec; 5V-only supply eliminates need for auxiliary voltage regulators. |
| Motor Drive Calibration Memory | Medical Device Setup Profile Storage |
Use Scenario: Holding torque compensation curves and encoder offset values in servo amplifiers subject to vibration and thermal cycling. IC Role / Device Role / Timing Role: Field-programmable calibration store written once per maintenance cycle; accessed only during startup initialization. Use Value: 10-year data retention ensures accuracy between recalibrations; 200 µA standby current minimizes heat generation in sealed enclosures. | Use Scenario: Storing patient-specific therapy profiles and safety limits in Class II medical infusion pumps requiring traceable configuration history. IC Role / Device Role / Timing Role: Secure parameter archive with write-protection enabled via software lock; accessed via isolated microcontroller interface. Use Value: Dual protection (hardware VCC sense + software unlock) meets IEC 62304 SW safety requirements; 64-byte ID area stores manufacturing lot traceability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar paged parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C256-15PU | Same electrical specs and pinout; packaged in 28-lead PDIP instead of SOIC | Preferred for through-hole prototyping or legacy board rework where SOIC footprint unavailable | Select when manual soldering or socket-based testing is required |
| AT28C256-15SU | Identical SOIC package but rated for 10,000 write cycles (standard endurance) vs. 100,000 in AT28C256E-15TU | Suitable for infrequently updated configuration storage where extended endurance unnecessary | Choose for cost-sensitive applications with <100 lifetime writes |
Compared with AT28C256-15PU and AT28C256-15SU, the AT28C256E-15TU uniquely delivers extended 100,000-cycle endurance in a surface-mount SOIC package-enabling long-life field upgrades without compromising PCB density or assembly process compatibility.
Availability
AT28C256E-15TU is available at Aetrix Electronics and suitable for industrial automation, legacy system repair, and medical device manufacturing requiring stable component supply and long-term lifecycle assurance.
Supply support for AT28C256E-15TU 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 ISO 9001-certified manufacturing.
The AT28C256 product line delivers industrial-grade parallel EEPROMs optimized for firmware backup, configuration storage, and calibration data retention in harsh environments where reliability and long-term availability are critical.
FAQ
What is the guaranteed write endurance of the AT28C256E-15TU?
The AT28C256E-15TU is specified for 100,000 write/erase cycles, validated per Microchip's DS20006386B datasheet. This extended endurance rating applies specifically to the "E" variant and supports frequent field updates in industrial control applications. The AT28C256E-15TU maintains full functionality across its entire industrial temperature range during endurance testing.
Does the AT28C256E-15TU require a 12V supply for any operation?
The AT28C256E-15TU operates from a single 5V ±10% supply for all standard read/write operations. A 12V ±0.5V supply on A9 is required only for accessing the optional 64-byte device identification area (7FC0h–7FFFh); this is not needed for normal memory operation. The AT28C256E-15TU includes internal VCC sensing that inhibits writes below ~3.8V to prevent corruption during power ramp-up.
How does DATA polling work on the AT28C256E-15TU?
During a write cycle, reading the last-written address returns the complement of the data on I/O7 until programming completes; once valid, true data appears on all I/O lines. This allows the host MCU to poll I/O7 without fixed delays. The AT28C256E-15TU supports continuous polling at any point during tWC (≤10 ms), enabling responsive firmware update routines in real-time systems.
Can the AT28C256E-15TU replace standard SRAM in existing designs?
Yes-the AT28C256E-15TU uses JEDEC-approved byte-wide pinout and matches SRAM read timing (150 ns access), allowing drop-in replacement in many 8-bit systems. Unlike SRAM, it retains data without power and requires no external battery. The AT28C256E-15TU's CE/OE/WE control logic is functionally identical to static RAM, simplifying integration into legacy 8051 or Z80-based platforms.
What package type is used for the AT28C256E-15TU?
The AT28C256E-15TU is supplied in a 28-lead SOIC package with 300 mil body width (package code "TU"). Its pinout and electrical characteristics are identical to the PDIP ("PU") and PLCC ("GU") variants per Microchip's datasheet DS20006386B, ensuring design flexibility across assembly methods while maintaining full functional compatibility.
AT28C256E-15TU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-TSSOP (0.465", 11.80mm Width)
- Packaging:
- Tray
- Product Status:
- Obsolete
- 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:
- 28-TSOP
AT28C256E-15TU FAQ
1.How can I place an order for AT28C256E-15TU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C256E-15TU 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-15TU reliable?
The price and inventory of AT28C256E-15TU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28C256E-15TU is usually 5 days.
3.What payment methods are accepted for AT28C256E-15TU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C256E-15TU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C256E-15TU?
AT28C256E-15TU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C256E-15TU 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-15TU?
For technical support, including AT28C256E-15TU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C256E-15TU requirements.
6.How does Aetrix verify that AT28C256E-15TU is sourced from the original manufacturer or authorized distributors?
All AT28C256E-15TU 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-15TU meets industry standards.
7.What is the process for return or replacement of AT28C256E-15TU?
All AT28C256E-15TU units undergo pre-shipment inspection (PSI). If there is an issue with AT28C256E-15TU, 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-15TU part is unused and in its original packaging.
Return procedure for AT28C256E-15TU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28C256E-15TU 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…
