My Inquiry
My Account
Microchip Technology AT28C256F-15JU
- Part No.:
- AT28C256F-15JU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT28C256F-15JU.pdf
- Description:
- IC EEPROM 256KBIT PAR 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,214
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT28C256F-15JU 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 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 AT28C256F-15JU datasheet, AT28C256F-15JU pinout, AT28C256F-15JU application, or AT28C256F-15JU equivalent, key selection considerations include JEDEC byte-wide pinout compatibility, 64-byte page register architecture, CMOS/TTL I/O compatibility, industrial temperature range (–40°C to +85°C), and fast 3 ms page write timing specific to the 'F' variant.
Technical Context
The AT28C256F-15JU implements a paged write architecture with an internal 64-byte latch that accepts sequential data within 150 µs intervals, enabling efficient firmware updates without bus blocking. Its dual-line chip enable (CE) and output enable (OE) control allows flexible bus contention management in microcontroller-based systems.
Write completion is verified via either 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 (<3.8 V inhibits writes), 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 address/data bus systems |
| Page Write Cycle Time | 3 ms max - 3× faster than standard AT28C256 (10 ms), reducing firmware update latency |
| Supply Voltage | 5V ±10% - compatible with legacy 5V TTL/CMOS logic families without level shifting |
| Operating Temperature | –40°C to +85°C - qualified for industrial automation and motor control environments |
| Endurance | 10,000 write cycles - sufficient for configuration storage and infrequent firmware patching |
| Data Retention | 10 years - ensures long-term reliability in unpowered storage applications |
Pinout & Package
AT28C256F-15JU is supplied in a 32-lead PLCC (Plastic Leaded Chip Carrier) package with JEDEC-standard byte-wide pinout. The 'JU' suffix explicitly denotes this PLCC variant per Microchip's marking convention (DS20006386B, p.21).
| 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 | Byte-wide parallel interface; I/O7 used for DATA polling, I/O6 for toggle-bit status monitoring |
| CE | Chip Enable | Active-low device select; must be low with OE low and WE high for read operations |
| OE | Output Enable | Active-low output gate; controls high-impedance state to prevent bus contention |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; initiates byte or page programming |
| VCC / GND | Power Supply | Single 5V supply with <200 µA CMOS standby current; decoupling required per AC characteristics |
| DC (Pins 1 & 17) | Don't Connect | No internal bond wire; must remain unconnected per datasheet Table 2-1 |
| NC (Pins 12 & 26) | No Connect | Unbonded terminals; no electrical function; leave floating |
Key Features
| Feature | Design Value |
|---|---|
| 64-byte page register | Enables burst loading of up to 64 bytes before internal programming begins, freeing address/data bus for other tasks |
| DATA polling on I/O7 | Allows real-time write status verification without timer delays or external hardware interrupts |
| Software data protection (SDP) | Three-step command sequence (AAh/55h/A0h) prevents accidental writes during power transitions or noise events |
| VCC sense & power-on delay | Hardware-level write inhibition below 3.8 V and automatic 5 ms lockout after power-up ensure robustness in unstable supplies |
| JEDEC byte-wide pinout | Direct drop-in compatibility with legacy 28-pin EPROM/EEPROM sockets when used in PDIP/SOIC variants; PLCC maintains same signal mapping |
Applications
| Industrial PLC Configuration Storage | Firmware Patch Storage for 8-bit MCUs |
|---|---|
Use Scenario: Storing user-defined I/O mapping tables and calibration coefficients in programmable logic controllers operating in factory-floor environments. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed via parallel bus during boot or runtime reconfiguration; 150 ns read speed supports real-time scan cycle timing. Use Value: Eliminates need for battery-backed SRAM while maintaining deterministic read latency and industrial temperature resilience. | Use Scenario: Holding field-upgradable firmware patches for legacy 8-bit microcontrollers in medical diagnostic equipment where full flash reprogramming is prohibited. IC Role / Device Role / Timing Role: External code repository accessed over shared address/data bus; 3 ms page write enables rapid patch deployment without system reset. Use Value: Enables secure, verified firmware updates using SDP commands while preserving main MCU flash endurance. |
| Embedded HMI Display Settings | Motor Drive Parameter Backup |
Use Scenario: Retaining display brightness, language, and contrast settings across power cycles in human-machine interface panels used in HVAC control systems. IC Role / Device Role / Timing Role: Low-power nonvolatile storage interfaced to an 8051-family controller; <200 µA standby current extends battery backup life. Use Value: Guarantees settings persistence without capacitor-based hold-up, reducing BOM cost and failure modes. | Use Scenario: Backing up torque limits, acceleration profiles, and fault thresholds in variable-frequency drives subject to EMI-rich industrial environments. IC Role / Device Role / Timing Role: Ruggedized parameter store with hardware write protection activated during power ramp-up/down sequences. Use Value: Prevents corruption of safety-critical motor parameters during brownout conditions via VCC-sense and SDP enforcement. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C256-15PU | 28-pin PDIP package; 10 ms page write cycle; identical 150 ns read timing and pinout | Through-hole mounting; slower write performance unsuitable for time-critical patching | Select for legacy board rework or prototyping where PLCC footprint is unavailable |
| M95256-DW | 256-Kbit SPI EEPROM; 5 MHz interface; no parallel bus; 5 ms write cycle; 2.5–5.5 V supply | Serial interface reduces pin count but increases software overhead; lacks DATA polling/toggle-bit status | Select for space-constrained designs where serial interface and wider voltage range outweigh parallel bus advantages |
Compared with AT28C256F-15JU, the AT28C256-15PU offers identical functionality in PDIP but sacrifices 3 ms write speed, while the M95256-DW trades parallel simplicity for serial flexibility and broader supply tolerance-neither is pin-compatible, requiring PCB redesign.
Availability
AT28C256F-15JU is available at Aetrix Electronics and suitable for industrial automation, embedded HMI, motor drive parameter backup, and legacy microcontroller firmware storage requiring stable component supply and long-lifecycle support.
Supply support for AT28C256F-15JU 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 a focus on industrial, automotive, and aerospace reliability standards.
The AT28C256 product line delivers high-endurance, parallel-interface EEPROMs designed for firmware storage, configuration retention, and parameter backup in resource-constrained 8-bit and 16-bit embedded systems.
FAQ
What is the meaning of the 'F' and 'JU' suffixes in AT28C256F-15JU?
The 'F' suffix indicates the fast 3 ms page write variant (vs. standard 10 ms), and 'JU' specifies the 32-lead PLCC package per Microchip's marking convention in DS20006386B. This distinguishes AT28C256F-15JU from PDIP (PU) or SOIC (SU) versions and confirms its 3 ms write capability and PLCC mechanical form factor.
Does AT28C256F-15JU support both byte and page write operations?
Yes, AT28C256F-15JU supports both byte and page write modes. Page writes accept 1–64 bytes within a 150 µs window per byte, leveraging the internal 64-byte latch. Byte writes operate independently, with each byte triggering its own 3 ms internal programming cycle. Both modes use the same CE/OE/WE control logic defined in Table 6-1.
How is write completion detected on AT28C256F-15JU?
AT28C256F-15JU provides two hardware-supported methods: DATA polling on I/O7 (returns complement of written data during write, true data upon completion) and toggle-bit monitoring on I/O6 (toggles between 0/1 until write ends). Both can be polled at any time during tWC and require no external components or timers.
Is software data protection enabled by default on AT28C256F-15JU?
No, software data protection (SDP) is disabled by default on AT28C256F-15JU. It must be explicitly enabled using the three-byte command sequence (AAh to 5555h, 55h to 2AAAh, A0h to 5555h). Once enabled, all subsequent writes require repeating this sequence; power cycling does not disable SDP, ensuring persistent protection.
What is the purpose of the DC pins (1 and 17) on the AT28C256F-15JU PLCC package?
Pins 1 and 17 on AT28C256F-15JU are designated "Don't Connect" (DC) per Table 2-1. They have no internal bond wire and must remain unconnected in the PCB layout. Connecting them risks undefined behavior or damage, as confirmed in the Pin Descriptions section (DS20006386B, p.5).
AT28C256F-15JU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- 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:
- 3ms
- 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)
AT28C256F-15JU FAQ
1.How can I place an order for AT28C256F-15JU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C256F-15JU 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 AT28C256F-15JU reliable?
The price and inventory of AT28C256F-15JU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28C256F-15JU is usually 5 days.
3.What payment methods are accepted for AT28C256F-15JU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C256F-15JU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C256F-15JU?
AT28C256F-15JU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C256F-15JU 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 AT28C256F-15JU?
For technical support, including AT28C256F-15JU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C256F-15JU requirements.
6.How does Aetrix verify that AT28C256F-15JU is sourced from the original manufacturer or authorized distributors?
All AT28C256F-15JU 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 AT28C256F-15JU meets industry standards.
7.What is the process for return or replacement of AT28C256F-15JU?
All AT28C256F-15JU units undergo pre-shipment inspection (PSI). If there is an issue with AT28C256F-15JU, 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 AT28C256F-15JU part is unused and in its original packaging.
Return procedure for AT28C256F-15JU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28C256F-15JU 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…
