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Microchip Technology AT28C64E-25PC
- Part No.:
- AT28C64E-25PC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-DIP (0.600", 15.24mm)
- Datasheet:
-
AT28C64E-25PC.pdf
- Description:
- IC EEPROM 64KBIT PARALLEL 28DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,605
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Product details
Overview
AT28C64E-25PC from Microchip Technology (formerly Atmel) is a 64K-bit (8K × 8) parallel EEPROM designed for nonvolatile data storage in microprocessor systems. It features 250 ns read access time, 200 µs fast byte write, JEDEC-standard 28-pin PDIP package, and operates at 5V ±10% with CMOS/TTL compatibility. Used in firmware storage, configuration memory, and boot code retention where field-upgradable persistent storage is required.
For engineers reviewing the AT28C64E-25PC datasheet, AT28C64E-25PC pinout, AT28C64E-25PC application, or AT28C64E-25PC equivalent, key selection criteria include byte-write timing (200 µs), RDY/BUSY and DATA polling support, 100K-cycle endurance, industrial temperature range (–40°C to +85°C), and JEDEC-compliant parallel interface compatibility with legacy 8-bit microcontrollers.
Technical Context
The AT28C64E-25PC implements a self-timed byte-write architecture with internal address/data latching and automatic erase-before-write. Its READY/BUSY open-drain output and I/O7 DATA polling provide deterministic write completion detection without external timing components.
It supports direct microprocessor interfacing via standard CE/OE/WE control logic, operates as a drop-in replacement for SRAM in read cycles, and includes VCC sense, power-on delay, and signal-level write inhibit for robust inadvertent-write protection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8,192 × 8) - supports full firmware image or configuration table storage in 8-bit bus systems |
| Read Access Time | 250 ns - enables direct execution from memory on 4 MHz Z80 or 8051-class controllers without wait states |
| Byte Write Time | 200 µs - allows full device rewrite in ≤1.6 seconds, critical for field firmware updates |
| Endurance | 100,000 write cycles - ensures >10 years of daily reconfiguration in industrial logging applications |
| Data Retention | 10 years at +85°C - guarantees long-term integrity of calibration data in unpowered equipment |
| Supply Voltage | 5V ±10% - compatible with legacy 5V logic rails and eliminates need for dedicated voltage regulators |
| Operating Temp | –40°C to +85°C - qualified for use in industrial PLCs, automotive body controllers, and outdoor metering hardware |
Pinout & Package
AT28C64E-25PC uses a 28-lead, 0.600" wide plastic DIP (PDIP) package per JEDEC MS-011 AB, with 0.3" row spacing and through-hole mounting. Pin 1 is RDY/BUSY (open-drain), and pins 1 and 17 are NC in PLCC variants-but in this PDIP variant, all 28 pins are functional per JEDEC byte-wide layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A12 | Address Inputs | 13-bit address bus for 8K-word addressing; compatible with 8085, Z80, and 68000 lower-address lines |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel interface; high-impedance when CE or OE is high to prevent bus contention |
| CE | Chip Enable | Active-low chip select; enables device only when low-used for memory-mapped decoding |
| OE | Output Enable | Active-low read strobe; controls output drivers independently of CE for flexible bus arbitration |
| WE | Write Enable | Active-low write strobe; initiates self-timed byte write on falling edge with data latched on rising edge |
| RDY/BUSY | Status Output | Open-drain active-low signal indicating write in progress; supports wired-OR of multiple devices |
| VCC, GND | Power Supply | Single 5V supply with <100 µA standby current-enables low-power sleep modes in battery-backed systems |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed byte write | Eliminates external timing circuitry; internal control timer handles erase-and-program sequence automatically |
| DATA Polling on I/O7 | Enables software-controlled write completion detection without dedicated status lines or interrupts |
| RDY/BUSY open-drain output | Allows multi-device status sharing on single bus line-reduces PCB routing complexity in dense memory arrays |
| VCC sense & power-on delay | Prevents corruption during brown-out or power ramp-up by inhibiting writes until stable 5V is confirmed |
| JEDEC byte-wide pinout | Ensures mechanical and electrical compatibility with existing SRAM, EPROM, and flash sockets in legacy designs |
Applications
| Industrial PLC Configuration Storage | Legacy Microcontroller Boot Memory |
|---|---|
Use Scenario: Storing I/O mapping tables, PID tuning parameters, and alarm thresholds in programmable logic controllers deployed in factory automation environments. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed during system power-up and runtime parameter updates via serial host interface. Use Value: 100K endurance and 10-year data retention ensure reliable operation across decades of maintenance cycles without recalibration drift. | Use Scenario: Holding boot code and initialization vectors for Z80, 8051, or 68000-based embedded controllers in medical analyzers and test equipment. IC Role / Device Role / Timing Role: Parallel boot ROM replacement that supports in-system reprogramming without socket removal. Use Value: 250 ns read access avoids wait-state insertion, enabling deterministic boot timing critical for safety-critical startup sequences. |
| Point-of-Sale Terminal Settings | Energy Meter Calibration Data |
Use Scenario: Retaining tax rate tables, receipt formatting rules, and user preferences in retail terminals subject to frequent firmware patches. IC Role / Device Role / Timing Role: Field-upgradable firmware storage with dual write-detection methods (RDY/BUSY + DATA Polling) for robust update validation. Use Value: 200 µs byte write enables sub-second over-the-air configuration updates, minimizing terminal downtime during store rollouts. | Use Scenario: Preserving meter-specific calibration coefficients and tamper logs in ANSI C12.20-certified electricity meters operating in outdoor enclosures. IC Role / Device Role / Timing Role: High-reliability nonvolatile memory storing metrology-critical constants accessible only during factory programming and periodic verification. Use Value: –40°C to +85°C operation and 10-year retention guarantee accuracy compliance under extreme thermal cycling in utility-grade deployments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C64B-25PC | Lower endurance (10K cycles); 1 ms write time vs. 200 µs; same pinout and voltage | Suitable for infrequently updated configuration storage, not for frequent field updates | Select when cost sensitivity outweighs write speed and endurance requirements |
| MX28F640J3F-25PC | Flash-based (not EEPROM); requires sector erase; no RDY/BUSY pin; 250 ns read, but write latency unpredictable | Requires firmware redesign to manage erase-before-write; lacks hardware write-completion signaling | Consider only if migrating to flash architecture and accepting software complexity for density/cost trade-off |
Compared with AT28C64B-25PC and MX28F640J3F-25PC, the AT28C64E-25PC uniquely delivers guaranteed 200 µs byte writes with hardware status signaling-enabling real-time, interrupt-driven firmware updates without polling overhead or erase management.
Availability
AT28C64E-25PC is available at Aetrix Electronics and suitable for industrial control, legacy microcontroller boot, and energy metering applications requiring stable component supply, long-lifecycle support, and verified second-source availability.
Supply support for AT28C64E-25PC 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 acquired Atmel in 2016 and maintains full support for the AT28C64 family, including datasheets, application notes, and long-term manufacturing commitments.
The AT28C64 series was designed specifically for 8-bit microprocessor systems needing pin-compatible, easy-to-integrate nonvolatile memory with SRAM-like read access and robust write reliability-targeting industrial, instrumentation, and telecom infrastructure markets.
FAQ
What is the maximum write endurance specification for the AT28C64E-25PC?
The AT28C64E-25PC is rated for 100,000 write/erase cycles per memory location. This high endurance is achieved through Atmel's enhanced EEPROM process and internal error correction, making it suitable for applications requiring frequent field updates such as configuration storage in industrial HMIs. The AT28C64E-25PC retains data for 10 years at +85°C, ensuring long-term reliability even under thermal stress.
Does the AT28C64E-25PC support both RDY/BUSY and DATA polling for write completion detection?
Yes, the AT28C64E-25PC supports both methods. Pin 1 provides an open-drain RDY/BUSY output that goes low during write cycles and releases upon completion. Simultaneously, DATA polling is implemented on I/O7: reading the target address returns the complement of the written data until the write finishes, then returns true data. This dual-mode support gives designers flexibility in hardware- or software-driven timing control for the AT28C64E-25PC.
What is the operating voltage range and power consumption of the AT28C64E-25PC?
The AT28C64E-25PC operates from a single 5V ±10% supply (4.5V to 5.5V). Its active current is 30 mA (typical) at 5 MHz, and standby current is ≤100 µA in CMOS mode-achieved by asserting CE high. These values are specified across the full industrial temperature range (–40°C to +85°C), confirming stable low-power behavior for the AT28C64E-25PC in battery-backed or thermally constrained environments.
Is the AT28C64E-25PC pin-compatible with standard SRAM devices?
The AT28C64E-25PC uses a JEDEC-approved byte-wide pinout identical to common 28-pin SRAMs (e.g., 6264), supporting direct replacement in read cycles. However, write timing differs: WE must be pulsed with proper setup/hold times, and write completion requires RDY/BUSY or DATA polling-not simple strobe timing. So while pinout and read behavior match SRAM, the AT28C64E-25PC requires minor firmware adaptation for writes.
What package type and lead finish does the AT28C64E-25PC use?
The AT28C64E-25PC is supplied in a 28-lead, 0.600" wide plastic dual in-line package (PDIP), designated as package code "28P6" per Atmel's ordering guide. It features standard matte tin (Sn) lead finish, RoHS-compliant, and is rated for through-hole reflow or wave soldering. The package meets JEDEC MS-011 AB mechanical specifications, ensuring compatibility with legacy sockets and automated assembly processes for the AT28C64E-25PC.
AT28C64E-25PC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-DIP (0.600", 15.24mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 64Kbit
- Memory Organization:
- 8K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 200µs
- Access Time:
- 250 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-PDIP
AT28C64E-25PC FAQ
1.How can I place an order for AT28C64E-25PC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C64E-25PC 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 AT28C64E-25PC reliable?
The price and inventory of AT28C64E-25PC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28C64E-25PC is usually 5 days.
3.What payment methods are accepted for AT28C64E-25PC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C64E-25PC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C64E-25PC?
AT28C64E-25PC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C64E-25PC 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 AT28C64E-25PC?
For technical support, including AT28C64E-25PC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C64E-25PC requirements.
6.How does Aetrix verify that AT28C64E-25PC is sourced from the original manufacturer or authorized distributors?
All AT28C64E-25PC 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 AT28C64E-25PC meets industry standards.
7.What is the process for return or replacement of AT28C64E-25PC?
All AT28C64E-25PC units undergo pre-shipment inspection (PSI). If there is an issue with AT28C64E-25PC, 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 AT28C64E-25PC part is unused and in its original packaging.
Return procedure for AT28C64E-25PC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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