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Microchip Technology AT28C64E-25SI
- Part No.:
- AT28C64E-25SI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
AT28C64E-25SI.pdf
- Description:
- IC EEPROM 64KBIT PARALLEL 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,377
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Product details
Overview
AT28C64E-25SI from Atmel is a 64 Kbit (8K × 8) parallel EEPROM with JEDEC-standard byte-wide pinout, 250 ns read access time, 200 µs fast byte write cycle, and industrial temperature range (–40°C to +85°C). It operates from 5V ±10%, supports DATA polling and RDY/BUSY signaling, and is used in firmware storage, configuration memory, and boot code retention for microcontroller-based systems.
For engineers reviewing the AT28C64E-25SI datasheet, AT28C64E-25SI pinout, AT28C64E-25SI application, or AT28C64E-25SI equivalent, key selection criteria include write endurance (10⁵ cycles), CMOS standby current (100 µA), self-timed write architecture, and compatibility with 5V microprocessor buses requiring nonvolatile byte-write capability without external timing logic.
Technical Context
The AT28C64E-25SI implements a self-timed byte write cycle with internal address/data latches and automatic clear-before-write logic, eliminating need for external write pulse control. Its RDY/BUSY open-drain output and I/O7 data polling provide two hardware- and software-based write completion detection methods.
It features dual-line chip enable (CE) and output enable (OE) control for bus contention prevention, TTL/CMOS-compatible I/O, and VCC sense circuitry that inhibits writes below 3.8 V. The device includes 32 bytes of dedicated identification EEPROM accessible via A9 = 12 V and addresses 1FE0H–1FFFH.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8,192 × 8 bits); sufficient for small boot loaders, calibration tables, or device configuration data. |
| Read Access Time | 250 ns max; compatible with 4 MHz Z80, 8051, and similar legacy microprocessors without wait states. |
| Byte Write Time | 200 µs max (AT28C64E variant); enables full 64 Kbit rewrite in ≤1.6 seconds-critical for field-upgradable firmware. |
| Endurance | 100,000 write/erase cycles; supports frequent reprogramming in test equipment or programmable logic controllers. |
| Standby Current | 100 µA typical at VCC = 5 V; enables low-power retention in battery-backed systems. |
| Operating Voltage | 5 V ±10%; eliminates need for dedicated voltage regulators in 5 V logic systems. |
| Temperature Range | –40°C to +85°C (industrial grade); qualified for use in motor drives, industrial HMIs, and outdoor telemetry units. |
Pinout & Package
AT28C64E-25SI is packaged in a 28-lead SOIC (28S) with JEDEC MS-012 standard footprint (0.300" width), pin 1 marked by notch or dot, and lead finish compliant with RoHS requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A12 | Address Inputs | 13-bit address bus for 8K-word addressing; compatible with 8086/8051 16-bit address buses using lower 13 bits. |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel interface; electrically compatible with TTL/CMOS logic levels and microprocessor data buses. |
| CE | Chip Enable | Active-low chip select; when high, places outputs in high-impedance state regardless of OE/WE state. |
| OE | Output Enable | Active-low read control; allows CE to remain asserted during multi-chip reads while gating output drivers. |
| WE | Write Enable | Active-low write strobe; initiates self-timed byte write on falling edge; latches address and data internally. |
| RDY/BUSY | Open-Drain Status Output | Pulled low during write; released high at completion; supports wired-OR connection across multiple EEPROMs. |
| VCC | Power Supply | +5 V ±10% supply; powers core logic and memory array; includes internal VCC sense for write inhibition. |
| GND | Ground Reference | Signal and power return path; decoupling capacitor required within 1 cm of VCC pin per datasheet layout guidelines. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed byte write | Eliminates external timing circuitry; microprocessor releases address/data bus immediately after WE assertion. |
| DATA polling (I/O7) | Enables write completion detection via software read loop-no extra GPIO or interrupt line required. |
| RDY/BUSY open-drain output | Supports hardware handshaking and multi-device status aggregation on shared bus lines. |
| 32-byte ID memory | Provides factory-programmable or user-writable serial number, revision, or calibration offset storage. |
| VCC write protection | Prevents inadvertent writes during power ramp-up or brownout conditions below 3.8 V threshold. |
Applications
| Industrial PLC Configuration Storage | Legacy Microcontroller Boot Memory |
|---|---|
Use Scenario: Storing I/O mapping, PID tuning parameters, and alarm thresholds in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed during startup and runtime parameter updates via RS-485 host. Use Value: 100,000-cycle endurance ensures reliable field reconfiguration over 10+ years; 200 µs write time enables sub-second parameter saves without disrupting control loops. |
Use Scenario: Holding boot loader code and hardware initialization vectors for 8051- or Z80-based embedded instruments with no external flash controller. IC Role / Device Role / Timing Role: Parallel boot ROM mapped into processor's lower memory space; accessed as static RAM during reset sequence. Use Value: 250 ns read access avoids wait states on 4 MHz bus; JEDEC pinout simplifies PCB layout reuse across multiple Atmel EEPROM variants. |
| Medical Device Calibration Data | Telecom Line Card Identity |
Use Scenario: Retaining sensor calibration coefficients and usage logs in portable diagnostic equipment subject to periodic recalibration. IC Role / Device Role / Timing Role: Secure, tamper-resistant storage for NIST-traceable calibration data; accessed only during service mode. Use Value: 10-year data retention meets FDA Class II device requirements; VCC-sense write protection prevents corruption during battery swaps. |
Use Scenario: Embedding unique MAC address, firmware version, and hardware revision in telecom DSLAM line cards for inventory and remote diagnostics. IC Role / Device Role / Timing Role: Identity EEPROM read during card power-up by host FPGA or ARM controller via parallel bus. Use Value: Dedicated 32-byte ID area isolates identity data from main memory; industrial temp rating ensures reliability in chassis with >70°C ambient. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C64B-25SI | Same pinout and timing, but 10K-cycle endurance and 1 ms write time; lacks fast write and high-endurance features. | Suitable for infrequently updated configuration storage where write speed and longevity are secondary. | Select AT28C64B-25SI only if cost sensitivity outweighs need for field firmware updates or high-reliability logging. |
| MX28F640J3F-25SI | Intel-compatible 64 Kbit parallel EEPROM; 250 ns read, 10 ms write, 100K cycles; requires 12 V for chip erase, no RDY/BUSY pin. | Used in legacy Intel MCS-51 systems requiring strict 28F-series compatibility; lacks hardware busy signaling. | Choose MX28F640J3F-25SI only when replacing existing 28F-family designs; AT28C64E-25SI offers superior write speed and simpler system integration. |
Compared with AT28C64B-25SI, the AT28C64E-25SI delivers 5× faster writes and 10× higher endurance-critical for dynamic configuration systems. Against MX28F640J3F-25SI, it eliminates 12 V programming voltage and adds RDY/BUSY signaling, reducing BOM count and improving real-time write monitoring.
Availability
AT28C64E-25SI is available at Aetrix Electronics and suitable for industrial control, medical instrumentation, and legacy microcontroller boot applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for AT28C64E-25SI 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
Atmel Corporation (now part of Microchip Technology) is a fabless semiconductor company specializing in microcontrollers, nonvolatile memory, and secure authentication ICs.
The AT28C64E-25SI belongs to Atmel's parallel EEPROM product line, designed specifically for 5 V microprocessor systems needing pin-compatible, drop-in nonvolatile memory with fast write capability and industrial-grade reliability.
FAQ
What is the maximum write endurance specification for AT28C64E-25SI?
The AT28C64E-25SI is rated for 100,000 write/erase cycles, as confirmed in the "Features" section and ordering information table. This high endurance is enabled by the "E" variant's enhanced oxide process and internal error correction, distinguishing it from the standard AT28C64 (10K cycles). Each cycle refers to a full byte write-and-verify operation at the specified VCC and temperature conditions.
Does AT28C64E-25SI require a 12 V programming voltage?
No, the AT28C64E-25SI operates exclusively from a single 5 V ±10% supply for both read and write operations. A 12 V supply is only required for optional CHIP CLEAR or DEVICE IDENTIFICATION functions-not for normal byte writes. Standard write cycles use internal charge pumps powered by VCC alone, simplifying system power design.
How is write completion detected on AT28C64E-25SI?
AT28C64E-25SI provides two independent write completion detection methods: (1) hardware signaling via the open-drain RDY/BUSY pin (pin 1), which goes high when write finishes; and (2) software polling of I/O7, which toggles to complement-of-data during write and returns true data upon completion. Both methods are fully supported in the AT28C64E-25SI variant.
What package type does AT28C64E-25SI use, and is it RoHS-compliant?
AT28C64E-25SI uses a 28-lead SOIC (28S) package per JEDEC MS-012, with 0.300" body width and gull-wing leads. The device is RoHS-compliant, with lead-free terminations and halogen-free molding compound, as documented in Atmel's packaging specifications and certified material declarations.
Can AT28C64E-25SI be used as a direct replacement for AT28C64-25SI in existing designs?
Yes-AT28C64E-25SI is a pin- and function-compatible upgrade to AT28C64-25SI, sharing identical pinout, AC/DC electrical specifications, and timing parameters. The "E" suffix denotes enhanced endurance (100K vs. 10K cycles) and faster write time (200 µs vs. 1 ms), with no changes to PCB layout, firmware, or system-level timing margins required.
AT28C64E-25SI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-SOIC (0.295", 7.50mm Width)
- 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:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOIC
AT28C64E-25SI FAQ
1.How can I place an order for AT28C64E-25SI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C64E-25SI 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-25SI reliable?
The price and inventory of AT28C64E-25SI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28C64E-25SI is usually 5 days.
3.What payment methods are accepted for AT28C64E-25SI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C64E-25SI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C64E-25SI?
AT28C64E-25SI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C64E-25SI 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-25SI?
For technical support, including AT28C64E-25SI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C64E-25SI requirements.
6.How does Aetrix verify that AT28C64E-25SI is sourced from the original manufacturer or authorized distributors?
All AT28C64E-25SI 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-25SI meets industry standards.
7.What is the process for return or replacement of AT28C64E-25SI?
All AT28C64E-25SI units undergo pre-shipment inspection (PSI). If there is an issue with AT28C64E-25SI, 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-25SI part is unused and in its original packaging.
Return procedure for AT28C64E-25SI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28C64E-25SI Tags
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M24C02-WMN6TP
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AT24C02C-XHM-T
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AT21CS01-STUM10-T
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24LC01BT-I/OT
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M24C02-FMC6TG
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AT24CS02-SSHM-T
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93LC46BT-I/OT
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AT24C04C-SSHM-T
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24LC01BT-I/SN
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