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Microchip Technology AT28C64E-12SU
- Part No.:
- AT28C64E-12SU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
AT28C64E-12SU.pdf
- Description:
- IC EEPROM 64KBIT PARALLEL 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,120
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Product details
Overview
AT28C64E-12SU from Microchip Technology (formerly Atmel) is a 64 Kbit (8K × 8) parallel EEPROM with 120 ns read access time, 200 µs byte write cycle, and JEDEC-standard 28-pin SOIC package. It operates at 5V ±10%, supports industrial temperature range (–40°C to +85°C), and delivers 30 mA active current and 100 µA CMOS standby current for embedded nonvolatile storage in microcontroller systems.
For engineers reviewing the AT28C64E-12SU datasheet, AT28C64E-12SU pinout, AT28C64E-12SU application, or AT28C64E-12SU equivalent, key selection criteria include self-timed byte write with RDY/BUSY and DATA polling, VCC sense write protection, chip erase capability, and compatibility with TTL/CMOS buses in legacy control and instrumentation designs.
Technical Context
The AT28C64E-12SU implements a parallel interface with dual-line chip enable (CE) and output enable (OE) control, enabling bus contention avoidance during read cycles. Its internal address and data latching frees the microprocessor bus during self-timed writes, while the open-drain RDY/BUSY output supports OR-tying of multiple devices.
Write operation includes automatic clear-before-write, VCC sensing (inhibit below 3.8 V), 5 ms power-on delay, and three independent write-inhibit conditions (CE high, OE low, or WE high). Chip erase requires 12 V on OE and a 10 ms WE pulse, and device identification uses 32 bytes at addresses 1FE0H–1FFFH with A9 raised to 12 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8,192 × 8 bits); sufficient for firmware patch storage or configuration tables in 8-bit MCU systems |
| Read Access Time | 120 ns maximum; enables direct replacement of SRAM in timing-critical legacy designs without wait-state insertion |
| Byte Write Time | 200 µs maximum; allows full memory rewrite in ≤1.6 seconds, suitable for infrequent field updates |
| Supply Voltage | 5 V ±10%; compatible with standard TTL/CMOS logic rails and eliminates need for auxiliary voltage regulators |
| Operating Temperature | –40°C to +85°C; qualified for industrial control panels, test equipment, and factory automation hardware |
| Standby Current | 100 µA typical (CMOS mode); reduces system-level power budget in battery-backed or energy-sensitive applications |
| Endurance | 10⁵ write/erase cycles; supports >10 years of daily reconfiguration in programmable logic controllers |
| Data Retention | 10 years at 85°C; ensures long-term reliability in unattended embedded deployments without refresh circuitry |
Pinout & Package
AT28C64E-12SU is supplied in a 28-lead, 0.300" wide plastic gull-wing small outline (SOIC) package per JEDEC MS-013, with pin 1 marked by notch or bevel. Pin functions are fully compatible with industry-standard parallel EEPROM footprints.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A12 | Address Inputs | 13-bit address bus supporting full 8K-word addressing; compatible with Z80, 8051, and 68K family address lines |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel data path; electrically compatible with TTL/CMOS logic levels and drive strengths |
| CE | Chip Enable | Active-low global enable; when high, places all outputs in high-impedance state regardless of OE/WE state |
| OE | Output Enable | Active-low read control; used with CE to prevent bus contention during partial decode or shared-memory configurations |
| 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 for multi-device status monitoring |
| VCC, GND | Power Supply | Single 5 V supply with decoupling recommended near pin 28 (VCC) and pin 14 (GND) |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed byte write | Eliminates external timing circuitry; internal control timer manages clear-before-write and write completion autonomously |
| RDY/BUSY and DATA polling | Dual asynchronous write-complete detection: hardware flag (pin 1) and software-readable I/O7 toggle for flexible system integration |
| VCC sense and power-on delay | Prevents inadvertent writes during power ramp-up or brown-out; 3.8 V threshold and 5 ms delay ensure stable programming conditions |
| JEDEC byte-wide pinout | Drop-in replacement for industry-standard 28-pin parallel EEPROMs (e.g., 28C64, 28C256) without PCB redesign |
| 32-byte device ID area | User-accessible memory block at 1FE0H–1FFFH (A9 = 12 V) for serialization, calibration data, or firmware version tracking |
Applications
| Industrial PLC Configuration Storage | Legacy Test Equipment Calibration Tables |
|---|---|
Use Scenario: Storing user-modifiable I/O mapping and alarm thresholds in programmable logic controllers deployed in manufacturing cells. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed via 8-bit parallel bus during boot and runtime parameter updates. Use Value: 10⁵ endurance and 10-year data retention ensure reliable operation across maintenance cycles without backup batteries or refresh routines. | Use Scenario: Holding instrument-specific calibration coefficients and sensor linearization curves in benchtop multimeters and signal generators. IC Role / Device Role / Timing Role: Read-once/write-rarely memory mapped into microcontroller address space for deterministic startup loading. Use Value: 120 ns read access avoids CPU wait states; self-timed 200 µs writes allow background calibration updates without interrupting measurement sequences. |
| Medical Device Setup Parameters | Avionics Ground Support Interface Modules |
Use Scenario: Preserving operator-selected therapy modes, safety limits, and patient presets in portable infusion pumps and diagnostic monitors. IC Role / Device Role / Timing Role: Secure, tamper-resistant storage accessible only during authorized service mode via dedicated command sequence. Use Value: VCC-sense write protection prevents corruption during power transitions; industrial temperature rating supports operation in clinical environments. | Use Scenario: Storing protocol translation tables and hardware revision identifiers in ground-test adapters for aircraft subsystem diagnostics. IC Role / Device Role / Timing Role: Static memory resource for FPGA or MCU-based interface logic, updated only during depot-level firmware upgrades. Use Value: JEDEC-compliant pinout enables reuse of existing PCB layouts; RDY/BUSY signaling simplifies synchronization with host test sequencers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C64B-12SU | Successor variant with identical pinout, speed, and capacity but improved data retention (20 years vs. 10 years) and enhanced ESD robustness | Suitable for new designs requiring extended archival reliability; not recommended for field replacements where qualification testing is constrained | Select AT28C64B-12SU for new industrial designs prioritizing long-term data integrity; verify compatibility with existing programming algorithms. |
| ST M28C64-12S1 | Functionally equivalent 64 Kbit parallel EEPROM with same 120 ns access, 200 µs write, and SOIC-28 package; differs in RDY/BUSY polarity and chip erase voltage (12.5 V) | Requires minor firmware adaptation for status polling and erase sequencing; validated for automotive-grade temperature range (–40°C to +125°C) | Choose ST M28C64-12S1 only when extended temperature operation or alternate supply chain diversification is required; validate timing margins in target system. |
Compared with AT28C64E-12SU, AT28C64B-12SU offers doubled data retention without layout changes, while ST M28C64-12S1 provides higher temperature tolerance at the cost of minor interface requalification-both serve as functional alternatives but require verification of write-protection behavior and erase sequencing in production firmware.
Availability
AT28C64E-12SU is available at Aetrix Electronics and suitable for industrial control, test instrumentation, medical device configuration, and avionics ground support applications requiring stable component supply and long-lifecycle support.
Supply support for AT28C64E-12SU 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 product continuity, quality assurance, and long-term supply commitment for legacy Atmel memory devices.
The AT28C64E belongs to Atmel's parallel EEPROM product line, designed specifically for byte-addressable nonvolatile storage in resource-constrained 8-bit and 16-bit microcontroller systems where simplicity, reliability, and JEDEC compatibility are critical.
FAQ
What is the correct voltage level for chip erase on the AT28C64E-12SU?
The AT28C64E-12SU requires 12.0 V ± 0.5 V applied to the OE pin (pin 18) while holding CE low and applying a 10 ms low pulse to WE. This voltage must be stable and well-regulated; exceeding 12.5 V risks permanent damage. The AT28C64E-12SU does not support chip erase via standard 5 V signaling-dedicated high-voltage programming circuitry is mandatory.
Does the AT28C64E-12SU support true simultaneous read and write operations?
No, the AT28C64E-12SU does not support concurrent read and write. During a byte write cycle, the device enters a busy state and returns indeterminate data on I/O lines until completion. Reads initiated during write execution function as polling operations-specifically, I/O7 toggles to indicate progress. The AT28C64E-12SU relies on RDY/BUSY or DATA polling to determine write readiness before issuing subsequent commands.
How is write protection implemented on the AT28C64E-12SU?
The AT28C64E-12SU implements three-tiered hardware write protection: (1) VCC sense inhibits writes if supply drops below 3.8 V; (2) a 5 ms internal power-on delay prevents writes during voltage stabilization; and (3) any of CE high, OE low, or WE high blocks write initiation. These mechanisms operate independently and require no software configuration-protection is inherent to the AT28C64E-12SU's analog design.
Can the AT28C64E-12SU be used as a direct replacement for older 28C64 variants in existing PCBs?
Yes-the AT28C64E-12SU uses the JEDEC-approved byte-wide 28-pin SOIC footprint and matches the pinout, timing, and electrical characteristics of legacy 28C64 devices. Its 120 ns access time, 5 V operation, and TTL/CMOS compatibility ensure drop-in functionality. However, verify that existing firmware correctly handles RDY/BUSY assertion and DATA polling behavior, as subtle timing differences may affect legacy drivers.
What is the purpose of the 32-byte device identification area in the AT28C64E-12SU?
The AT28C64E-12SU reserves 32 bytes (addresses 1FE0H–1FFFH) for user-defined device identification data, accessible only when A9 is raised to 12 V. This area supports serialization, calibration storage, or firmware version tagging without consuming main array space. Unlike standard memory, this region requires elevated voltage and separate addressing-its use does not impact the endurance or retention specifications of the primary 64 Kbit array.
AT28C64E-12SU 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:
- 120 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-12SU FAQ
1.How can I place an order for AT28C64E-12SU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C64E-12SU 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-12SU reliable?
The price and inventory of AT28C64E-12SU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28C64E-12SU is usually 5 days.
3.What payment methods are accepted for AT28C64E-12SU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C64E-12SU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C64E-12SU?
AT28C64E-12SU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C64E-12SU 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-12SU?
For technical support, including AT28C64E-12SU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C64E-12SU requirements.
6.How does Aetrix verify that AT28C64E-12SU is sourced from the original manufacturer or authorized distributors?
All AT28C64E-12SU 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-12SU meets industry standards.
7.What is the process for return or replacement of AT28C64E-12SU?
All AT28C64E-12SU units undergo pre-shipment inspection (PSI). If there is an issue with AT28C64E-12SU, 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-12SU part is unused and in its original packaging.
Return procedure for AT28C64E-12SU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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