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Microchip Technology AT28C64-20SI
- Part No.:
- AT28C64-20SI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
AT28C64-20SI.pdf
- Description:
- IC EEPROM 64KBIT PARALLEL 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,729
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Product details
Overview
AT28C64-20SI from Atmel is a 64 Kbit (8K × 8) parallel EEPROM with JEDEC-standard byte-wide pinout, 200 ns read access time, 1 ms or 200 µs byte write capability, and CMOS/TTL-compatible I/O - used for nonvolatile configuration storage in industrial microcontroller systems requiring field-updatable firmware parameters.
For engineers reviewing the AT28C64-20SI datasheet, AT28C64-20SI pinout, AT28C64-20SI application, or AT28C64-20SI equivalent, this page delivers verified electrical specs, validated industrial-temperature operation (-40°C to +85°C), self-timed write architecture, RDY/BUSY and DATA polling support, and direct microprocessor interface compatibility without external timing logic.
Technical Context
The AT28C64-20SI implements a self-timed byte write cycle with internal address/data latching and automatic erase-before-write, eliminating external timing control. Its READY/BUSY open-drain output and I/O7 data polling provide two independent methods to detect write completion.
It operates on a single 5V ±10% supply, draws ≤30 mA active current and ≤100 µA CMOS standby current, and supports both CE- and WE-controlled write initiation while maintaining TTL/CMOS input/output compatibility across all operating modes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8,192 × 8 bits) - provides sufficient space for boot configuration tables, calibration data, or device identity storage in embedded controllers. |
| Read Access Time | 200 ns max - enables direct interfacing with 5 MHz microprocessors without wait states. |
| Byte Write Time | 1 ms (standard) or 200 µs (E-version only) - determines minimum time between successive byte writes; AT28C64-20SI uses standard 1 ms timing. |
| Supply Voltage | 5 V ±10% - compatible with legacy 5V logic systems and eliminates need for voltage translation. |
| Operating Temperature | -40°C to +85°C - qualified for industrial environments including factory automation and motor control systems. |
| Endurance | 10,000 write/erase cycles - supports long-term field updates of infrequently changed system parameters. |
| Data Retention | 10 years at 85°C - ensures reliable storage of critical settings over product lifetime without refresh. |
Pinout & Package
AT28C64-20SI is packaged in a 28-lead SOIC (Small Outline Integrated Circuit), 0.300" wide, JEDEC MS-012 compliant, with 1.27 mm pitch and surface-mount footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A12 | Address Inputs | 13-bit address bus supporting full 8K-word addressing; decoded internally without external logic. |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel interface compatible with microprocessor data buses; supports true read/write without direction control pins. |
| CE | Chip Enable | Active-low chip select; when high, places outputs in high-impedance state and reduces power consumption to 100 µA. |
| OE | Output Enable | Active-low read control; used with CE to prevent bus contention during multi-device memory access. |
| 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 | Actively pulled low during write; released high at completion - supports wired-OR connection for multi-device status monitoring. |
| VCC, GND | Power Supply | Single 5V supply with decoupling required; no separate VPP or programming voltage needed for standard operation. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed byte write | Eliminates external timing circuitry; internal control timer manages erase-and-write sequence automatically after WE pulse. |
| Dual write-completion detection | RDY/BUSY output and I/O7 data polling provide hardware- and software-based options for synchronizing host processor operations. |
| Write protection logic | VCC sense (disable below 3.8 V), 5 ms power-on delay, and triple-input inhibit (CE high / OE low / WE high) prevent accidental writes. |
| JEDEC-standard pinout | Ensures drop-in compatibility with existing SRAM and EPROM sockets in legacy 28-pin DIP/SOIC designs. |
| Industrial temperature range | Validated operation from -40°C to +85°C supports deployment in harsh environments without derating. |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Data |
|---|---|
|
Use Scenario: Storing I/O mapping, scaling factors, and alarm thresholds in programmable logic controllers deployed in factory floors. IC Role / Device Role / Timing Role: Nonvolatile parameter register accessed via 8-bit parallel bus during system boot and runtime reconfiguration. Use Value: Enables field updates without firmware reflashing; 10,000-cycle endurance supports decades of maintenance cycles in fixed-installation equipment. |
Use Scenario: Retaining sensor offset corrections and patient-specific therapy profiles in portable diagnostic instruments. IC Role / Device Role / Timing Role: Secure, low-power configuration memory accessed during power-up and calibration routines. Use Value: 10-year data retention at 85°C ensures accuracy compliance across shelf life and repeated sterilization cycles. |
| Automotive Body Control Module Settings | Test Equipment Firmware Patch Storage |
|
Use Scenario: Holding door lock logic variants, lighting sequences, and regional compliance settings in vehicle BCMs. IC Role / Device Role / Timing Role: Parallel EEPROM interfaced directly to 8051-class MCUs for fast read access and infrequent write updates. Use Value: 200 ns read timing meets real-time response requirements; 5V operation matches legacy automotive MCU voltage domains. |
Use Scenario: Storing hotfix patches and calibration coefficients in benchtop oscilloscopes and signal generators. IC Role / Device Role / Timing Role: Field-upgradable configuration store accessed during instrument initialization and service mode. Use Value: RDY/BUSY signaling allows test firmware to pause execution safely during patch writes without polling overhead. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C64B-20SI | Revised revision with improved data retention (100 years @ 25°C) and tighter tACC tolerance (200 ns guaranteed vs. 200 ns max); same pinout and timing. | Preferred for new designs requiring extended data integrity; backward-compatible replacement for AT28C64-20SI in existing boards. | Select AT28C64B-20SI when long-term archival reliability is critical and board layout cannot be modified. |
| MX28LV640BTC-20G | 3.3V-only supply (no 5V support); 200 ns read; 5 ms typical byte write; different pinout (no RDY/BUSY); requires level-shifting for 5V systems. | Suitable only in 3.3V-native designs; lacks hardware busy signaling and JEDEC pin compatibility. | Choose MX28LV640BTC-20G only if migrating to 3.3V architecture and redesigning PCB layout and firmware polling logic. |
Compared with AT28C64-20SI, AT28C64B-20SI offers enhanced data retention without layout changes, while MX28LV640BTC-20G demands voltage domain redesign and firmware adaptation due to incompatible supply and signaling.
Availability
AT28C64-20SI is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, automotive body electronics, and test equipment requiring stable component supply with guaranteed long-term availability.
Supply support for AT28C64-20SI 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 semiconductor manufacturer specializing in microcontrollers, nonvolatile memory, and secure authentication devices.
The AT28C64 family was designed specifically for 5V microprocessor systems needing simple, reliable, pin-compatible EEPROM replacement for battery-backed SRAM or UV-erasable EPROM in industrial and automotive applications.
FAQ
What is the maximum read access time specified for AT28C64-20SI?
The AT28C64-20SI has a maximum read access time (tACC) of 200 ns under industrial temperature conditions (-40°C to +85°C) and 5V ±10% supply. This value is guaranteed across the full operating range and enables direct interface with 5 MHz microprocessors without wait-state insertion. The "20" in the part number explicitly denotes this 200 ns speed grade.
Does AT28C64-20SI require a high-voltage programming supply?
No, AT28C64-20SI operates from a single 5V ±10% supply for all read and write functions. High voltage (12 V) is only required for optional features - chip erase (applying 12 V to OE) and device identification memory access (12 V on A9) - not for standard byte writes. Normal operation uses no external VPP.
How does AT28C64-20SI indicate write completion?
AT28C64-20SI provides two independent write-completion signals: (1) the RDY/BUSY pin goes high-impedance at completion (active-low during write), and (2) DATA polling reads complemented data on I/O7 until the write finishes, then returns true data. Both methods are fully supported in the AT28C64-20SI variant.
Is AT28C64-20SI pin-compatible with standard SRAM devices?
Yes, AT28C64-20SI uses a JEDEC-approved byte-wide pinout identical to common 28-pin 8K×8 SRAMs (e.g., 6264). Address, data, CE, OE, and WE pins align directly, enabling drop-in replacement in existing sockets - though firmware must handle write timing differences and lack of true random write capability.
What is the endurance rating of AT28C64-20SI?
The AT28C64-20SI is rated for 10,000 write/erase cycles per memory location. This endurance level is sufficient for applications involving infrequent updates - such as configuration storage in industrial controllers or calibration data in test equipment - where writes occur only during commissioning or maintenance.
AT28C64-20SI 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:
- 1ms
- Access Time:
- 200 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
AT28C64-20SI FAQ
1.How can I place an order for AT28C64-20SI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C64-20SI 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 AT28C64-20SI reliable?
The price and inventory of AT28C64-20SI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28C64-20SI is usually 5 days.
3.What payment methods are accepted for AT28C64-20SI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C64-20SI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C64-20SI?
AT28C64-20SI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C64-20SI 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 AT28C64-20SI?
For technical support, including AT28C64-20SI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C64-20SI requirements.
6.How does Aetrix verify that AT28C64-20SI is sourced from the original manufacturer or authorized distributors?
All AT28C64-20SI 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 AT28C64-20SI meets industry standards.
7.What is the process for return or replacement of AT28C64-20SI?
All AT28C64-20SI units undergo pre-shipment inspection (PSI). If there is an issue with AT28C64-20SI, 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 AT28C64-20SI part is unused and in its original packaging.
Return procedure for AT28C64-20SI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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