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Microchip Technology AT28C040-20FI
- Part No.:
- AT28C040-20FI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-CFlatPack
- Datasheet:
-
AT28C040-20FI.pdf
- Description:
- IC EEPROM 4MBIT PAR 32FLATPACK
- Quantity:
- Payment:
- Shipping:
Inventory:4,127
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Product details
Overview
AT28C040-20FI from Atmel is a 4-Mbit (512K × 8) paged parallel EEPROM with 200 ns read access time, JEDEC-standard byte-wide pinout, and single 5V ±10% supply operation. It supports automatic page write of up to 256 bytes, hardware/software data protection, and Data Polling for write completion detection - deployed in industrial embedded systems requiring nonvolatile configuration storage and firmware parameter retention.
For engineers reviewing the AT28C040-20FI datasheet, AT28C040-20FI pinout, AT28C040-20FI application, or AT28C040-20FI equivalent, key selection criteria include industrial temperature range (-40°C to +85°C), 10,000 write endurance cycles, 10 ms max page write time, CMOS/TTL compatibility, and 32-lead flatpack (32F) packaging with MIL-STD-883-tested SL703 variant availability.
Technical Context
The AT28C040-20FI implements a static RAM-compatible read interface with dual-line chip enable (CE) and output enable (OE) control to prevent bus contention. Its internal 256-byte page register latches address and data during write initiation, freeing the bus for concurrent operations while an internal timer executes the programming sequence.
Write completion is verified via I/O7 Data Polling (complement-to-true transition) or I/O6 Toggle Bit behavior. Hardware protection includes VCC sense (<3.8 V inhibit), 5 ms power-on delay, noise filtering (<15 ns pulse rejection), and CE/OE/WE state-dependent write inhibition - all active without software intervention.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Capacity | 4 Mbit (524,288 × 8 bits); supports full memory mapping without external banking logic |
| Read Access Time | 200 ns maximum; enables direct replacement of SRAM in legacy 5 MHz bus systems |
| Page Write Cycle | 10 ms maximum; allows burst programming of up to 256 bytes per cycle, reducing host CPU overhead |
| Endurance | 10,000 write/erase cycles; sufficient for field-updatable calibration tables and infrequent firmware patches |
| Data Retention | 10 years at 85°C; validated for long-life industrial deployments without refresh mechanisms |
| Supply Voltage | 5V ±10%; eliminates need for dedicated voltage regulators in 5V-only systems |
| Operating Temperature | -40°C to +85°C (Industrial grade); qualified per MIL-STD-883 when ordered as SL703 variant |
Pinout & Package
AT28C040-20FI is supplied in a 32-lead non-windowed ceramic bottom-brazed flatpack (32F), JEDEC MO-115 AA compliant, with 0.050" lead pitch and 0.830" × 0.811" body dimensions.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | 19-bit address bus supporting full 512K-word addressing; A8–A18 define page boundaries for 256-byte page writes |
| I/O0–I/O7 | Bi-directional Data Bus | Byte-wide parallel interface compatible with 8-bit microcontrollers and legacy ISA-style buses |
| CE | Chip Enable | Active-low global device select; must be low with OE low and WE high for read access |
| OE | Output Enable | Active-low output gate; high-Z state prevents bus contention during shared-memory arbitration |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; controls byte vs. page write mode |
| VCC | Power Supply | +5V ±10% main supply; powers core logic and charge pumps for EEPROM programming |
| VSS | Ground | Signal and power reference plane; decoupling required within 10 mm of VCC pin |
Key Features
| Feature | Design Value |
|---|---|
| Automatic Page Write | Latches up to 256 bytes internally, enabling host CPU to resume processing after initial write trigger |
| Data Polling (I/O7) | Provides deterministic, bus-compatible method to detect write completion without timers or interrupts |
| Hardware Write Inhibit | VCC sense + 5 ms power-on delay + noise filtering eliminate need for external power-monitoring circuitry |
| Software Data Protection (SDP) | User-configurable 3-byte command sequence prevents accidental writes during power transitions or debug sessions |
| JEDEC Byte-Wide Pinout | Direct drop-in replacement for industry-standard EPROMs and SRAMs in existing PCB layouts |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Data |
|---|---|
|
Use Scenario: Storing I/O module mappings, PID tuning parameters, and safety thresholds in programmable logic controllers operating continuously in factory environments. IC Role / Device Role / Timing Role: Nonvolatile configuration register bank with guaranteed 10-year data retention at 85°C ambient. Use Value: Eliminates battery-backed SRAM and associated maintenance; supports field updates via serial interface without system reboot. |
Use Scenario: Retaining sensor calibration coefficients, patient-specific therapy settings, and regulatory audit logs in Class II medical equipment. IC Role / Device Role / Timing Role: Secure, tamper-resistant parameter store with hardware/software write lock and MIL-883-tested reliability. Use Value: Meets IEC 62304 data integrity requirements; SDP prevents unintended changes during ESD-prone servicing. |
| Avionics System Bootloader Parameters | Telecom Line Card Firmware Patching |
|
Use Scenario: Holding boot configuration flags, checksum-verified bootloader offsets, and redundancy switch settings in airborne computing modules. IC Role / Device Role / Timing Role: Extended temperature-grade (-55°C to +125°C) nonvolatile storage for critical startup metadata. Use Value: Qualified to MIL-STD-883 (SL703 variant); withstands thermal cycling and vibration without data corruption. |
Use Scenario: Storing hot-swappable line card firmware patches, vendor ID strings, and optical transceiver calibration data in carrier-grade switches. IC Role / Device Role / Timing Role: High-speed parallel EEPROM enabling sub-100ms patch loading during service windows. Use Value: 200 ns read access and 10 ms page write support zero-downtime upgrades without external buffering. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar paged parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Microchip 28C040-20I/P | Same 4 Mbit capacity, 200 ns access, but uses 28-pin PDIP package; no MIL-883 option; 5 mA lower active current (45 mA) | Lacks SL703 qualification and 32F flatpack; suited for prototyping or cost-sensitive non-military designs | Select when DIP socketing or lower power is prioritized over extended temp or ruggedized packaging |
| ON Semiconductor CAT28C040WI-20 | Identical pinout and timing; rated for -40°C to +85°C only; no optional 12V A9 programming for device ID area | No extended temperature or device identification EEPROM extension; simplified feature set | Select when basic EEPROM functionality suffices and A9-based ID storage is unnecessary |
Compared with Microchip 28C040-20I/P and ON Semiconductor CAT28C040WI-20, the AT28C040-20FI offers unique MIL-STD-883 testability (SL703), 32F ceramic flatpack for thermal/mechanical stability, and user-accessible 256-byte device ID region - making it optimal for high-reliability industrial and aerospace deployments where layout compatibility and long-term traceability are mandatory.
Availability
AT28C040-20FI is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostic instruments, avionics subsystems, and telecom infrastructure requiring stable component supply across extended product lifecycles.
Supply support for AT28C040-20FI 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 AT28C040 belongs to Atmel's parallel EEPROM product line, designed specifically for legacy system upgrades and industrial applications demanding pin-compatible replacements for EPROMs and battery-backed SRAMs with zero external support components.
FAQ
What is the operating temperature range for the AT28C040-20FI?
The AT28C040-20FI is rated for industrial temperature operation from -40°C to +85°C. When ordered with the SL703 suffix, it undergoes MIL-STD-883 testing and supports extended case temperatures up to +125°C, making AT28C040-20FI suitable for harsh-environment applications such as motor drives and outdoor telecom equipment.
Does the AT28C040-20FI require external high-voltage programming circuitry?
No, the AT28C040-20FI operates from a single 5V ±10% supply and integrates on-chip charge pumps for EEPROM programming. All write operations - including byte, page, and chip erase - execute autonomously after standard 5V-level address and data setup, eliminating external VPP generators or programming adapters for AT28C040-20FI integration.
How does Data Polling work on the AT28C040-20FI?
Data Polling on the AT28C040-20FI uses I/O7 to signal write completion: during a write cycle, reading the last written byte returns the complement of the data on I/O7; once true data appears, the write is complete. This allows host firmware to poll AT28C040-20FI without timers or interrupts, using standard read instructions for deterministic synchronization.
Can the AT28C040-20FI be used as a direct replacement for standard SRAM in existing designs?
Yes - the AT28C040-20FI features JEDEC-approved byte-wide pinout and static RAM-compatible read timing (200 ns access, CE/OE-controlled outputs). For read-only operation, AT28C040-20FI drops into SRAM sockets without layout changes; write operations require additional WE control but retain identical address/data bus behavior during reads.
What is the purpose of the extra 256-byte EEPROM region in the AT28C040-20FI?
The AT28C040-20FI includes an additional 256-byte EEPROM segment accessible via A9 = 12V ±0.5V and addresses 7FF80H–7FFFFH. This region is intended for permanent device identification, manufacturing traceability, or calibration data that must survive full memory erasure - a capability not present in standard AT28C040-20FI competitors.
AT28C040-20FI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-CFlatPack
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 4Mbit
- Memory Organization:
- 512K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 10ms
- 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:
- 32-FlatPack, Ceramic Bottom-Brazed
AT28C040-20FI FAQ
1.How can I place an order for AT28C040-20FI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C040-20FI 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 AT28C040-20FI reliable?
The price and inventory of AT28C040-20FI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28C040-20FI is usually 5 days.
3.What payment methods are accepted for AT28C040-20FI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C040-20FI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C040-20FI?
AT28C040-20FI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C040-20FI 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 AT28C040-20FI?
For technical support, including AT28C040-20FI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C040-20FI requirements.
6.How does Aetrix verify that AT28C040-20FI is sourced from the original manufacturer or authorized distributors?
All AT28C040-20FI 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 AT28C040-20FI meets industry standards.
7.What is the process for return or replacement of AT28C040-20FI?
All AT28C040-20FI units undergo pre-shipment inspection (PSI). If there is an issue with AT28C040-20FI, 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 AT28C040-20FI part is unused and in its original packaging.
Return procedure for AT28C040-20FI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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