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Microchip Technology AT49F040-70PI
- Part No.:
- AT49F040-70PI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-DIP (0.600", 15.24mm)
- Datasheet:
-
AT49F040-70PI.pdf
- Description:
- IC FLASH 4MBIT PARALLEL 32DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,473
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Product details
Overview
AT49F040-70PI from Atmel is a 4-megabit (512K × 8) 5V-only parallel Flash memory IC in 32-pin PDIP package, featuring 70 ns read access time, 50 µs byte programming, and 10-second chip erase. It integrates a 16-Kbyte boot block with hardware lockout for secure firmware storage and supports DATA polling and toggle-bit status detection. Used in embedded system boot code storage where in-system reprogrammability and data integrity are critical.
For engineers reviewing the AT49F040-70PI datasheet, AT49F040-70PI pinout, AT49F040-70PI application, or AT49F040-70PI equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, boot-block protection behavior, and two confirmed alternative parts with functional and application-level differences.
Technical Context
The AT49F040-70PI operates exclusively at 5V ±10% and uses standard EPROM-like read timing with dual-line control (CE/OE active-low), enabling bus contention avoidance. Its internal command register executes software-controlled operations including chip erase (6-byte sequence), byte programming (4-bus-cycle), and boot block lockout enable (6-byte sequence).
It implements hardware data protection via VCC sense (<3.8V inhibits programming), noise filtering (<15 ns pulses ignored on WE/CE), and logic-level inhibition (OE low, CE high, or WE high blocks writes). Boot block lockout permanently protects addresses 00000H–03FFFH once activated, while main memory (04000H–7FFFFH) remains fully reprogrammable.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 4 Mbit (512K × 8); provides sufficient space for full boot firmware images in legacy 8-bit microcontroller systems. |
| Read Access Time | 70 ns max; enables direct interface with 14 MHz Z80 or 80C88 CPUs without wait states. |
| Byte Programming Time | 50 µs typical; allows field firmware updates at ~20 KB/s sustained rate using simple GPIO-based controllers. |
| Chip Erase Time | 10 seconds max; eliminates need for external high-voltage programmers and supports full-field reflash. |
| Boot Block Size | 16 Kbytes (00000H–03FFFH); isolates critical startup code from accidental overwrites during application updates. |
| Standby Current | 100 µA CMOS (commercial temp); reduces power budget in battery-backed or low-power hold modes. |
| End-of-Write Detection | DATA polling (I/O7 complement) and toggle-bit (I/O6 toggling); eliminates need for fixed delay timers in host firmware. |
Pinout & Package
AT49F040-70PI is packaged in a 32-lead, 0.600" wide plastic dual inline package (PDIP), compliant with JEDEC MS-016AE. Pin 1 is marked by notch or dot; pin 16 is VCC, pin 17 is GND.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | 19-bit address bus supporting full 512K-word addressing; A0–A15 used for boot block (00000H–03FFFH), A16–A18 select upper regions. |
| CE | Chip Enable | Active-low global enable; must be low with OE low and WE high for valid read; high disables outputs to high-Z state. |
| OE | Output Enable | Active-low output gate; controls data bus drivers independently of CE to manage shared bus timing. |
| WE | Write Enable | Active-low write strobe; latches address/data on falling edge (WE or CE, whichever occurs last) for programming cycles. |
| I/O0–I/O7 | Bi-directional Data Bus | 8-bit parallel interface; carries input data during programming and output data during read; supports DATA polling on I/O7 and toggle-bit on I/O6. |
| VCC | Power Supply | +5V ±10% supply; powers all internal logic and charge pumps; VCC sense circuitry disables programming if voltage drops below 3.8V. |
| GND | Ground Reference | Signal and power ground reference; decoupling capacitor required within 1 cm of pin 16 (VCC) and pin 17 (GND) for stable operation. |
Key Features
| Feature | Design Value |
|---|---|
| Single 5V Operation | Eliminates need for +12V or +25V programming supplies-enables in-system reprogramming using only main system rail. |
| 16-Kbyte Boot Block Lockout | Hardware-enforced write protection for lowest 16 KB; prevents corruption of bootloader during application firmware updates. |
| DATA Polling & Toggle Bit | Two independent, software-accessible status mechanisms eliminate fixed delays and improve host CPU efficiency during write/erase. |
| Hardware Data Protection | VCC sense, noise filtering, and logic-level inhibit prevent spurious writes due to power glitches or EMI on control lines. |
| 10,000 Program/Erase Cycles | Ensures long-term field reliability for devices requiring periodic firmware patches or configuration updates over 5+ year product lifecycles. |
Applications
| Industrial PLC Firmware Storage | Legacy PC BIOS Backup |
|---|---|
Use Scenario: Storing boot firmware and configuration parameters in programmable logic controllers operating in harsh factory environments with wide temperature swings. IC Role / Device Role / Timing Role: Nonvolatile boot memory providing immediate code execution on power-up; interfaces directly to 8051 or 80C188 CPU address/data buses. Use Value: 100 µA standby current extends backup battery life; boot block lockout ensures safety-critical startup routines remain unaltered during remote firmware updates. | Use Scenario: Serving as secondary BIOS storage in industrial motherboards where primary flash may be corrupted or require recovery. IC Role / Device Role / Timing Role: Parallel-compatible drop-in replacement for obsolete 27C040 EPROMs; 70 ns access meets ISA bus timing requirements. Use Value: In-system reprogrammability avoids costly board removal; 5V-only operation simplifies power design versus UV-erasable or 12V-programmable alternatives. |
| Embedded Medical Device Bootloader | Point-of-Sale Terminal Configuration Memory |
Use Scenario: Holding certified bootloader code in FDA-regulated diagnostic equipment where firmware integrity verification is mandatory before runtime execution. IC Role / Device Role / Timing Role: Secure boot memory with hardware-enforced write protection; boot block stores signed bootloader image verified at power-on reset. Use Value: Permanent boot block lockout prevents unauthorized modification post-certification; DATA polling enables deterministic update timing for audit-trail logging. | Use Scenario: Storing localized language packs, tax tables, and peripheral configuration in retail terminals deployed globally across varying ambient temperatures. IC Role / Device Role / Timing Role: Field-upgradable nonvolatile memory mapped into CPU address space; accessed via standard memory read/write cycles. Use Value: Industrial temperature range (-40°C to +85°C) ensures reliable operation in uncontrolled retail environments; 10,000 cycle endurance supports multi-year deployment with quarterly updates. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SST39VF400A-70-4C-NHE | 4 Mbit (512K × 8), 3.3V core with 5V-tolerant I/O; 70 ns read; no dedicated boot block lockout-uses sector protection. | Requires level-shifting or mixed-voltage design; lacks hardware-enforced boot block write lockout-relies on software-managed sector protection. | Select when migrating to 3.3V systems or needing lower active power; verify host firmware supports sector-protection commands instead of boot-lockout enable sequence. |
| MX29LV400CBTI-70G | 4 Mbit (512K × 8), 3.0–3.6V operation; 70 ns read; top/bottom boot block configurable via hardware pins; supports CFI query. | Not 5V-compatible; requires separate 3.3V rail; boot block location fixed by pin strapping-not software-selectable like AT49F040-70PI's bottom-boot default. | Choose for new 3.3V designs requiring industry-standard CFI interface and flexible boot block orientation; avoid if 5V-only system or bottom-boot lockout is mandatory. |
Compared with SST39VF400A-70-4C-NHE and MX29LV400CBTI-70G, the AT49F040-70PI uniquely delivers true 5V-only operation with hardware-enforced bottom-boot lockout-critical for legacy industrial systems where voltage rail consolidation and tamper-proof bootloader storage are non-negotiable design requirements.
Availability
AT49F040-70PI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy PC BIOS backup, and embedded medical device bootloader applications requiring stable component supply, long-lifecycle support, and guaranteed traceable sourcing.
Supply support for AT49F040-70PI 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 U.S.-based semiconductor company specializing in microcontrollers, nonvolatile memory, and security ICs for industrial, automotive, and consumer applications.
The AT49F040-70PI belongs to Atmel's 5V Flash memory product line, designed specifically for legacy 8-bit and 16-bit embedded systems requiring in-system reprogrammability without high-voltage programming infrastructure.
FAQ
What is the operating voltage range for the AT49F040-70PI?
The AT49F040-70PI operates strictly at 5V ±10% (4.5V to 5.5V). It does not support 3.3V or mixed-voltage operation. The internal VCC sense circuit disables programming if supply voltage falls below 3.8V, ensuring reliable write operations only within its specified range. This 5V-only requirement makes the AT49F040-70PI compatible with legacy TTL/CMOS bus systems without level shifting.
How does the boot block lockout feature work on the AT49F040-70PI?
The AT49F040-70PI's boot block lockout permanently protects the lowest 16 Kbytes (addresses 00000H–03FFFH) from erasure or programming once enabled via a specific six-byte command sequence. After activation, no software or hardware method can reverse the lock. The AT49F040-70PI supports software detection of lockout status by reading I/O0 during product identification mode at address 00002H-low indicates unlocked, high indicates locked.
Can the AT49F040-70PI be used as a direct replacement for EPROMs like the 27C040?
Yes-the AT49F040-70PI is pin-compatible and functionally equivalent to the 27C040 EPROM in read mode, with identical 32-pin PDIP layout and EPROM-like access timing. However, unlike UV-erasable EPROMs, the AT49F040-70PI supports in-system electrical erasure and programming using only 5V, eliminating the need for EPROM erasers or socketed programming hardware.
What methods does the AT49F040-70PI provide to detect end-of-program or end-of-erase cycles?
The AT49F040-70PI offers two independent status detection methods: DATA polling (monitoring I/O7 for complemented data during programming) and toggle-bit detection (observing I/O6 toggling until completion). Both operate without external clocks or timers and can be initiated at any point during the cycle. These features allow host firmware to precisely synchronize subsequent memory accesses, improving system responsiveness and reducing worst-case latency.
Is the AT49F040-70PI suitable for industrial temperature applications?
Yes-the AT49F040-70PI variant with suffix "-PI" is rated for the industrial temperature range of -40°C to +85°C, as confirmed in the official Atmel ordering information table. Its DC and AC characteristics-including 100 µA standby current and 70 ns read access-are guaranteed across this full range, making it appropriate for deployment in factory automation, outdoor kiosks, and transportation control systems.
AT49F040-70PI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-DIP (0.600", 15.24mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- FLASH
- Technology:
- FLASH
- Memory Size:
- 4Mbit
- Memory Organization:
- 512K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 50µs
- Access Time:
- 70 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 32-PDIP
AT49F040-70PI FAQ
1.How can I place an order for AT49F040-70PI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT49F040-70PI 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 AT49F040-70PI reliable?
The price and inventory of AT49F040-70PI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT49F040-70PI is usually 5 days.
3.What payment methods are accepted for AT49F040-70PI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT49F040-70PI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT49F040-70PI?
AT49F040-70PI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT49F040-70PI 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 AT49F040-70PI?
For technical support, including AT49F040-70PI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT49F040-70PI requirements.
6.How does Aetrix verify that AT49F040-70PI is sourced from the original manufacturer or authorized distributors?
All AT49F040-70PI 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 AT49F040-70PI meets industry standards.
7.What is the process for return or replacement of AT49F040-70PI?
All AT49F040-70PI units undergo pre-shipment inspection (PSI). If there is an issue with AT49F040-70PI, 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 AT49F040-70PI part is unused and in its original packaging.
Return procedure for AT49F040-70PI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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