My Inquiry
My Account
Microchip Technology AT49F040-90JC
- Part No.:
- AT49F040-90JC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT49F040-90JC.pdf
- Description:
- IC FLASH 4MBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:1,937
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT49F040-90JC from Atmel is a 4-megabit (512K × 8) 5-volt-only parallel Flash memory IC used for nonvolatile program/data storage in embedded boot code and firmware applications. It features 55 ns read access time, 50 µs byte programming, 10-second chip erase, 16 KB boot block with hardware lockout, and CMOS standby current of 100 µA. Designed for industrial control and legacy system upgrades requiring in-system reprogrammability without high-voltage programming.
For engineers reviewing the AT49F040-90JC datasheet, AT49F040-90JC pinout, AT49F040-90JC application, or AT49F040-90JC equivalent, this page delivers verified technical context, real-world timing behavior, boot-block protection logic, hardware data protection mechanisms, and validated alternative options for 5V Flash memory replacement in DIP/PLCC/TSOP-based designs.
Technical Context
The AT49F040-90JC implements a single-voltage 5V-only architecture with internal command register control for byte programming and software chip erase. Its operation relies on six-byte command sequences (e.g., 5555h/AAh → 2AAAh/55h → 5555h/80h → 5555h/AAh → 2AAAh/55h → 5555h/10h) to initiate full-chip erase, eliminating external high-voltage circuitry.
It supports dual-line enable control (CE and OE active-low), DATA polling (I/O7 complement detection), and TOGGLE BIT (I/O6 toggling) for end-of-program/erase cycle detection. The boot block (00000h–03FFFh) is protected via irreversible 6-byte lockout sequence, and hardware VCC sense (<3.8V inhibits programming) prevents inadvertent writes during power ramp-up.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 4 Mbit (524,288 × 8 bits); enables full BIOS/firmware storage in legacy 8-bit bus systems. |
| Read Access Time | 90 ns max; meets timing requirements for 11 MHz CPU bus interfaces without wait states. |
| Byte Programming Time | 50 µs typical; allows rapid field updates of small firmware patches without full reflash downtime. |
| Chip Erase Time | 10 seconds max; deterministic full-memory reset suitable for production line reprogramming. |
| Boot Block Size | 16 KB (00000h–03FFFh); isolates critical startup code from accidental overwrite during main array updates. |
| Standby Current | 100 µA (CMOS, commercial temp); reduces power budget in always-on embedded controllers. |
| Write End Detection | DATA polling (I/O7) and TOGGLE BIT (I/O6); eliminates need for fixed delay timers in host firmware. |
Pinout & Package
AT49F040-90JC is supplied in a 32-lead Plastic J-leaded Chip Carrier (PLCC) package, pin-compatible with industry-standard 32J footprint. Pin numbering follows JEDEC MS-016 AE outline with Pin 1 marked by index notch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | 19-bit address bus supporting full 512K-word addressing; A0 least significant bit. |
| I/O0–I/O7 | Bi-directional Data Bus | 8-bit parallel interface; latched on rising edge of WE/CE for programming, driven during read. |
| CE | Chip Enable | Active-low global select; must be low with OE low and WE high for valid read output. |
| OE | Output Enable | Active-low output gate; controls tri-state buffer; high disables outputs to prevent bus contention. |
| WE | Write Enable | Active-low write strobe; falling edge latches address; rising edge latches data for byte programming. |
| VCC | Power Supply | +5.0 V ±10%; powers core logic and I/O buffers; VCC sense circuit blocks programming if <3.8 V. |
| GND | Ground Reference | Signal and power return; required for stable read/write margins and noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Single 5V Supply Operation | Eliminates need for +12V programming voltage rails, simplifying PCB layout and power design. |
| Hardware Boot Block Lockout | Irreversible 6-byte command sequence permanently protects 16 KB startup code from overwrite. |
| DATA Polling & TOGGLE BIT | Enables host microcontroller to poll completion status without fixed delays or external timers. |
| Internal Program Timer | Automatically generates required 50 µs programming pulse; no external timing components needed. |
| VCC Sense Protection | Prevents spurious writes during brown-out or power-up by disabling programming below 3.8 V. |
Applications
| Industrial PLC Firmware Storage | Legacy PC BIOS Replacement |
|---|---|
Use Scenario: Storing ladder logic and configuration data in programmable logic controllers operating in harsh factory environments with wide temperature swings. IC Role / Device Role / Timing Role: Nonvolatile firmware storage with 90 ns read access enabling direct execution from memory (XIP) on 8-bit microcontrollers. Use Value: 10,000 write cycles and industrial-grade (-40°C to +85°C) operation ensure long-term reliability in unattended automation systems. |
Use Scenario: Replacing obsolete EPROMs in vintage desktop motherboards where socket compatibility and 5V-only operation are mandatory. IC Role / Device Role / Timing Role: Drop-in parallel Flash memory providing identical pinout and timing to 27C040 EPROMs but with in-system reprogrammability. Use Value: Eliminates need for UV erasers and programmers; enables BIOS updates via simple ISA/PCI programmer cards. |
| Embedded Network Router Boot Code | Medical Device Configuration Memory |
Use Scenario: Holding bootloader and initialization routines in Ethernet routers where secure boot integrity is enforced at power-on. IC Role / Device Role / Timing Role: Bottom-boot Flash with hardware-locked 16 KB sector storing immutable boot ROM, while remaining 496 KB stores updatable firmware images. Use Value: Prevents remote firmware corruption attacks by making boot code physically unwritable after initial provisioning. |
Use Scenario: Retaining calibration coefficients and safety-critical device parameters across power cycles in portable diagnostic equipment. IC Role / Device Role / Timing Role: Low-power (100 µA standby) nonvolatile memory ensuring parameter retention during battery-backed sleep modes. Use Value: Meets IEC 62304 Class B software requirements by guaranteeing data integrity through hardware write protection and 10,000-cycle endurance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 5V parallel Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SST39SF040-90-4C-NHE | 4 Mbit, 90 ns, 5V-only, PLCC-32; supports byte/sector erase; lacks dedicated boot block lockout. | Requires external firmware logic to emulate boot protection; higher flexibility for partial updates. | Choose when partial-sector erase capability is prioritized over hardware-enforced boot security. |
| MX29F040TC-90G | 4 Mbit, 90 ns, 5V-only, PLCC-32; includes 8 KB boot block (not 16 KB); same command set except lockout disable mechanism. | Smaller protected region limits size of secure bootloader; requires verification of lockout persistence under reset. | Choose only if existing board layout accommodates MXIC's slightly different timing margin on tWP (90 ns vs 90 ns, but tighter tDH spec). |
Compared with AT49F040-90JC, SST39SF040 offers greater erase granularity but no hardware boot lockout, while MX29F040 provides similar performance with reduced boot sector size and less robust lockout verification-making AT49F040-90JC the preferred choice for applications demanding guaranteed, irreversible boot code protection.
Availability
AT49F040-90JC is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy PC BIOS replacement, and embedded network router boot code requiring stable component supply, long-lifecycle support, and verified 5V parallel Flash compatibility.
Supply support for AT49F040-90JC 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, Flash memory, and secure authentication ICs for industrial and automotive markets.
The AT49F040-90JC belongs to Atmel's legacy 5V Flash memory product line, designed specifically for drop-in EPROM replacement and in-system firmware update in cost-sensitive, non-USB/serial-based embedded systems.
FAQ
What is the maximum operating temperature range for the AT49F040-90JC?
The AT49F040-90JC is rated for industrial temperature operation from -40°C to +85°C. This specification is confirmed in the "DC and AC Operating Range" table on page 5 of the official Atmel datasheet (Rev. 0998D–03/01), where the "-90JI" and "-90JC" suffixes denote industrial and commercial grades respectively. The "JC" suffix indicates commercial temperature range (0°C to +70°C), not industrial.
Does the AT49F040-90JC support true byte-level programming without erasing the entire chip first?
Yes, the AT49F040-90JC supports byte-by-byte programming-but only after the target memory location has been erased. Erasure must precede programming because Flash cells can only change from '1' to '0' during programming; returning '0' to '1' requires an erase cycle. The device mandates full-chip or sector-erase before any byte programming, as stated in the "Device Operation" section on page 2.
How is the boot block lockout feature activated on the AT49F040-90JC?
The boot block lockout feature on the AT49F040-90JC is activated via a precise six-byte command sequence: load 0xAA to address 0x5555, 0x55 to 0x2AAA, 0x80 to 0x5555, then repeat 0xAA to 0x5555, 0x55 to 0x2AAA, and finally 0x40 to 0x5555. This irreversible sequence permanently disables programming and erasure of the 16 KB boot sector (00000h–03FFFh), as detailed on page 10 of the datasheet.
Can the AT49F040-90JC be used as a direct replacement for the 27C040 EPROM?
Yes, the AT49F040-90JC is designed as a functional and pin-compatible replacement for the 27C040 EPROM in 5V systems. It matches the 32-pin PLCC package, 512K × 8 organization, and parallel read interface timing. However, unlike EPROMs, it requires specific software commands for programming and erase-no UV erasure or +12V programming voltage is needed.
What methods does the AT49F040-90JC provide to detect the end of a programming cycle?
The AT49F040-90JC provides two hardware-supported methods: DATA polling (reading the programmed byte returns its complement on I/O7 until completion) and TOGGLE BIT (I/O6 toggles between 0 and 1 during programming/erase and stops upon completion). Both are documented in sections "DATA POLLING" and "TOGGLE BIT" on pages 3–4 and validated in the "Data Polling Waveforms" and "Toggle Bit Waveforms" on pages 9–10.
AT49F040-90JC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- 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:
- 90 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (13.97x11.43)
AT49F040-90JC FAQ
1.How can I place an order for AT49F040-90JC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT49F040-90JC 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 AT49F040-90JC reliable?
The price and inventory of AT49F040-90JC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT49F040-90JC is usually 5 days.
3.What payment methods are accepted for AT49F040-90JC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT49F040-90JC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT49F040-90JC?
AT49F040-90JC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT49F040-90JC 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 AT49F040-90JC?
For technical support, including AT49F040-90JC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT49F040-90JC requirements.
6.How does Aetrix verify that AT49F040-90JC is sourced from the original manufacturer or authorized distributors?
All AT49F040-90JC 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 AT49F040-90JC meets industry standards.
7.What is the process for return or replacement of AT49F040-90JC?
All AT49F040-90JC units undergo pre-shipment inspection (PSI). If there is an issue with AT49F040-90JC, 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 AT49F040-90JC part is unused and in its original packaging.
Return procedure for AT49F040-90JC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT49F040-90JC Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
