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Microchip Technology AT29C040A-90JU-T
- Part No.:
- AT29C040A-90JU-T
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT29C040A-90JU-T.pdf
- Description:
- IC FLASH 4MBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:4,128
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Product details
Overview
AT29C040A-90JU-T from Atmel is a 4-Mbit (512K × 8) 5V-only Flash memory IC organized in 2048 sectors of 256 bytes each, featuring 90 ns read access time, sector-based reprogramming, and hardware/software data protection. It operates across -40°C to +85°C and supports in-system programming for embedded firmware storage in microcontroller boot applications.
For engineers reviewing the AT29C040A-90JU-T datasheet, AT29C040A-90JU-T pinout, AT29C040A-90JU-T application, or AT29C040A-90JU-T equivalent, key selection criteria include sector erase granularity, 5V-only operation compatibility, boot block lockout capability, DATA polling/Toggle Bit program status detection, and PLCC-32 packaging for legacy board designs.
Technical Context
The AT29C040A-90JU-T implements a sector-program architecture with internal address/data latches for 256-byte loads, automatic erase-and-program sequencing, and dual-line chip enable (CE)/output enable (OE) control to prevent bus contention during read cycles. Its timing is governed by tACC = 90 ns, tWC = 10 ms per sector, and tWP = 90 ns write pulse width.
Hardware data protection includes VCC sense (<3.8 V inhibits programming), 5 ms power-on delay, and noise filtering (<15 ns pulses ignored); software protection uses a three-command sequence (AAh/55h/A0h at 5555h/2AAAh/5555h) to enable/disable write locks across all sectors. Boot block lockout applies independently to two 16K-byte regions (0x00000–0x03FFF and 0x7C000–0x7FFFF).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 4 Mbit (512K × 8), enabling full firmware image storage for 8-bit MCUs |
| Read Access Time | 90 ns - meets timing requirements for high-speed 8051 and Z80-based systems |
| Sector Size | 256 bytes - allows fine-grained firmware updates without full-chip erasure |
| Program Cycle Time | 10 ms per sector - enables predictable field firmware patching latency |
| VCC Supply | 5 V ±10% - eliminates need for dedicated programming voltage rails |
| Endurance | >10,000 write/erase cycles per sector - supports long-life industrial logging |
| Standby Current | 100 µA CMOS - suitable for low-power battery-backed configuration storage |
Pinout & Package
AT29C040A-90JU-T is packaged in a 32-lead Plastic J-Leaded Chip Carrier (PLCC), compliant with JEDEC MS-016 Variation AE, with body dimensions 12.47 mm × 14.96 mm × 3.35 mm and lead coplanarity ≤0.102 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | 19-bit addressing for full 512K-word space; A0–A7 select byte within 256-byte sector |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel interface compatible with standard microprocessor buses; supports DATA polling on I/O7 and Toggle Bit on I/O6 |
| CE | Chip Enable | Active-low global device select; must be stable before address setup for valid read/write |
| OE | Output Enable | Active-low output control; used with CE to manage bus contention during reads |
| WE | Write Enable | Active-low command input for byte load and sector programming; initiates internal timers when pulsed |
| NC | No Connect | Unbonded pin; must remain unconnected to avoid signal integrity issues |
| VCC | Power Supply | +5 V ±10% supply; powers core logic and charge pumps for sector erase |
| GND | Ground | Reference for all inputs/outputs; requires low-impedance PCB return path |
Key Features
| Feature | Design Value |
|---|---|
| Single-cycle sector reprogram | Eliminates external erase commands - internal timer handles erase+program sequence automatically |
| Hardware data protection | VCC sense and 5 ms power-on delay prevent spurious writes during brown-out or startup |
| Software data protection | Three-command unlock sequence required before any sector write - prevents accidental firmware corruption |
| Boot block lockout | Independent 16K-byte lock for upper/lower memory regions - secures bootloader code from overwrite |
| DATA polling & Toggle Bit | Dual asynchronous status reporting via I/O7 complement and I/O6 toggling - enables non-blocking firmware update routines |
Applications
| Industrial PLC Firmware Storage | Legacy Embedded System Boot Code |
|---|---|
Use Scenario: Storing firmware images and configuration parameters in programmable logic controllers operating in harsh factory environments with wide temperature swings. IC Role / Device Role / Timing Role: Nonvolatile program memory holding boot loader and application code, accessed via 8-bit parallel bus with 90 ns read timing. Use Value: Sector-level reprogramming allows field updates without removing the module; 10,000-cycle endurance ensures multi-year service life under periodic firmware revision. | Use Scenario: Hosting boot code for 8051- or Z80-based medical instruments where firmware integrity is critical and redesign is cost-prohibitive. IC Role / Device Role / Timing Role: Primary boot ROM with lockable 16K lower-block protecting initialization routines from accidental overwrites. Use Value: Hardware/software data protection and boot block lockout prevent unauthorized or erroneous modifications during service or calibration procedures. |
| Automated Test Equipment Configuration | Point-of-Sale Terminal Firmware |
Use Scenario: Holding calibration tables and test sequence definitions in benchtop ATE systems requiring reliable long-term data retention. IC Role / Device Role / Timing Role: Configuration memory mapped into CPU address space; accessed via CE/OE-controlled read cycles with 90 ns latency. Use Value: 100 µA standby current minimizes power draw during idle periods; sector granularity enables selective table updates without disrupting active test sequences. | Use Scenario: Storing payment processing firmware and localization assets in retail POS terminals deployed globally with infrequent but mission-critical updates. IC Role / Device Role / Timing Role: Field-upgradable flash memory supporting secure OTA patches via serial bootloader interfacing through parallel I/O0–I/O7. Use Value: Software data protection and toggle bit status reporting ensure robust update verification even on low-cost, resource-constrained host processors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM29LV040B-90JC | 3.3 V core with 5 V I/O tolerance; 90 ns access; 64K-byte uniform blocks instead of 256-byte sectors | Lacks boot block lockout; requires level-shifting for pure 5 V systems | Choose only if migrating to 3.3 V design with compatible voltage translation |
| MX29LV040CTTI-90G | 3.3 V supply; 90 ns access; 64K-byte blocks; supports CFI query mode | No hardware boot block lockout; software protection differs in command sequence | Prefer for new 3.3 V designs needing industry-standard CFI compatibility |
Compared with AT29C040A-90JU-T, AM29LV040B-90JC and MX29LV040CTTI-90G offer faster block erase but lack its 256-byte sector granularity and dual-boot-block lockout-critical for legacy 5 V systems requiring fine-grained, tamper-resistant firmware updates.
Availability
AT29C040A-90JU-T is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy embedded system boot code, and automated test equipment configuration requiring stable component supply and long-lifecycle support.
Supply support for AT29C040A-90JU-T 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 security ICs for industrial, automotive, and consumer applications.
The AT29C040A-90JU-T belongs to Atmel's 5V-only Flash memory product line, designed specifically for in-system reprogrammability in legacy 8-bit and 16-bit embedded platforms without requiring high-voltage programming circuitry.
FAQ
What is the maximum operating temperature range for the AT29C040A-90JU-T?
The AT29C040A-90JU-T is rated for industrial temperature operation from -40°C to +85°C. This range is confirmed in the DC and AC Operating Range section of the official datasheet, and applies to both read and program operations under specified VCC and timing conditions. The device maintains full functionality-including 90 ns read access and 10 ms sector programming-across this entire range. AT29C040A-90JU-T does not support extended or military temperature grades.
Does the AT29C040A-90JU-T support full-chip erase?
Yes, the AT29C040A-90JU-T supports optional software chip erase using a 6-byte command sequence documented in the Software Chip Erase application note. However, if either boot block lockout feature has been activated, chip erase is disabled. Full-chip erase is distinct from sector erase and affects all 512K words. AT29C040A-90JU-T does not support hardware chip erase via pin strapping.
How does the boot block lockout function work on the AT29C040A-90JU-T?
The AT29C040A-90JU-T provides independent programming lockout for two 16K-byte regions: the lowest 16K bytes (0x00000–0x03FFF) and highest 16K bytes (0x7C000–0x7FFFF). Activation requires a seven-command algorithm writing specific values to fixed addresses. Once enabled, those blocks become permanently read-only-no erase or program operations are possible. AT29C040A-90JU-T retains lockout state across power cycles.
Can the AT29C040A-90JU-T be used in a 3.3 V system?
No, the AT29C040A-90JU-T is a 5 V-only device requiring VCC = 5 V ±10% (4.5 V to 5.5 V). Its input thresholds (VIL = 0.8 V, VIH = 2.0 V) and internal charge pumps are designed exclusively for 5 V operation. Applying 3.3 V to VCC will result in failure to meet AC timing specs, inability to program, and undefined behavior. AT29C040A-90JU-T is incompatible with 3.3 V I/O interfaces without level translation.
What package type is used for the AT29C040A-90JU-T?
The AT29C040A-90JU-T uses a 32-lead Plastic J-Leaded Chip Carrier (PLCC) package, designated "32J" in Atmel's ordering information. It complies with JEDEC MS-016 Variation AE, features a ceramic body with J-bend leads, and is RoHS-compliant and halide-free. The "JU" suffix in the part number explicitly denotes this PLCC packaging variant.
AT29C040A-90JU-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- Packaging:
- Tape & Reel (TR)
- 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:
- 10ms
- Access Time:
- 90 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (13.97x11.43)
AT29C040A-90JU-T FAQ
1.How can I place an order for AT29C040A-90JU-T through Aetrix?
Please submit a Request for Quotation (RFQ) for AT29C040A-90JU-T 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 AT29C040A-90JU-T reliable?
The price and inventory of AT29C040A-90JU-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT29C040A-90JU-T is usually 5 days.
3.What payment methods are accepted for AT29C040A-90JU-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT29C040A-90JU-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT29C040A-90JU-T?
AT29C040A-90JU-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT29C040A-90JU-T 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 AT29C040A-90JU-T?
For technical support, including AT29C040A-90JU-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT29C040A-90JU-T requirements.
6.How does Aetrix verify that AT29C040A-90JU-T is sourced from the original manufacturer or authorized distributors?
All AT29C040A-90JU-T 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 AT29C040A-90JU-T meets industry standards.
7.What is the process for return or replacement of AT29C040A-90JU-T?
All AT29C040A-90JU-T units undergo pre-shipment inspection (PSI). If there is an issue with AT29C040A-90JU-T, 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 AT29C040A-90JU-T part is unused and in its original packaging.
Return procedure for AT29C040A-90JU-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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