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Microchip Technology AT29C040A-12JI
- Part No.:
- AT29C040A-12JI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT29C040A-12JI.pdf
- Description:
- IC FLASH 4MBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:1,693
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Product details
Overview
AT29C040A-12JI from Atmel is a 4-megabit (512K × 8) 5-volt-only Flash memory IC organized as 524,288 words by 8 bits, featuring 90 ns read access time, 256-byte sector architecture, and hardware/software data protection. It supports in-system reprogramming without high-voltage programming, with two 16K-byte boot blocks having independent lockout capability - used in embedded firmware storage for industrial controllers and legacy BIOS modules.
For engineers reviewing the AT29C040A-12JI datasheet, AT29C040A-12JI pinout, AT29C040A-12JI application, or AT29C040A-12JI equivalent, key selection considerations include its 120 ns maximum access time, 10 ms sector program cycle, CMOS/TTL-compatible I/O, 5V ±10% supply requirement, and PLCC-32 industrial-grade packaging for temperature-stable firmware retention.
Technical Context
The AT29C040A-12JI implements sector-based Flash programming with internal address/data latches for 256-byte pages, automatic erase-and-program sequencing, and DATA polling (I/O7) or toggle-bit (I/O6) end-of-cycle detection. Its dual-line chip enable (CE) and output enable (OE) control enables bus contention avoidance in shared-memory systems.
Hardware data protection includes VCC sense (<3.8 V inhibits programming), 5 ms power-on delay, noise filtering (<15 ns pulses ignored), and write-inhibit logic (OE low/CE high/WE high). Software protection uses a three-byte command sequence (AAh/55h/A0h) to enable/disable write locking across all sectors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 4 Mbit (524,288 × 8), enabling full firmware images for 8-bit microcontrollers |
| Read Access Time | 120 ns max - meets timing for 8 MHz Z80/8051 bus interfaces |
| Sector Size | 256 bytes - allows fine-grained firmware updates without erasing entire device |
| Program Cycle Time | 10 ms per sector - enables predictable update latency in field-upgrade scenarios |
| VCC Supply | 5 V ±10% - eliminates need for dedicated programming voltage rails |
| Operating Temp | –40°C to +85°C - qualified for industrial control and automotive body electronics |
| Endurance | >10,000 write/erase cycles - supports frequent firmware patching over product lifetime |
| Standby Current | 300 µA max - suitable for battery-backed systems requiring low quiescent power |
Pinout & Package
AT29C040A-12JI is packaged in a 32-lead Plastic J-Leaded Chip Carrier (PLCC-32), pin-compatible with industry-standard JEDEC MS-016 variation AE. The package features gull-wing leads, 1.27 mm pitch, and 12.3–12.6 mm body width, optimized for surface-mount reflow and socketed prototyping.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | 19-bit addressing for full 524,288-word space; A0–A7 select byte within 256-byte sector |
| I/O0–I/O7 | Bidirectional Data Bus | CMOS/TTL-compatible 8-bit parallel interface; I/O7 used for DATA polling, I/O6 for toggle-bit status |
| CE | Chip Enable | Active-low global select; must be low for read/program; high disables outputs and inhibits writes |
| OE | Output Enable | Active-low output gate; controls data assertion during reads; high places outputs in high-Z state |
| WE | Write Enable | Active-low write strobe; initiates byte load or sector program; combined with CE for timing-critical sequences |
| NC | No Connect | Pin 16 (PLCC top view) - must remain unconnected; no internal connection or function |
| VCC | Power Supply | +5 V ±10% main supply; powers core logic and I/O buffers; requires local 0.1 µF decoupling |
| GND | Ground Reference | Signal and power ground return; must be low-inductance connection to minimize noise during programming |
Key Features
| Feature | Design Value |
|---|---|
| Single 5V Reprogramming | Eliminates need for external 12 V programming supplies - simplifies system-level power design |
| Boot Block Lockout | Two independent 16K-byte regions (0x00000–0x03FFF and 0x7C000–0x7FFFF) prevent accidental overwrite of critical startup code |
| Software Data Protection | Three-byte unlock sequence (AAh/55h/A0h) required before any sector program - prevents spurious writes during power transients |
| DATA Polling & Toggle Bit | Real-time program status via I/O7 complement or I/O6 toggling - enables interrupt-driven firmware update without fixed delays |
| Hardware Write Inhibit | VCC sense, 5 ms power-on delay, and noise filtering ensure robustness against ESD and brown-out conditions |
| Product Identification Mode | Software entry (AAh/55h/90h) returns manufacturer code 1Fh and device code A4h - enables runtime density verification in multi-part BOMs |
Applications
| Industrial PLC Firmware Storage | Legacy PC BIOS Modules |
|---|---|
Use Scenario: Storing configuration logic and motion-control algorithms in programmable logic controllers operating in factory-floor environments with wide temperature swings and electrical noise. IC Role / Device Role / Timing Role: Nonvolatile firmware repository with sector-level update capability; provides deterministic 120 ns read access for real-time instruction fetch. Use Value: Boot block lockout protects startup routines from corruption during field firmware upgrades; 300 µA standby current extends battery backup life during power loss. | Use Scenario: Holding BIOS initialization code and hardware abstraction layer in desktop motherboards using ISA/PCI legacy architectures. IC Role / Device Role / Timing Role: EPROM-replacement Flash memory accessed via standard x86 memory-mapped I/O; supports hot-swap reprogramming without removing from socket. Use Value: 256-byte sector granularity enables patching of specific BIOS modules (e.g., video POST) without full image reflash; TTL compatibility ensures direct interface with older chipset buses. |
| Medical Device Bootloader Storage | Telecom Line Card Configuration |
Use Scenario: Secure storage of bootloader and safety-critical calibration data in Class II medical instruments requiring traceable firmware revisions and tamper resistance. IC Role / Device Role / Timing Role: Trusted firmware anchor with hardware-enforced write inhibit and software data protection - prevents unauthorized modification during service mode. Use Value: Dual boot blocks allow A/B firmware partitioning; software identification mode (1Fh/A4h) enables automated part verification during manufacturing test. | Use Scenario: Retaining line-specific configuration parameters (e.g., impedance settings, protocol stacks) in carrier-grade DSLAM and ONU line cards deployed in central offices. IC Role / Device Role / Timing Role: Field-upgradable parameter store accessed via microcontroller SPI-to-parallel bridge; withstands 10,000+ reprogramming cycles over 10-year service life. Use Value: Fast 10 ms sector programming enables rapid provisioning of new services; PLCC-32 package supports socketed replacement in field maintenance without PCB rework. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MX29LV040CTTI-12G | 3.3 V core with 5 V I/O tolerance; 120 ns access; 512K × 8; supports CFI query mode | Requires level-shifting for pure 5 V systems; lacks boot block lockout; supports JEDEC-standard command sets | Preferred for new designs migrating to 3.3 V domains; not drop-in compatible due to voltage and protection feature gaps |
| EN29LV040A-120HIP | 3.3 V supply only; 120 ns access; 512K × 8; hardware reset pin; no software data protection | Needs external 3.3 V regulator; no boot block lockout or SDP; includes RESET# for power-on initialization | Used where lower active power (25 mA) is critical; unsuitable for legacy 5 V-only systems or secure boot requirements |
Compared with AT29C040A-12JI, MX29LV040CTTI-12G offers modern CFI compatibility but sacrifices 5 V simplicity and boot security, while EN29LV040A-120HIP reduces power consumption at the cost of voltage incompatibility and missing firmware protection - making AT29C040A-12JI uniquely suited for industrial 5 V systems requiring robust, field-proven write safeguards.
Availability
AT29C040A-12JI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy PC BIOS modules, and medical device bootloader storage requiring stable component supply across extended product lifecycles.
Supply support for AT29C040A-12JI 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 company specializing in microcontrollers, nonvolatile memory, and secure authentication ICs, headquartered in San Jose, California.
The AT29C040A-12JI belongs to Atmel's 5-volt-only Flash memory family designed for seamless EPROM replacement in legacy embedded systems, emphasizing in-system reprogrammability, industrial temperature resilience, and hardware-enforced data integrity.
FAQ
What is the maximum read access time specified for the AT29C040A-12JI?
The AT29C040A-12JI has a maximum read access time of 120 ns, as defined by the "-12" speed grade suffix. This value represents the worst-case delay from address stabilization and CE/OE activation to valid data on I/O0–I/O7 under industrial temperature conditions (–40°C to +85°C) and 5 V ±10% supply. The AT29C040A-12JI achieves this timing while maintaining full compatibility with legacy 8-bit microprocessor buses such as Z80 and 8051.
Does the AT29C040A-12JI require high-voltage programming signals?
No, the AT29C040A-12JI operates with 5-volt-only reprogramming and does not require external high-voltage (e.g., 12 V) programming signals. All program and erase operations are initiated using standard 5 V logic levels applied to CE, OE, and WE pins in specific command sequences. This eliminates the need for charge pumps or auxiliary voltage rails, simplifying system design and improving reliability in AT29C040A-12JI-based applications.
How many sectors does the AT29C040A-12JI have, and what is the size of each sector?
The AT29C040A-12JI contains 2048 sectors, each 256 bytes in size, totaling 524,288 bytes (4 Mbit) of addressable memory space. Sector boundaries align to 256-byte boundaries (e.g., 0x00000–0x000FF, 0x00100–0x001FF), and programming is performed on a per-sector basis - meaning any byte change within a sector requires loading and reprogramming the entire 256-byte block. This architecture is explicitly confirmed in the AT29C040A-12JI datasheet Feature section and Device Operation chapter.
What package type is used for the AT29C040A-12JI, and is it socket-compatible with other variants?
The AT29C040A-12JI uses a 32-lead Plastic J-Leaded Chip Carrier (PLCC-32) package conforming to JEDEC MS-016 variation AE. It is pin-compatible with other AT29C040A speed grades in the same PLCC-32 variant (e.g., AT29C040A-90JI, AT29C040A-15JI), sharing identical footprint, lead pitch (1.27 mm), and mechanical dimensions. Socket compatibility is maintained across all -J suffixed industrial-grade parts, enabling speed-bin interchangeability without PCB redesign.
Can the AT29C040A-12JI be used in systems requiring secure firmware updates?
Yes, the AT29C040A-12JI supports secure firmware updates through dual-layer protection: hardware write inhibit (VCC sensing, noise filtering, power-on delay) and software data protection (SDP) enabled via a three-byte unlock sequence (AAh/55h/A0h). Once SDP is activated, all program cycles require this sequence - preventing accidental or malicious writes during power transitions or noise events. This capability is fully documented in the AT29C040A-12JI datasheet under Software Data Protection and is integral to its use in certified industrial and medical firmware systems.
AT29C040A-12JI 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:
- 10ms
- Access Time:
- 120 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-12JI FAQ
1.How can I place an order for AT29C040A-12JI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT29C040A-12JI 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-12JI reliable?
The price and inventory of AT29C040A-12JI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT29C040A-12JI is usually 5 days.
3.What payment methods are accepted for AT29C040A-12JI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT29C040A-12JI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT29C040A-12JI?
AT29C040A-12JI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT29C040A-12JI 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-12JI?
For technical support, including AT29C040A-12JI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT29C040A-12JI requirements.
6.How does Aetrix verify that AT29C040A-12JI is sourced from the original manufacturer or authorized distributors?
All AT29C040A-12JI 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-12JI meets industry standards.
7.What is the process for return or replacement of AT29C040A-12JI?
All AT29C040A-12JI units undergo pre-shipment inspection (PSI). If there is an issue with AT29C040A-12JI, 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-12JI part is unused and in its original packaging.
Return procedure for AT29C040A-12JI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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