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Microchip Technology AT29C040A-12TU
- Part No.:
- AT29C040A-12TU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-TFSOP (0.724", 18.40mm Width)
- Datasheet:
-
AT29C040A-12TU.pdf
- Description:
- IC FLASH 4MBIT PARALLEL 32TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,497
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Product details
Overview
AT29C040A-12TU from Atmel is a 4-megabit (512K × 8) 5-volt-only Flash memory IC organized in 2048 sectors of 256 bytes each, featuring 120 ns read access time, hardware/software data protection, and two 16K-byte boot blocks with independent programming lockout - used for firmware storage and system boot code in embedded controllers and industrial microcontroller systems.
For engineers reviewing the AT29C040A-12TU datasheet, AT29C040A-12TU pinout, AT29C040A-12TU application, or AT29C040A-12TU equivalent, key selection criteria include sector-based reprogrammability, DATA polling/toggle-bit program completion detection, 5V ±10% single-supply operation, CMOS standby current <300 µA, and PLCC/TSOP package compatibility with legacy 8-bit bus interfaces.
Technical Context
The AT29C040A-12TU implements sector-erase-and-program architecture with internal latching of 256-byte sector data, eliminating external address/data bus hold requirements during programming. Its dual-line chip enable (CE) and output enable (OE) control enables flexible bus contention management during read operations.
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 data protection uses a three-command sequence (AAh/55h/A0h at 5555h/2AAAh/5555h) to globally enable/disable write access.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 4 Mbit (512K × 8), sufficient for full firmware images in 8-bit microcontroller systems |
| Read Access Time | 120 ns max - meets timing budgets for 8-MHz Z80/8051 bus cycles without wait states |
| Sector Size | 256 bytes - enables fine-grained firmware updates without erasing entire device |
| Program Cycle Time | 10 ms per sector - deterministic erase+program latency for predictable update sequencing |
| Supply Voltage | 5 V ±10% - compatible with legacy TTL/CMOS logic rails without auxiliary regulators |
| Standby Current | 300 µA max (CMOS mode) - supports low-power sleep modes in battery-backed systems |
| Endurance | >10,000 program/erase cycles per sector - suitable for field-upgradable firmware with moderate revision frequency |
Pinout & Package
AT29C040A-12TU is available in 32-lead TSOP (Type 1, 8 × 20 mm) package per JEDEC MO-142 BD, with gull-wing leads and pin 1 identifier marked on top surface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | 19-bit address bus supporting full 512K-word addressing; A0–A7 select byte within 256-byte sector |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel interface compatible with standard microprocessor data buses; supports byte load and DATA polling on I/O7 |
| CE | Chip Enable | Active-low device select; must be low for read/program; high forces outputs to high-Z and disables programming |
| OE | Output Enable | Active-low read control; used with CE to manage bus contention; must be high during program cycles |
| WE | Write Enable | Active-low control for byte loading and sector programming initiation; toggling triggers internal latching and timer |
| VCC | Power Supply | +5 V ±10% supply; powers core logic and I/O drivers; VCC sense circuitry prevents programming below 3.8 V |
| GND | Ground | Reference for all signals and power; decoupling required near VCC pin to suppress switching noise |
| NC | No Connect | Unbonded pin; must remain unconnected to avoid parasitic coupling or ESD paths |
Key Features
| Feature | Design Value |
|---|---|
| Single 5V Reprogramming | Eliminates need for +12 V programming voltage, simplifying power design and enabling in-system updates via standard logic-level signals |
| DATA Polling & Toggle Bit | I/O7 complement read and I/O6 toggle provide real-time, bus-compatible program completion status without requiring external timers or interrupts |
| Two Independent Boot Blocks | 16K-byte lower and upper memory regions support secure boot code storage with programmable lockout - prevents accidental overwrite of critical startup routines |
| Hardware + Software Data Protection | VCC sensing, noise filtering, and 3-command software lock provide layered defense against unintended writes during power transients or noise events |
| Internal Address/Data Latches | 256-byte sector data and address are held internally after load, freeing bus for concurrent operations during 10 ms program cycle |
Applications
| Industrial PLC Firmware Storage | Legacy Microcontroller Boot Memory |
|---|---|
Use Scenario: Storing ladder logic firmware 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 mapped to CPU address space; provides 120 ns read access for deterministic scan-cycle execution. Use Value: Sector erase enables field updates of individual function blocks without disrupting operational runtime code stored elsewhere in memory. | Use Scenario: Hosting boot ROM and BIOS for 8-bit microcontrollers (e.g., Z80, 8051) in medical instrumentation where firmware integrity is safety-critical. IC Role / Device Role / Timing Role: Primary boot device accessed at power-on reset; boot block lockout secures first 16K bytes containing initialization vectors and self-test routines. Use Value: Hardware VCC-sense and software protection prevent corruption during brown-out conditions or accidental debug writes. |
| Point-of-Sale Terminal Code Storage | Telecom Line Card Configuration |
Use Scenario: Holding application firmware and localized language packs in retail POS terminals subject to frequent software upgrades and regional deployment variants. IC Role / Device Role / Timing Role: In-system reprogrammable flash memory interfaced directly to microcontroller data/address bus; supports over-the-air update staging. Use Value: 256-byte sector granularity allows differential updates - only changed language strings are rewritten, minimizing wear and update time. | Use Scenario: Storing line-card-specific calibration data, protocol stacks, and feature-enable bits in carrier-grade DSLAMs and optical line terminals. IC Role / Device Role / Timing Role: Configuration memory accessed during card initialization; boot block lockout protects factory-calibrated parameters from field modification. Use Value: >10,000 endurance cycles support repeated provisioning and firmware patching across multi-year product lifecycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM29LV040B-120EC | 3.3 V core with 5 V I/O tolerance; 120 ns access; 512K × 8 organization; no boot block lockout | Lacks dedicated boot block protection; requires level-shifting for pure 5 V systems | Choose when migrating to lower-power 3.3 V designs with mixed-voltage interfaces |
| MX29LV040CTTC-12G | 3.3 V supply; 120 ns access; 512K × 8; software-controlled sector protection | Requires 3.3 V regulator; no hardware VCC-sense protection; different command set | Prefer for new 3.3 V designs where footprint compatibility with TSOP-32 is retained |
Compared with AT29C040A-12TU, AM29LV040B-120EC and MX29LV040CTTC-12G offer modern 3.3 V operation but lack its dual-boot-block lockout and 5 V–only simplicity - making AT29C040A-12TU preferable for maintaining legacy 5 V embedded systems with stringent boot security requirements.
Availability
AT29C040A-12TU is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy microcontroller boot memory, and point-of-sale terminal code storage requiring stable component supply and long-term obsolescence management.
Supply support for AT29C040A-12TU 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 secure authentication devices.
The AT29C040A-12TU belongs to Atmel's 5-volt-only Flash memory family, designed specifically for drop-in EPROM replacement in legacy 8-bit embedded systems requiring in-system reprogrammability without high-voltage programming circuits.
FAQ
What is the maximum read access time specified for the AT29C040A-12TU?
The AT29C040A-12TU has a maximum read access time of 120 ns, as confirmed by its ordering code suffix "-12" and AC Read Characteristics table. This value applies across the full industrial temperature range (−40°C to +85°C) and ensures compatibility with 8-MHz microprocessor buses without wait-state insertion. The AT29C040A-12TU achieves this timing under VCC = 5 V ±10% and CL = 5 pF load conditions.
Does the AT29C040A-12TU support in-system programming without external high-voltage supplies?
Yes, the AT29C040A-12TU supports full in-system programming using only a single 5 V ±10% supply - no external +12 V or +21 V programming voltage is required. Programming is initiated via standard logic-level WE/CE pulses and validated command sequences (e.g., AAh/55h/A0h), making it compatible with embedded host processors and eliminating need for dedicated programmers. This capability is intrinsic to the AT29C040A-12TU's 5-volt-only Flash architecture.
How does the boot block lockout feature work on the AT29C040A-12TU?
The AT29C040A-12TU contains two independent 16K-byte boot blocks - one at the lowest addresses (0x00000–0x03FFF) and one at the highest (0x7C000–0x7FFFF). Each can be permanently locked against programming/erasure using a seven-command algorithm (AAh/55h/80h/AAh/55h/40h followed by 00h at 0x00000 or FFh at 0x7FFFF). Once enabled, the AT29C040A-12TU prevents any write to that block, even during chip erase - ensuring boot code integrity.
What methods does the AT29C040A-12TU provide to detect program completion?
The AT29C040A-12TU offers two hardware-supported methods: DATA polling (reading I/O7 returns complement of last loaded byte until completion, then true data) and Toggle Bit (I/O6 alternates logic states during programming and stabilizes upon completion). Both operate without halting the host processor and are accessible over the standard data bus - enabling efficient polling loops or interrupt-driven handling in firmware managing AT29C040A-12TU updates.
Is the AT29C040A-12TU available in RoHS-compliant packaging?
Yes, the AT29C040A-12TU is offered in green (Pb/Halide-free) packaging per Atmel's ordering information. The "TU" suffix denotes the 32-lead TSOP package with RoHS-compliant finish, and the datasheet explicitly lists "Green (Pb/Halide-free) Packaging Option" as a feature. This version meets JEDEC J-STD-609A Class 1 moisture sensitivity and IPC/JEDEC J-STD-020D reflow profile requirements.
AT29C040A-12TU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-TFSOP (0.724", 18.40mm Width)
- Packaging:
- Tray
- 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-TSOP
AT29C040A-12TU FAQ
1.How can I place an order for AT29C040A-12TU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT29C040A-12TU 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-12TU reliable?
The price and inventory of AT29C040A-12TU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT29C040A-12TU is usually 5 days.
3.What payment methods are accepted for AT29C040A-12TU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT29C040A-12TU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT29C040A-12TU?
AT29C040A-12TU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT29C040A-12TU 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-12TU?
For technical support, including AT29C040A-12TU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT29C040A-12TU requirements.
6.How does Aetrix verify that AT29C040A-12TU is sourced from the original manufacturer or authorized distributors?
All AT29C040A-12TU 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-12TU meets industry standards.
7.What is the process for return or replacement of AT29C040A-12TU?
All AT29C040A-12TU units undergo pre-shipment inspection (PSI). If there is an issue with AT29C040A-12TU, 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-12TU part is unused and in its original packaging.
Return procedure for AT29C040A-12TU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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