My Inquiry
My Account
Microchip Technology AT29C040A-90PI
- Part No.:
- AT29C040A-90PI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-DIP (0.600", 15.24mm)
- Datasheet:
-
AT29C040A-90PI.pdf
- Description:
- IC FLASH 4MBIT PARALLEL 32DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,651
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT29C040A-90PI from Atmel is a 4-Mbit (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, hardware/software data protection, and two 16K-byte boot blocks with independent lockout - used in embedded system firmware storage and BIOS/UEFI code retention.
For engineers reviewing the AT29C040A-90PI datasheet, AT29C040A-90PI pinout, AT29C040A-90PI application, or AT29C040A-90PI equivalent, this page delivers verified timing specs, sector-program behavior, boot-block lockout logic, DIP/PLCC/TSOP package mapping, and industrial-grade (-40°C to +85°C) operation for legacy industrial controller and telecom equipment design-in.
Technical Context
The AT29C040A-90PI implements a sector-based reprogramming architecture where each 256-byte sector is erased and programmed in a single internal cycle using latched address/data and an autonomous timer. It supports both CE- and WE-controlled byte loading, with DATA polling on I/O7 and toggle-bit detection on I/O6 for end-of-program indication.
Hardware protection includes VCC sense (<3.8 V inhibits programming), 5 ms power-on delay, noise filtering (<15 ns pulses rejected), and active inhibit via OE low/CE high/WE high states. 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 (512K × 8), enabling full BIOS or bootloader storage in single-package footprint |
| Read Access Time | 90 ns max - meets timing for 10 MHz bus interfaces without wait states |
| Sector Size | 256 bytes - allows fine-grained firmware updates without erasing entire device |
| Program Cycle Time | 10 ms per sector - enables predictable field update latency in embedded systems |
| Endurance | >10,000 program/erase cycles per sector - supports long-life industrial firmware revision cycles |
| Supply Voltage | 5 V ±10% - compatible with legacy 5 V logic rails and eliminates need for charge pumps |
| Operating Temperature | -40°C to +85°C - qualified for industrial control, base station, and automotive under-hood applications |
| Standby Current | 100 µA CMOS - enables low-power sleep modes in battery-backed systems |
Pinout & Package
AT29C040A-90PI is supplied in a 32-lead Plastic Dual Inline Package (PDIP), 0.600" wide (package code 32P6), with through-hole mounting and industry-standard pin spacing. Pin 1 identifier is top-left corner with notch or dot marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | 19-bit address bus supporting full 524,288-word addressing; A8–A18 select sector, A0–A7 select byte within sector |
| CE | Chip Enable | Active-low chip select; must be low for read/program; high disables outputs and enters standby mode |
| OE | Output Enable | Active-low output control; used with CE to manage bus contention during reads |
| WE | Write Enable | Active-low control for byte load and program initiation; dual-role with CE for software command entry |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit data path for read, program, and identification modes; I/O7 used for DATA polling, I/O6 for toggle-bit status |
| VCC | Power Supply | +5 V ±10% supply; powers core logic and I/O buffers; VCC sense circuitry prevents programming below 3.8 V |
| GND | Ground | Reference for all inputs/outputs and internal circuitry; requires low-impedance connection for stable erase/write |
| NC | No Connect | Unbonded pin; must remain floating - no external connection permitted |
Key Features
| Feature | Design Value |
|---|---|
| Single 5V Reprogramming | Eliminates need for 12 V programming voltage - simplifies power design and enables in-system updates via standard logic rails |
| 2048 Independent Sectors | Enables selective firmware patching: only modified 256-byte sectors require reprogramming, reducing update time and wear |
| Boot Block Lockout | Two 16K-byte regions (first/last) can be permanently write-locked - secures critical boot code against accidental overwrite |
| DATA Polling & Toggle Bit | Dual asynchronous status mechanisms (I/O7 complement, I/O6 toggling) allow host CPU to poll completion without fixed delays or timers |
| Hardware + Software Protection | VCC sensing, noise filtering, and 3-byte unlock sequence prevent unintended writes during power transients or software faults |
| CMOS/TTL Compatibility | Input thresholds (VIL = 0.8 V, VIH = 2.0 V) and output drive (VOH = 2.4 V @ -400 µA) ensure interoperability with mixed-logic systems |
Applications
| Industrial PLC Firmware Storage | Telecom Base Station Boot Code |
|---|---|
Use Scenario: Storing firmware images and configuration parameters in programmable logic controllers deployed in factory automation environments with wide temperature swings. IC Role / Device Role / Timing Role: Nonvolatile code storage with 90 ns read access supporting real-time scan-cycle execution and in-field firmware upgrades via RS-485 or Ethernet. Use Value: Sector-level reprogramming enables delta updates without full flash erase, minimizing downtime; boot block lockout preserves startup integrity after power loss. |
Use Scenario: Holding boot loader and FPGA configuration bitstreams in wireless infrastructure equipment requiring high reliability and secure boot. IC Role / Device Role / Timing Role: Primary firmware repository with hardware-enforced write protection and software identification mode for automatic density detection during initialization. Use Value: Dual 16K boot blocks allow redundant boot images; DATA polling ensures deterministic update completion for carrier-grade availability SLAs. |
| Legacy PC BIOS Retention | Automotive Engine Control Module (ECM) |
Use Scenario: Replacing EPROMs in older desktop/server motherboards where socketed firmware storage is required for BIOS recovery and vendor customization. IC Role / Device Role / Timing Role: Drop-in EPROM replacement with identical pinout and read protocol, supporting JEDEC-standard programming algorithms. Use Value: 5 V-only operation avoids high-voltage programming adapters; 10,000-cycle endurance exceeds typical BIOS update frequency over product lifetime. |
Use Scenario: Storing calibration tables and diagnostic routines in engine control units operating in under-hood environments with thermal cycling and EMI exposure. IC Role / Device Role / Timing Role: Industrial-temperature-rated nonvolatile memory interfacing directly to 8051 or HC11 microcontrollers via parallel bus. Use Value: Hardware data protection prevents corruption during cranking voltage dips; sector architecture isolates calibration updates from safety-critical boot code. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM29F040B-90JC | 90 ns access, 4 Mbit, 5 V-only, but uses AMD's command set and lacks boot block lockout | Requires different software unlock sequence; no dedicated protected boot sectors | Choose if existing AMD-compatible toolchain is in place and boot security is handled externally |
| SST39VF400A-90-4C-NHE | 90 ns access, 4 Mbit, 3.3 V core with 5 V tolerant I/O; supports byte-write without sector erase | Lower power, but requires level-shifting for pure 5 V systems and has different sector map (2 Kbyte sectors) | Prefer for new 3.3 V designs with frequent small updates; not drop-in for AT29C040A-90PI's 5 V-only interface |
Compared with AM29F040B-90JC and SST39VF400A-90-4C-NHE, the AT29C040A-90PI provides unique boot-block lockout and Atmel's sector-program algorithm - making it optimal for legacy 5 V systems requiring firmware partitioning and robust in-system reprogrammability without voltage translation.
Availability
AT29C040A-90PI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, telecom base station boot code, and legacy PC BIOS retention requiring stable component supply across extended product lifecycles.
Supply support for AT29C040A-90PI 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 fabless semiconductor company specializing in microcontrollers, nonvolatile memory, and security ICs, with deep expertise in Flash technology for embedded applications.
The AT29C040A-90PI belongs to Atmel's 5-volt-only Flash family designed specifically for in-system programmability in industrial, telecom, and computing systems where high-reliability firmware storage and simple 5 V integration are essential.
FAQ
What is the maximum operating temperature range for the AT29C040A-90PI?
The AT29C040A-90PI is rated for industrial temperature operation from -40°C to +85°C, as confirmed by its ordering code suffix "I" and the DC/AC operating range table in the official datasheet. This makes the AT29C040A-90PI suitable for deployment in harsh environments such as factory floors, outdoor telecom cabinets, and automotive under-hood modules where thermal stability is critical.
Does the AT29C040A-90PI require high-voltage programming signals?
No, the AT29C040A-90PI operates exclusively at 5 V ±10% for both read and program operations - no 12 V or other high-voltage signals are needed. Programming is initiated using standard 5 V logic-level commands (e.g., AAh/55h/A0h), making the AT29C040A-90PI compatible with conventional microcontroller GPIOs and eliminating external voltage boosters.
How does boot block lockout work on the AT29C040A-90PI?
The AT29C040A-90PI features 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 via a seven-command software sequence. Once enabled, that block becomes read-only; the AT29C040A-90PI will reject all erase/write attempts to it, preserving critical boot code integrity.
Can the AT29C040A-90PI be used as a direct replacement for EPROMs like the 27C040?
Yes, the AT29C040A-90PI is pin- and function-compatible with 27C040 EPROMs in read mode (CE/OE/WE timing matches), allowing drop-in replacement in existing sockets. However, unlike EPROMs, the AT29C040A-90PI supports in-system reprogramming without UV erasure - the AT29C040A-90PI retains full EPROM read behavior while adding Flash flexibility.
What methods are available to detect program completion on the AT29C040A-90PI?
The AT29C040A-90PI provides two hardware-supported methods: DATA polling (monitoring complement-to-data on I/O7) and Toggle Bit detection (observing I/O6 toggling state). Both operate asynchronously and can be polled at any time during programming - no fixed timeout is required. These mechanisms are fully documented in the AT29C040A-90PI datasheet's Device Operation section.
AT29C040A-90PI 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:
- 10ms
- Access Time:
- 90 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
AT29C040A-90PI FAQ
1.How can I place an order for AT29C040A-90PI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT29C040A-90PI 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-90PI reliable?
The price and inventory of AT29C040A-90PI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT29C040A-90PI is usually 5 days.
3.What payment methods are accepted for AT29C040A-90PI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT29C040A-90PI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT29C040A-90PI?
AT29C040A-90PI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT29C040A-90PI 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-90PI?
For technical support, including AT29C040A-90PI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT29C040A-90PI requirements.
6.How does Aetrix verify that AT29C040A-90PI is sourced from the original manufacturer or authorized distributors?
All AT29C040A-90PI 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-90PI meets industry standards.
7.What is the process for return or replacement of AT29C040A-90PI?
All AT29C040A-90PI units undergo pre-shipment inspection (PSI). If there is an issue with AT29C040A-90PI, 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-90PI part is unused and in its original packaging.
Return procedure for AT29C040A-90PI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT29C040A-90PI 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…
