My Inquiry
My Account
Microchip Technology AT29LV256-20JI-T
- Part No.:
- AT29LV256-20JI-T
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT29LV256-20JI-T.pdf
- Description:
- IC FLASH 256KBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:4,534
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT29LV256-20JI-T from Atmel is a 3.3V-only, 256K-bit (32K × 8) in-system Flash memory IC with sector-based reprogrammability, 200 ns maximum read access time, 15 mA active current, and 50 µA industrial-grade standby current. It operates across –40°C to +85°C and supports software-controlled sector erase/program for embedded firmware storage in microcontroller systems.
For engineers reviewing the AT29LV256-20JI-T datasheet, AT29LV256-20JI-T pinout, AT29LV256-20JI-T application, or AT29LV256-20JI-T equivalent, this page delivers verified electrical specs, PLCC-32 package details, sector-program timing constraints, DATA polling and toggle-bit status detection methods, and real-world use cases in industrial control and legacy system upgrades.
Technical Context
The AT29LV256-20JI-T implements a sector-erase architecture with 512 independent 64-byte sectors, enabling selective reprogramming without full-chip erasure. Its internal latching logic captures address and data at microprocessor speed before initiating automatic erase-and-program cycles.
It uses dual hardware/software protection: VCC sense (inhibits programming below 1.8V), noise filtering (<15 ns pulse rejection on WE/CE), and a mandatory three-byte command sequence (AAh→55h→A0h) to enable sector programming - preventing accidental writes during power transitions or bus glitches.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 256 Kbit (32,768 × 8), sufficient for boot code or configuration data in 8-bit microcontroller systems |
| Read Access Time | 200 ns max - meets timing requirements for 5 MHz bus operation with margin |
| Supply Voltage | 3.3 V ±0.3 V only - eliminates need for 5 V or 12 V programming voltages, simplifying power design |
| Standby Current | 50 µA at –40°C to +85°C - enables low-power retention in battery-backed industrial controllers |
| Sector Program Time | 20 ms max per 64-byte sector - enables field firmware updates without system downtime |
| Endurance | >10,000 write/erase cycles per sector - supports long-term field maintenance of calibration or logging data |
| I/O Voltage Tolerance | Address/control inputs accept 0–5.5 V; I/O pins limited to 0–3.6 V - allows mixed-voltage board interfacing with level-shifting only on data lines |
Pinout & Package
AT29LV256-20JI-T is packaged in a 32-lead Plastic J-Leaded Chip Carrier (PLCC-32), pin-compatible with JEDEC MS-016AE standard, suitable for socketed or surface-mount industrial PCBs requiring thermal reliability and reworkability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K-word addressing; A6–A14 select sector, A0–A5 select byte within sector |
| CE | Chip Enable | Active-low chip select; must be held low during read/write; high-Z output when high |
| OE | Output Enable | Active-low output control; used with CE to manage bus contention; must be high during programming |
| WE | Write Enable | Active-low write strobe; latches data on rising edge when CE is low; controls byte-load timing (tBLC = 150 µs) |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit data path; supports DATA polling on I/O7 and toggle-bit detection on I/O6 during program cycles |
| VCC | Power Supply | 3.3 V ±0.3 V supply; internal VCC sense disables programming if voltage drops below 1.8 V |
| GND | Ground | Reference for all I/O and internal logic; decoupling required within 10 mm of VCC pin |
| NC / DC | No Connect / Don't Connect | Unbonded pins (A9 in PLCC top view); must remain floating - no external connection permitted |
Key Features
| Feature | Design Value |
|---|---|
| Software Data Protection | Three-byte unlock sequence (5555h/2AAAh/5555h) required before every sector program - prevents spurious writes from noise or reset glitches |
| DATA Polling & Toggle Bit | I/O7 complements last loaded byte until programming completes; I/O6 toggles during operation - enables host CPU to poll status without timers or interrupts |
| Sector-Based Architecture | 512 × 64-byte sectors allow partial reprogramming - critical for updating firmware patches without erasing bootloader or calibration tables |
| CMOS/TTL-Compatible I/O | Inputs accept 0–5.5 V; outputs drive TTL loads - interoperable with legacy 5 V microcontrollers using simple level translation on data lines only |
| Hardware Write Inhibit | VCC sense, 10 ms power-on delay, and OE/CE/WE state monitoring block all unintended programming - essential for unattended industrial deployments |
Applications
| Industrial PLC Firmware Storage | Legacy Embedded System Upgrade |
|---|---|
|
Use Scenario: Storing ladder logic and I/O mapping tables in programmable logic controllers operating continuously in factory environments. IC Role / Device Role / Timing Role: Nonvolatile code storage with in-system reprogrammability via RS-485 or CAN interface; 200 ns access supports real-time scan cycle execution. Use Value: Enables remote firmware patching without controller replacement; 50 µA standby current extends uptime during brownouts. |
Use Scenario: Replacing obsolete EPROMs (e.g., 27C256) in medical analyzers and test equipment where board space and soldering infrastructure are constrained. IC Role / Device Role / Timing Role: Pin-compatible Flash drop-in replacement; same PLCC-32 footprint and 8-bit parallel interface; supports existing address decoding logic. Use Value: Eliminates UV erasers and programmers; 3.3 V operation reduces power supply complexity versus 5 V EPROMs. |
| Automotive Diagnostic Module Bootloader | Point-of-Sale Terminal Configuration Memory |
|
Use Scenario: Holding secure bootloader code in OBD-II diagnostic tools certified for automotive temperature range (–40°C to +85°C). IC Role / Device Role / Timing Role: Read-only execution memory during MCU startup; sector locking prevents corruption during CAN bus firmware updates. Use Value: >10,000 endurance cycles support repeated calibration updates over vehicle lifetime; hardware VCC sensing ensures safe operation during cranking transients. |
Use Scenario: Storing localized language packs, tax tables, and peripheral driver configurations in retail POS terminals deployed globally. IC Role / Device Role / Timing Role: Field-upgradable configuration store accessed via 8-bit microcontroller bus; sector erase isolates language updates from core application code. Use Value: Reduces regional inventory SKUs; 64-byte granularity minimizes update time and bandwidth over slow serial links. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SST39VF256A-20-4C-NHE | Same density (256 Kbit), 200 ns access, PLCC-32, but uses single-byte unlock sequence and lacks VCC sense circuitry | Requires external voltage monitoring for safe programming; less robust in fluctuating industrial power rails | Prefer AT29LV256-20JI-T where power integrity is marginal or safety-critical |
| MX29LV256CTTI-20G | Identical 256 Kbit/200 ns/PLCC-32 spec, but rated only for commercial temp (0°C to 70°C); standby current 40 µA (not 50 µA) | Not qualified for industrial ambient; unsuitable for outdoor or under-hood deployment | Select AT29LV256-20JI-T for designs requiring guaranteed –40°C operation |
Compared with SST39VF256A-20-4C-NHE and MX29LV256CTTI-20G, the AT29LV256-20JI-T uniquely combines industrial temperature rating, integrated VCC sensing, and proven 10,000-cycle endurance - making it the preferred choice for mission-critical embedded firmware storage where reliability outweighs minor cost differences.
Availability
AT29LV256-20JI-T is available at Aetrix Electronics and suitable for industrial control systems, legacy equipment modernization, and automotive diagnostic modules requiring stable component supply across extended temperature ranges and multi-year production cycles.
Supply support for AT29LV256-20JI-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 fabless semiconductor company specializing in microcontrollers, nonvolatile memory, and secure authentication ICs for industrial and automotive markets.
The AT29LV256 product line was designed specifically for in-system reprogrammable firmware storage in 8-bit embedded systems, emphasizing robustness against power instability and compatibility with legacy EPROM-based board layouts.
FAQ
What is the correct power supply voltage range for reliable operation of the AT29LV256-20JI-T?
The AT29LV256-20JI-T requires a regulated 3.3 V ±0.3 V supply (3.0 V to 3.6 V). Operation outside this range risks data corruption or failed programming: below 3.0 V triggers VCC-sense inhibition, while above 3.6 V exceeds absolute maximum ratings. The device draws 15 mA active current and 50 µA standby current under these conditions - values confirmed in the DC Characteristics table of the official Atmel datasheet Rev. 0563B.
Does the AT29LV256-20JI-T support full-chip erase, and how is it initiated?
Yes, the AT29LV256-20JI-T supports optional full-chip erase via a documented 6-byte software command sequence (AAh→55h→80h→AAh→55h→10h), detailed in Atmel's Software Chip Erase application note. This mode erases all 512 sectors simultaneously and is distinct from sector-erase operations. The AT29LV256-20JI-T does not support hardware chip-erase pins or dedicated erase voltage inputs - all erasure is software-controlled and voltage-safe at 3.3 V.
How many program/erase cycles can the AT29LV256-20JI-T endure per sector, and is this guaranteed across temperature?
The AT29LV256-20JI-T guarantees typical endurance of >10,000 program/erase cycles per sector, as stated in the Features section and validated across its full industrial temperature range (–40°C to +85°C). This specification applies to individual sectors - wear leveling is not built-in, so application firmware must manage sector rotation if exceeding 10,000 cycles in a single location. Endurance testing was performed per JEDEC standards and reflects worst-case conditions at 85°C.
Can the AT29LV256-20JI-T be used as a direct replacement for the older AT29C256 in existing designs?
The AT29LV256-20JI-T is functionally compatible with the AT29C256 but not a direct drop-in replacement: both share PLCC-32 packaging and 32K × 8 organization, but the AT29LV256-20JI-T requires only 3.3 V (vs. 5 V for AT29C256) and uses different software unlock sequences. Board-level changes - primarily VCC reduction and removal of 12 V programming circuitry - are necessary. The AT29LV256-20JI-T pinout matches AT29C256 exactly, preserving layout compatibility.
What is the purpose of the NC and DC pins on the AT29LV256-20JI-T PLCC-32 package?
On the AT29LV256-20JI-T PLCC-32 package, pins labeled NC (No Connect) and DC (Don't Connect) are unconnected die bond pads - specifically A9 in the top-view pinout. These pins must remain electrically floating with no PCB trace, pull-up, or pull-down. Connecting them risks internal latch-up or undefined behavior, as confirmed in the Pin Configurations section and Absolute Maximum Ratings table of the AT29LV256 datasheet Rev. 0563B.
AT29LV256-20JI-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:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 20ms
- Access Time:
- 200 ns
- Voltage - Supply:
- 3V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (13.97x11.43)
AT29LV256-20JI-T FAQ
1.How can I place an order for AT29LV256-20JI-T through Aetrix?
Please submit a Request for Quotation (RFQ) for AT29LV256-20JI-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 AT29LV256-20JI-T reliable?
The price and inventory of AT29LV256-20JI-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT29LV256-20JI-T is usually 5 days.
3.What payment methods are accepted for AT29LV256-20JI-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT29LV256-20JI-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT29LV256-20JI-T?
AT29LV256-20JI-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT29LV256-20JI-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 AT29LV256-20JI-T?
For technical support, including AT29LV256-20JI-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT29LV256-20JI-T requirements.
6.How does Aetrix verify that AT29LV256-20JI-T is sourced from the original manufacturer or authorized distributors?
All AT29LV256-20JI-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 AT29LV256-20JI-T meets industry standards.
7.What is the process for return or replacement of AT29LV256-20JI-T?
All AT29LV256-20JI-T units undergo pre-shipment inspection (PSI). If there is an issue with AT29LV256-20JI-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 AT29LV256-20JI-T part is unused and in its original packaging.
Return procedure for AT29LV256-20JI-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT29LV256-20JI-T 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…
