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Microchip Technology AT27LV256A-12RI
- Part No.:
- AT27LV256A-12RI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.342", 8.69mm Width)
- Datasheet:
-
AT27LV256A-12RI.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,715
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Product details
Overview
AT27LV256A-12RI from Atmel is a 256K-bit (32K × 8) one-time programmable EPROM optimized for low-voltage operation at 3.0–3.6V or standard 5V ±10%, with 120 ns maximum access time, 20 µA max standby current at VCC = 3.6V, and JEDEC-standard 28-lead SOIC packaging. It serves as nonvolatile program storage in battery-powered embedded controllers and legacy industrial firmware modules.
For engineers reviewing the AT27LV256A-12RI datasheet, AT27LV256A-12RI pinout, AT27LV256A-12RI application, or AT27LV256A-12RI equivalent, key selection criteria include dual-supply compatibility, OTP reliability, rapid programming algorithm (100 µs/byte), JEDEC pin compatibility with AT27C256R, and industrial temperature range support (−40°C to +85°C).
Technical Context
The AT27LV256A-12RI implements a CMOS-based OTP EPROM architecture with two-line control (CE/OE), enabling bus contention avoidance in shared-memory systems. Its read timing is defined by tACC ≤ 120 ns and tOE ≤ 50 ns under 3.0–3.6V supply, with TTL- and CMOS-compatible I/O levels ensuring interoperability across mixed-voltage logic families.
Programming uses a dedicated VPP = 13.0V supply and Rapid™ algorithm requiring 100 µs CE pulses per byte, verified via PGM Verify mode. The device integrates product identification code (Manufacturer ID = 0x1E, Device ID = 0x8C) accessible via A9/VH and A0 toggling, supporting automated programming equipment recognition.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32K × 8) - supports full 8-bit data bus interface without address multiplexing |
| Access Time | 120 ns max - ensures compatibility with 8 MHz Z80 or 68000-based systems operating at ≤8.3 MHz clock rate |
| Supply Voltage | 3.0–3.6V or 4.5–5.5V - enables dual-voltage system integration without level shifters |
| Standby Current | 20 µA max at VCC = 3.6V - reduces quiescent power in always-on embedded modules |
| Operating Temp | −40°C to +85°C - certified for industrial control panels and automotive body electronics |
| Package | 28-lead SOIC (28R) - JEDEC MS-012 compliant, 0.330" width, surface-mount compatible |
| ESD Protection | 2,000V HBM - meets IEC 61000-4-2 Level 2 for board-level robustness |
Pinout & Package
AT27LV256A-12RI is packaged in a 28-lead SOIC (28R) per JEDEC MS-012, with 0.330" body width and gull-wing leads. Pin 1 is marked by notch or beveled corner; pin 17 is NC (no connect).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus accepts 0–32767; all must be stable before CE/OE assertion for valid read |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus; high-impedance when OE = VIH or CE = VIH |
| CE | Chip Enable | Active-low chip select; controls device activation and power state transition between active/standby |
| OE | Output Enable | Active-low output gate; allows multiple devices on same data bus without external tri-state logic |
| VCC | Power Supply | Primary supply input; must be applied simultaneously with or before VPP during programming |
| GND | Ground Reference | Common return path for all signals and supplies; requires local 0.1 µF ceramic decoupling |
| VPP | Programming Voltage | 13.0V programming supply; isolated from VCC except during programming cycles |
| NC | No Connect | Pins 17 and 18 are unconnected; must remain floating per datasheet pin configuration |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming | 100 µs/byte typical - cuts firmware update time by >90% vs. legacy EPROMs requiring 10+ ms/byte |
| Dual-Voltage Read | 3.0–3.6V or 4.5–5.5V operation - eliminates need for separate 5V regulators in mixed-supply designs |
| JEDEC Pin Compatibility | Pin-for-pin match with AT27C256R - enables drop-in replacement in existing 5V PCB layouts |
| Integrated ID Code | Manufacturer ID 0x1E / Device ID 0x8C - enables auto-detection and algorithm selection in universal programmers |
| Low-Power Standby | 20 µA max ICC at 3.6V - extends battery life in portable diagnostic tools and handheld terminals |
Applications
| Industrial PLC Firmware Storage | Legacy Embedded Controller Boot ROM |
|---|---|
Use Scenario: Storing fixed ladder logic and I/O mapping tables in DIN-rail mounted programmable logic controllers operating in factory environments with wide ambient temperature swings. IC Role / Device Role / Timing Role: Nonvolatile boot memory providing deterministic startup sequence and runtime instruction fetch at ≤8 MHz bus speed. Use Value: Industrial temperature rating (−40°C to +85°C) and 2,000V ESD protection ensure reliable operation in electrically noisy plant-floor settings. | Use Scenario: Holding BIOS and peripheral initialization code in 1990s-era embedded controllers based on Z80 or 80C88 CPUs deployed in medical analyzers and test equipment. IC Role / Device Role / Timing Role: Primary read-only program memory accessed via 8-bit parallel bus with 120 ns tACC timing margin. Use Value: Pin compatibility with AT27C256R allows direct replacement in aging designs without PCB rework or layout changes. |
| Automotive Body Control Module | Portable Diagnostic Tool Memory |
Use Scenario: Storing calibration constants and CAN message lookup tables in vehicle door modules and lighting controllers where space and power budget are constrained. IC Role / Device Role / Timing Role: Low-voltage OTP storage enabling 3.3V microcontroller interfacing without voltage translation circuitry. Use Value: 3.0–3.6V operation and 20 µA standby current reduce system-level power consumption in always-on modules. | Use Scenario: Hosting firmware images and protocol stacks in handheld OBD-II scanners and field service tools powered by rechargeable Li-ion batteries. IC Role / Device Role / Timing Role: Compact, low-power nonvolatile memory supporting fast firmware updates via Rapid™ programming in field-deployed units. Use Value: 100 µs/byte programming speed enables full 32K-byte image reload in <3.3 seconds, minimizing technician downtime. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C256R-12JC | 5V-only operation (4.5–5.5V); no 3.3V support; identical 120 ns tACC and 28-lead SOIC package | Requires dedicated 5V rail; unsuitable for mixed-voltage or battery-operated systems | Select when legacy 5V design prohibits voltage scaling and VPP = 12.5V programming is acceptable |
| MN65E256AP-12 | Same 256K×8 OTP EPROM function; 120 ns access; but uses 28-lead TSOP package and lacks integrated ID code | TSOP footprint requires PCB redesign; no auto-programmer ID detection capability | Select when board space is critical and programming infrastructure supports manual algorithm selection |
Compared with AT27LV256A-12RI, AT27C256R-12JC offers identical timing and pinout but lacks low-voltage operation, while MN65E256AP-12 provides same speed in smaller TSOP but sacrifices programmable ID features and industrial temp support.
Availability
AT27LV256A-12RI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy embedded controller boot ROM, and automotive body control module applications requiring stable component supply and long-term lifecycle assurance.
Supply support for AT27LV256A-12RI 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 was a U.S.-based semiconductor company specializing in microcontrollers, nonvolatile memory, and programmable logic, acquired by Microchip Technology in 2016.
The AT27LV256A product line delivers low-voltage, one-time programmable EPROMs targeting cost-sensitive, space-constrained embedded systems needing reliable firmware storage without reprogrammability overhead.
FAQ
What is the maximum access time specified for the AT27LV256A-12RI?
The AT27LV256A-12RI has a maximum address-to-output delay (tACC) of 120 ns under both 3.0–3.6V and 4.5–5.5V supply conditions, as confirmed in the AC Characteristics table. This value applies across the full industrial temperature range (−40°C to +85°C) and defines the worst-case timing margin for synchronous read operations in systems like Z80-based controllers.
Does the AT27LV256A-12RI support true 3.3V-only operation?
Yes, the AT27LV256A-12RI operates fully within 3.0V to 3.6V for read mode, delivering TTL-compatible outputs even at VCC = 3.0V. It does not require 5V for functionality-unlike older EPROMs-and maintains 120 ns access time and 20 µA standby current across this low-voltage range, making it suitable for battery-powered applications.
Can the AT27LV256A-12RI be used as a direct replacement for AT27C256R in existing designs?
Yes, the AT27LV256A-12RI is pin-compatible with JEDEC-standard AT27C256R and shares identical 28-lead SOIC pinout, address/data bus structure, and CE/OE control logic. However, it requires VPP = 13.0V for programming (vs. 12.5V for AT27C256R) and supports 3.3V read operation, so system-level voltage rails must be verified.
What programming voltage and current requirements apply to the AT27LV256A-12RI?
The AT27LV256A-12RI requires VPP = 13.0V ± 0.25V and VCC = 6.5V ± 0.25V during programming, with maximum IPP2 = 25 mA and ICC2 = 25 mA. A 0.1 µF capacitor must be placed directly across VPP and GND to suppress transients, and VCC must be applied simultaneously with or before VPP per the Absolute Maximum Ratings section.
Is the AT27LV256A-12RI qualified for industrial temperature operation?
Yes, the AT27LV256A-12RI is explicitly rated for −40°C to +85°C operation per its ordering code suffix "I" and the Industrial column in the Ordering Information table. This qualification covers all DC and AC parameters including tACC, standby current, and programming characteristics, making it suitable for deployment in harsh environmental conditions.
AT27LV256A-12RI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-SOIC (0.342", 8.69mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EPROM
- Technology:
- EPROM - OTP
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 120 ns
- Voltage - Supply:
- 3V ~ 3.6V, 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOIC
AT27LV256A-12RI FAQ
1.How can I place an order for AT27LV256A-12RI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27LV256A-12RI 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 AT27LV256A-12RI reliable?
The price and inventory of AT27LV256A-12RI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27LV256A-12RI is usually 5 days.
3.What payment methods are accepted for AT27LV256A-12RI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27LV256A-12RI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27LV256A-12RI?
AT27LV256A-12RI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27LV256A-12RI 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 AT27LV256A-12RI?
For technical support, including AT27LV256A-12RI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27LV256A-12RI requirements.
6.How does Aetrix verify that AT27LV256A-12RI is sourced from the original manufacturer or authorized distributors?
All AT27LV256A-12RI 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 AT27LV256A-12RI meets industry standards.
7.What is the process for return or replacement of AT27LV256A-12RI?
All AT27LV256A-12RI units undergo pre-shipment inspection (PSI). If there is an issue with AT27LV256A-12RI, 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 AT27LV256A-12RI part is unused and in its original packaging.
Return procedure for AT27LV256A-12RI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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