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Microchip Technology AT27LV256A-55RI
- Part No.:
- AT27LV256A-55RI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.342", 8.69mm Width)
- Datasheet:
-
AT27LV256A-55RI.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,967
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Product details
Overview
AT27LV256A-55RI from Atmel is a 256K-bit (32K × 8) one-time programmable EPROM optimized for low-voltage operation at 3.0V–3.6V or standard 5V ±10%, with 55 ns read 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-55RI datasheet, AT27LV256A-55RI pinout, AT27LV256A-55RI application, or AT27LV256A-55RI equivalent, key selection criteria include dual-voltage compatibility, rapid 100 µs/byte programming, TTL/CMOS I/O compatibility, JEDEC pin alignment with AT27C256R, and industrial temperature support (−40°C to +85°C).
Technical Context
The AT27LV256A-55RI implements a two-line control architecture using CE (Chip Enable) and OE (Output Enable) to manage bus contention and output tri-state behavior. Its internal OTP memory array uses high-reliability CMOS technology with 2,000V ESD protection and 200 mA latchup immunity.
It supports Rapid™ programming with 100 µs/byte typical pulse width at VCC = 6.5V and VPP = 13.0V, and includes integrated product identification code accessible via A9 = 12.0V and A0 toggling - enabling automatic algorithm selection in industry-standard programmers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32K × 8), fixed organization for firmware boot code storage |
| Read Access Time | 55 ns max at VCC = 3.0V–3.6V, enabling real-time execution in 8-bit microcontroller systems |
| Supply Voltage Range | 3.0V–3.6V or 4.5V–5.5V, allowing direct integration into mixed-voltage backplane designs |
| Standby Current | 20 µA max at VCC = 3.6V, supporting ultra-low-power sleep modes in portable instrumentation |
| Operating Temperature | −40°C to +85°C, qualified for industrial control panels and automotive under-hood ECUs |
| Programming Voltage | VPP = 13.0V ±0.25V required only during programming; VCC = 6.5V ±0.25V during write cycles |
| I/O Compatibility | CMOS and TTL compatible inputs/outputs per LVTTL standard, ensuring interoperability with legacy 5V logic families |
Pinout & Package
AT27LV256A-55RI is supplied in a 28-lead 330-mil SOIC package (package code 28R), with 0.050" lead pitch and JEDEC MS-012AA compliance. Pin 1 is marked by a beveled corner and located at top-left when viewed from top with notch up.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus accepting 0x0000–0x7FFF range; all must be stable before CE assertion |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus in read mode; high-impedance when OE or CE inactive |
| CE | Chip Enable | Active-low global enable; controls device power state and output driver activation |
| OE | Output Enable | Active-low output gate; allows shared bus operation without disabling chip power |
| VCC | Power Supply | Primary supply input (3.0V–3.6V or 4.5V–5.5V); requires local 0.1 µF ceramic decoupling |
| GND | Ground Reference | Signal and power return path; must be connected to system ground plane with minimal impedance |
| VPP | Programming Voltage | 13.0V programming supply; must be applied after VCC and removed before VCC during programming |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming | 100 µs/byte typical programming time reduces firmware update cycle duration in production test |
| Dual-Voltage Operation | Single device supports both 3.3V portable systems and 5V legacy host cards without redesign |
| JEDEC Pin Compatibility | Pin-for-pin identical to AT27C256R, enabling drop-in replacement in existing PCB layouts |
| Integrated ID Code | Manufacturer (0x1E) and device code (0x8C) readable via A9/VH and A0 toggle, enabling automated programmer validation |
| Industrial Temp Range | −40°C to +85°C operation verified across full voltage range, suitable for uncontrolled ambient environments |
Applications
| Industrial PLC Firmware Storage | Legacy Medical Device Boot ROM |
|---|---|
Use Scenario: Storing fixed ladder logic firmware in DIN-rail mounted programmable logic controllers deployed in factory automation lines. IC Role / Device Role / Timing Role: Nonvolatile boot memory providing deterministic 55 ns instruction fetch timing for real-time scan cycle execution. Use Value: Dual-voltage support enables reuse across 3.3V controller boards and 5V retrofit modules without BOM change. | Use Scenario: Holding certified diagnostic firmware in Class II medical instruments requiring long-term data retention and regulatory traceability. IC Role / Device Role / Timing Role: One-time programmable ROM preventing unauthorized runtime modification of safety-critical boot code. Use Value: Industrial temperature rating and 2,000V ESD protection ensure reliability in hospital-grade EMI environments. |
| Automotive Body Control Module | Test Equipment Calibration Data |
Use Scenario: Storing vehicle-specific configuration tables and CAN message routing logic in under-dash BCMs operating near engine compartments. IC Role / Device Role / Timing Role: OTP EPROM delivering guaranteed read stability across −40°C to +85°C without refresh or wear-out concerns. Use Value: Low 20 µA standby current extends battery life during vehicle sleep mode while maintaining firmware integrity. | Use Scenario: Embedding factory-calibrated ADC offset/gain coefficients and sensor linearization curves in benchtop multimeters and oscilloscopes. IC Role / Device Role / Timing Role: Immutable reference data store accessed once at power-up to initialize measurement subsystems. Use Value: Rapid programming enables efficient calibration data loading during final test, reducing throughput time per unit. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C256R-70PC | 5V-only operation (4.5V–5.5V); no 3.3V support; 70 ns access; PDIP package | Lacks low-voltage capability; requires separate 5V rail; not suitable for battery-powered designs | Select when legacy 5V-only systems demand pin-compatible replacement with no voltage scaling needed |
| MN65C256B-55PL | Same 3.0V–3.6V/5V dual range; 55 ns access; 28-pin PLCC; different ID code and programming algorithm | Requires revalidation of programming equipment setup; not Rapid™-compatible | Choose when PLCC footprint is mandatory and Atmel's Rapid™ algorithm is not required |
Compared with AT27LV256A-55RI, AT27C256R-70PC sacrifices low-voltage operation for broader 5V ecosystem compatibility, while MN65C256B-55PL retains voltage flexibility but lacks integrated ID code and Rapid™ programming - impacting production line efficiency and auto-detection capability.
Availability
AT27LV256A-55RI is available at Aetrix Electronics and suitable for industrial control systems, legacy medical instrumentation, automotive body electronics, and test equipment calibration requiring stable component supply across extended lifecycle demands.
Supply support for AT27LV256A-55RI 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 manufacturer specializing in microcontrollers, nonvolatile memory, and secure authentication ICs before its acquisition by Microchip Technology in 2016.
The AT27LV256A product line delivers low-voltage OTP EPROMs engineered for firmware storage in space-constrained, power-sensitive embedded systems where data immutability and industrial-grade reliability are critical.
FAQ
What is the maximum read access time specified for AT27LV256A-55RI?
The AT27LV256A-55RI has a maximum read access time of 55 ns when operated at VCC = 3.0V–3.6V and within the industrial temperature range (−40°C to +85°C). This value is guaranteed across the full voltage and temperature envelope and is measured from address valid to valid data on O0–O7 outputs under CE = OE = VIL conditions.
Does AT27LV256A-55RI support both 3.3V and 5V operation simultaneously?
No - AT27LV256A-55RI operates in either 3.0V–3.6V or 4.5V–5.5V supply ranges, but not both at once. The device automatically adapts I/O levels: at 3.3V it produces TTL-compatible outputs usable with 5V logic, while at 5V it meets standard TTL thresholds. System design must select one supply voltage per power domain.
What package type is used for AT27LV256A-55RI?
AT27LV256A-55RI is packaged in a 28-lead, 0.330" wide plastic gull-wing small outline integrated circuit (SOIC), designated as package code 28R per Atmel's ordering information. It complies with JEDEC MS-012AA and features a 0.050" lead pitch and standard surface-mount footprint.
Can AT27LV256A-55RI be programmed using standard EPROM programmers?
Yes - AT27LV256A-55RI uses the same programming protocol and pinout as AT27C256R and is supported by industry-standard programmers that implement the Rapid™ algorithm. It requires VPP = 13.0V and VCC = 6.5V during programming, with A9 set to 12.0V for ID code verification. No special hardware adaptation is needed beyond correct voltage provisioning.
Is AT27LV256A-55RI suitable for new designs given its OTP nature?
Yes - AT27LV256A-55RI remains viable for new designs where firmware is finalized before production and field updates are unnecessary. Its industrial temperature rating, low standby current, and JEDEC compatibility make it appropriate for cost-sensitive, long-lifecycle applications such as industrial controllers and test equipment calibration storage, provided programming infrastructure is available.
AT27LV256A-55RI 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:
- 55 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-55RI FAQ
1.How can I place an order for AT27LV256A-55RI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27LV256A-55RI 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-55RI reliable?
The price and inventory of AT27LV256A-55RI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27LV256A-55RI is usually 5 days.
3.What payment methods are accepted for AT27LV256A-55RI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27LV256A-55RI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27LV256A-55RI?
AT27LV256A-55RI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27LV256A-55RI 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-55RI?
For technical support, including AT27LV256A-55RI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27LV256A-55RI requirements.
6.How does Aetrix verify that AT27LV256A-55RI is sourced from the original manufacturer or authorized distributors?
All AT27LV256A-55RI 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-55RI meets industry standards.
7.What is the process for return or replacement of AT27LV256A-55RI?
All AT27LV256A-55RI units undergo pre-shipment inspection (PSI). If there is an issue with AT27LV256A-55RI, 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-55RI part is unused and in its original packaging.
Return procedure for AT27LV256A-55RI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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