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Microchip Technology AT27LV256A-90RI
- Part No.:
- AT27LV256A-90RI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.342", 8.69mm Width)
- Datasheet:
-
AT27LV256A-90RI.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,768
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Product details
Overview
AT27LV256A-90RI from Atmel is a 256K-bit (32K × 8) one-time programmable EPROM optimized for low-voltage battery-powered systems, featuring 90 ns read access time at 3.0–3.6 V, dual-voltage operation (3.0–3.6 V or 4.5–5.5 V), and industrial temperature range (−40°C to +85°C). It delivers 8 mA active current at 5 MHz and <20 µA standby current, with JEDEC-standard 28-pin SOIC packaging.
For engineers reviewing the AT27LV256A-90RI datasheet, AT27LV256A-90RI pinout, AT27LV256A-90RI application, or AT27LV256A-90RI equivalent, key selection criteria include its OTP architecture, rapid 100 µs/byte programming, TTL/CMOS compatibility, integrated product identification code, and support for both 3.3 V and 5 V host environments without level-shifting.
Technical Context
The AT27LV256A-90RI implements a two-line control interface (CE and OE) enabling bus contention avoidance in shared-memory systems. Its address decoding covers A0–A14 (15-bit), supporting full 32K-word access, while output drivers deliver TTL-compatible VOH ≥ 2.4 V and VOL ≤ 0.4 V under specified load conditions.
It uses high-reliability CMOS process technology with 2,000 V ESD protection and 200 mA latchup immunity. Programming requires VPP = 13.0 V and VCC = 6.5 V, with Rapid™ algorithm ensuring verified byte programming in ≤10 pulses per failed location - distinct from standard EPROM erase-and-reflash cycles.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32K × 8) - supports firmware storage for microcontroller boot code or configuration data. |
| Read Access Time | 90 ns max at VCC = 3.0–3.6 V - enables direct interface with 10 MHz microcontrollers without wait states. |
| Supply Voltage Range | 3.0–3.6 V or 4.5–5.5 V - allows plug-and-play use in mixed-voltage systems including legacy 5 V and modern 3.3 V designs. |
| Standby Current | 20 µA max at VCC = 3.6 V - reduces quiescent power in always-on embedded controllers. |
| Active Current | 8 mA max at 5 MHz, VCC = 3.6 V - enables low-power operation in portable instrumentation and handheld devices. |
| Programming Speed | 100 µs/byte typical - cuts production programming time by >5× vs. conventional EPROMs. |
| Operating Temperature | −40°C to +85°C - qualified for industrial control, automotive body electronics, and outdoor telemetry units. |
Pinout & Package
AT27LV256A-90RI is supplied in a 28-lead 330-mil SOIC package (package code R), with pins arranged as defined in Atmel's official SOIC top-view diagram. Pin 1 is VPP; pin 14 is GND; pin 15 is VCC; pin 28 is A13.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus accepting full 32K-word memory map; TTL/CMOS compatible thresholds. |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus with VOH ≥ 2.4 V at IOH = −400 µA, compatible with 5 V TTL logic. |
| CE | Chip Enable | Active-low chip select; controls device activation and entry into standby mode when high. |
| OE | Output Enable | Active-low output gate; enables tristate output drivers independently of CE for bus sharing. |
| VPP | Programming Voltage | 13.0 V input required only during programming; must be applied after and removed before VCC. |
| VCC | Power Supply | 3.0–3.6 V or 4.5–5.5 V main supply; powers core logic and I/O buffers in read/standby modes. |
| GND | Ground Reference | Common return path for all internal circuits and I/O; requires local 0.1 µF ceramic decoupling. |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC Pin Compatibility | Direct replacement for AT27C256R in existing 28-pin SOIC layouts - no PCB redesign needed. |
| Rapid™ Programming Algorithm | Reduces average programming time to <1 second per device (32K bytes), improving manufacturing throughput. |
| Integrated Product ID Code | Manufacturer ID (0x1E) and Device Code (0x8C) accessible via A9/VH and A0 toggle - enables auto-detection in universal programmers. |
| Two-Line Control Architecture | Independent CE and OE inputs allow flexible memory mapping and elimination of bus contention in multi-peripheral systems. |
| High-Reliability Process | 2,000 V HBM ESD rating and 200 mA latchup immunity ensure robustness in industrial assembly and field operation. |
Applications
| Industrial PLC Firmware Storage | Legacy System BIOS Replacement |
|---|---|
Use Scenario: Storing fixed ladder logic and I/O configuration in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: Non-volatile firmware ROM providing boot-time instruction fetch for microcontroller-based PLC CPUs. Use Value: 90 ns access time eliminates wait-state insertion, enabling deterministic scan-cycle timing critical for real-time control loops. | Use Scenario: Replacing obsolete 27C256 EPROMs in aging PC motherboards and embedded x86-based controllers. IC Role / Device Role / Timing Role: Pin-compatible OTP memory holding POST routines and hardware initialization code. Use Value: Dual-voltage support allows seamless integration into both 5 V legacy boards and newer 3.3 V hybrid designs without voltage translation. |
| Portable Medical Instrument Boot Memory | Automotive Body Control Module Configuration |
Use Scenario: Holding calibration tables and safety-critical startup sequences in handheld diagnostic tools powered by Li-ion batteries. IC Role / Device Role / Timing Role: Low-power OTP storage accessed during cold start; operates reliably across battery discharge range (3.0–3.6 V). Use Value: <20 µA standby current extends battery life between calibrations; industrial temp rating ensures operation in clinical environments. | Use Scenario: Storing vehicle-specific configuration data (e.g., door lock logic, lighting profiles) in BCMs subject to under-hood thermal cycling. IC Role / Device Role / Timing Role: Immutable configuration ROM interfaced with 8-bit microcontrollers in CAN-connected modules. Use Value: −40°C to +85°C qualification and 200 mA latchup immunity prevent corruption during engine compartment thermal transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C256R-90JC | 5 V-only operation (4.5–5.5 V); no low-voltage mode; same 90 ns speed and 28-pin SOIC package. | Requires dedicated 5 V rail; unsuitable for battery-powered or mixed-voltage systems. | Select when legacy 5 V design constraints prohibit voltage scaling and VPP = 12.5 V programming is already supported. |
| MX27C256A-90PC | 5 V-only; identical 256K × 8 organization and 90 ns speed; 28-pin PDIP package instead of SOIC. | Larger footprint and through-hole mounting; incompatible with surface-mount production lines using AT27LV256A-90RI. | Choose only for hand-soldered prototypes or repair of vintage equipment where PDIP is mandated. |
Compared with AT27C256R-90JC and MX27C256A-90PC, the AT27LV256A-90RI uniquely supports dual-voltage operation and lower standby power, making it the sole option for new designs requiring 3.3 V compatibility, extended battery runtime, or industrial temperature resilience without package change.
Availability
AT27LV256A-90RI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy system BIOS replacement, and portable medical instrument boot memory requiring stable component supply across extended lifecycle demands.
Supply support for AT27LV256A-90RI 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, non-volatile memory, and secure authentication ICs for industrial, automotive, and consumer applications.
The AT27LV256A product line was designed to replace legacy 5 V EPROMs in cost-sensitive, space-constrained embedded systems while delivering low-voltage operation, rapid programming, and industrial-grade reliability - targeting firmware storage in programmable logic, instrumentation, and automotive subsystems.
FAQ
What is the maximum operating voltage for VPP on the AT27LV256A-90RI during programming?
The AT27LV256A-90RI requires VPP = 13.0 ± 0.25 V during programming, with absolute maximum rating of +14.0 V on A9 and VPP pins. Exceeding this risks permanent damage. The AT27LV256A-90RI datasheet specifies that VPP must be applied after and removed before VCC to prevent latchup. This voltage is only used in programming mode and must be isolated from read-mode circuitry.
Does the AT27LV256A-90RI support true 3.3 V logic-level outputs when powered at 3.3 V?
Yes, the AT27LV256A-90RI produces TTL-compatible outputs (VOH ≥ 2.4 V, VOL ≤ 0.4 V) when VCC = 3.0–3.6 V, allowing direct interface with 5 V TTL inputs without level shifters. This behavior is confirmed in the DC Operating Characteristics table for VCC = 3.0–3.6 V, where VOH is specified at IOH = −400 µA. The AT27LV256A-90RI achieves this via internal output driver design, not external biasing.
Can the AT27LV256A-90RI be used as a drop-in replacement for AT27C256R in an existing 28-pin SOIC socket?
The AT27LV256A-90RI is pin-compatible with AT27C256R per JEDEC standards and shares identical 28-pin SOIC pinout, but requires attention to VPP handling: AT27C256R uses VPP = 12.5 V, while AT27LV256A-90RI needs VPP = 13.0 V. In read mode, both operate identically. The AT27LV256A-90RI supports the same programming equipment and algorithms, making it a functional upgrade path.
What decoupling capacitance is required for stable operation of the AT27LV256A-90RI?
The AT27LV256A-90RI requires a minimum 0.1 µF ceramic capacitor placed between VCC and GND, mounted as close as possible to the device pins. For systems with multiple AT27LV256A-90RI devices or high-noise environments, a 4.7 µF bulk electrolytic capacitor should also be added near the power entry point. These values are specified in the "System Considerations" section of the AT27LV256A-90RI datasheet to suppress transient excursions during CE switching.
How is the Integrated Product Identification Code accessed on the AT27LV256A-90RI?
The AT27LV256A-90RI identification code is read by setting A9 to VH = 12.0 ± 0.5 V, holding A1–A14 low, and toggling A0: low selects Manufacturer ID (0x1E), high selects Device Code (0x8C). Both bytes appear on O7–O0. This feature is electrically identical to the AT27C256R and enables automatic detection in industry-standard programmers. The AT27LV256A-90RI uses the same ID codes as its 5 V counterpart.
AT27LV256A-90RI 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:
- 90 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-90RI FAQ
1.How can I place an order for AT27LV256A-90RI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27LV256A-90RI 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-90RI reliable?
The price and inventory of AT27LV256A-90RI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27LV256A-90RI is usually 5 days.
3.What payment methods are accepted for AT27LV256A-90RI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27LV256A-90RI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27LV256A-90RI?
AT27LV256A-90RI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27LV256A-90RI 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-90RI?
For technical support, including AT27LV256A-90RI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27LV256A-90RI requirements.
6.How does Aetrix verify that AT27LV256A-90RI is sourced from the original manufacturer or authorized distributors?
All AT27LV256A-90RI 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-90RI meets industry standards.
7.What is the process for return or replacement of AT27LV256A-90RI?
All AT27LV256A-90RI units undergo pre-shipment inspection (PSI). If there is an issue with AT27LV256A-90RI, 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-90RI part is unused and in its original packaging.
Return procedure for AT27LV256A-90RI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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