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Microchip Technology AT27LV256A-55JU
- Part No.:
- AT27LV256A-55JU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT27LV256A-55JU.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,685
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Product details
Overview
AT27LV256A-55JU from Atmel is a 32K × 8-bit one-time programmable EPROM (OTP EPROM) operating at 3.0–3.6 V or 4.5–5.5 V, with 55 ns read access time, 20 µA max standby current at 3.6 V, and JEDEC-standard 32-lead PLCC packaging. It serves as nonvolatile program storage in embedded controllers, legacy industrial firmware modules, and boot memory for microprocessor-based systems.
For engineers reviewing the AT27LV256A-55JU datasheet, AT27LV256A-55JU pinout, AT27LV256A-55JU application, or AT27LV256A-55JU equivalent, key selection criteria include dual-voltage compatibility, rapid 100 µs/byte programming, TTL/CMOS I/O compatibility, industrial temperature range (−40°C to +85°C), and green Pb/halide-free PLCC packaging.
Technical Context
The AT27LV256A-55JU implements a two-line control architecture (CE and OE) to prevent bus contention and supports both CMOS and TTL logic levels across its voltage ranges. Its integrated product identification code enables automatic algorithm selection in industry-standard programmers.
It uses high-reliability CMOS technology with 2,000 V ESD protection and 200 mA latchup immunity. Programming requires VCC = 6.5 V and VPP = 13.0 V, while read operation tolerates VCC = 3.0–3.6 V or 4.5–5.5 V - enabling drop-in use in mixed-voltage host systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 262,144-bit (32K × 8) OTP EPROM - fixed firmware storage without re-erasure capability |
| Read Access Time | 55 ns max at VCC = 3.0–3.6 V - meets timing requirements for 18 MHz CPU address strobes |
| Supply Voltage Range | 3.0–3.6 V or 4.5–5.5 V - interoperable with both 3.3 V and 5 V logic domains |
| Standby Current | 20 µA max at VCC = 3.6 V - enables low-power retention in battery-backed systems |
| Active Power Dissipation | 29 mW max at 5 MHz and VCC = 3.6 V - reduces thermal load in dense PCB layouts |
| Operating Temperature | −40°C to +85°C - qualified for industrial-grade embedded environments |
| ESD Protection | 2,000 V HBM - withstands handling and board-level electrostatic discharge events |
Pinout & Package
AT27LV256A-55JU is supplied in a 32-lead Plastic J-Leaded Chip Carrier (PLCC) package per JEDEC MS-016, Variation AE. Pin 1 is marked by a corner notch; pins 1 and 17 are no-connect (NC).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus interface supporting full 32K memory space decoding |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus outputs compatible with TTL/CMOS logic thresholds |
| CE | Chip Enable | Active-low chip select enabling memory mapping into system address space |
| OE | Output Enable | Active-low output gate controlling bus drive timing independent of CE |
| VPP | Programming Voltage | 13.0 V input required only during programming; must be sequenced with VCC |
| VCC | Power Supply | Primary supply for read/standby (3.0–3.6 V or 4.5–5.5 V); 6.5 V for programming |
| GND | Ground Reference | Common return path for all digital and programming currents |
Key Features
| Feature | Design Value |
|---|---|
| Rapid Programming Algorithm | 100 µs/byte typical - cuts firmware update time vs. legacy EPROMs requiring ms-scale pulses |
| Dual-Voltage Read Operation | 3.0–3.6 V or 4.5–5.5 V - eliminates level shifters in mixed-supply systems |
| Integrated Product ID Code | Manufacturer byte 0x1E and device byte 0x8C - enables auto-detection in universal programmers |
| JEDEC Pin Compatibility | Pins match AT27C256R - allows direct replacement in existing 5 V designs with voltage scaling |
| Green Packaging | Pb/halide-free PLCC - satisfies RoHS compliance without derating or performance trade-offs |
Applications
| Industrial PLC Firmware Storage | Legacy Microcontroller Boot ROM |
|---|---|
Use Scenario: Storing fixed ladder logic and I/O configuration in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: Nonvolatile boot memory providing deterministic startup sequence and runtime instruction fetch. Use Value: 55 ns access ensures real-time response to sensor interrupts; industrial temp rating guarantees uptime in unconditioned control cabinets. | Use Scenario: Holding bootloader code and hardware initialization routines in 8-bit microcontroller-based instrumentation. IC Role / Device Role / Timing Role: Standalone ROM executing before RAM initialization, delivering verified firmware on power-up. Use Value: Dual-voltage support allows same part to serve both 3.3 V MCU designs and legacy 5 V boards, reducing BOM variants. |
| Embedded Test Equipment Memory | Avionics Maintenance Terminal Storage |
Use Scenario: Storing calibration tables and self-test algorithms in portable field test sets used for analog/digital circuit validation. IC Role / Device Role / Timing Role: Read-only data repository accessed via parallel bus during diagnostic mode execution. Use Value: 20 µA max standby current extends battery life between calibrations; green packaging meets environmental compliance for field-deployed tools. | Use Scenario: Holding aircraft subsystem diagnostics and configuration data in ground maintenance terminals interfacing with ARINC-429 buses. IC Role / Device Role / Timing Role: Secure, tamper-resistant firmware store immune to accidental overwrite or corruption. Use Value: 2,000 V ESD protection prevents field failure during technician handling; industrial temp range covers hangar-to-ramp operational extremes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C256R-55JI | 5 V only (4.5–5.5 V); no low-voltage mode; identical 55 ns speed and PLCC package | Requires dedicated 5 V rail; not suitable for battery-powered or mixed-voltage systems | Select when legacy 5 V design forbids voltage scaling and board layout cannot accommodate decoupling for dual-rail operation |
| MX27C256 (Macronix) | 5 V only; 55 ns speed; 28-pin SOIC/PLCC; lacks integrated ID code and rapid programming algorithm | Needs external programmer setup; no auto-identification; higher programming time per byte | Choose for cost-sensitive replacements where programming infrastructure already supports non-ID devices and timing margins allow |
Compared with AT27LV256A-55JU, AT27C256R-55JI offers identical speed and footprint but sacrifices low-voltage flexibility, while MX27C256 provides functional equivalence at lower cost but requires manual algorithm selection and lacks ESD/latchup hardening.
Availability
AT27LV256A-55JU is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy microcontroller boot ROM, and embedded test equipment memory requiring stable component supply and long-term lifecycle assurance.
Supply support for AT27LV256A-55JU 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 secure authentication ICs before its acquisition by Microchip Technology in 2016.
The AT27LV256A-55JU belongs to Atmel's low-voltage OTP EPROM product line, designed specifically for portable, battery-operated, and mixed-voltage embedded systems needing reliable, pin-compatible firmware storage without UV erasure.
FAQ
What voltage ranges does the AT27LV256A-55JU support during normal read operation?
The AT27LV256A-55JU supports two distinct read voltage ranges: 3.0 V to 3.6 V for low-voltage operation and 4.5 V to 5.5 V for standard 5 V systems. It does not operate at intermediate voltages like 3.7–4.4 V. Both ranges deliver the rated 55 ns access time, and outputs remain TTL-compatible across both - enabling seamless integration into dual-rail host platforms without level translation.
Is the AT27LV256A-55JU pin-compatible with the AT27C256R series?
Yes, the AT27LV256A-55JU is JEDEC-pin-compatible with the AT27C256R series in the same PLCC package. All signal pins (A0–A14, O0–O7, CE, OE, VCC, GND) occupy identical positions. However, AT27LV256A-55JU adds VPP functionality and supports 3.3 V operation - meaning it can replace AT27C256R in 5 V systems but requires proper VPP sequencing and voltage domain management in low-voltage designs.
What programming voltage and sequence are required for the AT27LV256A-55JU?
The AT27LV256A-55JU requires VCC = 6.5 V ± 0.25 V and VPP = 13.0 V ± 0.25 V during programming. VCC must be applied simultaneously with or before VPP, and removed simultaneously with or after VPP. A 0.1 µF ceramic capacitor is mandatory between VPP and GND to suppress transients. Programming uses 100 µs CE pulses, and the integrated product ID code (0x1E/0x8C) enables automatic algorithm selection in compliant programmers.
Does the AT27LV256A-55JU support industrial temperature operation?
Yes, the AT27LV256A-55JU is fully specified for industrial temperature operation from −40°C to +85°C. This rating applies across all electrical parameters including 55 ns access time, standby current (≤20 µA), and programming reliability. The device uses high-reliability CMOS process technology with 2,000 V HBM ESD protection and 200 mA latchup immunity - ensuring robustness in thermally demanding environments such as factory floors and outdoor equipment enclosures.
What package type is used for the AT27LV256A-55JU?
The AT27LV256A-55JU uses a 32-lead Plastic J-Leaded Chip Carrier (PLCC) package, designated "32J" per Atmel's ordering guide. It conforms to JEDEC standard MS-016, Variation AE, with body dimensions of 12.32 mm × 14.86 mm and 1.27 mm lead pitch. Pins 1 and 17 are no-connect (NC). This green (Pb/halide-free) variant replaces the legacy "J" suffix and meets RoHS Directive 2011/65/EU without performance compromise.
AT27LV256A-55JU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- 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:
- 32-PLCC (13.97x11.43)
AT27LV256A-55JU FAQ
1.How can I place an order for AT27LV256A-55JU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27LV256A-55JU 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-55JU reliable?
The price and inventory of AT27LV256A-55JU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27LV256A-55JU is usually 5 days.
3.What payment methods are accepted for AT27LV256A-55JU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27LV256A-55JU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27LV256A-55JU?
AT27LV256A-55JU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27LV256A-55JU 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-55JU?
For technical support, including AT27LV256A-55JU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27LV256A-55JU requirements.
6.How does Aetrix verify that AT27LV256A-55JU is sourced from the original manufacturer or authorized distributors?
All AT27LV256A-55JU 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-55JU meets industry standards.
7.What is the process for return or replacement of AT27LV256A-55JU?
All AT27LV256A-55JU units undergo pre-shipment inspection (PSI). If there is an issue with AT27LV256A-55JU, 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-55JU part is unused and in its original packaging.
Return procedure for AT27LV256A-55JU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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