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Microchip Technology AT27LV256A-90JU
- Part No.:
- AT27LV256A-90JU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT27LV256A-90JU.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:1,419
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Product details
Overview
AT27LV256A-90JU from Atmel is a 32K × 8-bit, one-time programmable (OTP) EPROM with 90 ns read access time, 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 TTL-compatible outputs at 3.0 V, supports rapid programming at 100 µs/byte, and features integrated product identification for automated programming equipment - ideal for battery-powered portable systems and mixed-voltage embedded controllers.
For engineers reviewing the AT27LV256A-90JU datasheet, AT27LV256A-90JU pinout, AT27LV256A-90JU application, or AT27LV256A-90JU equivalent, key selection criteria include low-voltage standby current (<1 µA typical at 3.3 V), JEDEC-standard 32-lead PLCC package compatibility, dual-supply interoperability with 5 V hosts, and verified programming equivalence to AT27C256R.
Technical Context
The AT27LV256A-90JU implements a CMOS-based OTP EPROM architecture with two-line control (CE/OE) enabling bus contention avoidance in multi-device systems. Its dual-voltage design allows seamless integration into both 3.3 V portable subsystems and legacy 5 V backplanes without level-shifting.
It uses a rapid programming algorithm requiring VCC = 6.5 V and VPP = 13.0 V, with built-in verification loops per byte and integrated manufacturer/device ID codes (0x1E/0x8C) accessible via A9 and A0 toggling - ensuring compatibility with standard EPROM programmers calibrated for AT27C256R.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 262,144 bits (32K × 8), sufficient for firmware boot code or configuration tables in microcontroller-based systems |
| Read access time | 90 ns max at VCC = 3.0–3.6 V, enabling real-time execution from memory in 5 MHz–10 MHz embedded systems |
| Supply voltage range | 3.0–3.6 V or 4.5–5.5 V, supporting direct interface with both modern low-voltage logic and legacy 5 V peripherals |
| Standby current | 20 µA max (CMOS mode), <1 µA typical at 3.3 V - critical for battery life extension in always-on portable devices |
| Active power dissipation | 29 mW max at 5 MHz and VCC = 3.6 V, less than 20% of equivalent 5 V EPROMs, reducing thermal load on PCB |
| ESD protection | 2,000 V HBM, meeting industrial handling requirements without external protection circuitry |
| Programming speed | 100 µs/byte typical, accelerating production programming throughput versus older EPROM families |
Pinout & Package
AT27LV256A-90JU is housed in a JEDEC-standard 32-lead plastic J-leaded chip carrier (PLCC), designated 32J, with pins 1 and 17 marked "don't connect" per datasheet.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address inputs | 15-bit address bus supporting full 32K address space; TTL/CMOS compatible, no external level translation needed |
| O0–O7 | Data outputs | 8-bit bidirectional data bus with VOH ≥ 2.4 V at IOH = −2.0 mA (3.3 V mode), directly driving standard TTL loads |
| CE | Chip Enable | Active-low enable controlling device selection; transition between active/standby induces transient voltage excursions requiring local 0.1 µF decoupling |
| OE | Output Enable | Active-low output gate; tOE = 50 ns ensures fast data valid timing when CE is already asserted |
| VCC | Power supply | Primary supply pin accepting either 3.0–3.6 V or 4.5–5.5 V; must be applied simultaneously with VPP during programming |
| VPP | Programming voltage | 13.0 V ± 0.25 V input required only during programming; requires 0.1 µF capacitor to ground to suppress transients |
| GND | Ground reference | Common return path for all signals and supplies; decoupling capacitors must connect here as close as possible to the device |
| NC | No Connect | Pins 3, 4, 12, 17, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 are unconnected - must remain floating per design |
Key Features
| Feature | Design Value |
|---|---|
| Rapid programming algorithm | 100 µs/byte typical programming time with automatic verify-and-reprogram loop, reducing production line cycle time vs. legacy EPROMs |
| Integrated product ID code | Manufacturer ID (0x1E) and device ID (0x8C) readable via A9/VH and A0 toggle - enables auto-detection by universal programmers |
| Dual-voltage interoperability | 3.0 V operation yields TTL-level outputs compatible with 5 V logic, eliminating need for bus buffers in mixed-supply systems |
| Two-line control interface | Independent CE and OE pins allow flexible bus arbitration - e.g., CE used for chip select, OE for output gating during shared-bus transfers |
| Industrial reliability enhancements | 200 mA latchup immunity and 2,000 V ESD protection reduce field failure risk in harsh environments without added protection components |
Applications
| Portable Medical Instrumentation | Industrial PLC Firmware Storage |
|---|---|
Use Scenario: Battery-powered handheld diagnostic devices requiring nonvolatile firmware storage with minimal quiescent power draw. IC Role / Device Role / Timing Role: OTP EPROM storing boot loader and calibration constants; accessed during cold start and periodic self-test sequences. Use Value: <1 µA typical standby current at 3.3 V extends single-charge battery life to >2 years in sleep mode, while 90 ns access enables sub-millisecond boot response. | Use Scenario: Programmable logic controller modules operating in factory-floor environments with mixed 3.3 V and 5 V I/O subsystems. IC Role / Device Role / Timing Role: Firmware storage for real-time control engine; interfaced via ISA or custom parallel bus with legacy 5 V peripherals. Use Value: Dual-voltage support eliminates level shifters; 5 V tolerance on inputs and TTL-compatible outputs at 3.0 V ensure plug-and-play compatibility across generations of PLC hardware. |
| Legacy Embedded System Upgrade | Secure Boot ROM for Microcontrollers |
Use Scenario: Retrofitting aging industrial controllers originally designed for AT27C256R to reduce power consumption without board redesign. IC Role / Device Role / Timing Role: Pin- and function-compatible drop-in replacement for AT27C256R; same programming algorithm and ID code. Use Value: Identical pinout and programming protocol allow reuse of existing programming fixtures and firmware images, cutting upgrade cost and validation time by >70%. | Use Scenario: Secure boot sequence in safety-critical avionics subsystems where firmware integrity must be guaranteed at power-on. IC Role / Device Role / Timing Role: One-time programmable ROM holding immutable cryptographic keys and bootloader signature verification logic. Use Value: OTP architecture prevents post-deployment tampering; rapid 100 µs/byte programming enables secure key injection during final test without exposing keys to production software tools. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C256R-90PU | 5 V-only operation (4.5–5.5 V); no low-voltage mode; identical 32K × 8 organization and 90 ns access | Requires dedicated 5 V rail; incompatible with battery-powered or mixed-voltage designs | Select when system lacks 3.3 V supply but needs identical timing and programming behavior |
| MX27C256AP-12 | 120 ns access time; 5 V-only; higher standby current (100 µA typical); same PLCC-32 package | Suitable only where timing margin permits slower access; not recommended for portable systems due to power penalty | Select only if AT27LV256A-90JU is unavailable and 120 ns latency is acceptable in target application |
Compared with AT27C256R-90PU and MX27C256AP-12, the AT27LV256A-90JU uniquely enables dual-voltage operation with sub-1 µA standby current - making it the sole choice for energy-constrained, field-upgradable embedded systems requiring OTP security and industrial temperature resilience.
Availability
AT27LV256A-90JU is available at Aetrix Electronics and suitable for portable medical instrumentation, industrial PLC firmware storage, legacy embedded system upgrades, and secure boot ROM applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant green packaging.
Supply support for AT27LV256A-90JU 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 U.S.-based semiconductor company specializing in microcontrollers, nonvolatile memory, and secure authentication ICs for industrial, automotive, and consumer applications.
The AT27LV256A belongs to Atmel's low-voltage OTP EPROM product line, engineered to replace legacy 5 V EPROMs in portable and mixed-supply systems while maintaining full programming and pin compatibility with the AT27C256R family.
FAQ
What is the maximum operating temperature range for the AT27LV256A-90JU?
The AT27LV256A-90JU is rated for industrial temperature operation from −40°C to +85°C. This range is validated across all electrical specifications including read access time (90 ns), standby current (≤20 µA), and output drive capability (VOH ≥ 2.4 V at −2.0 mA), ensuring reliable performance in factory automation, outdoor instrumentation, and vehicle-mounted electronics where ambient conditions vary widely. The AT27LV256A-90JU maintains full functionality across this range without derating.
Can the AT27LV256A-90JU be programmed using standard AT27C256R programming equipment?
Yes, the AT27LV256A-90JU is fully programming-compatible with AT27C256R equipment. It shares identical pinout, product identification codes (0x1E/0x8C), and rapid programming algorithm - requiring only VCC = 6.5 V and VPP = 13.0 V during programming. The AT27LV256A-90JU uses the same 100 µs CE pulse width and verification sequence as AT27C256R, allowing reuse of existing programmer firmware and socket fixtures without modification.
Does the AT27LV256A-90JU require external decoupling capacitors, and if so, what values?
Yes, the AT27LV256A-90JU requires two decoupling capacitors per device: a 0.1 µF high-frequency ceramic capacitor placed between VCC and GND as close as possible to the device pins, and a 4.7 µF bulk electrolytic capacitor near the power entry point for arrays. These are mandatory to suppress transient voltage excursions caused by CE transitions, which otherwise may exceed absolute maximum ratings and cause nonconformance. The AT27LV256A-90JU datasheet specifies these values explicitly in Section 3.
What is the meaning of the "JU" suffix in AT27LV256A-90JU?
The "JU" suffix in AT27LV256A-90JU denotes the 32-lead plastic J-leaded chip carrier (PLCC) package with matte tin lead finish and industrial temperature grade (−40°C to +85°C). Per Atmel's ordering information table, "32J" is the package code, and "JU" confirms green (Pb/halide-free) compliance. The AT27LV256A-90JU is not available in SOIC or TSOP variants - only in this JEDEC MS-016 compliant PLCC format.
How does the AT27LV256A-90JU achieve TTL-compatible outputs while operating at 3.0 V?
The AT27LV256A-90JU achieves TTL-compatible outputs at 3.0 V through optimized CMOS output driver design that guarantees VOH ≥ 2.4 V at IOH = −2.0 mA and VOL ≤ 0.4 V at IOL = 2.0 mA - meeting LVTTL voltage thresholds. This allows direct connection to standard 5 V TTL inputs without level shifters. The AT27LV256A-90JU maintains this compatibility across its full 3.0–3.6 V supply range, verified in Table 5-3 of the datasheet under DC characteristics.
AT27LV256A-90JU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- 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:
- 32-PLCC (13.97x11.43)
AT27LV256A-90JU FAQ
1.How can I place an order for AT27LV256A-90JU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27LV256A-90JU 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-90JU reliable?
The price and inventory of AT27LV256A-90JU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27LV256A-90JU is usually 5 days.
3.What payment methods are accepted for AT27LV256A-90JU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27LV256A-90JU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27LV256A-90JU?
AT27LV256A-90JU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27LV256A-90JU 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-90JU?
For technical support, including AT27LV256A-90JU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27LV256A-90JU requirements.
6.How does Aetrix verify that AT27LV256A-90JU is sourced from the original manufacturer or authorized distributors?
All AT27LV256A-90JU 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-90JU meets industry standards.
7.What is the process for return or replacement of AT27LV256A-90JU?
All AT27LV256A-90JU units undergo pre-shipment inspection (PSI). If there is an issue with AT27LV256A-90JU, 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-90JU part is unused and in its original packaging.
Return procedure for AT27LV256A-90JU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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