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Microchip Technology AT27LV520-90XU
- Part No.:
- AT27LV520-90XU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
AT27LV520-90XU.pdf
- Description:
- IC EPROM 512KBIT PAR 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:750
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Product details
Overview
AT27LV520-90XU from Atmel is a 524,288-bit (64K × 8) one-time programmable EPROM with multiplexed address/data bus, 90 ns max read access time, dual-voltage operation (3.0–3.6 V or 4.5–5.5 V), and TSSOP-20 packaging. It serves as nonvolatile program storage in embedded controllers and legacy industrial systems requiring low-power, battery-compatible memory with TTL/CMOS compatibility.
For engineers reviewing the AT27LV520-90XU datasheet, AT27LV520-90XU pinout, AT27LV520-90XU application, or AT27LV520-90XU equivalent, key selection criteria include its 90 ns tACC timing grade, 20 µA max standby current at 3.6 V, pin compatibility with AT27C520, and support for rapid 50 µs/byte programming - critical for field-programmable firmware updates and manufacturing test environments.
Technical Context
The AT27LV520-90XU implements an 8-bit multiplexed bus architecture where AD0–AD7 serve as both lower-address latches and data I/O, reducing PCB trace count in space-constrained designs. Its ALE-controlled internal latching enables synchronous address capture independent of OE/VPP timing.
It supports two distinct operating modes: standard read (with OE/VPP = VIL) and rapid programming (with OE/VPP = VPP = 13.0 V and VCC = 6.5 V). The device integrates a JEDEC-standard product identification code (0x1E9D) readable via A9 high-voltage select, enabling automated programming equipment recognition.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 524,288 bits (64K × 8), sufficient for boot code or configuration tables in microcontroller-based systems |
| Max Read Access Time (tACC) | 90 ns at VCC = 3.0–3.6 V or 4.5–5.5 V - defines minimum CPU wait-state requirement for zero-wait-state interface |
| Supply Voltage Range | 3.0–3.6 V or 4.5–5.5 V - enables interoperability across 3.3 V logic domains and legacy 5 V backplanes |
| Standby Current (ISB) | 20 µA max at VCC = 3.6 V and ALE = VIH - enables ultra-low-power retention in battery-backed systems |
| Programming Speed | 50 µs/byte typical - reduces production programming cycle time versus conventional EPROMs |
| ESD Protection | 2,000 V HBM - meets industrial handling requirements without additional protection circuitry |
| Operating Temperature | -40°C to +85°C - qualified for industrial-grade embedded control and instrumentation |
Pinout & Package
AT27LV520-90XU is housed in a 20-lead TSSOP (JEDEC MO-153 AC) package with 4.4 mm body width, 0.65 mm lead pitch, and gull-wing leads. Pin 1 is marked by an index notch; leads are compliant with Pb/halide-free requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A8–A15 | Address Inputs | Upper 8 address bits; latched on ALE high-to-low transition to enable multiplexed bus operation |
| AD0–AD7 | Multiplexed Address/Data | Lower 8 address bits during ALE high; bidirectional data bus during read/write; eliminates need for external address latch |
| OE/VPP | Output Enable / Programming Supply | Active-low output enable in read mode; supplies 13.0 V programming voltage during rapid programming |
| ALE | Address Latch Enable | Edge-triggered latch control; captures AD0–AD7 as A0–A7 when high, enabling address/data time-division multiplexing |
| VCC | Power Supply | Single supply input supporting dual voltage ranges - simplifies power design in mixed-voltage systems |
| GND | Ground Reference | Common return path for all digital and programming currents; requires local 0.1 µF ceramic decoupling |
Key Features
| Feature | Design Value |
|---|---|
| Pin Compatibility with AT27C520 | Direct drop-in replacement in existing 5 V designs - no PCB or firmware changes required |
| Rapid Programming Algorithm | 50 µs/byte typical programming time with auto-verify loop - improves manufacturing throughput and yield |
| Integrated Product ID Code | Manufacturer ID 0x1E and Device ID 0x9D - enables automatic algorithm selection in industry-standard programmers |
| Low-Power CMOS Operation | 29 mW max active power at 5 MHz and 3.6 V - reduces thermal load and extends battery life in portable systems |
| TTL/CMOS Input/Output Compatibility | Meets JEDEC LVTTL standards - interfaces directly with 3.3 V and 5 V logic families without level shifters |
Applications
| Industrial PLC Firmware Storage | Legacy Embedded Controller Boot ROM |
|---|---|
|
Use Scenario: Storing fixed ladder logic and I/O mapping in programmable logic controllers deployed in factory automation cabinets. IC Role / Device Role / Timing Role: Nonvolatile program memory providing deterministic 90 ns instruction fetch latency to meet real-time scan cycle deadlines. Use Value: Dual-voltage support allows seamless integration into both modern 3.3 V control modules and retrofit 5 V chassis, minimizing redesign effort. |
Use Scenario: Holding boot code and hardware initialization routines in microcontroller-based medical diagnostic instruments with long product lifecycles. IC Role / Device Role / Timing Role: OTP EPROM acting as secure, tamper-resistant firmware repository with no risk of accidental overwrite during operation. Use Value: 2,000 V ESD rating and -40°C to +85°C qualification ensure reliability in uncontrolled clinical environments and transport conditions. |
| Automated Test Equipment (ATE) Pattern Memory | Avionics Maintenance Diagnostic Module |
|
Use Scenario: Storing test vector sequences in benchtop ATE systems used for semiconductor wafer probing and final test. IC Role / Device Role / Timing Role: High-speed read memory delivering pattern data to timing generators with sub-100 ns access to maintain test clock fidelity. Use Value: 90 ns tACC and 35 ns tOE guarantee precise edge alignment between stimulus and response sampling windows. |
Use Scenario: Providing aircraft-specific configuration data and fault-tree lookup tables in portable line-replaceable maintenance units. IC Role / Device Role / Timing Role: Radiation-tolerant OTP memory storing immutable operational parameters validated under DO-254 guidelines. Use Value: Green (Pb/halide-free) TSSOP packaging complies with aerospace RoHS directives while maintaining mechanical robustness in vibration-prone avionics bays. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C520-90SI | 5 V-only operation (4.5–5.5 V); no 3.3 V support; identical pinout and timing | Limited to legacy 5 V-only systems; lacks battery-friendly low-voltage capability | Select when system power rails are strictly 5 V and backward compatibility with older AT27C520 layouts is mandatory |
| AM27C512-90DC | 512 Kbit (64K × 8) OTP EPROM; 90 ns access; 28-pin DIP/SOIC; no multiplexed bus | Requires separate address/data buses and external latch; higher board area and component count | Choose when existing layout uses non-multiplexed architecture or when TSSOP footprint is incompatible with mechanical constraints |
Compared with AT27LV520-90XU, AT27C520-90SI offers identical timing and pinout but sacrifices 3.3 V operation and low-power advantage, while AM27C512-90DC provides same density but demands additional address latching logic and larger package - making AT27LV520-90XU optimal for compact, dual-voltage, low-power embedded designs.
Availability
AT27LV520-90XU is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy embedded controller boot ROM, and automated test equipment pattern memory requiring stable component supply and long-term lifecycle support.
Supply support for AT27LV520-90XU 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, nonvolatile memory, and security ICs for industrial, automotive, and consumer applications.
The AT27LV520 product line was designed to deliver low-power, pin-compatible OTP EPROM alternatives to 5 V-only predecessors - targeting cost-sensitive, battery-operated, and mixed-voltage embedded systems needing reliable firmware storage without re-engineering.
FAQ
What is the maximum operating temperature range for the AT27LV520-90XU?
The AT27LV520-90XU is rated for industrial temperature operation from -40°C to +85°C. This range is verified per the datasheet's Operating Modes and DC Characteristics sections and applies to both 3.0–3.6 V and 4.5–5.5 V supply conditions. The specification ensures reliable read performance and data retention across harsh environmental conditions encountered in factory automation and outdoor instrumentation - critical for deployments where thermal cycling is routine. AT27LV520-90XU maintains full timing compliance (e.g., 90 ns tACC) across this entire range.
Does the AT27LV520-90XU support true 3.3 V operation, or does it require 5 V for programming?
The AT27LV520-90XU supports true 3.3 V operation for read mode (3.0–3.6 V), but programming requires elevated voltages: VCC = 6.5 V and OE/VPP = 13.0 V, as defined in the DC Programming Characteristics table. These levels are supplied externally by compatible EPROM programmers - the device itself does not generate them. During normal system operation, only the 3.3 V or 5 V rail is needed. AT27LV520-90XU's dual-voltage design separates runtime simplicity from programming infrastructure, enabling low-power embedded use while retaining compatibility with standard programming equipment.
Is the AT27LV520-90XU pin-compatible with the AT27C520, and what does that mean for PCB layout?
Yes, the AT27LV520-90XU is explicitly pin-compatible with the AT27C520 per the datasheet's Features section and Pin Configurations diagrams. Both share identical 20-pin TSSOP (20X) and SOIC (20S) footprints, matching pin functions including ALE, OE/VPP, AD0–AD7, and A8–A15. This means AT27LV520-90XU can replace AT27C520 on existing PCBs without layout modification - preserving signal integrity and timing margins. However, verify that VCC decoupling (0.1 µF ceramic near VCC/GND) meets the AT27LV520-90XU's requirements, especially when migrating from 5 V to 3.3 V operation.
What is the purpose of the Integrated Product Identification Code in the AT27LV520-90XU?
The AT27LV520-90XU incorporates a JEDEC-standard 16-bit identification code (Manufacturer ID 0x1E, Device ID 0x9D) accessible via A9 high-voltage select. This code allows industry-standard programming equipment to automatically detect the device type and apply correct programming algorithms, voltages, and verification sequences - eliminating manual setup errors. It ensures consistent, repeatable programming across production lines and field service tools. The AT27LV520-90XU shares the same ID code as the AT27C520, confirming their programming equivalence and enabling shared programmer configurations.
How does the multiplexed address/data bus of the AT27LV520-90XU reduce system complexity?
The AT27LV520-90XU uses AD0–AD7 for both lower-address latching (when ALE is high) and data I/O (when ALE is low), eliminating the need for an external octal latch like the 74LS373. This reduces component count, PCB area, and interconnect delay - particularly valuable in space-constrained embedded designs. The ALE signal synchronizes address capture, allowing microcontrollers with multiplexed buses (e.g., 8051 derivatives) to interface directly. AT27LV520-90XU's architecture cuts BOM cost and improves signal integrity by minimizing trace stubs and fanout loading compared to discrete address/data implementations.
AT27LV520-90XU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EPROM
- Technology:
- EPROM - OTP
- Memory Size:
- 512Kbit
- Memory Organization:
- 64K 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:
- 20-TSSOP
AT27LV520-90XU FAQ
1.How can I place an order for AT27LV520-90XU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27LV520-90XU 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 AT27LV520-90XU reliable?
The price and inventory of AT27LV520-90XU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27LV520-90XU is usually 5 days.
3.What payment methods are accepted for AT27LV520-90XU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27LV520-90XU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27LV520-90XU?
AT27LV520-90XU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27LV520-90XU 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 AT27LV520-90XU?
For technical support, including AT27LV520-90XU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27LV520-90XU requirements.
6.How does Aetrix verify that AT27LV520-90XU is sourced from the original manufacturer or authorized distributors?
All AT27LV520-90XU 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 AT27LV520-90XU meets industry standards.
7.What is the process for return or replacement of AT27LV520-90XU?
All AT27LV520-90XU units undergo pre-shipment inspection (PSI). If there is an issue with AT27LV520-90XU, 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 AT27LV520-90XU part is unused and in its original packaging.
Return procedure for AT27LV520-90XU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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