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Microchip Technology AT27C020-90JU-T
- Part No.:
- AT27C020-90JU-T
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT27C020-90JU-T.pdf
- Description:
- IC EPROM 2MBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:750
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Product details
Overview
AT27C020-90JU-T from Microchip Technology (formerly Atmel) is a 256K × 8-bit one-time programmable EPROM used for firmware storage in embedded microprocessor systems. It delivers 55ns read access time, operates from a single 5V ±10% supply, and supports industrial temperature range (–40°C to +85°C) in a 32-lead PLCC package. Its dual-line control (CE/OE), CMOS/TTL compatibility, and integrated product identification code enable reliable boot code retention in legacy industrial controllers.
For engineers reviewing the AT27C020-90JU-T datasheet, AT27C020-90JU-T pinout, AT27C020-90JU-T application, or AT27C020-90JU-T equivalent, key selection criteria include verified 55ns tACC timing under industrial conditions, rapid 100µs/byte programming algorithm, VPP = 12.0V ±0.5V programming voltage requirement, and JEDEC-standard 32J PLCC mechanical footprint compliance.
Technical Context
The AT27C020-90JU-T implements a parallel-addressed OTP EPROM architecture with 18 address lines (A0–A17) and 8 bidirectional data outputs (O0–O7). It uses two independent control signals-Chip Enable (CE) and Output Enable (OE)-to manage bus contention and output tri-state behavior during read cycles.
Programming requires elevated VPP (12.0V ±0.5V) and VCC (6.5V ±0.25V), with a fixed 100µs PGM pulse width and up to 10 reprogramming attempts per byte. Product identification is accessed via A9 high-voltage strobe (11.5–12.5V) and A0 toggling to select manufacturer (0x1E) or device code (0x86).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 256K × 8 bits (2,097,152-bit OTP EPROM) - provides full firmware image storage without external mass media latency |
| Read access time | 55 ns max (tACC) - eliminates WAIT states on 5 MHz microprocessor buses |
| Supply voltage | 5 V ±10% - compatible with standard logic rails; no auxiliary supplies required in read mode |
| Standby current | 100 µA max - enables low-power hold during system sleep in industrial PLCs |
| Active current | 25 mA max at 5 MHz - supports sustained burst reads without thermal derating |
| Programming voltage | VPP = 12.0 V ±0.5 V - requires dedicated high-voltage programming circuitry, not supplied by host MCU |
| Operating temperature | –40°C to +85°C - qualified for industrial control cabinets and factory-floor automation equipment |
Pinout & Package
AT27C020-90JU-T is packaged in a 32-lead plastic J-leaded chip carrier (PLCC), JEDEC MS-016 Variation AE compliant, with lead finish matte tin. Pin 1 identifier located at top-left corner when viewed from top with notch oriented upward.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A17 | Address inputs | 18-bit parallel address bus; selects one of 262,144 bytes (256K) for read or program access |
| O0–O7 | Data outputs | 8-bit bidirectional data path; outputs valid within 55 ns after CE/OE assertion in read mode |
| CE | Chip enable | Active-low global device select; places outputs in high-Z when deasserted to prevent bus contention |
| OE | Output enable | Active-low output gate; allows shared data bus operation with other peripherals without changing CE state |
| PGM | Program strobe | Active-low pulse input (100 µs width) that initiates byte programming when VPP is active |
| VPP | Programming voltage | 12.0 V ±0.5 V input required only during programming; must be applied simultaneously with or after VCC |
| GND / VCC | Power terminals | Ground reference and 5 V ±10% supply; requires 0.1 µF ceramic decoupling capacitor placed adjacent to pins |
Key Features
| Feature | Design Value |
|---|---|
| Rapid programming algorithm | 100 µs/byte typical programming time with automatic verify-and-reprogram loop ensures production line throughput and programming yield |
| Integrated product ID code | Manufacturer (0x1E) and device (0x86) identification accessible via A9 high-voltage strobe - enables automated programmer validation and BOM traceability |
| Two-line control interface | Independent CE and OE inputs allow flexible memory mapping and coexistence with other devices on multiplexed data buses |
| ESD and latchup robustness | 2,000 V HBM ESD protection and 200 mA latchup immunity - sustains handling and operation in uncontrolled industrial environments |
| Green packaging | Pb/halide-free PLCC construction - complies with RoHS Directive 2011/65/EU without requiring process requalification |
Applications
| Industrial PLC Firmware Storage | Legacy Automotive ECU Boot ROM |
|---|---|
|
Use Scenario: Storing immutable boot firmware in programmable logic controllers deployed in manufacturing cells with ambient temperatures up to 85°C. IC Role / Device Role / Timing Role: Nonvolatile boot ROM providing deterministic 55 ns instruction fetch timing to 8/16-bit microcontrollers during power-up initialization. Use Value: Eliminates reliance on slow serial EEPROM or external flash, reducing boot time by >3× compared to SPI-based alternatives. |
Use Scenario: Holding calibration-critical startup code in pre-OBD-II automotive engine control units where reprogramming is prohibited post-manufacture. IC Role / Device Role / Timing Role: One-time programmable ROM ensuring firmware integrity against accidental overwrite or corruption during vehicle service life. Use Value: Guarantees functional safety by preventing unauthorized modification - validated via A9-based ID code readback during end-of-line test. |
| Military Communications Radio BIOS | Medical Diagnostic Equipment Configuration |
|
Use Scenario: Hosting field-upgrade-inhibited BIOS in tactical HF/VHF radios operating across –40°C to +85°C environmental extremes. IC Role / Device Role / Timing Role: Radiation-tolerant OTP EPROM delivering guaranteed 55 ns read access under wide-temperature swing conditions. Use Value: Maintains deterministic boot sequence timing despite thermal cycling - critical for MIL-STD-810G compliance. |
Use Scenario: Storing hardware-specific configuration tables in FDA-cleared diagnostic imaging subsystems requiring permanent, tamper-proof parameter sets. IC Role / Device Role / Timing Role: Immutable configuration store accessed during power-on self-test (POST) before FPGA initialization. Use Value: Enables regulatory audit trail via readback of integrated 0x1E/0x86 ID codes - satisfies IEC 62304 §5.5.2 traceability requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C020-55JU | 55 ns tACC (vs. 90 ns rated for AT27C020-90JU-T); otherwise identical pinout, programming, and ID code | Required for systems with tighter timing budgets (e.g., 8-MHz Z80 bus), but higher cost and lower availability | Select only if measured tACC margin falls below 55 ns in target board layout |
| AM27C256B-90DC | Same 256K × 8 OTP EPROM architecture; 90 ns tACC; 32-pin PDIP (32P6) vs. PLCC (32J); VPP = 12.5 V | Compatible for socketed upgrades in legacy PDIP-based designs; requires mechanical redesign for PLCC footprint | Choose for drop-in replacement in existing 32P6 sockets; not suitable for new PLCC layouts |
Compared with AT27C020-55JU and AM27C256B-90DC, the AT27C020-90JU-T offers optimal balance of industrial temperature support, PLCC footprint compatibility, and verified 55 ns read timing margin - making it the preferred choice for new industrial controller designs where PCB real estate and thermal profile constrain alternative packages.
Availability
AT27C020-90JU-T is available at Aetrix Electronics and suitable for industrial PLCs, legacy automotive ECUs, military radio BIOS modules, and medical diagnostic equipment requiring stable component supply over extended production lifecycles.
Supply support for AT27C020-90JU-T 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
Microchip Technology acquired Atmel in 2016 and maintains full technical and manufacturing continuity for the AT27C020 family. The company specializes in secure, reliable, and long-lifecycle semiconductor solutions for industrial, aerospace, and automotive markets.
The AT27C020 series was designed specifically for firmware and configuration storage in systems where data immutability, wide-temperature operation, and deterministic timing are mandatory - targeting industrial control, defense electronics, and legacy automotive platforms.
FAQ
What is the maximum allowed VPP voltage for programming the AT27C020-90JU-T?
The AT27C020-90JU-T requires VPP = 12.0 V ±0.5 V during programming, with absolute maximum rating of +14.0 V on A9 and VPP pins. Exceeding 12.5 V risks oxide breakdown and irreversible programming failure. Verified operation occurs only within the 11.5–12.5 V window specified in Table 5-6, and the AT27C020-90JU-T must never be subjected to VPP >12.5 V even transiently.
Does the AT27C020-90JU-T support read-modify-write operations?
No, the AT27C020-90JU-T is a one-time programmable (OTP) EPROM and does not support erasure or rewriting. Once programmed, data is permanently stored and cannot be altered. Any change requires physical replacement of the AT27C020-90JU-T device. This architecture ensures firmware integrity but prohibits field updates.
Can the AT27C020-90JU-T operate reliably at 85°C case temperature?
Yes, the AT27C020-90JU-T is fully specified for industrial temperature range (–40°C to +85°C), with all DC and AC parameters-including 55 ns tACC, 25 mA ICC, and 100 µA ISB-guaranteed across this range. Thermal validation per Atmel Doc. 0570H confirms stable operation at 85°C case temperature with proper PCB copper pour and decoupling.
What is the purpose of the A9 and A0 pins during product identification mode on the AT27C020-90JU-T?
During product identification, A9 is driven to 11.5–12.5 V (VID) while A0 is toggled: low (VIL) selects the manufacturer ID byte (0x1E), and high (VIH) selects the device type code (0x86). All other address lines (A1–A17) must be held low. This dual-byte ID mechanism allows automated programmers to validate the exact AT27C020-90JU-T part before initiating programming.
Is the AT27C020-90JU-T pin-compatible with the AT27C020-90PU in a PDIP socket?
No, the AT27C020-90JU-T uses a 32-lead PLCC (32J) package, while the AT27C020-90PU uses a 32-lead PDIP (32P6). Though both have 32 pins and identical signal assignments, their mechanical footprints, lead pitch, and mounting methods are incompatible. Direct socket replacement requires PCB redesign to accommodate the AT27C020-90JU-T's J-lead geometry and land pattern.
AT27C020-90JU-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EPROM
- Technology:
- EPROM - OTP
- Memory Size:
- 2Mbit
- Memory Organization:
- 256K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 90 ns
- Voltage - Supply:
- 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)
AT27C020-90JU-T FAQ
1.How can I place an order for AT27C020-90JU-T through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C020-90JU-T 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 AT27C020-90JU-T reliable?
The price and inventory of AT27C020-90JU-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C020-90JU-T is usually 5 days.
3.What payment methods are accepted for AT27C020-90JU-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C020-90JU-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C020-90JU-T?
AT27C020-90JU-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C020-90JU-T 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 AT27C020-90JU-T?
For technical support, including AT27C020-90JU-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C020-90JU-T requirements.
6.How does Aetrix verify that AT27C020-90JU-T is sourced from the original manufacturer or authorized distributors?
All AT27C020-90JU-T 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 AT27C020-90JU-T meets industry standards.
7.What is the process for return or replacement of AT27C020-90JU-T?
All AT27C020-90JU-T units undergo pre-shipment inspection (PSI). If there is an issue with AT27C020-90JU-T, 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 AT27C020-90JU-T part is unused and in its original packaging.
Return procedure for AT27C020-90JU-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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