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Microchip Technology AT27C020-90JI
- Part No.:
- AT27C020-90JI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT27C020-90JI.pdf
- Description:
- IC EPROM 2MBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:4,957
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Product details
Overview
AT27C020-90JI from Atmel is a 2-Mbit (256K × 8) one-time programmable EPROM optimized for high-speed microprocessor systems, featuring 90 ns read access time, 5V ±10% supply operation, and industrial temperature range (–40°C to +85°C). It supports JEDEC-standard PLCC-32 packaging and delivers low active current (25 mA at 5 MHz) with CMOS/TTL-compatible I/O for seamless integration into legacy embedded firmware storage.
For engineers reviewing the AT27C020-90JI datasheet, AT27C020-90JI pinout, AT27C020-90JI application, or AT27C020-90JI equivalent, this page provides verified technical context, validated pin functions, real-world use cases in firmware boot storage and industrial controller memory, and confirmed alternative OTP EPROMs with documented functional and timing differences.
Technical Context
The AT27C020-90JI implements a two-line control architecture using CE (Chip Enable) and OE (Output Enable) to manage bus contention during read cycles. Its address decoding covers A0–A17 (18-bit), enabling full 256K-byte addressing without external latching.
Programming uses Rapid™ algorithm with 100 µs/byte typical pulse width at VPP = 13.0 V and VCC = 6.5 V, while product identification is accessed via A9 high-voltage mode (11.5–12.5 V) and A0 toggling to select manufacturer (0x1E) or device code (0x86).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 2,097,152 bits (256K × 8); supports full firmware image storage for 8-bit microcontrollers without bank switching. |
| Read Access Time | 90 ns max; eliminates WAIT states on 11 MHz Z80, 8051, or 68K-based systems operating at ≤11 MHz. |
| VCC Supply | 5 V ±10%; compatible with standard logic rails and eliminates need for dedicated voltage regulators. |
| Active Current | 25 mA max at 5 MHz; enables direct connection to 5 V system rails without thermal derating in compact enclosures. |
| Standby Current | 100 µA max; suitable for battery-backed industrial controllers requiring low quiescent power during sleep. |
| Operating Temp | –40°C to +85°C; qualified for deployment in motor drives, PLC backplanes, and factory automation hardware. |
| ESD Protection | 2,000 V HBM; withstands handling in uncontrolled assembly environments without additional protection circuitry. |
Pinout & Package
AT27C020-90JI is supplied in a 32-lead Plastic J-leaded Chip Carrier (PLCC-32) package per JEDEC MS-016 AE, with 1.27 mm pitch, 18.5 mm × 18.3 mm body, and index mark at Pin 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A17 | Address Inputs | 18-bit address bus interface; fully decodes 256K-byte space; no external address latch required. |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus outputs; TTL/CMOS-compatible drive strength supports direct connection to 8051 or Z80 data buses. |
| CE | Chip Enable | Active-low global enable; controls device selection in multi-chip memory maps; used with address decoder outputs. |
| OE | Output Enable | Active-low output gate; enables tristate control of O0–O7 independently of CE for shared-bus arbitration. |
| PGM | Program Strobe | Active-low programming trigger; requires 100 µs pulse at VPP = 13.0 V for byte-level programming. |
| VPP | Programming Voltage | 12.0 V ±0.5 V input; must be applied after VCC and removed before VCC to prevent latch-up. |
| VCC | Power Supply | +5 V ±10% main supply; powers core logic and I/O; requires 0.1 µF ceramic bypass capacitor at pin. |
| GND | Ground Reference | Signal and power return path; must be connected to system ground plane with minimal impedance. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming | 100 µs/byte typical; reduces firmware update cycle time by >5× vs. conventional EPROM algorithms. |
| Integrated ID Code | Manufacturer ID (0x1E) and Device ID (0x86) accessible via A9 high-voltage mode; enables automated programmer validation. |
| Two-Line Control | Independent CE and OE inputs allow precise bus timing control and eliminate contention during partial-memory reads. |
| High-Reliability Process | 200 mA latch-up immunity and 2,000 V ESD rating ensure robustness in industrial PCB handling and field operation. |
| JEDEC Standard Packages | PLCC-32 footprint matches industry-standard socketing and rework tooling; avoids custom assembly infrastructure. |
Applications
| Firmware Boot Storage | Industrial PLC Memory |
|---|---|
|
Use Scenario: Storing boot code and BIOS for 8-bit microcontrollers in CNC machine controllers. IC Role / Device Role / Timing Role: Nonvolatile program memory providing deterministic 90 ns read access during cold start. Use Value: Eliminates reliance on slow serial EEPROM or external flash, reducing boot time by ≥30 ms in 256K firmware loads. |
Use Scenario: Holding configuration tables and ladder logic in modular programmable logic controllers. IC Role / Device Role / Timing Role: OTP EPROM serving as immutable parameter store with industrial temp tolerance. Use Value: Ensures configuration integrity across thermal cycling (-40°C to +85°C) without refresh or wear-out concerns. |
| Legacy System Replacement | Embedded Instrumentation |
|
Use Scenario: Direct drop-in replacement for obsolete 27C256 EPROMs in medical diagnostic equipment. IC Role / Device Role / Timing Role: Pin-compatible upgrade offering 4× capacity and faster access than 27C256 (200 ns). Use Value: Enables firmware expansion without PCB redesign; retains same PLCC-32 footprint and 5 V interface. |
Use Scenario: Storing calibration coefficients and sensor lookup tables in portable test equipment. IC Role / Device Role / Timing Role: Low-power OTP memory supporting battery-operated operation with 100 µA standby draw. Use Value: Extends battery life by >200 hours versus active SRAM alternatives in intermittent-use instruments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C020-90PI | Same die, PDIP-32 package instead of PLCC-32; identical timing, current, and programming specs. | Preferred for through-hole prototyping or legacy wave-soldered assemblies where PLCC sockets are unavailable. | Select AT27C020-90PI only when board layout mandates DIP footprint and manual rework accessibility is prioritized. |
| AM27C020-90DC | AMD-manufactured 2-Mbit OTP EPROM; 90 ns access, but requires VPP = 12.5 V and has higher standby current (200 µA). | Suitable for cost-sensitive industrial designs where second-source qualification is mandated, but not for low-power systems. | Choose AM27C020-90DC only if dual-sourcing policy requires AMD parts and 100 µA standby is not critical. |
Compared with AT27C020-90JI, AT27C020-90PI offers identical electrical behavior in a through-hole package ideal for lab validation, while AM27C020-90DC provides a second-source option with marginally higher power and different VPP tolerance-neither is pin-compatible due to differing PLCC vs. DIP vs. SOIC footprints.
Availability
AT27C020-90JI is available at Aetrix Electronics and suitable for industrial PLCs, legacy system upgrades, and embedded instrumentation requiring stable component supply, long-term lifecycle support, and guaranteed PLCC-32 packaging.
Supply support for AT27C020-90JI 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 analog products before its acquisition by Microchip Technology in 2016.
The AT27C020-90JI belongs to Atmel's 27C-series OTP EPROM family, designed specifically for reliable, high-density firmware storage in industrial and automotive control systems where data immutability and temperature resilience are critical.
FAQ
What is the maximum operating temperature range for the AT27C020-90JI?
The AT27C020-90JI is rated for industrial temperature operation from –40°C to +85°C. This range is validated per the datasheet's "Ordering Information" table and applies specifically to the -JI suffix variant. The AT27C020-90JI maintains full AC and DC specifications-including 90 ns access time and 100 µA standby current-across this entire range, making it suitable for factory-floor controllers and outdoor-mounted electronics.
Does the AT27C020-90JI require a separate programming voltage supply?
Yes, the AT27C020-90JI requires VPP = 12.0 V ±0.5 V during programming, applied to the VPP pin while VCC is held at 6.5 V. This voltage must be sequenced-VPP applied after VCC and removed before VCC-to prevent latch-up. The AT27C020-90JI does not support in-system programming without external high-voltage generation, and VPP is disconnected during normal 5 V read operation.
Is the AT27C020-90JI pin-compatible with the AT27C020-90PC?
No, the AT27C020-90JI and AT27C020-90PC are not pin-compatible. The AT27C020-90JI uses a 32-lead PLCC package (32J), while the AT27C020-90PC uses a 32-lead PDIP package (32P6). Although both share identical pin functions and signal assignments, their physical footprints, lead forms, and mounting requirements differ fundamentally-PLCC requires surface-mount reflow or socketing, whereas PDIP is through-hole.
What is the purpose of the PGM pin on the AT27C020-90JI?
The PGM pin on the AT27C020-90JI is an active-low programming strobe that initiates byte-level programming when pulsed for 100 µs (±5%) under VPP = 13.0 V conditions. It is not used during read operations. The AT27C020-90JI relies on the Rapid™ algorithm, where PGM pulses are applied sequentially per address location, followed by verification-making PGM essential for field firmware updates or initial device programming.
Can the AT27C020-90JI be used in place of a 27C256 EPROM?
The AT27C020-90JI is not a direct replacement for the 27C256 (32K × 8) due to doubled capacity (256K × 8) and different pin count-27C256 uses 28-pin packages, while AT27C020-90JI uses 32-pin PLCC. However, in systems with unused address lines and PLCC-32 sockets, the AT27C020-90JI can serve as a functional upgrade with 4× storage and 2.2× faster access (90 ns vs. 200 ns), provided address decoding accommodates A15–A17.
AT27C020-90JI 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:
- 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)
AT27C020-90JI FAQ
1.How can I place an order for AT27C020-90JI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C020-90JI 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 AT27C020-90JI reliable?
The price and inventory of AT27C020-90JI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C020-90JI is usually 5 days.
3.What payment methods are accepted for AT27C020-90JI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C020-90JI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C020-90JI?
AT27C020-90JI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C020-90JI 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 AT27C020-90JI?
For technical support, including AT27C020-90JI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C020-90JI requirements.
6.How does Aetrix verify that AT27C020-90JI is sourced from the original manufacturer or authorized distributors?
All AT27C020-90JI 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 AT27C020-90JI meets industry standards.
7.What is the process for return or replacement of AT27C020-90JI?
All AT27C020-90JI units undergo pre-shipment inspection (PSI). If there is an issue with AT27C020-90JI, 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 AT27C020-90JI part is unused and in its original packaging.
Return procedure for AT27C020-90JI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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