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Microchip Technology AT27C020-12JI
- Part No.:
- AT27C020-12JI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT27C020-12JI.pdf
- Description:
- IC EPROM 2MBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
AT27C020-12JI from Atmel is a 2-Mbit (256K × 8) one-time programmable EPROM designed for firmware storage in microprocessor systems. It delivers 55 ns read access time, operates from a single 5V ±10% supply, and supports industrial temperature range (–40°C to +85°C). Its dual-line control (CE/OE), CMOS/TTL compatibility, and Rapid™ programming (100 µs/byte) enable reliable boot code retention in embedded controllers and legacy industrial controllers.
For engineers reviewing the AT27C020-12JI datasheet, AT27C020-12JI pinout, AT27C020-12JI application, or AT27C020-12JI equivalent, key selection criteria include verified 55 ns access timing, industrial-grade VPP = 12.0 V programming voltage, JEDEC-standard 32-lead PLCC package (32J), and OTP reliability for unalterable firmware images in safety-critical or field-deployed systems.
Technical Context
The AT27C020-12JI implements a parallel-addressed OTP EPROM architecture with 18 address lines (A0–A17) and 8 bidirectional data outputs (O0–O7), enabling direct byte-level access without WAIT states. Its two-line enable scheme (CE active-low, OE active-low) provides bus contention control in shared-memory systems.
Programming uses a dedicated VPP = 12.0 V ±0.5 V supply and PGM strobe with 100 µs pulse width; device identification is accessed via A9 high-voltage mode (11.5–12.5 V) and A0 toggling to read manufacturer (0x1E) and device (0x86) codes. Standby current is specified at ≤100 µA, active current at ≤25 mA @ 5 MHz.
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 external paging logic. |
| Read Access Time | 55 ns max - eliminates WAIT states on 12–18 MHz Z80, 8051, or 68K-based systems requiring deterministic boot timing. |
| Supply Voltage | 5V ±10% - compatible with standard TTL/CMOS logic rails; no auxiliary voltage regulators required for read operation. |
| Programming Voltage (VPP) | 12.0 V ±0.5 V - requires dedicated HV programming circuitry; not derived from VCC during programming. |
| Operating Temperature | –40°C to +85°C - qualified for industrial control panels, motor drives, and factory automation equipment. |
| Standby Current | ≤100 µA - enables low-power retention in battery-backed or energy-constrained systems during idle periods. |
| ESD Protection | 2,000V HBM - ensures robustness during manual handling and PCB assembly in non-EPA environments. |
Pinout & Package
AT27C020-12JI is packaged in a 32-lead Plastic J-leaded Chip Carrier (PLCC), JEDEC MS-016 AE compliant, with 1.27 mm pitch and body size 18.5 × 18.5 mm. Pin 1 is marked by index notch and corner chamfer per JEDEC standard.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A17 | Address Inputs | 18-bit parallel address bus; selects one of 256K bytes; driven by CPU address lines with no decoding overhead. |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus; outputs valid within 55 ns after CE/OE assertion; high-impedance when disabled. |
| CE | Chip Enable | Active-low global chip select; controls device power state and output drivers; used for memory banking. |
| OE | Output Enable | Active-low output gate; allows multiple devices on same data bus without hardware bus transceivers. |
| PGM | Program Strobe | Active-low programming pulse input; initiates 100 µs write cycle when VPP = 12 V and address valid. |
| VPP | Programming Supply | 12 V input during programming only; must be applied simultaneously with or after VCC and removed before or with VCC. |
| VCC | Power Supply | +5 V main supply; powers logic and outputs; draws ≤25 mA active, ≤100 µA standby. |
| GND | Ground Reference | Signal and power return; requires local 0.1 µF ceramic decoupling per device per datasheet layout guidance. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time - reduces firmware update cycles in production programming stations by >5× vs. legacy EPROMs. |
| Integrated Product Identification Code | Manufacturer ID (0x1E) and Device ID (0x86) readable via A9/A0 voltage-select mode - enables automated programmer validation and BOM traceability. |
| Two-Line Control Architecture | Independent CE and OE inputs - permits flexible memory mapping and eliminates need for external bus arbitration logic in multi-peripheral systems. |
| JEDEC-Standard Packaging | 32J (PLCC), 32P6 (PDIP), 32T (TSOP) options - ensures drop-in replacement across board revisions and sourcing channels without footprint redesign. |
| High-Reliability Process | 200 mA latch-up immunity and 2,000 V ESD protection - sustains operation in electrically noisy industrial environments with minimal external protection. |
Applications
| Industrial PLC Firmware Storage | Legacy Medical Device Boot ROM |
|---|---|
Use Scenario: Storing immutable boot loader and safety-critical control logic in programmable logic controllers deployed in factory floors with wide ambient temperature swings and EMI exposure. IC Role / Device Role / Timing Role: Non-volatile firmware ROM providing deterministic 55 ns instruction fetch timing to 80C188 or 68EC000 CPUs during cold start and runtime recovery. Use Value: Eliminates reliance on slow serial EEPROM or volatile RAM + battery backup; withstands 85°C ambient and 200 mA transient currents without corruption. |
Use Scenario: Holding certified diagnostic firmware in Class II medical instruments (e.g., infusion pumps) where reprogramming is prohibited post-certification and long-term data retention is mandated. IC Role / Device Role / Timing Role: One-time programmable code storage ensuring firmware integrity over 10+ year product lifecycle; accessed only during power-on self-test (POST). Use Value: Meets IEC 62304 clause 5.5.3 for unalterable software storage; OTP prevents accidental or malicious firmware modification during service or calibration. |
| Automotive Engine Control Unit (ECU) Calibration Data | Avionics Display System Boot Image |
Use Scenario: Storing engine calibration maps and fail-safe routines in Tier-1 automotive ECUs operating across –40°C to +85°C under high vibration and conducted EMI. IC Role / Device Role / Timing Role: Read-only memory mapped into microcontroller address space for real-time lookup of fuel injection timing tables during closed-loop combustion control. Use Value: 55 ns access ensures sub-microsecond latency for critical timing decisions; 2,000 V ESD rating survives ISO 10605 discharge events on production test fixtures. |
Use Scenario: Hosting boot firmware for cockpit display processors in regional aircraft, where DO-254 compliance requires hardware-level firmware immutability and radiation tolerance verification. IC Role / Device Role / Timing Role: Primary boot ROM accessed by PowerPC 750 or ColdFire MCF54xx during cold start; provides secure initialization vector and memory test routines. Use Value: OTP architecture satisfies DO-254 Level A hardware assurance requirements for unchangeable configuration data; PLCC package supports manual rework in avionics repair depots. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C256B-12JC | 256K × 8 OTP EPROM; 120 ns access; 5V only; no integrated ID code; PLCC package. | Lacks Rapid™ programming (200 µs/byte typical); no manufacturer/device ID readback; lower speed limits use in >8 MHz systems. | Select when cost sensitivity outweighs speed and traceability needs; verify system timing margins with 120 ns tACC. |
| MX27C256-12J | 256K × 8 OTP EPROM; 120 ns access; 5V ±10%; PLCC; no VPP-controlled programming ID. | No high-voltage A9 mode for ID read; programming algorithm undocumented; limited industrial temp support (-25°C to +70°C). | Acceptable for commercial-grade replacements where firmware update frequency is zero and qualification testing is not required. |
Compared with AM27C256B-12JC and MX27C256-12J, the AT27C020-12JI offers faster 55 ns access, guaranteed 100 µs/byte programming, and electronic ID verification-critical for production line traceability and high-speed microcontroller interfacing in industrial and automotive contexts.
Availability
AT27C020-12JI is available at Aetrix Electronics and suitable for industrial PLCs, legacy medical devices, automotive ECUs, avionics displays, and factory automation systems requiring stable component supply, long-lifecycle support, and verified OTP reliability.
Supply support for AT27C020-12JI 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, non-volatile memory, and security ICs for industrial, automotive, and consumer applications.
The AT27C020 belongs to Atmel's 27C-series OTP EPROM product line, engineered for high-reliability firmware storage in systems where code immutability, fast read access, and industrial temperature operation are mandatory design requirements.
FAQ
What is the maximum read access time specification for AT27C020-12JI?
The AT27C020-12JI has a maximum read access time (tACC) of 55 ns under industrial temperature conditions (–40°C to +85°C) and VCC = 5V ±10%. This value is guaranteed across all operating corners and is measured from address/CE/OE assertion to valid data on O0–O7. The "-12" suffix explicitly denotes the 55 ns speed grade, confirmed in the Ordering Information table on page 9 of the datasheet.
Does AT27C020-12JI require a separate programming voltage, and what is its value?
Yes, the AT27C020-12JI requires a dedicated programming supply voltage (VPP) of 12.0 V ±0.5 V applied to the VPP pin during programming. This voltage is distinct from the 5V VCC supply and must be sequenced correctly: VPP must be applied simultaneously with or after VCC and removed simultaneously with or before VCC. The 12.0 V value is specified in the DC Programming Characteristics table (page 6) and is essential for oxide breakdown during byte programming.
Which package type does AT27C020-12JI use, and how is it identified in the ordering code?
The AT27C020-12JI uses the 32-lead Plastic J-leaded Chip Carrier (PLCC) package, designated as "32J" per Atmel's packaging nomenclature. This is confirmed in the Ordering Information table (page 9), where "JI" suffix indicates Industrial temperature range and PLCC package, and the package column explicitly lists "32J" for all -12JI variants. The physical dimensions and JEDEC MS-016 AE outline are detailed on page 10.
Can AT27C020-12JI be used in systems requiring extended temperature operation beyond –40°C to +85°C?
No, the AT27C020-12JI is rated exclusively for the industrial temperature range of –40°C to +85°C. For automotive applications requiring –40°C to +125°C, Atmel specifies the "JA" suffix variant (e.g., AT27C020-12JA). The -12JI's electrical characteristics-including tACC, ICC, and ISB-are only guaranteed within its stated industrial range; operation outside this range may result in timing violations or data corruption.
How is the manufacturer and device identification code read from AT27C020-12JI?
The AT27C020-12JI's Integrated Product Identification Code is read by applying 11.5–12.5 V to A9 while holding A1–A17 low, then toggling A0: low (VIL) reads the Manufacturer ID (0x1E), and high (VIH) reads the Device ID (0x86). This mode is documented in the Operating Modes table (page 3) and the Product Identification section (page 8). No special programming hardware is needed-only controlled VPP and A9 voltage sequencing.
AT27C020-12JI 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:
- 120 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)
AT27C020-12JI FAQ
1.How can I place an order for AT27C020-12JI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C020-12JI 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 AT27C020-12JI reliable?
The price and inventory of AT27C020-12JI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C020-12JI is usually 5 days.
3.What payment methods are accepted for AT27C020-12JI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C020-12JI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C020-12JI?
AT27C020-12JI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C020-12JI 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 AT27C020-12JI?
For technical support, including AT27C020-12JI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C020-12JI requirements.
6.How does Aetrix verify that AT27C020-12JI is sourced from the original manufacturer or authorized distributors?
All AT27C020-12JI 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 AT27C020-12JI meets industry standards.
7.What is the process for return or replacement of AT27C020-12JI?
All AT27C020-12JI units undergo pre-shipment inspection (PSI). If there is an issue with AT27C020-12JI, 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 AT27C020-12JI part is unused and in its original packaging.
Return procedure for AT27C020-12JI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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