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Microchip Technology AT27C020-12PI
- Part No.:
- AT27C020-12PI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-DIP (0.600", 15.24mm)
- Datasheet:
-
AT27C020-12PI.pdf
- Description:
- IC EPROM 2MBIT PARALLEL 32DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,561
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Product details
Overview
AT27C020-12PI 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 on a single 5V ±10% supply, and supports industrial temperature range (–40°C to +85°C) in a 32-lead PDIP package. It enables high-speed, low-latency code execution without WAIT states in embedded controllers and legacy instrumentation.
For engineers reviewing the AT27C020-12PI datasheet, AT27C020-12PI pinout, AT27C020-12PI application, or AT27C020-12PI equivalent, key selection criteria include OTP reliability, 5V-only read operation, rapid programming algorithm (100 µs/byte), CMOS/TTL compatibility, and JEDEC-standard PDIP packaging with dual-line control (CE/OE).
Technical Context
The AT27C020-12PI implements a parallel-addressed OTP memory architecture with 18 address lines (A0–A17) and 8 bidirectional data outputs (O0–O7). Its two-line enable scheme (CE and OE) allows precise bus contention control during read cycles, while PGM and VPP pins support 13.0V programming with Rapid™ algorithm verification loops.
It uses high-reliability CMOS technology featuring 2,000V ESD protection and 200 mA latch-up immunity. In active read mode at 5 MHz, it draws ≤25 mA; standby current is ≤100 µA, with typical consumption of 8 mA (read) and <10 µA (standby).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 2,097,152 bits (256K × 8) - supports full firmware images for 8-bit microcontrollers without external banking logic |
| Read Access Time | 120 ns max (–12 speed grade) - ensures compatibility with 8-MHz Z80, 68K, and early ARM7 bus timing |
| Supply Voltage | 5V ±10% - eliminates need for auxiliary voltage rails in legacy 5V system designs |
| Operating Temperature | –40°C to +85°C - qualified for industrial control, motor drives, and telecom line cards |
| Programming Voltage | VPP = 13.0V ±0.25V - requires dedicated programming hardware; not compatible with standard 5V-only programmers |
| Input Compatibility | CMOS- and TTL-compatible I/O - interoperates directly with 74LS, 74HC, and microcontroller GPIO without level shifters |
| ESD/Latch-up | 2,000V HBM ESD; 200 mA latch-up immunity - enhances field reliability in unshielded industrial environments |
Pinout & Package
AT27C020-12PI is supplied in a 32-lead, 0.600" wide plastic dual in-line package (PDIP), per JEDEC MS-016 AE. Pin 1 is marked by a notch or dot; package height is 0.195" (4.95 mm), with 0.1" lead pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A17 | Address Inputs | 18-bit parallel address bus; selects one of 256K bytes; A17 is MSB for full 2-Mbit decoding |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus; outputs valid within 120 ns after CE/OE assertion; high-impedance when disabled |
| CE | Chip Enable | Active-low global enable; must be low before OE to avoid bus contention; controls power state transition |
| OE | Output Enable | Active-low output gate; decouples memory from data bus during DMA or interrupt servicing |
| PGM | Program Strobe | Active-low pulse input (100 µs width); initiates byte programming cycle when VPP = 13V and CE = low |
| VPP | Programming Supply | 13.0V programming voltage input; must be applied after VCC and removed before VCC per sequencing rules |
| VCC | Power Supply | +5V ±10% main supply; powers logic and outputs; requires 0.1 µF ceramic bypass capacitor at pin |
| GND | Ground | Signal and power reference; separate ground plane recommended for noise-sensitive applications |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time with automatic verify-and-reprogram loop up to 10 pulses per byte |
| Integrated Product ID Code | Manufacturer ID (0x1E) and Device Code (0x86) readable via A9/VH and A0 toggle - enables auto-detection in universal programmers |
| Two-Line Control Architecture | Independent CE and OE inputs allow flexible bus arbitration, enabling shared data bus with peripherals or multiple EPROMs |
| Low-Power Standby | ≤100 µA max ICC in standby (CE high) - suitable for battery-backed or energy-conscious industrial modules |
| JEDEC-Standard Packaging | 32P6 PDIP footprint ensures drop-in replacement for legacy 27C256, 27C512, and other 32-pin EPROMs |
Applications
| Industrial PLC Firmware Storage | Legacy Microcontroller Boot ROM |
|---|---|
Use Scenario: Fixed logic firmware for ladder-logic execution engines in programmable logic controllers requiring long-term data retention without reprogramming. IC Role / Device Role / Timing Role: Non-volatile boot and runtime instruction store accessed via 8-bit parallel bus; provides deterministic 120 ns read latency for real-time scan cycles. Use Value: Eliminates reliance on volatile RAM + battery backup; withstands industrial vibration, EMI, and thermal cycling over 10+ year deployments. |
Use Scenario: Bootloader and kernel image storage for Z80, 8085, or 68000-based embedded systems where flash memory was unavailable or unreliable. IC Role / Device Role / Timing Role: Primary code memory mapped into CPU address space; supports zero-wait-state execution at 4–8 MHz clock rates. Use Value: Guarantees bit-perfect firmware integrity across power cycles; avoids firmware corruption risks inherent in early EEPROM technologies. |
| Telecom Line Card Configuration | Automated Test Equipment (ATE) Pattern Memory |
Use Scenario: Storing calibration tables, protocol stacks, and hardware configuration data in T1/E1 interface cards operating in controlled but thermally variable environments. IC Role / Device Role / Timing Role: Read-only configuration database accessed during initialization and diagnostics; supports burst reads via CE/OE handshaking. Use Value: Delivers guaranteed data retention >20 years; immune to radiation-induced bit flips common in telecom central offices. |
Use Scenario: Holding fixed test pattern sequences for digital IC functional testing where pattern stability and repeatability are critical. IC Role / Device Role / Timing Role: High-speed pattern source synchronized to ATE timing controller; outputs stable data within 120 ns of address assertion. Use Value: Enables sub-microsecond pattern turnaround; eliminates jitter introduced by serial interfaces or DRAM refresh cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C020-12JC | Same die, 32-lead PLCC package; no heatsink pad; higher thermal resistance | Preferred for surface-mount PCBs with space constraints; unsuitable for through-hole prototyping | Select when board assembly uses automated SMT and thermal management permits PLCC's lower power dissipation margin |
| AT27C020-12TI | Same die, 32-lead TSOP package; thinner profile (1.2 mm); tighter pin pitch (0.5 mm) | Used in compact portable or modular test equipment; requires fine-pitch routing and reflow profiling | Choose for space-constrained industrial modules where PDIP socket height or PLCC footprint is prohibitive |
Compared with AT27C020-12PI, the -12JC offers SMT compatibility at the cost of manual rework difficulty, while the -12TI enables ultra-thin designs but demands precision layout and thermal derating - the -12PI remains optimal for through-hole prototyping, field serviceability, and legacy board upgrades.
Availability
AT27C020-12PI is available at Aetrix Electronics and suitable for industrial control systems, legacy microcontroller upgrades, and telecom infrastructure requiring stable component supply, long-lifecycle support, and JEDEC-standard PDIP compatibility.
Supply support for AT27C020-12PI 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 semiconductor manufacturer specializing in microcontrollers, non-volatile memory, and secure authentication devices.
The AT27C020 series was developed to provide high-reliability, low-power OTP EPROMs for firmware storage in industrial, automotive, and telecom applications where flash endurance or EEPROM write latency were unacceptable.
FAQ
What is the maximum operating frequency supported by the AT27C020-12PI?
The AT27C020-12PI does not specify a maximum clock frequency because it is an asynchronous memory device. Its timing is governed by access parameters: tACC ≤ 120 ns, tCE ≤ 120 ns, and tOE ≤ 35 ns. When interfaced with a microprocessor running at ≤8.3 MHz (120 ns period), the AT27C020-12PI operates without WAIT states. Higher-frequency CPUs require insertion of wait states or use of faster speed grades like –90 or –70.
Can the AT27C020-12PI be reprogrammed after initial programming?
No, the AT27C020-12PI is a one-time programmable (OTP) EPROM. Once programmed, its contents cannot be electrically erased or rewritten. The oxide breakdown mechanism used during programming is irreversible. For field-upgradable firmware, consider flash alternatives such as the AT29C020 or modern Microchip SST39VFxxxF devices instead of the AT27C020-12PI.
What is the purpose of the VPP pin on the AT27C020-12PI?
The VPP pin on the AT27C020-12PI supplies +13.0V ±0.25V during programming operations only. It enables the high-voltage Fowler-Nordheim tunneling required to permanently program the floating-gate transistors. During normal 5V read operation, VPP must be tied to VCC (5V) or left unconnected per datasheet guidance - applying 13V during read will damage the AT27C020-12PI.
Does the AT27C020-12PI require external pull-up resistors on its output pins?
No, the AT27C020-12PI features active pull-up circuitry on its O0–O7 outputs and does not require external pull-ups. Its VOH is specified at ≥2.4V with IOH = –400 µA, and VOL ≤ 0.4V with IOL = 2.1 mA, ensuring direct compatibility with TTL and CMOS logic families. External pull-ups may cause excessive current draw or signal integrity issues and are unnecessary for the AT27C020-12PI.
How is the Integrated Product Identification Code read from the AT27C020-12PI?
The AT27C020-12PI identification code is read by asserting VPP = 12.0V ±0.5V, holding A1–A17 = VIL, setting A9 = VH (12V), and toggling A0 between VIL (to read Manufacturer ID 0x1E) and VIH (to read Device Code 0x86). Outputs O0–O7 reflect the 8-bit code. This feature enables automatic device detection in programming tools and avoids manual part selection errors for the AT27C020-12PI.
AT27C020-12PI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-DIP (0.600", 15.24mm)
- 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:
- Through Hole
- Supplier Device Package:
- 32-PDIP
AT27C020-12PI FAQ
1.How can I place an order for AT27C020-12PI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C020-12PI 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 AT27C020-12PI reliable?
The price and inventory of AT27C020-12PI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C020-12PI is usually 5 days.
3.What payment methods are accepted for AT27C020-12PI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C020-12PI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C020-12PI?
AT27C020-12PI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C020-12PI 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 AT27C020-12PI?
For technical support, including AT27C020-12PI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C020-12PI requirements.
6.How does Aetrix verify that AT27C020-12PI is sourced from the original manufacturer or authorized distributors?
All AT27C020-12PI 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 AT27C020-12PI meets industry standards.
7.What is the process for return or replacement of AT27C020-12PI?
All AT27C020-12PI units undergo pre-shipment inspection (PSI). If there is an issue with AT27C020-12PI, 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 AT27C020-12PI part is unused and in its original packaging.
Return procedure for AT27C020-12PI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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