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Microchip Technology AT27C020-70PI
- Part No.:
- AT27C020-70PI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-DIP (0.600", 15.24mm)
- Datasheet:
-
AT27C020-70PI.pdf
- Description:
- IC EPROM 2MBIT PARALLEL 32DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,425
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Product details
Overview
AT27C020-70PI from Atmel is a 2-Mbit (256K × 8) one-time programmable EPROM designed for firmware storage in microprocessor systems. It delivers 70 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. Used in embedded boot code storage where non-volatility, reliability, and TTL/CMOS compatibility are required.
For engineers reviewing the AT27C020-70PI datasheet, AT27C020-70PI pinout, AT27C020-70PI application, or AT27C020-70PI equivalent, key selection criteria include read speed (70 ns), OTP programming integrity, VPP-dependent programming voltage (12.0 V), industrial-grade thermal operation, and JEDEC-standard 32P6 PDIP footprint compatibility.
Technical Context
The AT27C020-70PI implements a two-line control architecture using CE (Chip Enable) and OE (Output Enable) to manage bus contention and output tri-state behavior. Its address space spans A0–A17 (18-bit), supporting full 256K-byte decoding with byte-wide parallel outputs O0–O7.
Programming uses Rapid™ algorithm with 100 µs/byte typical pulse width at VPP = 12.0 V and VCC = 6.5 V; verification occurs per-byte with up to 10 reprogramming attempts before failure declaration. Product identification is enabled via A9 high-voltage (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 external banking logic. |
| Read Access Time | 70 ns max - eliminates WAIT states in 5 MHz Z80, 8051, or 68K-based systems requiring deterministic timing. |
| Supply Voltage | 5V ±10% - compatible with standard logic rails; no auxiliary voltage regulators needed in read mode. |
| Standby Current | 100 µA max - enables low-power retention in battery-backed or intermittently powered systems. |
| Programming Voltage (VPP) | 12.0 V ±0.5 V - requires dedicated programming circuitry; not compatible with standard 5V-only programmers. |
| Operating Temperature | −40°C to +85°C - qualified for industrial control, motor drives, and factory automation environments. |
| ESD Protection | 2,000 V HBM - reduces handling sensitivity during manual PCB assembly or field replacement. |
Pinout & Package
AT27C020-70PI is supplied in a 32-lead, 0.600" wide plastic dual inline package (PDIP), designated 32P6 per JEDEC MS-016AE. Pin 1 is marked by a notch or dot; package height ≤ 0.220", width ≈ 0.630", and lead pitch = 0.100".
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A17 | Address Inputs | 18-bit address bus interface; fully decoded to access any of 256K bytes without external address latching. |
| O0–O7 | Data Outputs | True TTL/CMOS-compatible bidirectional data bus drivers; high-impedance when CE or OE inactive. |
| CE | Chip Enable | Active-low global enable; must be asserted before OE to avoid bus contention in multi-device systems. |
| OE | Output Enable | Active-low output gate; allows shared data bus operation with other memory/peripheral devices. |
| PGM | Program Strobe | Active-low programming control; initiates 100 µs pulse-driven write cycle only when VPP = 12 V applied. |
| VPP | Programming Voltage | 12 V input pin; must be ramped after VCC and ramped down before VCC to prevent latch-up or data corruption. |
| VCC | Power Supply | 5 V main supply; powers all logic and output drivers; requires local 0.1 µF ceramic decoupling per device. |
| GND | Ground Reference | Signal and power return; must be connected to low-impedance ground plane to maintain timing integrity. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time - reduces production burn-in cycle duration by >90% vs. legacy EPROMs. |
| Integrated Product ID Code | Manufacturer ID (0x1E) and Device Code (0x86) readable via A9/A0 - enables automated programmer validation and BOM traceability. |
| Two-Line Control (CE/OE) | Independent chip and output gating - permits flexible memory mapping and avoids bus conflicts in dense peripheral layouts. |
| 200 mA Latch-up Immunity | Withstands transient overcurrent events - improves robustness in noisy industrial power environments with shared ground returns. |
| JEDEC Standard Packages | 32P6 PDIP footprint - ensures drop-in compatibility with legacy sockets, test fixtures, and hand-soldered prototyping boards. |
Applications
| Industrial PLC Firmware Storage | Legacy Microcontroller Boot ROM |
|---|---|
Use Scenario: Storing ladder logic interpreter and I/O configuration in modular programmable logic controllers operating in factory-floor environments. IC Role / Device Role / Timing Role: Non-volatile boot memory providing deterministic 70 ns instruction fetch timing for real-time scan-cycle execution. Use Value: Eliminates reliance on slow serial EEPROM or unreliable battery-backed SRAM; withstands −40°C cold starts and 85°C cabinet temperatures. |
Use Scenario: Holding initialization code and interrupt vectors for 8051 or Z80-based instrumentation front-ends with no external memory controller. IC Role / Device Role / Timing Role: Parallel-addressed ROM delivering zero-wait-state opcode reads synchronized to system clock. Use Value: Enables direct CPU address bus connection without glue logic; supports TTL-level signaling for legacy board designs. |
| Automotive ECU Calibration Data | Medical Device Diagnostic Firmware |
Use Scenario: Storing engine calibration maps and diagnostic routines in Tier-1 automotive ECUs certified for −40°C to +125°C operation (via -A variants; -PI supports industrial range). IC Role / Device Role / Timing Role: OTP memory ensuring tamper-resistant, unalterable firmware post-deployment. Use Value: Prevents unauthorized field updates while maintaining JEDEC-pin compatibility for design reuse across temperature grades. |
Use Scenario: Hosting self-test sequences and regulatory-compliant diagnostic routines in Class II medical devices requiring long-term data retention. IC Role / Device Role / Timing Role: High-reliability firmware store with 2,000 V ESD protection for safe handling during service and repair. Use Value: Meets IEC 60601-1 creepage/clearance requirements via robust CMOS process and verified latch-up immunity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C020-70JI | Same die, PLCC (32J) package instead of PDIP; identical timing, voltage, and programming specs. | Surface-mount assembly; requires reflow profile validation and PCB land pattern change. | Select when board space constraints or automated assembly favor SMT over through-hole. |
| AM27C256B-120DC | 256K × 8 OTP EPROM with 120 ns access; 5 V only (no VPP); TTL-compatible but lacks Rapid™ programming or ID code. | Lower-cost alternative where programming speed and traceability are non-critical. | Choose only if 120 ns read latency is acceptable and VPP-free programming simplifies tooling. |
Compared with AT27C020-70JI, the AT27C020-70PI offers identical functionality in through-hole PDIP for legacy socketed designs, while AM27C256B-120DC trades speed and programmability for simpler voltage requirements - making it suitable only where timing margins allow and ID verification is unnecessary.
Availability
AT27C020-70PI is available at Aetrix Electronics and suitable for industrial control systems, legacy microcontroller platforms, and medical diagnostic equipment requiring stable component supply across extended product lifecycles.
Supply support for AT27C020-70PI 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, was a leading designer of non-volatile memory and microcontroller solutions, known for high-reliability industrial and automotive-grade ICs.
The AT27C020 belongs to Atmel's OTP EPROM product line, engineered specifically for firmware storage in resource-constrained embedded systems where data integrity, long-term retention, and JEDEC-standard packaging are mandatory.
FAQ
What is the maximum read access time specified for the AT27C020-70PI?
The AT27C020-70PI has a maximum read access time of 70 ns under standard conditions (VCC = 5 V, TA = −40°C to +85°C). This value is guaranteed across the full industrial temperature range and applies to both CE- and OE-controlled access paths, enabling integration into 5 MHz microprocessor buses without wait-state insertion. The AT27C020-70PI achieves this performance using optimized CMOS decoding and output driver design.
Does the AT27C020-70PI require a programming voltage higher than VCC?
Yes, the AT27C020-70PI requires VPP = 12.0 V ±0.5 V during programming, which is distinct from its 5 V read-mode supply. This elevated voltage is applied to the VPP pin only during PGM strobe pulses and must be sequenced after VCC application and before VCC removal to prevent data corruption. The AT27C020-70PI does not support in-system programming without external VPP generation.
Can the AT27C020-70PI be used in place of the AT27C020-55PC?
No - the AT27C020-70PI and AT27C020-55PC differ in both speed grade (70 ns vs. 55 ns) and package (32P6 PDIP vs. 32P6 PDIP), but more critically, the -55PC is rated for commercial temperature (0°C to +70°C), whereas the AT27C020-70PI is rated for industrial range (−40°C to +85°C). Substituting the AT27C020-70PI in a commercial-design system may incur unnecessary cost and qualification overhead unless extended temperature operation is required.
What is the purpose of the PGM pin on the AT27C020-70PI?
The PGM pin on the AT27C020-70PI is an active-low programming strobe that initiates the 100 µs byte-programming pulse when VPP = 12 V is present. It is not used during read operations. The AT27C020-70PI relies on precise timing between PGM, CE, and address setup to execute the Rapid™ algorithm, and improper PGM pulse width or sequencing will result in incomplete or failed programming. This pin must be driven by a certified EPROM programmer.
How is the product identification code accessed on the AT27C020-70PI?
The AT27C020-70PI provides a two-byte identification code: Manufacturer ID (0x1E) and Device Code (0x86). To read it, A9 must be driven to 11.5–12.5 V (VID), A0 toggled between low and high, and all other address lines held low (VIL). The AT27C020-70PI outputs the selected byte on O0–O7 during normal read cycles with CE and OE asserted - a feature used by automated programmers for algorithm auto-selection and traceability logging.
AT27C020-70PI 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:
- 70 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
AT27C020-70PI FAQ
1.How can I place an order for AT27C020-70PI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C020-70PI 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 AT27C020-70PI reliable?
The price and inventory of AT27C020-70PI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C020-70PI is usually 5 days.
3.What payment methods are accepted for AT27C020-70PI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C020-70PI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C020-70PI?
AT27C020-70PI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C020-70PI 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 AT27C020-70PI?
For technical support, including AT27C020-70PI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C020-70PI requirements.
6.How does Aetrix verify that AT27C020-70PI is sourced from the original manufacturer or authorized distributors?
All AT27C020-70PI 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 AT27C020-70PI meets industry standards.
7.What is the process for return or replacement of AT27C020-70PI?
All AT27C020-70PI units undergo pre-shipment inspection (PSI). If there is an issue with AT27C020-70PI, 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 AT27C020-70PI part is unused and in its original packaging.
Return procedure for AT27C020-70PI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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