Microchip Technology AT29C020-70JI

Overview

AT29C020-70JI from Atmel is a 2-Mbit (256K × 8) 5V-only Flash memory IC used for nonvolatile code and data storage in embedded systems. It delivers 70 ns read access time, supports sector-based reprogramming with 1024 × 256-byte sectors, features hardware/software data protection, and operates across -40°C to +85°C industrial temperature range - ideal for firmware storage in industrial controllers and boot loaders.

For engineers reviewing the AT29C020-70JI datasheet, AT29C020-70JI pinout, AT29C020-70JI application, or AT29C020-70JI equivalent, key selection considerations include its 5V-only operation, 10 ms sector program cycle, DATA polling and toggle-bit programming status detection, dual 8K boot block lockout, and PLCC-32 packaging for legacy board compatibility.

Technical Context

The AT29C020-70JI implements a sector-erase/program architecture where each 256-byte sector is internally latched before simultaneous programming, freeing the address/data bus during t_WC = 10 ms. It uses standard EPROM-like read timing with CE/OE dual enable control and supports byte-load programming via WE or CE pulse sequencing.

Hardware data protection includes V_CC sense (<3.8 V inhibits programming), 5 ms power-on delay, and noise filtering (<15 ns pulses ignored); software protection requires a 3-byte command sequence (AAh/55h/A0h at 5555h/2AAAh/5555h) to enable/disable write operations. Boot block lockout is independently configurable for the first and last 8K bytes using a 7-command algorithm.

Key Specifications

Pinout & Package

AT29C020-70JI is packaged in a 32-lead Plastic J-Leaded Chip Carrier (PLCC-32), compliant with JEDEC MS-016 Variation AE, with lead coplanarity ≤0.102 mm and body dimensions 12.45 mm × 14.95 mm × 3.35 mm (max height).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Flash memory applications.

Compared with AM29LV020B-70JC and MX29LV020CTI-70G, the AT29C020-70JI offers true 5 V-only operation, hardware-enforced boot block lockout, and proven legacy system compatibility - making it the preferred choice for maintaining existing industrial and telecom hardware without redesign.

Availability

AT29C020-70JI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy embedded system boot memory, and telecom line card configuration requiring stable component supply and long-term obsolescence management.

Supply support for AT29C020-70JI 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, nonvolatile memory, and secure authentication ICs.

The AT29C020-70JI belongs to Atmel's legacy 5V Flash memory product line, engineered for drop-in EPROM replacement in industrial, telecom, and embedded systems where reliability, in-system reprogrammability, and wide temperature operation were critical.

FAQ

What is the operating temperature range for the AT29C020-70JI?

The AT29C020-70JI is rated for industrial temperature operation from -40°C to +85°C. This specification is confirmed in the Ordering Information table and DC Operating Range section of the datasheet, where "I" suffix denotes industrial grade. The device maintains full functionality-including 70 ns read access and 10 ms sector programming-across this full range, making it suitable for deployment in harsh environmental conditions without derating.

Does the AT29C020-70JI require a high-voltage programming supply?

No, the AT29C020-70JI operates with a single 5 V ±10% supply for both read and program operations. Unlike older EPROMs or some early Flash devices, it does not require +12 V (VPP) for programming. All programming commands-including sector erase, byte load, and software data protection-are executed using standard 5 V logic levels, as explicitly stated in the Features and Device Operation sections of the datasheet.

How many sectors does the AT29C020-70JI have, and what is the size of each sector?

The AT29C020-70JI contains 1024 sectors, each 256 bytes in size. This is clearly specified in the Features section ("1024 Sectors (256 Bytes/Sector)") and reinforced in the Description ("Reprogramming the AT29C020 is performed on a sector basis; 256 bytes of data are loaded into the device and then simultaneously programmed"). Sector addressing uses A8–A17, enabling precise targeting of any 256-byte region for update.

What package type is used for the AT29C020-70JI?

The AT29C020-70JI uses a 32-lead Plastic J-Leaded Chip Carrier (PLCC-32) package, identified by the "J" suffix in the ordering code and detailed in the Packaging Information section (Drawing No. 32J). Its dimensions conform to JEDEC MS-016 Variation AE, with body size 12.45 mm × 14.95 mm and maximum height 3.35 mm. Pin 1 is marked by a corner notch on the PLCC body.

Can the AT29C020-70JI be used as a direct replacement for standard EPROMs like the 27C020?

Yes, the AT29C020-70JI is designed as a functional and pin-compatible replacement for the 27C020 EPROM. As stated in the Description, "Reading data out of the device is similar to reading from an EPROM," and the pin functions (A0–A17, I/O0–I/O7, CE, OE, WE) match standard EPROM configurations. However, unlike EPROMs, it supports in-system reprogramming without UV erasure - requiring only proper WE/CE/OE timing and 5 V supply.