Microchip Technology AT29C020-15JI

Overview

AT29C020-15JI from Atmel is a 2-megabit (256K × 8) 5-volt-only Flash memory IC organized as 262,144 bytes, featuring 70 ns read access time, 10 ms sector program cycle time, and industrial temperature range (–40°C to +85°C). It supports in-system reprogramming via sector-based architecture with 1024 × 256-byte sectors and integrates hardware/software data protection for embedded firmware storage applications.

For engineers reviewing the AT29C020-15JI datasheet, AT29C020-15JI pinout, AT29C020-15JI application, or AT29C020-15JI equivalent, key selection criteria include its PLCC-32 industrial-grade packaging, 5V ±10% single-supply operation, DATA polling and toggle-bit programming status detection, boot block lockout capability, and compatibility with EPROM-style read interfaces in legacy microcontroller systems.

Technical Context

The AT29C020-15JI implements a sector-erase-and-program architecture where each 256-byte sector is internally latched before simultaneous programming, freeing the address/data bus during t_WC = 10 ms internal cycle. Its dual-line chip enable (CE) and output enable (OE) control enables bus contention avoidance in shared-memory systems.

Hardware data protection includes V_CC sense (<3.8 V inhibits programming), 5 ms power-on delay, and noise filtering on WE/CE inputs (<15 ns pulses ignored); software protection requires a three-byte command sequence (AAh/55h/A0h) to enable/disable write operations, persisting across power cycles.

Key Specifications

Pinout & Package

AT29C020-15JI is packaged in a 32-lead Plastic J-Leaded Chip Carrier (PLCC-32), JEDEC MS-016 compliant, with 1.27 mm pitch, 12.45 mm × 14.95 mm body, and lead coplanarity ≤0.102 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MX29LV200CTTI-70G and EN29LV200AB-70TIP, the AT29C020-15JI delivers true 5V-only operation, integrated boot block lockout, and hardware/software write protection - making it uniquely suitable for legacy 5V industrial and automotive systems requiring zero-changes retrofit and robust firmware security.

Availability

AT29C020-15JI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, automotive body control modules, and legacy telecom equipment upgrades requiring stable component supply and long-term obsolescence management.

Supply support for AT29C020-15JI 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 nonvolatile memory, microcontrollers, and secure authentication ICs.

The AT29C020-15JI belongs to Atmel's legacy parallel-interface Flash memory product line, designed specifically for 5V embedded systems requiring in-system reprogrammability, industrial temperature resilience, and EPROM drop-in replacement capability.

FAQ

What is the maximum operating temperature range for the AT29C020-15JI?

The AT29C020-15JI 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 official Atmel datasheet (Rev. 0291N–FLASH–07/02), where "I" suffix denotes industrial grade. The device maintains full functionality-including 150 ns read access and 10 ms sector programming-across this entire range.

Does the AT29C020-15JI require high-voltage programming signals?

No, the AT29C020-15JI does not require high-voltage programming signals. As stated in the datasheet Description section, it is a "5-volt-only in-system Flash programmable" device. All programming commands-including sector erase, byte load, and software protection enable/disable-are executed using standard 5 V logic levels on CE, WE, and address/data lines, eliminating the need for +12 V or other elevated programming voltages.

How many sectors does the AT29C020-15JI have, and what is the size of each sector?

The AT29C020-15JI contains 1024 sectors, each 256 bytes in size. This is explicitly specified in the Features section ("1024 Sectors (256 Bytes/Sector)") and reinforced in the Device Operation section, which states that "reprogramming is performed on a sector basis" and that "A8 to A17 specify the sector address." The total capacity of 262,144 bytes (256K × 8) divided by 256 bytes per sector yields exactly 1024 sectors.

What is the purpose of the two boot blocks in the AT29C020-15JI?

The AT29C020-15JI includes two independent 8K-byte boot blocks-one at the lowest addresses (0x0000–0x1FFF) and one at the highest (0x3E000–0x3FFFF)-each configurable with a programming lockout feature. As detailed in the Boot Block Programming Lockout section, once enabled via a seven-command algorithm, these blocks become permanently read-only, protecting critical bootloader code from accidental erasure or overwrite during field firmware updates.

Can the AT29C020-15JI be used as a direct replacement for the 27C256 EPROM?

Yes, the AT29C020-15JI is designed as a functional and pin-compatible replacement for the 27C256 EPROM in 5V systems. Its read operation mirrors EPROM behavior (CE/OE low, WE high), it shares identical PLCC-32, PDIP-32, and TSOP-32 packages, and supports the same 256K × 8 organization. However, unlike EPROMs, it requires explicit sector programming commands and supports in-system reprogramming without UV erasure.