Microchip Technology AT49F002-90JC

Overview

AT49F002-90JC from Atmel is a 5V-only, 2 Mbit (256K × 8) in-system reprogrammable Flash memory IC with 90 ns read access time, 10 µs/byte typical programming time, and sector-based architecture including a 16K-byte boot block with programmable lockout. It operates across commercial temperature range (0°C to 70°C) and is used for firmware storage and boot code retention in embedded microcontroller systems.

For engineers reviewing the AT49F002-90JC datasheet, AT49F002-90JC pinout, AT49F002-90JC application, or AT49F002-90JC equivalent, key selection considerations include its PLCC-32 package, 5V single-supply operation, hardware data protection features, DATA polling/Toggle Bit erase-program status detection, and boot block write-protection capability.

Technical Context

The AT49F002-90JC implements a command-register-based architecture requiring six-byte sequences for chip/sector erase and boot lockout enable. Its internal program control logic manages timing without external clocks, supporting software-controlled erasure of parameter blocks (2 × 8K bytes) and main memory blocks (96K + 128K bytes).

It uses standard EPROM-compatible control signals (CE/OE/WE) for read access and supports hardware reset-driven boot block override at 12 V. The device integrates VCC sense, noise filtering on WE/CE, and TTL/CMOS-level input thresholds to prevent inadvertent writes during power transitions or noise events.

Key Specifications

Pinout & Package

AT49F002-90JC is housed in a 32-lead Plastic J-leaded Chip Carrier (PLCC) package, compliant with JEDEC MS-016 AE. Pin 1 is marked by index notch; pin 16 is GND, pin 32 is VCC. Pin 1 (RESET) functions as DC (no-connect) for AT49F002N(T) variants but is active on AT49F002(T); per ordering code suffix and documentation, AT49F002-90JC corresponds to the base AT49F002(N) variant where RESET is functional.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AM29LV002BT-90EC and SST39VF020-90-4C-NHE, the AT49F002-90JC uniquely supports true 5 V-only operation with functional RESET pin and 12 V boot override - making it the only option for maintaining legacy 5 V designs requiring field-recoverable boot integrity.

Availability

AT49F002-90JC is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy embedded controller boot memory, secure boot code retention, and telecom line card configuration storage requiring stable component supply and long-term obsolescence management.

Supply support for AT49F002-90JC 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, nonvolatile memory, and secure authentication solutions.

The AT49F002 product line was designed for 5 V embedded systems requiring in-system reprogrammable Flash memory with robust data integrity, sector-level erase granularity, and hardware-protected boot code storage.

FAQ

What is the operating temperature range for the AT49F002-90JC?

The AT49F002-90JC is rated for commercial temperature operation from 0°C to 70°C, as indicated by the "C" suffix in the ordering code. This makes it suitable for indoor industrial equipment, office automation devices, and consumer electronics where ambient thermal conditions remain within this envelope. The device's DC and AC characteristics-including 90 ns read access and 100 µA standby current-are guaranteed across this full range.

Does the AT49F002-90JC require a high-voltage programming supply?

No, the AT49F002-90JC operates with a single 5 V ±10% supply for both read and reprogramming functions. It does not require VPP or any external high-voltage source. All command sequences-including byte programming, sector erase, and boot lockout-execute using standard 5 V logic levels, simplifying power design and eliminating voltage translation circuitry in host systems.

How is boot block protection enabled and overridden on the AT49F002-90JC?

Boot block protection on the AT49F002-90JC is enabled via a six-cycle command sequence (AAh/55h/80h/AAh/55h/40h) written to address 5555h. Once enabled, the 16K-byte boot block (00000H–03FFFH) becomes permanently write-protected at ≤5.5 V. Override is achieved by applying 12.0 V ±0.5 V to the RESET pin, which temporarily disables lockout for chip/sector erase or byte programming - a feature confirmed for the AT49F002(N) variant used in AT49F002-90JC.

What package type is used for the AT49F002-90JC?

The AT49F002-90JC uses a 32-lead Plastic J-leaded Chip Carrier (PLCC) package, designated as 32J per Atmel's ordering information. It measures 1.67″ × 1.64″ (42.4 mm × 41.7 mm) with J-shaped leads, and features an index notch for pin 1 identification. This surface-mount package offers mechanical robustness and thermal performance suitable for reflow-soldered industrial assemblies.

Can the AT49F002-90JC be used as a direct replacement for standard EPROMs like the 27C256?

Yes, the AT49F002-90JC provides pin-for-pin and functionally compatible replacement for 27C256 EPROMs in 32-pin DIP or PLCC footprints, with identical CE/OE/WE control signaling and read timing. Unlike EPROMs, it supports in-system reprogramming without UV erasure or socket removal. However, firmware must implement Atmel's command sequences for erase/program - no hardware changes are needed, but software adaptation is required for non-read operations.