Microchip Technology AT29C020-70JU-T

Overview

AT29C020-70JU-T from Atmel is a 2-Mbit (256K × 8) 5V-only Flash memory IC used for nonvolatile code and data storage in embedded systems, supporting sector-based reprogramming with 70 ns read access time, 10 ms sector program cycle, and hardware/software data protection. It features two 8K-byte boot blocks with independent lockout, DATA polling and toggle-bit programming status detection, and operates across the industrial temperature range (–40°C to +85°C).

For engineers reviewing the AT29C020-70JU-T datasheet, AT29C020-70JU-T pinout, AT29C020-70JU-T application, or AT29C020-70JU-T equivalent, key selection considerations include sector erase granularity (256 bytes), 5V-only operation without high-voltage programming, boot block lockout for secure firmware storage, and PLCC-32 packaging compatibility with legacy board layouts.

Technical Context

The AT29C020-70JU-T implements a sector-program architecture where each 256-byte sector is erased and programmed in a single internal cycle using an on-chip timer and address/data latches. Programming requires no external high voltage-only standard 5V ±10% supply and TTL/CMOS-compatible control signals (CE, OE, WE).

It supports dual data-protection mechanisms: hardware-level VCC sensing (<3.8V inhibit), noise filtering (<15 ns pulse rejection), and software-controlled lockout via 3-byte command sequences for both sector programming and boot block protection. Boot blocks reside at addresses 0x00000–0x01FFF and 0x3E000–0x3FFFF, each independently configurable for write lockout.

Key Specifications

Pinout & Package

AT29C020-70JU-T is packaged in a 32-lead Plastic J-Leaded Chip Carrier (PLCC), JEDEC MS-016 compliant, with 1.27 mm pitch, 12.45 mm × 14.95 mm body size, and gull-wing leads suitable for through-hole or surface-mount reflow assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT29C020-70JU-T, AT29C020-70TU offers identical functionality in a lower-profile package ideal for modern SMT production, while MX29LV200CTTI-70G provides voltage flexibility at the cost of sector granularity and embedded security-making AT29C020-70JU-T uniquely suited for legacy 5V industrial systems requiring robust, fine-grained, and secure Flash updates.

Availability

AT29C020-70JU-T is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy embedded bootloader memory, and telecom line card configuration requiring stable component supply, long-lifecycle support, and RoHS-compliant green packaging.

Supply support for AT29C020-70JU-T 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 company specializing in microcontrollers, Flash memory, and touch solutions for industrial, automotive, and consumer applications.

The AT29C020-70JU-T belongs to Atmel's legacy 5V Flash memory product line, designed specifically for in-system reprogrammability in industrial control and embedded systems where reliability, sector-level update control, and 5V compatibility are mandatory.

FAQ

What is the maximum operating temperature range for the AT29C020-70JU-T?

The AT29C020-70JU-T is rated for industrial temperature operation from –40°C to +85°C. This range is validated per the device's DC and AC specifications, ensuring reliable read access time ≤70 ns, program cycle time ≤10 ms, and standby current ≤300 µA across the full span. The specification applies to the PLCC-32 package variant and is confirmed in the official Atmel datasheet revision 0291S–FLASH–11/08.

Does the AT29C020-70JU-T require high-voltage programming signals?

No, the AT29C020-70JU-T does not require high-voltage programming signals. It is a 5-volt-only Flash memory: all operations-including sector erase, byte load, and program execution-are performed using standard 5V ±10% VCC with TTL/CMOS-compatible CE, OE, and WE control inputs. Internal circuitry handles voltage translation and timing, eliminating external HV generators or charge pumps required by older EPROM or EEPROM technologies.

How many sectors does the AT29C020-70JU-T have, and what is the sector size?

The AT29C020-70JU-T contains 1024 sectors, each sized at 256 bytes. This 256-byte granularity enables precise firmware patching without erasing unrelated code or data. Sector addressing is controlled by A8–A17, while A0–A7 select the byte within the sector. The total 262,144-byte capacity (256K × 8) is fully partitioned into these uniform sectors, as verified in the device description and block diagram sections of the Atmel datasheet.

Can the boot blocks of the AT29C020-70JU-T be locked independently?

Yes, the AT29C020-70JU-T features two independent 8K-byte boot blocks-one at the lowest address range (0x00000–0x01FFF) and one at the highest (0x3E000–0x3FFFF)-each with its own programmable lockout bit. Activation requires a documented 7-step command sequence per block, and once set, the lock cannot be reversed without chip erase (which itself is disabled if either boot block is locked). This independence is explicitly defined in Section 4.10 and Algorithm 27 of the datasheet.

What methods does the AT29C020-70JU-T provide to detect program completion?

The AT29C020-70JU-T provides two hardware-supported methods: DATA polling on I/O7 (where the bit toggles to complement until programming completes) and toggle-bit detection on I/O6 (which alternates logic states during active programming). Both methods operate asynchronously and do not require fixed delays-allowing efficient CPU polling or interrupt-driven status checking. These mechanisms are electrically characterized and guaranteed across temperature and voltage per Sections 4.7 and 4.8 of the datasheet.