Intel JS28F320C3BD70 32Mb 3V Flash Memory Chip: Datasheet, Pinout, and Application Notes

The Intel JS28F320C3BD70 is a 32-megabit (4MB) 3.0-volt flash memory chip fabricated using Intel's advanced StrataFlash technology. As a key component in numerous embedded systems, this memory solution offers a reliable and cost-effective method for non-volatile storage. Its architecture is designed for high read performance and flexible write capabilities, making it suitable for a wide range of applications from telecommunications and networking equipment to industrial control systems and automotive electronics.

A thorough understanding of its datasheet is crucial for successful implementation. The chip operates on a single 3.0V power supply (VCC) for all read, program, and erase operations, simplifying power management design. It is organized as 4,194,304 words by 8 bits or 2,097,152 words by 16 bits, providing design flexibility. A critical feature is its command-driven architecture, which allows it to be controlled through a standard microprocessor interface. Writing data is managed through a write state machine embedded in the chip, which automates the complex algorithms for programming and erasure, significantly reducing the burden on the host processor. Key specifications include access times as low as 90ns and a high endurance of up to 100,000 program/erase cycles per sector, ensuring long-term reliability.

The pinout configuration is essential for PCB layout and system integration. The JS28F320C3BD70 is available in industry-standard packages, such as the 48-ball Intel Easy BGA or 56-lead TSOP. Key pins include:

Address Inputs (A0-A20): These pins define the memory location being accessed.

Data Inputs/Outputs (DQ0-DQ15): These bidirectional pins transfer 8 or 16 bits of data.

Chip Enable (CE): Activates the chip when driven low.

Output Enable (OE): Controls the data output buffers.

Write Enable (WE): Latches addresses and data during write operations.

VCC (3.0V) and VSS (Ground): Power supply pins.

WP/ACC: This pin offers hardware write protection for specified blocks when driven low and can accelerate programming when raised to a higher voltage (VHH).

Application notes for this device emphasize several best practices. Proper power supply decoupling is paramount; placing 0.1 µF ceramic capacitors close to the VCC and VSS pins is mandatory to suppress noise and ensure stable operation during program/erase cycles. System designers must also implement the recommended write protection schemes, both hardware (using the WP pin) and software (using specific command sequences), to prevent accidental corruption of critical boot code or firmware. Furthermore, to maximize the longevity of the memory array, firmware algorithms should be designed to minimize unnecessary write cycles and evenly distribute data wear across different sectors.

ICGOOODFIND: The Intel JS28F320C3BD70 remains a robust and versatile 3V flash memory solution, prized for its integration of a write state machine, flexible data bus width, and strong endurance. While newer serial flash devices are common, this parallel NOR flash chip is ideal for applications requiring high-speed, random-access reads and execute-in-place (XIP) capabilities, such as in legacy or specialized embedded systems.

Keywords: Flash Memory, Datasheet, Pinout, Write Protection, Embedded Systems.