PSD312B-90JI

Overview

The PSD312B-90JI is a low-cost field-programmable microcontroller peripheral from the PSD3XX family, designed to interface with 8-bit and 16-bit microcontrollers. It integrates up to 512 Kbit of UV EPROM and optional 16 Kbit SRAM into a single chip. The device features two programmable logic arrays (PAD A and PAD B) for address decoding and control logic, eliminating external glue logic. It supports multiplexed and non-multiplexed bus architectures and includes programmable I/O ports, input latches, and page logic to expand address space. The component operates on a single 5 V supply and offers configurable security modes.

Feature Summary

• Integrates high-performance user-configurable blocks of EPROM, programmable logic, and optional SRAM into one part.
• Provides a powerful microcontroller interface that eliminates the need for external glue logic.
• Features two programmable logic arrays (PAD A and PAD B) to replace discrete PLDs or decoders.
• Includes built-in address latches for multiplexed address/data buses and programmable I/O ports.

Applications

• Telecommunications equipment such as cellular phones, digital PBXs, and FAX machines
• Portable industrial equipment including industrial control systems and measurement meters
• Medical instrumentation devices like hearing aids and diagnostic tools
• Computer peripherals for notebooks, portable PCs, and palm-top computers

Procurement Notes

Verify the specific suffix configuration against the official STMicroelectronics selector guide to ensure correct voltage range and memory size. Confirm package type availability as the PSD3XX family utilizes multiple pinout options. Check for obsolete status notifications as this product line may have been superseded by newer integrated solutions.

Selection Notes

Select the PSD312 variant specifically when 512 Kbit of EPROM capacity is required. Ensure the system design accommodates the 44-pin package constraints. Verify compatibility with the target microcontroller's bus architecture, whether multiplexed or non-multiplexed, before finalizing the component choice.

Part Context

This component belongs to the PSD3XX family of low-cost field-programmable microcontroller peripherals. The family is characterized by its ability to integrate EPROM, SRAM, and programmable logic to simplify microcontroller system designs. The PSD312 model specifically denotes the 512 Kbit EPROM capacity within this series.

Replacement Considerations

Consult the official STMicroelectronics documentation for current replacement recommendations. Obsolete products often require evaluation of modern microcontroller peripherals or SoCs with integrated flash and programmable logic to maintain system functionality.