PSD835G2V-90U

Overview

The PSD835G2V is a Flash Programmable System Device (PSD) designed for 8-bit microcontrollers, operating on a single 3 V ±10% supply. It integrates dual-bank Flash memories comprising 4 Mbits of primary memory and 256 Kbits of secondary memory, alongside 64 Kbits of SRAM. The device features over 3000 gates of PLD logic, including CPLD and DPLD capabilities, and provides 52 reconfigurable I/O ports. Memory access times are specified at 90 ns for voltages between 3.0 V and 3.6 V. It supports in-system programming via JTAG and offers concurrent read/write operations across its memory banks.

Feature Summary

• Dual-bank Flash architecture with 4 Mbits primary and 256 Kbits secondary memory supporting concurrent operation
• Integrated PLD with over 3000 gates, featuring 16 output macrocells and 24 input macrocells
• 52 individually configurable I/O ports supporting multiple modes including MCU, PLD, and address output
• In-system programmability via built-in JTAG serial port with low standby current of 25 µA

Applications

• Expanding address space for 8-bit MCUs using the internal page register
• Implementing complex memory mapping and separate program/data spaces
• Replacing discrete logic components through user-defined chip select decoding

Procurement Notes

Verify component status as the PSD835G2V is listed as obsolete. Confirm availability through authorized distributors or surplus channels. Ensure compatibility with existing 8-bit MCU bus interfaces during design validation. Check for alternative replacement parts if long-term supply assurance is required.

Selection Notes

Select this device when interfacing with 8-bit microcontrollers requiring significant non-volatile storage and flexible logic expansion. The 80-LQFP package suits surface mount applications needing 52 I/O lines. Consider the 90 ns access time for system timing requirements. Verify that the 3 V supply voltage aligns with the target MCU's operating range.

Part Context

This component belongs to STMicroelectronics' Flash PSD family, specifically engineered to extend the capabilities of 8-bit microcontrollers. It combines high-density Flash memory with programmable logic to reduce board space and component count. The device facilitates both manufacturing programming and field updates through its JTAG interface.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.