HI there,
So the data sheet shows this:
RP2350 is a new family of microcontrollers from Raspberry Pi that offers significant enhancements over RP2040. Key
features include:
• Dual Cortex-M33 or Hazard3 processors at 150 MHz
• 520 kB on-chip SRAM, in 10 independent banks
• 8 kB of one-time-programmable storage (OTP)
• Up to 16 MB of external QSPI flash/PSRAM via dedicated QSPI bus
◦
Additional 16 MB flash/PSRAM accessible via optional second chip-select
and
◦
RP2350 uses external flash
1.2.1.1. QFN-60 (RP2350A)
◦
RP2354 has 24 × 128 kB = 2 MB of internal flash
HTH
GL 
PJ 
I don’t think it’s a PSRAM , just a Flash. check the flash Data sheet. 
FYI, I f you need MORE flash then this D0 compatible additional Flash on the bottom of this board.
works very well also see the demo HERE