Adafruit XTSD SPI Flash SD Card - 512MB

Overview

This breakout board is built around a clever SD NAND memory chip that looks like a standard SPI Flash IC but behaves exactly like a full SD card. It shows up as a 512 MB FAT-formatted SD card, allowing you to use familiar SD card libraries on Arduino, CircuitPython, and other microcontroller platforms—no custom drivers needed.

Unlike removable microSD cards, this SMT-mounted solution is ideal for high-vibration environments, space-constrained designs, or projects where the microcontroller exposes files over USB mass storage instead of removing media. The chip handles wear leveling and ECC internally, so you can read and write data just like a normal SD card without worrying about flash management.

The breakout is pre-wired in SPI mode, includes level shifting for 3.3 V and 5 V logic, an onboard 3.3 V regulator, and a CS pull-up resistor. Simply connect the SPI pins, load your favorite SD library, and you’re ready to start logging data in minutes.

Why choose this over SPI Flash or microSD?

Compared to SPI Flash

• Acts like a true SD card, not raw flash memory
• Built-in wear leveling and ECC — no manual block erase or flash management
• Works with standard SD libraries instead of custom flash drivers
• FAT-formatted storage makes file handling simple and portable

• No removable connector — perfect for high-vibration or industrial environments
• More compact and robust SMT package
• No risk of cards loosening or being removed accidentally
• Ideal when files are accessed via USB mass storage instead of physically removing media

Specification

Technical details for Adafruit XTSD SPI Flash SD Card - 512MB.

Pinout