Adafruit USB Isolator - 100mA Isolated Low/Full Speed USB

Have some USB logic analyser, multimeter or oscilloscope and bumping up against the frustration of a shared earth ground? The Offspring (known for being electrical engineers) wisely sang "Ya gotta keep'em isolated!" Power and signal isolation improves common-mode voltage, enhances noise rejection, and permits two circuits to operate at different voltage levels.

This handy little low-cost USB Isolator is exactly what you need to provide protection against harmful noise, ground loops, surges, and spikes. Works with any 1.5Mbps (low speed) or 12Mbps (full speed) USB device. Not for high-speed USB devices, often used for video cameras (check your product to make sure it's low/full compatible) Based on Analog Device's USB isolators.

It is particularly useful when paired with USB testing instruments, you need to separate or isolate your earth ground (through the USB connector to the computer to the power plug) from your circuit for high voltage, accident-protection, or floating ground needs. Best of all, this USB isolator even has its own isolated 5V power supply that can supply 100mA, making it perfect for your BitScope Micro USB! Protect your computer or laptop, use one of these in between your ports.

This is for use with 5V power, 3.3V logic USB devices only, we don't recommend it for use with any other protocol or voltages!

Revision History

• As of February 11th, 2025 - This board now has an SMT USB port. The previous version was THM. We've also updated this PCB with Adafruit Pinguin to make a lovely and legible silkscreen.
• As of April 20, 2018 - we've made a small revision to exchange the Mini USB for a Micro USB connector. The design is otherwise identical.

Specifications