Hash noise is an informal term for aggressive, broadband electromagnetic interference that couples into a sensitive circuit. It is typically generated by fast-switching transients from nearby switch-mode power supplies, brushed motors, or digital clock lines. On an oscilloscope, it appears as a thick, fuzzy baseline, and in audio circuits, it manifests as an irritating, grating buzz rather than a smooth hiss.
I'm picking up a lot of hash noise on the sensor input, probably radiating from that cheap buck converter next to it.
Also heard as
- hash
Related terms
EMI
An external memory interface connects a microcontroller or processor to off-chip memory.
SMPS
A switched-mode power supply uses high-frequency switching to efficiently convert electrical power.
PARD
Periodic and random deviation is a combined measurement of all ripple and noise on a DC power supply output.