Spontaneous oscillations in ZD digital headstages

Tech Note: TN0985
Product: ZD32, ZD64, ZD96, ZD128
Version: All
Date Added: 2017-09-22

Issue

There is a known issue with the Intan RHD2132 and RHD2164 chips used in the ZD32 and ZD64 headstages. When attaching an array to the headstage, some channels will sometimes stop returning valid data and instead only return a ±100 uV high frequency noise. The problem occurs on all headstages, but some exhibit the behavior more often than others. The two plots below are examples showing the plot decimated signal bandpass filtered at 300-5000 Hz (pNe1), raw signal (Wav1), LFP (LFP1), and Power Spectrum of the data in this state.

Workaround

This Intan chip issue is triggered by rapid changes in the impedance that the amplifier sees. Always power cycle the PZ5 after attaching the headstage to an array before starting your experiment.