Revision 15.00 / LB-0028
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Cerebus Instructions for Use
7
Figure 2- Simplified block diagram of the Cerebus system
Front End Amplifier
The Front End Amplifier (FEA), depicted in Figure 3, receives analog signals either directly from the
electrodes or via headstages (unity-gain voltage followers) depending on the impedance of the
electrodes. The analog signals are amplified (unity gain), filtered (1st-order high- pass at 0.3 Hz and 3rd-
order low-pass at 7,500 Hz), and digitized (30 kHz, 16-bits at 250 nV resolution), converted into the optical
domain and then transmitted to the NSP via a fiber-optic link, which is immune to electromagnetic field
interference.
The Amplifier ground is not connected to the earth ground. The Amplifier ground is isolated and floating.
There are ESD shunt circuits that will conduct differences of 1000 V or more. The Amplifier can be
connected to earth ground via any one of the four ground pins located on the input side of the Amplifier.
Amplifier Input
Figure 3-Isometric views of the Front End Amplifier showing the front (left) and back side
(right).
