ISSN:
1741-0444
Keywords:
Extracellular recording
;
Active neural probe
;
CMOS
;
Source follower
;
Differential amplifier
;
Signal-to-device-noise ratio
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract A noise performance design method for the pre-amplifiers of an active neural probe is given. The on-chip circuitry of the active neural probe consists of CMOS devices that show high-/ low-frequency noise, so that the device noise can become dominant. Analysis of the signal-to-device-noise ratio (SDNR) for the CMOS source follower buffer and two-stage differential voltage amplifier is given. Closed-form expressions for the output noise power are derived and exploited to tailor the parameters that are controllable during circuit design. The output SDNR is calculated considering the real extracellular action potentials, the electrode-electrolyte interface and the noise spectrum of CMOS devices from typical foundries. It is shown that the output device noise power can be much higher than the output signal power if the devices at the input stage of the pre-amplifier are made as small as given fabrication technology permits. Quantitative information of the circuit parameters to achieve an SDNR higher than 5 for neural spikes with 60μV amplitude are provided for both preamplifier types.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02345018
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