BANDPASS SELECTION FOR BIOPOTENTIAL AMPLIFIERS - Design and Development of Medical Electronic Instrumentation - page 95

IC2A and IC2D. At the same time, the capacitors of the high-pass fi filter are shorted, which

changes the con er with a gain of zero. After the

stimulus subsides, the blanking signal is released, and the ampli

fi guration of IC1B to an inverting ampli fi

er recovers within mil-
liseconds to allow detection of evoked or intrinsic potentials. Note that the circuit is pow-
ered from a single

fi

5-V supply. IC1A is used to bu ff er the 2.5-V voltage produced by

resistor divider R1 and R2 and filtered by C1. The 2.5 V at the output of IC1A is used as

an analog reference potential for the circuit.

fi

REFERENCES

Koide, F. T., Quick Estimate of Signal Bandwidth, Electronic Design , 115-116, December 16, 1996.
Moore, J. C., Method of Improving the Quality of an Electrocardiogram Obtained from a Patient
Undergoing Magnetic Resonance Imaging, U.S. patent 4,991,580, 1991.
Suesserman, M., Bootstrapped, AC-Coupled Differential Amplifier, U.S. patent 5,300,896, 1994.
Williams, A., Special Low-Pass Filter Limits Slope, Electronic Design , May 25, 1998.