SITUATION

The output of a pair of Electrocardiograph skin electrodes is to be amplified with the diagramed differential instrumentation amplifier. The minimum peak differential signal amplitude expected from the electrodes is 0.5mV. The maximum peak differential signal amplitude expected from the electrodes is 4.0 mV. The minimum peak signal amplitude desired from the differential amplifier output is 0.5V.

The gain of the output amplifier stage from V _c and V _d to V _o is desired to be 40 times the gain of the input amplifier state from V _? and V ₊ to V _c and V _d. The differential gain of the entire amplifier (G _D) is the differential gain of the output stage (G _Dout) times the differential gain of the input stage (G _Din), or G _D = G _Dout G _Din.

REQUIRED

1. If R ₂ is 100k ?, R ₄ is 10k ?, and R ₆ is 10k ?, what are the values of R ₁, R ₃, R ₅, and R ₇? Assume ideal op-amps.

2. If the op-amps are capable of producing an output voltage within 1 V of the power supply voltage, what should the power supply voltage be so that the maximum peak signal amplitude from the differential amplifier output is not clipped:

SOLUTION

1. G _D = G _Dout