Differential amp needs no power source: 05/02/2002 EDN -
Design Ideas / A true-differential, power-source-free,
high-input-impedance amplifier with bipolar output would present
distinct advantages in remote devices. Such an amplifier, with
its bipolar output, would be a better choice than a unipolar, 4-
to 20-mA device. It would also improve on common-mode
performance. In Figure 1, a Maxim MAX319 analog switch, IC2,
feeds the power from the coaxial signal cable to .... |