Differential amp needs no power source: 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 .... |