| 摘要 |
PURPOSE:To eliminate the influence of voltage fluctuation due to power source impedance by converting the output signal of a signal processing circuit into a current, and then supplying this current to a load resistance connected to a reference potential at one end. CONSTITUTION:One output signal of a demodulating circuit 16 is converted into a current by the current mirror circuit composed of a diode 351 and a transistor TR352, and the current is supplied to a load resistance 319 connected to an earth terminal 308 at one end. The other end of this resistance 319 is connected to an output terminal 317. Similarly, the other output of the circuit 16 is supplied to the current mirror circuit composed of a diode 353 and a TR354, and is converted into a current, which is supplied to a load resistance 321 connected to the terminal 308 at one end and to an output terminal 318 at the other end. In this constitution, voltages developed across the loads 19 and 321 are insensitive to fluctuation in power voltage. Therefore, even if the potentials at terminals 5 and 7 vary with the internal resistance 2 and fine resistance of a power source 1 during switching, the DC components of the voltage at output terminals 33 and 34 never vary. |
