| 摘要 |
<p>PURPOSE:To improve the performance of signal tracking while keeping noise immunity by providing a switch circuit of differential pair transistor (TR) constitution taking an output of a comparator as an input and constituting a Schmitt circuit where another electric line of the switch circuit is connected to a resistor of an input section of the comparator. CONSTITUTION:A circuit section comprising TRs 17, 18-21, a constant current source 22 and a resistor 23 constitute a comparison section and TRs 24, 25 constitute a differential amplifier. An output of the comparator is inputted to a base of the TR24 and the voltage is compared with a reference voltage source 27 and the collector of the TR25 is connected to a non-inverting input of the comparator. When the comparator output is lower than a reference voltage, the non-inverting input of the comparator and a constant current source 26 are connected and when the comparator output is higher than the reference voltage conversely, the non-inverting input of the comparator is not connected to the constant current source 26. Then, the collector of the TR21 is taken as an output terminal 28, from which an output signal is extracted.</p> |
