| 摘要 |
PURPOSE:To attain ease of connection to other circuit by absorbing the unbalance of currents of two constant current sources in a switch circuit so as to increase the input impedance without changing the circuit scale even at switch-on. CONSTITUTION:The sum of a collector current 12 of a transistor(TR) Q1 and a current I1 flowing to a constant current source 7 is designed to be a current I0 flowing to a constant current source 6 so as to eliminate the effect of the unbalance of the currents I0, I1 onto an external circuit. Moreover, the collector current I2 of the TR is a difference of currents flowing through the constant current sources 6, 7, then the unbalance current I between the currents I0 and I1 is superimposed on the collector current I2 of the TR. However, the current I at an input terminal 1 is multiplied by 1/beta (beta is current amplification factor) and the effect on the external circuit to be connected can be neglected. |
