| 摘要 |
PURPOSE:To obtain a switch circuit not susceptible to the temperature effect, variance of resistance and current amplification of transistors (TRs) by constitut ing the switch by an input TR, a current comparison TR in current mirror configuration. CONSTITUTION:The 1st diode D1 is connected in parallel between the base and emitter of a 1st TR Q1, a 1st current mirror circuit is constituted based on a 1st diode D1, a 2nd diode D2 is connected in parallel between the base and emitter of a 2nd TR Q2 to constitute a 2nd current mirror circuit based on the 2nd diode D2 as a reference. Thus, it is possible to form the switch circuit conductive/nonconductive depending on the current flowing to an input terminal almost independently of the input terminal voltage with respect to the current of a constant current source I00. Moreover, since the circuit is formed in current mirror configuration the switch circuit not susceptible to the effect of the variance in the current amplification factor of TRs and the resistance value can be attained.
|
