| 摘要 |
<p>PURPOSE:To prevent oscillation and to reduce crosstalk by inserting a FET in series with the output of an input emitter follower respectively, and controlling the gate voltage of the FET to damp the frequency characteristic of a selector circuit. CONSTITUTION:When a control signal v3 is brought into an L level, TRs Q3, Q7 are turned on and TRs Q4, Q5 are turned off, a TRQ1, R1, D1 are active and Q2, R2, D2 are cut off and only a signal relating to a signal source v1 appears at the output terminal 3. When the signal v3 is conversely brought into an H level, the TRs Q3, Q7 are turned on and the TRs Q4, Q8 are turned off, the TRQ1, R1, D1 are cut off and the Q2, R2, D2 are turned on and only a signal relating to a signal source v2 appears at the output terminal 3. Through the constitution above, the output signal of the selected TR Q1 or Q2 passes with pinch resistors R1, R2 inserted to the output of the emitter follower TRs Q1, Q2 and the sharpness Q is damped. Thus, the peaking of the frequency characteristic of the emitter follower is damped, the oscillation is prevented and the crosstalk is reduced.</p> |
