| 摘要 |
PROBLEM TO BE SOLVED: To prevent a through current from being generated in a push-pull circuit. SOLUTION: Comparators CMP1 and CMP2 compare the base-emitter voltages of transistors Q3 and Q4 of final stages constituting of push-pull circuits respectively with reference voltages VR1 and VR2 and output state detection signals which go down to a low level when the transistors Q3 and Q4 turn off. Gates NOR1 and NOR2 input command signals Vin / and Vin and the state detection signals from the comparators CMP2 and CMP1 and turn on the transistors Q3 and Q4 only when the command signal and state detection signals both go down to the low level. Consequently, the transistor Q3 or Q4 will never turn on while the other transistor is turned on and no through current will flow to the push-pull circuits.
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