| 摘要 |
PURPOSE:To stabilize a DC operating point and switching operation by connecting resistor between a common connecting point of each base of transistors (TR) constituting a current mirror circuit and a power supply so as to decrease the turn-off time by selecting the resistance value. CONSTITUTION:The major part of the current mirror circuit is constituted by PNP TRs 1-3, and reference current sources 4, 5, 6 offering the reference are connected to collectors of the TRs 1, 2, 3 respectively. The emitters of the TRs 1, 2, 3 are connected directly or via a resistor to a power supply terminal 10 and the collector and the base of the TR1 are connected in common and the bases of the TRs 1-3 are connected in common. The resistor 18 is connected between the common connecting point of the TRs 1-3 and the power supply terminal 10. The turn-off time is reduced by selecting the resistance value of this resistor 18 so as to stabilize the DC operating point and the switching operation without increasing the size of the IC chip.
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