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For bipolar transistors, the quiescent current increases proportionally with the output current, because the series pass element is a current-driven device. In addition, in the dropout region the quiescent current can increase due to the additional parasitic current path between the emitterand the base of the bipolar transistor, which is caused by a lower base voltage than that of the output voltage. For MOS transistors, the quiescent current has a near constant value with respect to the load current since the device is a voltage-driven device. The only things that contribute to the quiescent current for MOS transistors are the biasing currents of band–gap, sampling resistor, and error amplifier. In applications where power consumption is critical, or where small bias current is needed in comparison with the output current, an LDO voltage regulator using MOS transistors is essential. e0 [. w S/ I
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這是我在看LDO文章一段看不太懂..
: z }5 B8 A8 n j' P1 [為什麼在Drop-out region時,quiescent current 會變大??
5 @ H1 \; O& b有大大可以解釋一下原理給我 知道嗎?, S& n& R$ D0 m2 l
越詳細越好~謝謝
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