| 摘要 |
PURPOSE: A Low Drop-Out(LDO) voltage regulator having a cascode structure is provided to improve a performance of a circuit of a LDO voltage regulator during operating in a dropout region. CONSTITUTION: The device includes an amplifier(35), a transistor, a voltage divider, a current mirror(31,32), a regulated cascode structure(41,42) and a supply voltage. The amplifier has an input and an output. The input is a voltage between a reference voltage and a voltage at the voltage divider connected between a ground and the drain of the output transistor. The output is obtained from the gate of a transistor. The transistor at the output of the amplifier is connected to the output of the amplifier, to ground, to the regulated cascode, and to the gates of the current mirror. The voltage divider is hooked up between the ground and the drain of the output transistor of the current mirror. An input of the current mirror is connected to a regulated cascode and the output is obtained from the output of a Low Drop-Out(LDO). The regulated cascode structure regulates an entry voltage of the current mirror to be equal to the output voltage of the LDO.
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