| 摘要 |
<p>PURPOSE: A low drop out regulator (LDO) having a phase margin compensation unit and a method for compensating phase margin using the same are provided to minimize the variation of an output voltage of the LDO due to the external environmental factor by controlling a buffer current. CONSTITUTION: A reference voltage generation unit (410) outputs a reference voltage (Vout2), which is to be applied in a target circuit, by dropping a reference voltage supplied from a power supply unit. A supply voltage output unit (420) outputs a voltage (Vout1) supplied to the target circuit actually from the power supply unit, and controls phase margin by controlling a buffer current. A comparator (430) checks the oscillation of a supply voltage, and outputs a pulse signal according to the oscillation of the supply voltage, by comparing a reference voltage with the supply voltage. A duty cycle calculator (440) counts a random section of an output signal by a fixed frequency, and obtains duty cycle ratio and output bit according to the counting, and feeds the information back to the supply voltage output unit. [Reference numerals] (420) Supply voltage output unit; (440) Duty cycle calculator; (AA) Supply voltage to a target circuit</p> |
