LOW-NOISE SWITCHING REGULATOR AND METHOD FOR CONTROLLING SWITCHING REGULATOR

摘要

PROBLEM TO BE SOLVED: To reduce a high frequency noise component caused by switching an inductive load by installing a control circuit mechanism responding to a current and a voltage slew signal. SOLUTION: The voltage Vout at an output node 310 is differentiated by a differential amplifier 290 and then a first feedback signal is generated. The first feedback signal is input into an input terminal of an adder 210 and is used for controlling a slew of the Vout. The current at a signal node is converted into a voltage signal by means of a resistor 240 and then amplified by a sense amplifier 250 and differentiated by a differential amplifier 260 and then limited by a limiter 270. By these operations, a second feedback signal is generated. The second feedback signal is input into the input terminal of the adder 210 and thereby a slew of the current at the signal node is controlled.