Patent ID: 8604767

Claim:
A switching regulator for converting an input voltage to an output voltage or output current, wherein the switching regulator is capable of operating in continuous conduction mode (CCM), discontinuous conduction mode (DCM), or boundary conduction mode (BCM) which is between CCM and DCM, the switching regulator comprising: a power stage including at least one power transistor which switches according to a pulse width modulation (PWM) signal to convert the input voltage to the output voltage or output current; a mode detector coupling to the power stage for detecting the conduction mode in which the switching regulator is operating, and generating a mode signal indicating whether the switching regulator is operating in DCM or CCM, wherein the power transistor is electrically connected between a fixed level and a variable level node, and the mode detector detects a voltage level of the variable level node to determine whether the switching regulator is operating in DCM, wherein the mode detector includes: a low pass filter for filtering the voltage of the variable level node to generate a filtered signal; and a DCM feature detection circuit for detecting whether the filtered signal has a DCM feature and generating the mode signal accordingly; a feedback circuit generating a feedback signal according to the output voltage or output current; a control signal generator generating a control signal according to the mode signal; and a PWM controller generating the PWM signal according to the feedback signal, and adjusting On-time, Off-time, or frequency of the PWM signal according to the control signal, such that the switching regulator operates in or near BCM, wherein when the switching regulator is operating in DCM, the control signal reduces the On-time or Off-time of the PWM signal, or increases the frequency of the PWM signal; when the switching regulator is operating in CCM, the control signal increases the On-time or Off-time of the PWM signal, or reduces the frequency of the PWM signal, such that the switching regulator operates in or near BCM.