Patent ID: 7417879
Filing Date: 2008-08-26
Classification: H02M,Y02B

Abstract:
1. A circuit for controlling a switching regulator, the switching regulator receiving an input voltage and including a switch circuit coupled to generate a switching output voltage and an output circuit coupled to receive the switching output voltage and to supply current at a regulated output voltage to a load, the circuit comprising: an error amplifier having a first input node coupled to receive a first voltage indicative of the regulated output voltage, a second input node coupled to receive a reference voltage and an output node providing an error voltage responsive to the difference between the first voltage and the reference voltage; a first control circuit having an input node receiving the error voltage, a first output node providing a first control signal and a second output node providing a second control signal, the first control circuit generating the first control signal having a magnitude proportional to the error voltage for error voltages in a first voltage range, the first control signal having a maximum value for error voltage values greater than the first voltage range, the first control circuit further generating the second control signal having a minimum value for error voltages in a second voltage range, the second control signal having a magnitude proportional to the error voltage for error voltages greater than the second voltage range, the first and second voltage ranges being associated with low voltage values of the error voltage; a second control circuit coupled to receive the first control signal and providing an output signal responsive to the first control signal for controlling the switching frequency of the switching regulator; and a third control circuit coupled to receive the second control signal indicative of a peak current value for the current flowing through the switch circuit, the third control circuit providing an output signal responsive to the second control signal for controlling the peak current flowing through the switch circuit.