DC/DC Converter Having a Step-Up Converter Supplying a Step-Down Converter

摘要

There is described a DC-DC converter having a Step-Up stage (10) supplying a Step-Down stage (20). A common Step-Down controller is designed and configured such that a single reference voltage (VREF) is compared to the output voltage (VOUT_SD) of the Step-Down stage by a single comparator (61), producing a single error signal (VERROR). The error signal is then compared by comparators (62) and (63) to the two different saw signals (SAW1) and (SAW2) respectively in order to generate first and second pulse-width modulated signals (PWM_SU) and (PWW_SD) respectively that are inputted a the control unit (65) of the controller which, in turn, generates a first pair of control signals (1,2) and a second pair of control signals (3,4), which control switching of the Step-Up stage (10) supplying a Step-Down stage (20).

主权项

1. A DC-DC converter comprising:
an input terminal adapted to receive an input voltage; a Step-Up stage having an input connected to the input of the DC-DC converter to receive the input voltage and an output, and a step-down stage having an input coupled to the output of the step-up converter and an output, said step-up stage and step-down stage being controlled by a first control signals and by second control signals, respectively; an output terminal connected to the output of the step-down stage so as to receive an output voltage of said Step-Down stage to drive a load which may be coupled to said output terminal; and, a controller adapted to generate the first control signals and the second control signals, said controller comprising a single error signal generator adapted to generate a single error signal from the difference between the output voltage of the Step-Down stage and a single reference voltage, and to generate both the first control signals and the second control signals from said error signal.