Controller for buck and boost converter
AssigneeFreescale Semiconductor, Inc.
InventorMasami Aiura
Life of this patent
Estimating the term…
Abstract
A PWM controller for adjusting an output voltage of a buck and boost converter includes a first saw wave generator, which generates a first saw wave in accordance with the level of the output voltage. A first comparator coupled to the first saw wave generator compares the first saw wave with a first reference voltage and generates a first pulse. A peak hold circuit coupled to the first saw wave generator holds a peak value of the first saw wave. A second saw wave generator coupled to the peak hold circuit generates a second saw wave having a lower limit value that is the peak value of the first saw wave. A second comparator coupled to the second saw wave generator compares the second saw wave with the first reference voltage and generates a second pulse.
Claims17
A Pulse Width Modulation (PWM) controller for adjusting an output voltage of a buck and boost converter, the PWM controller comprising:
- a first saw wave generator, which generates a first saw wave in accordance with the level of the output voltage;
- a first comparator coupled to the first saw wave generator for comparing the first saw wave with a first reference voltage and generating a first pulse;
- a peak hold circuit coupled to the first saw wave generator, which holds a peak value of the first saw wave;
- a second saw wave generator coupled to the peak hold circuit for generating a second saw wave having a lower limit value that is the peak value of the first saw wave;
- and
- a second comparator coupled to the second saw wave generator for comparing the second saw wave with the first reference voltage and generating a second pulse.
A Pulse Width Modulation (PWM) controller for adjusting an output voltage of a buck and boost converter, the PWM controller comprising:
- a first saw wave generator, which generates a first saw wave including a first waveform portion formed in accordance with the level of the output voltage and a second waveform portion having a lower limit value that is a peak value of the first waveform portion of the first saw wave;
- a first comparator coupled to the first saw wave generator, which compares the first saw wave with a first reference voltage and generates a first pulse;
- a second saw wave generator, which generates a second saw wave including a first waveform portion formed in accordance with the level of the output voltage and a second waveform portion having a lower limit value that is a peak value of the first waveform portion of the second saw wave, the first waveform portion of the first saw wave being generated when the second waveform portion of the second saw wave is generated, and the first waveform portion of the second saw wave being generated when the second waveform portion of the first saw wave is generated;
- and
- a second comparator coupled to the second saw wave generator for comparing the second saw wave with the first reference voltage and generating a second pulse.
A buck and boost converter for generating an output voltage from an input voltage, the buck and boost converter comprising:
- a first output transistor;
- a second output transistor coupled to the first output transistor;
- an error amplifier coupled to the first and second output transistors, which generates an error voltage in accordance with a level of the output voltage;
- and
- a PWM controller, coupled to the error amplifier, for generating a first control pulse for driving the first output transistor and a second control pulse for driving the second output transistor;
- wherein the PWM controller generates the first control pulse based on the error voltage and a first reference voltage, and the PWM controller generates the second control pulse based on the error voltage, the first reference voltage, and a second reference voltage.
Dependencies are inferred from the claim text.