DC-DC converter having feedforward for enhanced output voltage regulation
Methods and apparatus for a DC-DC converter having input voltage feedforward for reducing the effects of input voltage signal transients. In embodiments, a feedback circuit receives an output voltage and generates a feedback signal and a modulation circuit receives the feedback signal and generates a control signal for a switching element for generating the output voltage, which is boosted from an input voltage. A feedforward module combines a slope compensation signal, the input voltage, and current information for an inductive energy storage element, which forms a boost circuit for generating the output voltage and generates a ramp signal to the modulation circuit. A duty cycle of the control signal is proportional to an impedance compensation input, inversely proportional to the slope compensation and the input voltage, and inversely proportional to the inductor current.
1. A system comprising:
a feedback circuit to receive an output voltage and generate a feedback signal;
a modulation circuit to receive the feedback signal and generate a control signal for a switching element configured to generate the output voltage, which is boosted from an input voltage; and
a feedforward module to combine a slope compensation signal, the input voltage, and current information for an inductive energy storage element, which forms a boost circuit for generating the output voltage, and generate a ramp signal to the modulation circuit, wherein the modulation circuit is configured to generate the control signal from the ramp signal and the feedback signal,
wherein a duty cycle of the control signal is proportional to an impedance compensation input, inversely proportional to the slope compensation and the input voltage, and inversely proportional to the inductor current.
2. The system according to claim 1 , wherein the input voltage and current information for the inductive energy storage element are combined and provided as a first input to a signal combiner and the slope compensation signal is provided as a second input to the signal combiner.
3. The system according to claim 2 , wherein an output of the signal combiner provides the ramp signal.
4. The system according to claim 3 , wherein the ramp signal is provided as a first input of a comparator and the feedback signal is provided as a second input of the comparator, wherein an output of the comparator is combined with an oscillator signal to generate the control signal for the switching element.
5. The system according to claim 1 , wherein the system is provided as an integrated circuit package.
6. A method, comprising:
receiving an output voltage as feedback an output voltage and generating a feedback signal;
receiving the feedback signal and generating a control signal for a switching element configured to generate the output voltage, which is boosted from an input voltage; and
combining a slope compensation signal, the input voltage, and current information for an inductive energy storage element, which forms a boost circuit for generating the output voltage;
generating a ramp signal; and
generating the control signal from the ramp signal and the feedback signal,
wherein a duty cycle of the control signal is proportional to an impedance compensation input, inversely proportional to the slope compensation and the input voltage, and inversely proportional to the inductor current.
7. The method according to claim 6 , wherein the input voltage and current information for the inductive energy storage element are combined and provided as a first input to a signal combiner and the slope compensation signal is provided as a second input to the signal combiner.
8. The method according to claim 7 , wherein an output of the signal combiner provides the ramp signal.
9. The method according to claim 8 , wherein the ramp signal is provided as a first input of a comparator and the feedback signal is provided as a second input of the comparator, wherein an output of the comparator is combined with an oscillator signal to generate the control signal for the switching element.
10. An integrated circuit package configured to perform the method of claim 6 .
11. An integrated circuit package converter, comprising:
a feedback means for receiving an output voltage and generating a feedback signal;
a modulation means for receiving the feedback signal and generating a control signal for a switching element configured to generate the output voltage, which is boosted from an input voltage and for generating the control signal from a ramp signal and the feedback signal; and
a feedforward means to combine a slope compensation signal, the input voltage, and current information for an inductive energy storage element, which forms a boost circuit for generating the output voltage, and generating the ramp signal for the modulation means,
wherein a duty cycle of the control signal is proportional to an impedance compensation input, inversely proportional to the slope compensation and the input voltage, and inversely proportional to the inductor current.
12. The converter according to claim 11 , wherein the input voltage and current information for the inductive energy storage element are combined and provided as a first input to a signal combiner and the slope compensation signal is provided as a second input to the signal combiner.
13. The converter according to claim 12 , wherein an output of the signal combiner provides the ramp signal.
14. The converter according to claim 13 , wherein the ramp signal is provided as a first input of a comparator and the feedback signal is provided as a second input of the comparator, wherein an output of the comparator is combined with an oscillator signal to generate the control signal for the switching element.