Offset peak current mode control circuit for multiple-phase power converter
First Claim
1. A multiple-phase DC-to-DC voltage converter comprising:
- a plurality of converter modules connected to a common load and having a common input voltage source;
a current sensor coupled to a sensing resistor disposed in series between said common input voltage source and said load to derive a current sense signal corresponding to current passing through said sensing resistor;
a voltage error sensor coupled to said load to derive a voltage error signal corresponding to difference between an output voltage of said voltage converter and a reference voltage;
a plurality of current mode control circuits connected to respective ones of said plurality of converter modules, said current mode control circuits receiving said current sense signal and said voltage error signal, said current mode control circuit providing gate driving signals to said converter modules having a duty cycle determined by said current sense signal and said voltage error signal; and
a phase select circuit coupled to said plurality of current mode control circuits and alternately providing said plurality of current mode control circuits a phase select signal to initiate successive phases of operation within a power cycle;
wherein, when there is an overlap between adjacent ones of said successive phases, said current mode control circuits are operative to compare said current sense signal and said voltage error signal during a non-overlapping portion of a phase, and stretch a duration of said duty cycle of said gate driving signals to extend at least partially into an overlapping portion of said phase.
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Accused Products
Abstract
An offset peak current mode control circuit is provided for use with a multiple-phase DC-to-DC voltage converter including a plurality of converter modules connected to a common load and having a common input voltage source, a current sensor coupled to a sensing resistor disposed in series between the common input voltage source and the load to derive a current sense signal corresponding to current passing through the sensing resistor, and a voltage error sensor coupled to the load to derive a voltage error signal corresponding to difference between an output voltage of the voltage converter and a reference voltage. When the DC-to-DC voltage converter is operated with a relatively low input voltage or a relatively high duty cycle resulting in an overlap of the current sense signal, the offset peak current mode control circuit utilizes information from the clean (i.e., non-overlapping) portion of the current sense signal, and then stretches the duty cycle applied to an associated voltage converter module so that it extends into the time of the overlapping portion of the current sense signal.
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Citations
20 Claims
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1. A multiple-phase DC-to-DC voltage converter comprising:
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a plurality of converter modules connected to a common load and having a common input voltage source;
a current sensor coupled to a sensing resistor disposed in series between said common input voltage source and said load to derive a current sense signal corresponding to current passing through said sensing resistor;
a voltage error sensor coupled to said load to derive a voltage error signal corresponding to difference between an output voltage of said voltage converter and a reference voltage;
a plurality of current mode control circuits connected to respective ones of said plurality of converter modules, said current mode control circuits receiving said current sense signal and said voltage error signal, said current mode control circuit providing gate driving signals to said converter modules having a duty cycle determined by said current sense signal and said voltage error signal; and
a phase select circuit coupled to said plurality of current mode control circuits and alternately providing said plurality of current mode control circuits a phase select signal to initiate successive phases of operation within a power cycle;
wherein, when there is an overlap between adjacent ones of said successive phases, said current mode control circuits are operative to compare said current sense signal and said voltage error signal during a non-overlapping portion of a phase, and stretch a duration of said duty cycle of said gate driving signals to extend at least partially into an overlapping portion of said phase. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. In a multiple-phase DC-to-DC voltage converter comprising a plurality of converter modules connected to a common load and having a common input voltage source, a method for providing current mode control of one of said plurality of converter modules when there is an overlap between adjacent phases of operation of said plurality of converter modules comprises the steps of:
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sensing output current delivered to said common load to thereby determine a current sense signal representative of the current, said current sense signal comprising a clean portion prior to the overlap and a distorted portion during the overlap;
sensing output voltage across said common load to thereby determine a voltage error signal representative of a difference between the output voltage and a reference;
comparing said current sense signal with said voltage error signal during said clean portion of said current sense signal to thereby generate an intermediate gate driving signal;
stretching said intermediate gate driving signal to provide a final gate drive signal; and
controlling operation of said one of said converter modules using said final gate drive signal. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A current mode control circuit for use in a multiple-phase DC-to-DC voltage converter comprising a plurality of converter modules connected to a common load and having a common input voltage source, a current sensor coupled to a sensing resistor disposed in series between said common input voltage source and said load to derive a current sense signal corresponding to current passing through said sensing resistor, a voltage error sensor coupled to said load to derive a voltage error signal corresponding to difference between an output voltage of said voltage converter and a reference voltage, said current mode control circuit providing gate driving signals to an associated one of said converter modules having a duty cycle determined by said current sense signal and said voltage error signal, said current mode control circuit comprising:
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means for comparing said current sense signal and said voltage error signal during a non-overlapping portion of a phase; and
means for stretching a duration of said duty cycle of said gate driving signals to extend at least partially into an overlapping portion of said phase. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification