Asymmetrical multiphase DC-to-DC power converter
A multiphase DC-DC converter architecture, in which respectively different channels have different operational performance parameters. These different parameters are selected so as to enable the converter to achieve an extended range of high efficiency. The converter contains a combination of one or more fast response time-based converter channels, and one or more highly efficient converter channels in respectively different phases thereof and combines the outputs of all the channels. The efficiency of the asymmetric multiphase converter is higher at light loads (up to approximately 12 amps), enabling it to offer longer battery life in applications that spend most of their operating time in the leakage mode, as noted above.
1. A multiphase DC-DC power converter for supplying power to a load comprising:
a plurality of DC-DC converter channels, outputs of which are combined at an output node to provide a composite DC current to said load, said plurality of DC-DC converter channels including a first, high efficiency channel having a first, relatively high power conversion efficiency and a first response time, and one or more second fast response time channels, each having a second power conversion efficiency less than said first, relatively high power conversion efficiency, and a second response time that is faster than said first response time; and
a single control loop, which monitors said output node and simultaneously and continuously enables each of said high efficiency channel and said one more fast response time channels, so as to cause said high efficiency channel to supply one-hundred percent of leakage current for a light load current condition and, in response to a dynamic increase in current demand from said leakage value to a full load current value, to cause said one more fast response time channels to respond by handling said full load current value, so as to realize a composite load current at said output node comprised of said leakage current and said full load current.
2. The multiphase DC-DC power converter according to claim 1 , wherein said high efficiency channel has a larger output inductance than said one or more fast response time channels.
3. A method of supplying power to a load comprising the steps of:
(a) providing a multiphase DC-DC converter having a plurality of DC-DC converter channels, outputs of which are combined at an output node to provide a composite DC current to said load, said plurality of DC-DC converter channels including a first, high efficiency channel having a first, relatively high power conversion efficiency and a first response time, and one or more second fast response time channels, each having a second power conversion efficiency less than said first, relatively high power conversion efficiency, and a second response time that is faster than said first response time;
(b) simultaneously and continuously controlling each of said high efficiency channel and said one or more second fast response time channels by way of a single control loop, which monitors said output node and continuously enables each of said high efficiency channel and said one more fast response time channels, so as to cause said high efficiency channel to supply one-hundred percent of leakage current for a light load current condition and, in response to a dynamic increase in current demand from said leakage value to a full load current value, said one more fast response time channels responds by handling said full load current value, so as to realize a composite load current at said output node comprised of said leakage current and said full load current.
4. The method according to claim 3 , wherein said high efficiency channel has a larger output inductance than said one or more fast response time channels.