Power DC/DC conversion circuit
A power conversion circuit includes a first node configured to receive a first voltage referenced to a second node configured to be coupled to a reference potential. A first power converter couples the first node to a third node. A second power converter couples a fourth node to an output node. A first capacitor couples the third node to the fourth node. A first switch connects the output node to the first node. An output switch connects the output node to a load.
1 . A power conversion circuit, comprising:
a first node configured to receive a first voltage referenced to a second node configured to be coupled to a reference potential;
a first power converter coupling the first node to a third node;
a second power converter coupling a fourth node to an output node;
a first capacitor coupling the third node to the fourth node;
a first switch connecting the output node to the first node; and
a second switch configured to connect the output node to a load.
2 . The circuit of claim 1 :
wherein the second power converter comprises an inductive element having a first terminal connected to a mid-point between a third switch and a fourth switch, and a second terminal connected to the output node; and
wherein the third switch couples the fourth node to said first terminal, and the fourth switch couples said first terminal to the second node.
3 . The circuit of claim 2 :
wherein the first power converter comprises another inductive element having a first terminal connected to a mid-point between a fifth switch and a sixth switch, and a second terminal connected to the third node; and
wherein the fifth switch couples the first node to said first terminal of said another inductive element, and the sixth switch couples said first terminal of said another inductive element to the second node.
4 . The circuit of claim 2 , wherein the first power converter comprises:
a fifth switch coupling the first node to the third node; and
a sixth switch coupling the third node to the second node.
5 . The circuit of claim 4 , wherein during a first operating phase, the first switch is ON, the second switch is OFF, a first switching step and a second switching step alternate at a first frequency and a third switching step and a fourth switching step alternate at a second frequency.
6 . The circuit of claim 5 , wherein during a second operating phase, the third switching step and the fourth switching step alternate at a third frequency, the first power converter being deactivated.
7 . The circuit of claim 6 , wherein during a third operating phase, the first switch is OFF, the second switch is ON, the first switching step and the second switching step alternate at a fourth frequency and the third switching step and the fourth switching step alternate at a fifth frequency.
8 . The circuit of claim 7 , wherein during a second operating phase, the third switching step and the fourth switching step alternate at a third frequency, the first power converter being deactivated, and wherein:
during the first operation phase, the first power converter is configured to operate as a buck DC/DC converter to regulate the voltage at the third node from the first voltage to 0V and the second power converter is configured to operate as a boost DC/DC converter to boost the voltage at the fourth node;
during the second operating phase, the second power converter is configured to operate as a boost DC/DC converter to boost the voltage at the fourth node up to a maximum voltage value while the voltage at the third node is maintained at the reference potential; and
during the third operating phase, the first power converter is configured to operate as a buck DC/DC converter to regulate the voltage at the third node from 0V to the first voltage, and simultaneously the second power converter is configured to operate as a buck DC/DC converter to discharge the fourth node.
9 . The circuit of claim 5 , wherein during the first switching step, the fifth switch is OFF and the sixth switch is ON, and wherein during the second switching step, the fifth switch is ON and the sixth switch is OFF.
10 . The circuit of claim 5 , wherein during the third switching step, the third switch is OFF and the fourth switch is ON, and wherein during the fourth switching step, the third switch is ON and the fourth switch is OFF.
11 . The circuit of claim 1 , further comprising a second capacitor coupling the third node to the second node.
12 . The circuit of claim 11 , further comprising a third capacitor coupling the fourth node to the second node.
13 . The circuit of claim 12 , further comprising a fourth capacitor coupling the output node to the second node.
14 . The circuit of claim 1 , wherein the first capacitor has a capacitance between 10 μF and 500 μF.
15 . The circuit of claim 1 , wherein the first capacitor is a ceramic capacitor.
16 . A power conversion circuit, comprising the power conversion circuit of claim 1 .
17 . An electronic device, comprising:
a power source configured to supply a first voltage;
a load;
the power conversion circuit according to claim 1 ;
wherein the power source is configured to apply the first voltage to the first node; and
wherein the load is connected to the output node.
18 . The electronic device of claim 17 , wherein the power source comprises a battery and the load is a light emitting source.