Power converter with improved efficiency
View Patent ↗A power converter ( 10 ) includes a controller ( 12 ) configured to generate a switching signal. A first section ( 14 ) is coupled to the controller ( 12 ) and has first and second switches ( 26,30 ). The first section ( 14 ) is configured such that the first and second switches ( 26,30 ) operate in an alternating manner in response to the switching signal. A second section ( 16 ) is coupled to the controller ( 12 ) and has third and fourth switches ( 50,54 ). The second section ( 16 ) is configured such that the third and fourth switches ( 50,54 ) operate in an alternating manner in response to the switching signal. The first and second sections ( 14,16 ) are coupled to a node ( 88 ). A detection circuit ( 18 ) is coupled to the second section ( 16 ). The detection circuit ( 18 ) is configured to measure a voltage at the node between the operation of the third and fourth switches ( 50,54 ) and deactivate the second section when the voltage is above a predetermined threshold.
1. A power converter comprising:
a controller configured to generate a switching signal;
a first section coupled to the controller and having first and second switches, the first section being configured such that the first and second switches operate in an alternating manner in response to the switching signal;
a second section coupled to the controller and having third and fourth switches, the second section being configured such that the third and fourth switches operate in an alternating manner in response to the switching signal, wherein the first and second sections are coupled to a node; and
a detection circuit coupled to the second section, the detection circuit being configured to measure a voltage at the node between the operation of the third and fourth switches and deactivate the second section when the voltage is above a predetermined threshold.
2. The power converter of claim 1 , wherein each of the switches has a low side and a high side and the low side of the third switch is electrically connected to the high side of the fourth switch.
3. The power converter of claim 2 , wherein the voltage is measured at a node between the low side of the third switch and the high side of the fourth switch.
4. The power converter of claim 1 , further comprising an inductor coupled to the first and second sections, the operation of the first, second, third, and fourth switches causing current to flow through the inductor.
5. The power converter of claim 1 , wherein the controller and the first section are configured such that the operation of the first and second switches continues after the deactivation of the second section.
6. The power converter of claim 1 , wherein the high sides of the first and third switches are connected to a voltage source and the low sides of the second and fourth switches are connected to a ground.
7. The power converter of claim 1 , wherein the operation of the third and fourth switches comprises repeatedly turning on and turning off the third and fourth switches and the second section is configured such that there is a delay between turning off the fourth switch and turning on the third switch and the measuring of the voltage occurs during the delay.
8. The power converter of claim 1 , wherein the detection circuit is coupled to the controller and measures the voltage in response to the switching signal.
9. The power converter of claim 8 , wherein the detection circuit comprises a flip-flop configured to output a signal representative of the voltage synchronously with an edge of the switching signal.
10. The power converter of claim 1 , wherein the first and second switches are formed on a first semiconductor substrate and the third and fourth switches are formed on a second semiconductor substrate.
11. A power converter comprising:
a controller configured to generate a switching signal;
a first section coupled to the controller and having first and second switches, the first section being configured such that the first and second switches operate in an alternating manner in response to the switching signal;
a second section coupled to the controller and having third and fourth switches, the second section being configured such that the third and fourth switches operate in an alternating manner in response to the switching signal, wherein the first and second sections are coupled to a node;
an inductor coupled the first and second sections, the operation of the first, second, third, and fourth switches causing current to flow through the inductor; and
a detection circuit coupled to the node and the second section, the detection circuit being configured to:
measure a voltage at the node synchronously with an edge of the switching signal;
deactivate the second section when the measured voltage is above a predetermined threshold; and
reactivate the second section when the measured voltage is below the predetermined threshold.
12. The power converter of claim 11 , wherein the operation of the third and fourth switches comprises repeatedly turning on and turning off the third and fourth switches.
13. The power converter of claim 12 , wherein the second section is configured such that there is a delay between turning off the fourth switch and turning on the third switch and the measuring of the voltage occurs during the delay, and the controller and the first section are configured such that the operation of the first and second switches continues after the deactivation of the second section.
14. A method for converting electric power comprising:
alternatingly operating first and second switches coupled to an inductor;
alternatingly operating third and fourth switches coupled to the inductor, the operation of the first, second, third, and fourth switches causing current to flow through the inductor;
measuring the current flowing through the inductor between the operation of the third and fourth switches; and
ceasing the operating of the third and fourth switches if the measured current is below a predetermined current threshold.
15. The method of claim 14 , further comprising continuing the operating of the first and second switches if the measured current is below the predetermined current threshold.
16. The method of claim 15 , wherein each of the switches has a low side and a high side, and the low side of the third switch is electrically connected to the high side of the fourth switch.
17. The method of claim 16 , wherein the measuring of the current flowing through the inductor comprises measuring a voltage at a node electrically connected to the low side of the third switch and the high side of the fourth switch.
18. The method of claim 17 , wherein a measured voltage greater than a predetermined voltage threshold is indicative of the current flowing through the inductor being below the predetermined current threshold.
19. The method of claim 18 , wherein the low side of the first switch is electrically connected to the high side of the second switch, the node is electrically connected to the low side of the first switch and the high side of the second switch, and the high sides of the first and third switches are electrically connected to a voltage source and the low sides of the second and fourth switches are electrically grounded.
20. The method of claim 19 , further comprising generating a switching signal and providing the switching signal to the first, second, third, and fourth switches to cause the operation of the first, second, third, and fourth switches, and wherein the measuring of the voltage and the ceasing of the operation of the third and fourth switches is performed with a flip-flop electrically connected to the node and in response to the switching signal.