METHOD AND ARRANGEMENT FOR GENERATING CURRENT

• US 20100270990A1
• Filed: 09/04/2008
• Published: 10/28/2010
• Est. Priority Date: 09/04/2007
• Status: Active Grant

• Current Assignee: Efore Telecom Finland Oy
• Original Assignee: Efore Oyj
• Inventors: Sippola, Mika, Ritamaki, Seppo
• Granted Patent: US 8,692,527 B2
• Time in Patent Office: Days
• US Class Current: 323/282
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel
• CPC Class Codes: H02M 7/42 Conversion of dc power input into ac power output without possibility of reversal

Abstract

The invention relates to power supplies where the output current is controllable. In prior art, there is a problem to provide both high rate of change in the current output and high efficiency. The solution of the present invention is based on combining current elements, whereby the current is controlled by switching the outputs of the current elements. The current elements can be implemented with e.g. buck converters, whereby the power dissipation is small.

Claims

1. A method for generating current, wherein the current is generated by combining current elements, whereby the current is controlled by switching the output of a current element between a load and ground, supply voltage or other low impedance potential.

2. A method for generating current according to claim 1, wherein the current elements are binarily weighted.

3. A method for generating current according to claim 1, wherein the current element comprises an inductor.

4. A method for generating current according to claim 3, wherein the current of the inductor is set by switching switches.

5. A method for according to claim 3, wherein the current of the inductor is set by a series resistor.

6. A method according to claim 1, wherein the output of the current element is switched with a frequency of at least 100 kHz, preferably at least 1 MHz, and most preferably at least 2 MHz.

7. A method according to claim 3, wherein current value of inductor-based current elements is set by switches, whereby inductors have an adjustment end and a load coupling end, and the adjustment end is connected between the supply voltage and ground and the load coupling end is connected between the load and ground.

8. A method according to claim 3, wherein current value of inductor-based current elements is set by switches, whereby inductors have an adjustment end and a load coupling end, and the adjustment end is connected between the supply voltage and ground and the load coupling end is connected between the load and the supply voltage.

9. A method according to claim 3, wherein current value of inductor-based current elements is set by switches, whereby inductors have an adjustment end and a load coupling end, and in which the adjustment end is switched between the supply voltage and ground and the load coupling end is switched between the load and ground, wherein the adjustment end is connected to the supply voltage by a controlled switch and to ground by a diode and the load coupling end is connected to ground by a controlled switch and to the load by a diode.

10. A method according to claim 1, wherein current hysteresis control is used for controlling the current of the current element.

11. An arrangement for generating current, wherein the arrangement comprises current elements for providing current at their outputs, and means for switching the output between a load and ground, supply voltage or other low impedance potential.

12. An arrangement for generating current according to claim 11, wherein the output current values of the current elements are binarily weighted.

13. An arrangement for generating current according to claim 11, wherein the current element comprises an inductor.

14. An arrangement for generating current according to claim 13, wherein the current element comprises a switch for switching the inductor in order to set the current of the inductor.

15. An arrangement for according to claim 13, wherein the current element comprises a series resistor for setting the current of the inductor.

16. An arrangement according to claim 11, characterized in that it comprises means for switching the output of the current element with a frequency of at least 100 kHz, preferably at least 1 MHz, and most preferably at least 2 MHz.

17. An arrangement according to claim 13, further comprising switches for setting current value of inductor-based current elements, whereby inductors have an adjustment end and a load coupling end, and the adjustment end is connected between the supply voltage and ground and the load coupling end is connected between the load and ground.

18. An arrangement according to claim 13, further comprising switches for setting current value of inductor-based current elements, whereby inductors have an adjustment end and a load coupling end, and the adjustment end is connected between the supply voltage and ground and the load coupling end is connected between the load and the supply voltage.

19. An arrangement according to claim 13, further comprising switches for setting current value of inductor-based current elements, whereby inductors have an adjustment end and a load coupling end, and in which the adjustment end is switched between the supply voltage and ground and the load coupling end is switched between the load and ground, wherein the adjustment end is connected to the supply voltage by a controlled switch and to ground by a diode and the load coupling end is connected to ground by a controlled switch and to the load by a diode.

20. An arrangement according to claim 11, further comprising means for controlling the current of a current element with a hysteresis control.