Wireless communication base station with current limiting capability
View Patent ↗A wireless communication system base station ( 20 ) includes a base station transceiver ( 26 ) that has at least one operative component ( 32 ) for facilitating wireless communications. A current limiting device ( 36 ) includes at least one field effect transistor for selectively controlling current flow to a capacitive stability device ( 34 ) associated with at least one of the operative components ( 32 ). In the disclosed example, the current limiting device ( 36 ) is in series with the capacitive stability device ( 34 ) but in parallel with the operative component ( 32 ).
1. A device for limiting a current through an operative component powered by a power supply, comprising:
a capacitive stability device coupled in parallel with the at least one operative component; and
a current limiting device coupled in series with the capacitive stability device between the power supply and the capacitive stability device, and coupled in parallel with the operative component;
wherein the current limiting device is configured to operate in an initial state to restrain a charging current to the capacitive stability device, and further configured to operate in a steady state to allow the charging current to flow to the capacitive stability device.
2. The device of claim 1 , wherein the current limiting device comprises a field effect transistor (FET) connected in series with the capacitive stability device.
3. The device of claim 2 , wherein the current limiting device further comprises a set of components connected across the operative component and to a gate terminal of the FET, for providing a biasing current for the FET.
4. The device of claim 3 , wherein the set of components includes a first resistor connected between a first terminal of the power supply and a gate terminal of the FET, for raising a gate voltage of the FET.
5. The device of claim 3 , wherein the set of components includes a parallel combination of a second resistor and a capacitor connected between the gate terminal of the FET and a second terminal of the power supply.
6. The device of claim 1 , wherein the capacitive stability device comprises a capacitor.
7. The device of claim 1 , wherein the capacitive stability device comprises a plurality of capacitors.
8. The device of claim 7 , wherein the current limiting device controls power supply to the capacitors in a sequential manner.
9. The device of claim 7 , wherein the current limiting device comprises a plurality of FETs in parallel with each other and in series with a respective capacitor of the plurality of capacitors.
10. The device of claim 1 , further comprising a circuit board substrate supporting the current limiting device.
11. The device of claim 10 , wherein the circuit board substrate is a primary heat sink for the current limiting device.
12. A method of controlling power supply to an operative component, comprising:
providing a current limiting device in series with a capacitive stability device, between the power supply and the capacitive stability device, and in parallel with the operative component;
operating the current limiting device in an initial state where the current limiting device restrains a charging current to the capacitive stability device, and without passing a steady state power supply to the operative component; and
operating the current limiting device in a steady state to allow the charging current to flow to the capacitive stability device.
13. The method of claim 12 , wherein the current limiting device comprises a field effect transistor (FET) operated to present a high internal resistance in the initial state and a low internal resistance in the steady state.
14. The method of claim 13 , wherein the FET is biased in the initial state and the steady state via a set of components connected across the operative component and to a gate terminal of the FET.
15. The method of claim 12 , wherein, during the steady state operation, a ripple current received by the capacitive stability device has a significantly lower magnitude than a current flowing through the operative component.
16. The method of claim 12 , wherein the capacitive stability device comprises a capacitor.
17. The method of claim 12 , wherein the capacitive stability device comprises a plurality of capacitors.
18. The method of claim 17 , further comprising the current limiting device controlling power supply to the plurality of capacitors in a sequential manner.
19. The method of claim 17 , wherein the current limiting device comprises a plurality of FETs in parallel with each other and in series with a respective capacitor of the plurality of capacitors.