Dual mode power supply

• US 6,774,508 B2
• Filed: 07/03/2001
• Issued: 08/10/2004
• Est. Priority Date: 07/03/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Persico, Charles J., Bargroff, Keith, Chan, Paul L., Klaren, Jonathan, Sithideth, Somphou, Charles, Walter Scott, Ballantyne, Gary J.
• Primary Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/898,680
• Publication Number:
  US 20030006651A1
• Time in Patent Office: 1,134 Days
• Field of Search: 307/85, 307/64, 307/66, 320/135, 320/DIG.14
• US Class Current: 307/85
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters

Abstract

A battery (102) powers a wireless telephone'"'"'s power amplifier (106) through a Switch Mode Power Supply (SMPS) (104). The SMPS has a capacity lower than the maximum power requirements of the amplifier. When a controller (116) senses that an amplifier power-requirement threshold has been exceeded, it closes a switch (114) parallel to the SMPS, allowing power to flow from the battery to the amplifier without passing through the SMPS. This architecture allows the use of a smaller SMPS, and eliminates SMPS-generated noise to the amplifier when the amplifier is least able to tolerate such noise, namely, under high power conditions.

Claims

1. An reduced-average-power electronic circuit comprising:

a power source;

a switch mode power supply (SMPS) powered by the power source, the SMPS having a capacity which is lower than the maximum power requirement for the hereafter-recited load;

a load, powered by the SMPS, having a requirement for varying amounts of power, the power having low noise during high power conditions and the load tolerating a low voltage during low power conditions; and

means for applying power from the power source to the load without passing through the SMPS when the applied power is higher than a threshold, the threshold being lower than or equal to the capacity of the SMPS,

wherein the means for applying power from the power source to the load without passing through the SMPS comprises a switch in parallel with the SMPS;

wherein the switch is coupled to a controller which is structured to close the switch when the applied power is higher than the threshold and to open the switch when the applied power is lower than the threshold; and

wherein the controller further comprises a timer which is structured;

to delay closing the switch, when the applied power is higher than the threshold, until a predetermined period of time has elapsed since the switch was last opened;

or to delay opening the switch, when the applied power is lower than the threshold, until a predetermined period of time has elapsed since the switch was last closed;

or both.

2. The electronic circuit of claim 1, wherein the power source comprises a battery.

3. The electronic circuit of claim 1, wherein the load comprises a transceiver power amplifier.

4. The electronic circuit of claim 1, wherein the threshold comprises a first threshold and a second threshold which is lower than the first threshold, and wherein the controller is structured to open the switch when the applied power is lower than a second threshold, thereby introducing hysteresis between closing the switch at the higher first threshold and opening the switch at the lower second threshold.

5. The electronic circuit of claim 4, wherein the controller further comprises a timer which is structured:

to delay closing the switch, when the applied power is higher than the threshold, until a predetermined period of time has elapsed since the switch was last opened;

or to delay opening the switch, when the applied power is lower than the threshold, until a predetermined period of time has elapsed since the switch was last closed;

or both.

6. A method for supplying a reduced average power to a load, comprising the steps of:

powering a switch mode power supply (SMPS) with a power source;

powering the load with the SMPS; and

applying power from the power source to the load without passing through the SMPS when the applied power is higher than a threshold;

wherein;

the load has a requirement for varying amounts of power;

the power source has low noise during high power conditions and the load tolerating a low voltage during low power conditions;

the SMPS has a capacity which is lower than the maximum power requirement for the load; and

the threshold is lower than or equal to the capacity of the SMPS,

wherein the step of applying power from the power source to the load without passing through the SMPS comprises the step of closing a switch in parallel with the SMPS;

wherein the step of closing the switch is preceded by the step of actuating a controller which is coupled to the switch, and which is actuated when the applied power is higher than the threshold; and

delaying closing the switch, when the applied power is higher than the threshold, until the predetermined period of time has elapsed since the switch was last opened;

or delaying opening the switch, when the applied power is lower than the threshold, until a predetermined period of time has elapsed since the switch was last closed;

or both.

7. The method of claim 6, wherein the power source comprises a battery.

8. The method of claim 6, wherein the load comprises a transceiver power amplifier.

9. The method of claim 6, wherein the threshold comprises a first threshold and a second threshold which is lower than the first threshold, and wherein the method further comprises the steps of:

opening the switch when the applied power is lower than the second threshold; and

closing the switch when the applied power is higher than the second threshold;

thereby introducing hysteresis between closing the switch at the higher first threshold and opening the switch at the lower second threshold.

10. The method of claim 9, further comprising the steps of:

delaying closing the switch, when the applied power is higher than the threshold, until a predetermined period of time has elapsed since the switch was last opened;

or delaying opening the switch, when the applied power is lower than the threshold, until a predetermined period of time has elapsed since the switch was last closed;

or both.

11. Apparatus for supplying a reduced average power to a load, comprising:

means for powering a switch mode power supply (SMPS) with a power source;

means for powering the load with the SMPS; and

means for applying power from the power source to the load without passing through the SMPS when the applied power is higher than a threshold;

wherein;

the load has a requirement for varying amounts of power;

the load tolerates a low voltage during low power conditions;

the power source has low noise during high power conditions;

the SMPS has a capacity which is lower than the maximum power requirement for the load; and

the threshold is lower than or equal to the capacity of the SMPS,

wherein the means for applying power from the power source to the load without passing through the SMPS comprises means for closing a switch in parallel with the SMPS;

wherein the means for closing the switch is coupled to preceding means for actuating a controller which is coupled to the switch, and which is actuated when the applied power is higher than the threshold; and

means for delaying closing the switch, when the applied power is higher than the threshold, until a predetermined period of time has elapsed since the switch was last opened;

or means for delaying opening the switch, when the applied power is lower than the threshold, until a predetermined period of time has elapsed since the switch was last closed;

or both.

12. The apparatus of claim 11, wherein the power source comprises a battery.

13. The apparatus of claim 11, wherein the load comprises a transceiver power amplifier.

14. The apparatus of claim 11, wherein the threshold comprises a first threshold and a second threshold which is lower than the first threshold, and wherein the apparatus further comprises:

means for opening the switch when the applied power is lower than the second threshold; and

means for closing the switch when the applied power is higher than the second threshold;

thereby introducing hysteresis between closing the switch at the higher first threshold and opening the switch at the lower second threshold.

15. The method of claim 14, further comprising:

means for delaying closing the switch, when the applied power is higher than the threshold, until a predetermined period of time has elapsed since the switch was last opened;

or means for delaying opening the switch, when the applied power is lower than the threshold, until a predetermined period of time has elapsed since the switch was last closed;

or both.