DC-DC CONVERTER AND METHOD FOR MINIMIZING BATTERY PEAK PULSE LOADING

• US 20090206772A1
• Filed: 01/27/2009
• Published: 08/20/2009
• Est. Priority Date: 01/30/2008
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments Deutschland Gesellschaft Mit Beschrã¤Nkter Haftung (Texas Instruments, Inc.)
• Inventors: Vaucourt, Christophe, Bayer, Erich Johann, Schmeller, Hans
• Granted Patent: US 8,174,209 B2
• Time in Patent Office: Days
• US Class Current: 315/294
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence

Abstract

The invention relates to an electronic device, comprising a DC-DC converter for converting a primary supply voltage into an output voltage at an output node to be coupled to a super capacitor and a control stage for operating the regulated DC-DC converter in a forward direction in a boost mode providing a boost voltage level at the output node and for operating the regulated DC-DC converter in a reverse direction in a buck mode providing a buck voltage level at an auxiliary node arranged between a primary voltage supply providing the primary supply voltage and the output node, wherein the control stage is adapted to control the DC-DC converter when operating in reverse direction to provide a current to the auxiliary node using the super capacitor as a power source.

Claims

1. An electronic device, comprising a DC-DC converter for converting a primary supply voltage into an output voltage at an output node to be coupled to a super capacitor and a control stage for operating the regulated DC-DC converter in a forward direction in a boost mode providing a boost voltage level at the output node and for operating the regulated DC-DC converter in a reverse direction in a buck mode providing a buck voltage level at an auxiliary node arranged between a primary voltage supply providing the primary supply voltage and the output node, wherein the control stage is adapted to control the DC-DC converter when operating in reverse direction to provide a current to the auxiliary node using the super capacitor as power source.

2. The electronic device according to claim 1, wherein the DC-DC converter operating in reverse direction is adapted to provide an amount of current to the auxiliary node sufficient for supplying a light-emitting semiconductor device coupled to the auxiliary node to produce a flash light.

3. The electronic device according to claim 1, further comprising a first switch coupled between the primary voltage supply and the auxiliary node for switching the path between auxiliary node and the primary voltage supply on for operating in forward direction and switching the path off for operating in reverse direction.

4. The electronic device according to claim 3, wherein the first switch is a PMOS transistor, and the electronic device further comprises a fifth and a sixth switch for switching alternately the bulk of the first switch to either the voltage level at the auxiliary node or to the voltage level of the primary voltage supply.

5. The electronic device according to claim 2, further comprising a current regulator coupled to the auxiliary node for regulating current through the light-emitting semiconductor device.

6. The electronic device according to claim 5, wherein the control stage is further adapted to control the auxiliary voltage at the auxiliary node so as to minimize power losses, in particular so as to minimize voltage drop across the current regulator.

7. A method of driving a load with a DC-DC converter, the method comprising:

operating the DC-DC converter in a forward direction in a boost mode for charging a super capacitor, and operating the DC-DC converter in a reverse direction in a buck mode for supplying the load with a current from the super capacitor.